Looks like the drywall removal is set to start on Monday, a month after the job was supposed to start. But because we removed the geothermal heat pump from the plan, the job should actually complete about two weeks before the original plan. I'm certainly happy that things are finally getting started.
On the other hand, less thrilling is the fact that the US government now has completely and totally abdicated doing anything serious about climate change. The Senate has dropped any attempt at pricing carbon and now is contemplating a few minor changes, primarily around responding to the Gulf oil spill disaster. It's business as usual on the policy front: we are completely on track for the IPCC's Business as Usual scenario in which the world roasts by 2100.
What happened? Obama basically gave up. He could have come out with a strong speech rallying wavering Democrats and even trying to corral a couple of Republicans who have been sympathetic, like Lindsey Graham. But he did nothing. Peculiarly, something similar happened with his ambitious plans to reform NASA. He unveiled plans in February to scale back on Bush's moon program because the plans were so grandiose and the technology being proposed so deficient that the US wouldn't have reached the goal until 2030 if then. The amount of money needed was much larger than the US could afford. His plan was to turn development of Earth to orbit transportation over to the new, entrepreneurial companies that are building rockets more cheaply than the government can. But he failed to push the plans, compromised at the first sign of opposition, and now the House wants to continue the Bush plan but at a lower funding level (practically guaranteeing that nothing will happen) purely as a jobs program.
Is there any commonality in these two occurrences? They both involve policy making about science and technology that require difficult decisions in which some political pain will be involved. In the case of pricing carbon, the price of carbon-based energy will go up. In the case of NASA, government employees will lose their jobs. In both cases, it seems the US government wants an easy political out, like buying an iPod for 400 bucks, rather than the hard and difficult work of making policy that will be expensive but, in the end, will make the country and the world a better place. The problem, particularly with climate change but also with space, is that the physics and economics aren't subject to compromise. For climate, if we continue on the BAU path, the planet will cook, and the only way to get off that path is to make carbon-based energy more expensive. For space, the government's record of technology development over the last 40 years has indicated that it can't develop economical solutions to the problem of getting to orbit. So it's back to where we were 2 years ago with the Bush administration as far as climate change goes.
What might the world look like after 2100 when the oil runs out and the ice caps are melted? An interesting perspective can be found in the science fiction book The Windup Girl (warning: don't follow the link if you don't want the plot revealed) by Paolo Bacigalupi. The book is set in 2100's Bangkok. Energy is supplied by windup springs, biogas, and human and animal labor, plus coal that is carefully rationed to avoid making global warming even worse. Bangkok is kept from flooding by enormous dikes and coal-fired pumps. Since mechanical technology no longer has any energy source to power it, the world has turned to genetic engineering and the results are environmental catastrophes in which most of the world's original biodiversity is gone and has been replaced by genetically hacked organisms. Like all science fiction, this book takes artistic license with the possible reality in order to generate a good, engaging story, but the general setting sounds plausible to me.
I think we can now reasonably concluded that neither the Democratic nor the Republican party are going to do anything about climate change.What will it take to get the government to finally put in place the policy changes needed to stop the world from cooking?
Saturday, July 24, 2010
Saturday, July 17, 2010
Projected Carbon Footprint
Since we removed the geothermal heat pump from the system remodel plan, I've recalculated the projected carbon footprint we can expect from our house plus cars next year, after we have the remodeling work completed (hopefully) and have an electric car powered by solar (again hopefully).
The assumptions I'm making are the following:
The chart shows an almost 90% reduction in carbon emissions from the estimated pre-2002 baseline. This includes extra capacity in the new solar PV (around 1131 kg/yr) which the house will not use and will therefore offset some of the natural gas emissions from heating.
Notice that the electricity footprint is now negative because the house is generating more carbon-free energy that it consumes. This offsets the natural gas and gasoline usage. One car will be completely carbon free, since it will run off electricity generated by the sun, but our current plug-in Prius will still require gasoline.
The cost takes into account the federal and state subsidy for the Nissan Leaf, which brings the price below $20,000.
The assumptions I'm making are the following:
- The reinsulation reduces gas usage by 30% below current average (around 350 therms per year for heating). Several years ago, I constructed a spreadsheet model of the house and calculated what the reduction in energy use would be for changing the insulation to closed cell foam. It came out to about 30%. This ignored the floor, which we will have done, and included the kitchen and master suite, which we won't, though the kitchen ceiling is now at R-30 using fiberglass batt.
- The on-demand electric hot water heater provides backup hot water heating in winter so that total hot water gas reduction including solar thermal and backup on-demand electric is 20%. The electric hot water heater will be offset from the solar PV.
- The heat recovery ventilation system is around 800 kwh per year (running in winter only) and is offset by solar PV.
- We swap out our current, 6 year old polycrystalline 165 watt per panel 18 module solar PV system for a new system consisting of 20 Sunpower 315 watt per panel modules.
- The Nissan Leaf which we are hoping to purchase next year uses 0.25 kilowatt-hours/mile and we drive it around 8000 miles per year, which is about what we usually drive our "commuting car" (as opposed to our long distance car which is more like 10,0000 miles per year).
The chart shows an almost 90% reduction in carbon emissions from the estimated pre-2002 baseline. This includes extra capacity in the new solar PV (around 1131 kg/yr) which the house will not use and will therefore offset some of the natural gas emissions from heating.
The contributions from each component (electricity, gas, and cars) to the total household footprint can be seen in this graph:
Notice that the electricity footprint is now negative because the house is generating more carbon-free energy that it consumes. This offsets the natural gas and gasoline usage. One car will be completely carbon free, since it will run off electricity generated by the sun, but our current plug-in Prius will still require gasoline.
Finally, the bottom line: the cost. The following graph shows the cost per kg carbon eliminated:
The cost takes into account the federal and state subsidy for the Nissan Leaf, which brings the price below $20,000.
The efficiency measures here are the most expensive. Reinsulating the house requires taking off the drywall, blowing in closed cell foam insulation and otherwise sealing up any air leaks, putting back the drywall, and installing a ventilation system to ensure that the house gets enough fresh air in the winter when the windows are all closed. This is expensive and disruptive work, but, unfortunately, there is no way around it if we want to reduce the energy use due to heating.
So by the time we finish next year, we should have achieved almost 90% reduction beyond the estimated pre-2002 baseline. Environmental groups are calling for an 80% reduction by 2050, and this is the aspirational target for governments, though, the steps they've been taking are laughable so far. We will have beat the deadline by almost 40 years. The house and cars will not be total net zero energy, but they will be as close as we can get them, given:
- We need some way to get out of town with the car, and gasoline or diesel are the only realistic fuel choices right now. We could do an under the table conversion of the plug-in Prius to E85, but unfortunately there is very little E85 available in California.
- We have little choice with the heating but to continue using natural gas. The complexity of installing a geothermal heat pump doesn't match the architectural configuration of this house. The house simply does not have enough room for the complex machinery. And the cost of a geothermal heat pump is far and away above the value it provides (something like $700 per kg of carbon eliminated). The amount of money we'll have put into the house for the upgrades even without the geothermal heat pump probably exceeds the resale value, not that we are thinking of selling it of course. Green remodeling does not yet pay in terms of resale value, at least according to a friend who is in real estate. As for cooking, continuing to use a gas stove is a choice: we both prefer gas to electric, and the existing gas stove is still in pretty good condition so we don't see any point in replacing it.
Now, I wish the contractors would finally get started on our system remodel! We are still waiting on a second bid for the drywall removal.
Saturday, July 10, 2010
Or Perhaps Not
We've been moved into the back bedroom and kitchen now for two weeks and the job still hasn't started due to unforseen complications. These are, of course, the bane of any remodelling project, but we seem to have them early and often.
As a consequence, we've decided to make a couple of changes in the plans. We will not put in a geothermal heat pump and we will not put in the skylight in the living room. I dearly wanted the geothermal heat pump and The Lovely Wife dearly wanted the skylight. So we both don't get what we really wanted, but, on the other hand, we may end up having a more successful experience.
The problem with the geothermal heat pump is that it is a complex and expensive technology which, as far as I can tell, is really not yet mature. For example, it requires a water storage tank that stores 6 gallons of heated or chilled water per ton of conditioning. Such a buffer is an invitation for energy loss, as you can see from my post last year on our solar thermal hot water system. The reason for this buffer is because the pump can't handle cycling two 300 foot columns of fluid over multiple short periods without possibly burning out sooner than it otherwise would. In colder climates, the buffer isn't needed because the pump stays on longer. But nothing I read in the literature about geothermal heat pumps indicated the need for such a tank. Besides the energy loss, it also takes up space in our garage. We already have a 80 gallon tank for our solar hot water heater, I don't see much point in another, or, more precisely, if we had known about this we could maybe have figured out how to integrate the two.
Another indication of the immaturity is that we will need two ventilation systems, one for the air conditioning from the heat pump and one for the heat recovery ventilation. This is a needless amount of waste. A properly designed ventilation system would have a heat exchanger built into the air handling system for the air conditioning, so that fresh air could be brought in from outside rather than recirculating stale air. In winter, when the radiant heat in the floor is on, the air handler would bring in fresh air and recover the heat without actually heating the incoming air. Now, the heat recovery ventilation and air conditioning are two separate systems, making them more expensive and more complicated to install, because essentially two separate sets of ducting are needed.
The complexity also leads to a certain amount of uncertainty. For example, suppose the drilling for the geothermal wells runs into a rock 100 feet down. We would have to drill another well to fill out the additional 200 feet (required depth is 300 ft.). But our driveway is not very big, so we might end up not having space, or having to go into the front garden. Of course, the cost would then skyrocket and there would be more delay. We (and especially The Lovely Wife) have very little tolerance for things going wrong, especially when they might run up the bill.
So we've decided to focus on securing the thermal envelope of the building so that it doesn't leak heat and air. This will require the heat recovery ventilation but that is relatively energy efficient and should not require too much in the way of installation. Not putting in another skylight (we already have 5) will help, since skylights are essentially R-3 holes in the R-30 insulation of the roof. We had planned for the skylight to have had a thermal shade, and we are also planning on putting thermal shades on the three existing ridge skylights to stop them from acting as radiators of heat into the sky at night in winter because they are so high up on the roof, but even with a thermal shade there would likely be more heat radiated out than if the roof is left intact.
On a more philosophical level, I recently returned from a business trip to Berlin, and had David Owen's book Green Metropolis along. Owen's thesis is that fancy technology, such as geothermal heat pumps, isn't the answer to climate change. The answer is a denser built environment. He believes that New York is, in effect, the greenest city in the US because driving is so unpleasant that people must take mass transit and walk, and the density of dwellings allows less energy for indoor conditioning. The message really struck home in Berlin, where my hotel was within walking distance of scores of great restaurants and the Ku Damm, which had lots of shopping. On the other hand, the hotel itself was a small European hotel without air conditioning and the temperatures were in the mid-90's with almost 100% relative humidity making the indoor temperature very uncomfortable especially at night, so there are downsides to the European style of building too. After my stint on the local Sustainability Task Force two years ago, I actually came to share Owen's opinion about density, but the barriers to making a denser built environment in the US are daunting. Practically every attempt to densify in our suburban town runs into a buzz saw of opposition from existing property owners. Given a choice, people really don't want to live close enough to their neighbors and shops that they can walk, they are perfectly happy using the car. In any case, thinking over our own efforts to reduce our carbon footprint while still living in a largely suburban built environment re-enforced the idea that we should rather concentrate on energy efficiency than fancy renewable energy technology, even if, in the end, our efforts were less effective than if we were to live in a denser built environment like New York.
And now for some "eye candy" after a somewhat depressing batch of text:
On the train from Berlin to Frankfurt, kilometer after kilometer of wind turbines outside the window as we pass. The Germans are really serious about renewable energy, unlike us lazy Americans.
As a consequence, we've decided to make a couple of changes in the plans. We will not put in a geothermal heat pump and we will not put in the skylight in the living room. I dearly wanted the geothermal heat pump and The Lovely Wife dearly wanted the skylight. So we both don't get what we really wanted, but, on the other hand, we may end up having a more successful experience.
The problem with the geothermal heat pump is that it is a complex and expensive technology which, as far as I can tell, is really not yet mature. For example, it requires a water storage tank that stores 6 gallons of heated or chilled water per ton of conditioning. Such a buffer is an invitation for energy loss, as you can see from my post last year on our solar thermal hot water system. The reason for this buffer is because the pump can't handle cycling two 300 foot columns of fluid over multiple short periods without possibly burning out sooner than it otherwise would. In colder climates, the buffer isn't needed because the pump stays on longer. But nothing I read in the literature about geothermal heat pumps indicated the need for such a tank. Besides the energy loss, it also takes up space in our garage. We already have a 80 gallon tank for our solar hot water heater, I don't see much point in another, or, more precisely, if we had known about this we could maybe have figured out how to integrate the two.
Another indication of the immaturity is that we will need two ventilation systems, one for the air conditioning from the heat pump and one for the heat recovery ventilation. This is a needless amount of waste. A properly designed ventilation system would have a heat exchanger built into the air handling system for the air conditioning, so that fresh air could be brought in from outside rather than recirculating stale air. In winter, when the radiant heat in the floor is on, the air handler would bring in fresh air and recover the heat without actually heating the incoming air. Now, the heat recovery ventilation and air conditioning are two separate systems, making them more expensive and more complicated to install, because essentially two separate sets of ducting are needed.
The complexity also leads to a certain amount of uncertainty. For example, suppose the drilling for the geothermal wells runs into a rock 100 feet down. We would have to drill another well to fill out the additional 200 feet (required depth is 300 ft.). But our driveway is not very big, so we might end up not having space, or having to go into the front garden. Of course, the cost would then skyrocket and there would be more delay. We (and especially The Lovely Wife) have very little tolerance for things going wrong, especially when they might run up the bill.
So we've decided to focus on securing the thermal envelope of the building so that it doesn't leak heat and air. This will require the heat recovery ventilation but that is relatively energy efficient and should not require too much in the way of installation. Not putting in another skylight (we already have 5) will help, since skylights are essentially R-3 holes in the R-30 insulation of the roof. We had planned for the skylight to have had a thermal shade, and we are also planning on putting thermal shades on the three existing ridge skylights to stop them from acting as radiators of heat into the sky at night in winter because they are so high up on the roof, but even with a thermal shade there would likely be more heat radiated out than if the roof is left intact.
On a more philosophical level, I recently returned from a business trip to Berlin, and had David Owen's book Green Metropolis along. Owen's thesis is that fancy technology, such as geothermal heat pumps, isn't the answer to climate change. The answer is a denser built environment. He believes that New York is, in effect, the greenest city in the US because driving is so unpleasant that people must take mass transit and walk, and the density of dwellings allows less energy for indoor conditioning. The message really struck home in Berlin, where my hotel was within walking distance of scores of great restaurants and the Ku Damm, which had lots of shopping. On the other hand, the hotel itself was a small European hotel without air conditioning and the temperatures were in the mid-90's with almost 100% relative humidity making the indoor temperature very uncomfortable especially at night, so there are downsides to the European style of building too. After my stint on the local Sustainability Task Force two years ago, I actually came to share Owen's opinion about density, but the barriers to making a denser built environment in the US are daunting. Practically every attempt to densify in our suburban town runs into a buzz saw of opposition from existing property owners. Given a choice, people really don't want to live close enough to their neighbors and shops that they can walk, they are perfectly happy using the car. In any case, thinking over our own efforts to reduce our carbon footprint while still living in a largely suburban built environment re-enforced the idea that we should rather concentrate on energy efficiency than fancy renewable energy technology, even if, in the end, our efforts were less effective than if we were to live in a denser built environment like New York.
And now for some "eye candy" after a somewhat depressing batch of text:
Thursday, June 24, 2010
Deep Energy Retrofit Start
Well, last weekend we moved out of the bulk of our house and into the master suite, kitchen, and garden. We'll be living in this space for the next 5 months while our house undergoes a deep energy retrofit. There's no standard product called a "deep energy retrofit" but in our case it consists of the following:
The house will, in the end, generate more energy than it uses. We intend to use the extra for an electric car and for our current plug-in Prius conversion.
Now for some pictures. Here's the pellet stove that we'll replace with a gas fireplace:
We've never used it since we moved in because it is such a hassle to start. Also, the neighbors who have one said that the heat is so intense next to the stove that the room feels like Hawaii, because there is no thermostat to regulate the heat.
Here's a picture of one of the ceiling fans in the family room that will be removed:
It turns out that there is only one model fan in the US that actually generates less heat from the motor than the air it pushes cools. Ceiling fans only work well in hot, humid climates where sweat doesn't evaporate fast enough to cool. That isn't California.
Here's a picture of the space above the upstairs bath entrance that will be converted into a mechanical closet for one of the two HRV systems and the on-demand electric hot water heater:
Because our house has two sides with a high, cathedral ceiling-ed hallway in the middle, we'll have two HRV units, one on the east side and one on the west side of the house. There isn't any other way to get the ventilation ducts across the hallway, except under the house and that space will be taken up by the air conditioning ducts.
We'll be donating the hydronic furnace, hot water heater, insulation under the house (it's only 4 years old), and the ceiling fans to charity so that somebody can reuse them.
In the coming 4 months, you'll be hearing how the work is going.
- Removing the drywall and 30 year old fiberglass batt insulation from the exterior shell and replacing it with closed cell foam insulation. Also removing the batt under the house and replacing it with closed cell foam. A thermal imaging test showed holes in the insulation at various places in the house.
- Installing a Heat Recovery Ventilation (HRV) system to maintain air quality when the windows are closed and to recover heat (or cool) when stale air is exhausted.
- Removing the gas hydronic boiler and installing a geothermal heat pump with hydronic heating and forced air air conditioning.
- Replacing the gas fired tank water heater with an on-demand electric hot water heater. The gas fired water heater has a pilot and the water often becomes luke warm if the pilot is off in the summer and we don't use any hot water for a few days. We get all of our hot water in summer from the solar thermal system.
- Replacing the current solar PV system with new panels that generate 2x as much power from the same amount of area (reminds me of the progress in PCs in the 1980's).
- Replacing the old, hand-started pellet stove with a 94% AFUE gas fire place.
- Putting in automatic thermal shades on the ridge skylight to reduce thermal losses through the glass in winter.
- A bunch of other aesthetic and structural work including refinishing the hardwood floors, retexturing the drywall and painting, putting a skylight in the living room, blocking up the unused forced air heating vents in the floor, removing ceiling fans, and replacing the carpet upstairs.
The house will, in the end, generate more energy than it uses. We intend to use the extra for an electric car and for our current plug-in Prius conversion.
Now for some pictures. Here's the pellet stove that we'll replace with a gas fireplace:
Here's a picture of one of the ceiling fans in the family room that will be removed:
Here's a picture of the space above the upstairs bath entrance that will be converted into a mechanical closet for one of the two HRV systems and the on-demand electric hot water heater:
We'll be donating the hydronic furnace, hot water heater, insulation under the house (it's only 4 years old), and the ceiling fans to charity so that somebody can reuse them.
In the coming 4 months, you'll be hearing how the work is going.
Friday, June 18, 2010
The Electric Car Resurrection VI: Retrospective
If the electric car died with the EV1, then this year will see its resurrection. By the end of the year, there should be at least 3 more or less affordable mass market electric car choices available to consumers - the Nissan Leaf, the Chevy Volt, and the smart4two electric - and one choice that is mostly not affordable - the Tesla Roadster. Next year, and continuing through 2015, there will be even more choices available, with Ford among other volume manufacturers introducing all-electric or plug-in hybrid models. So consumers will finally get to vote with their pocketbooks. By all accounts, most surveys show that consumers seem ready to consider alternative fuel vehicles, even if they are some what hesitant about the cost. What are the prospects that consumers will embrace electric cars in the years ahead and that a large shift away from ICE (Internal Combustion Engine) vehicles will make a significant dent in the carbon footprint cause by transportation?
One of the major barriers that many commentators see to widespread adoption of electric cars is "range anxiety". The argument is that because electric cars have much more limited range than ICE vehicles, people will be constantly afraid of running out of electricity so they will be hesitant to buy. The additional argument is made that the long charging times required for electric cars will contribute to range anxiety, because you can't simply wait until the last quarter tank before refueling, you must plan carefully to be near a charger. A related argument is the "but what about if I want to go to Lake Tahoe?" response that often comes up in discussion about electrics v.s. ICE vehicles. When you push people about how often they do these longer trips, the answer is: maybe two or three times a year, if that. So these trips are, in a sense, "aspirational travel" rather than truly factual range requirements. In many ways, it is like the people who buy a 4 wheel drive Ford Expedition even though they never go off-road and mostly use the vehicle for commuting back and forth to work. They want an ICE vehicle for the sense that they could, if they ever chose, take off and drive across the country without having to plan ahead. In other words, they are willing to pay a lot - for the initial purchase, for the gas, and for the negative impact on the environment - just to have a simple feeling of freedom, no matter how little that feeling matches the way they actually live their lives.
As I discussed in my blog post last week, the range anxiety argument doesn't hold if people buy the vehicles with the specific purpose of driving around town and commuting to work. The range available from the up coming all-electrics is sufficient for at least one and possibly two commutes per week between recharging, and the plug-in hybrids, like the Chevy Volt, don't even have that problem. So for people who approach the buying decision with a more or less rational idea about how they intend to use the vehicle, an electric car may be come a viable choice if the intended use is commuting and driving around town. On the other hand, for people with "aspirational travel" in mind, an electric car is never going to be an option. And, as a matter of principle, most multi-car families are likely to want at least one car with sufficient range and sufficiently short refueling time to allow longer, out of town trips such as vacations or long weekend outings. While a plug-in hybrid does cover these kinds of requirements, an ICE vehicle is probably going to be the more common choice.
This points to the more serious problem with plug-in hybrids and electrics in general: cost. For example, GM is pricing the Chevy Volt like a Cadillac ostensibly because of the cost of batteries. There is some evidence that they are not really serious about making the Volt a mass market car, and are merely using it to increase their fleet average gas consumption rating so that they can sell more Tahoes and other big trucks, on which they earn larger gross margins. But pricing on the Nissan Leaf before subsidy, which is far more competitive, is still way above what a consumer would pay for an equivalent ICE vehicle. After the state and federal subsidy, the Leaf actually comes in a bit below $20,000 which makes it even more competitive, at least, on a non-range adjusted basis. If you calculate the cost on a range adjusted basis, electric vehicles are overpriced by about a factor of 4x after state and federal subsidy when compared with a similar ICE vehicle, for example comparing the Nissan Leaf with the Honda Fit. If the Leaf were priced at the same miles of range per dollar ratio as the Fit, it would cost $5000, as much as a Tata Nano!
It is just a simple fact that batteries are far more expensive than ICEs, even if electric motors are cheaper. Prices are falling and smart deal making by the car manufacturers can lead to better value in the ultimate product. For example, GM is rumored to be getting their batteries for $700/kilowatt-hour while Nissan's battery cost is rumored to be $300/kilowatt-hour. This price differential probably explains the difference in cost between the Volt and the Leaf. But the cost per unit energy delivered is unlikely to match ICEs for some time, if ever. There is a fundamental limit in how much the cost on the rest of the vehicle can be reduced to compensate, before the product feels cheap and unstylish. People who buy and use electric vehicles are simply going to end up shelling out more to start with. For that, they pay considerably less (about a third less) when refueling with electricity as opposed to gas.
The reduced cost for fueling and for service could make up for some of the extra cost. If you figure most people drive around 12,000 miles per year and that the car gets the 35 mpg projected for the fleet average in 2016 and that the car needs at least 2 services per year for the 5,000 mile checkups, an ICE vehicle requires around $1600 per year if gas is around $3 per gallon. For an electric, the same miles require only around $300, and the vehicle will most likely require no service. Over a projected ten year lifetime, the electric will save around $13,000, which more than compensates for the after subsidy difference in cost between an ICE vehicle and an electric, but doesn't approach the before subsidy difference. Naturally, the range restriction remains.
There are some companies working on clever ways around the range restriction. Project Better Place is working on a system where the battery is swapped out at charging stations en route if your trip lasts longer than the range of the battery on a single charge. Most likely, cars with swappable batteries will be somewhat cheaper than those with built-in batteries. Since batteries do wear out, having the batteries be easily swappable will also extend the life of the rest of the car. But the requirements for putting in infrastructure for battery swapping are fairly daunting in a country the size of the US. Even proven carbon reduction options such as E85 fuel aren't available everywhere. This is one reason why Better Place is focusing on small countries like Israel and Denmark, or small places like Hawaii and metropolitan areas. But, in the end, Better Place is just one company and unless they can somehow get their system standardized, they are unlikely to make much of a dent in the transportation carbon footprint.
In fact, exactly this could be said for electric cars and plug-in hybrids in general. While the current enthusiasm for electric cars certainly is a hopeful sign, they are really unlikely to make much of a dent in the nation's transportation carbon footprint for some time. They are not priced competitively, and they are only useful for very limited purposes. Even more important, there are millions of ICE vehicles on the road today, and after the financial crisis of the past two years, most people are not even in a position to buy a new car, much less one that costs up to twice as much for a third the range. The only way to really reduce the nation's transportation carbon footprint is to get people to drive less. That option costs essentially nothing, or, if you consider public transit fares, far less than owning and driving a car.
For myself, I've pretty much decided that my next car will probably be a Nissan Leaf, an all electric. The reasons are pretty simple. The after subsidy cost is competitive with a Prius. I can fuel the car free from the electricity generated by my rooftop. And, most importantly, electric cars get to drive in the carpool lane with one driver. I often have meetings I need to go to during the day, and I am invariably pressed for time. If the meetings are near rush hour, the freeways can slow down, so being able to drive in the carpool lane is a really valuable perk. It's a somewhat perverse incentive, but one that I value.
On the other hand, I'm now bicycling to work once a week, which is not near what I was doing a couple years ago. But it is the best I can do with my current work circumstances, and I rarely use the car on the weekend unless it is raining or we're going out of town.
One of the major barriers that many commentators see to widespread adoption of electric cars is "range anxiety". The argument is that because electric cars have much more limited range than ICE vehicles, people will be constantly afraid of running out of electricity so they will be hesitant to buy. The additional argument is made that the long charging times required for electric cars will contribute to range anxiety, because you can't simply wait until the last quarter tank before refueling, you must plan carefully to be near a charger. A related argument is the "but what about if I want to go to Lake Tahoe?" response that often comes up in discussion about electrics v.s. ICE vehicles. When you push people about how often they do these longer trips, the answer is: maybe two or three times a year, if that. So these trips are, in a sense, "aspirational travel" rather than truly factual range requirements. In many ways, it is like the people who buy a 4 wheel drive Ford Expedition even though they never go off-road and mostly use the vehicle for commuting back and forth to work. They want an ICE vehicle for the sense that they could, if they ever chose, take off and drive across the country without having to plan ahead. In other words, they are willing to pay a lot - for the initial purchase, for the gas, and for the negative impact on the environment - just to have a simple feeling of freedom, no matter how little that feeling matches the way they actually live their lives.
As I discussed in my blog post last week, the range anxiety argument doesn't hold if people buy the vehicles with the specific purpose of driving around town and commuting to work. The range available from the up coming all-electrics is sufficient for at least one and possibly two commutes per week between recharging, and the plug-in hybrids, like the Chevy Volt, don't even have that problem. So for people who approach the buying decision with a more or less rational idea about how they intend to use the vehicle, an electric car may be come a viable choice if the intended use is commuting and driving around town. On the other hand, for people with "aspirational travel" in mind, an electric car is never going to be an option. And, as a matter of principle, most multi-car families are likely to want at least one car with sufficient range and sufficiently short refueling time to allow longer, out of town trips such as vacations or long weekend outings. While a plug-in hybrid does cover these kinds of requirements, an ICE vehicle is probably going to be the more common choice.
This points to the more serious problem with plug-in hybrids and electrics in general: cost. For example, GM is pricing the Chevy Volt like a Cadillac ostensibly because of the cost of batteries. There is some evidence that they are not really serious about making the Volt a mass market car, and are merely using it to increase their fleet average gas consumption rating so that they can sell more Tahoes and other big trucks, on which they earn larger gross margins. But pricing on the Nissan Leaf before subsidy, which is far more competitive, is still way above what a consumer would pay for an equivalent ICE vehicle. After the state and federal subsidy, the Leaf actually comes in a bit below $20,000 which makes it even more competitive, at least, on a non-range adjusted basis. If you calculate the cost on a range adjusted basis, electric vehicles are overpriced by about a factor of 4x after state and federal subsidy when compared with a similar ICE vehicle, for example comparing the Nissan Leaf with the Honda Fit. If the Leaf were priced at the same miles of range per dollar ratio as the Fit, it would cost $5000, as much as a Tata Nano!
It is just a simple fact that batteries are far more expensive than ICEs, even if electric motors are cheaper. Prices are falling and smart deal making by the car manufacturers can lead to better value in the ultimate product. For example, GM is rumored to be getting their batteries for $700/kilowatt-hour while Nissan's battery cost is rumored to be $300/kilowatt-hour. This price differential probably explains the difference in cost between the Volt and the Leaf. But the cost per unit energy delivered is unlikely to match ICEs for some time, if ever. There is a fundamental limit in how much the cost on the rest of the vehicle can be reduced to compensate, before the product feels cheap and unstylish. People who buy and use electric vehicles are simply going to end up shelling out more to start with. For that, they pay considerably less (about a third less) when refueling with electricity as opposed to gas.
The reduced cost for fueling and for service could make up for some of the extra cost. If you figure most people drive around 12,000 miles per year and that the car gets the 35 mpg projected for the fleet average in 2016 and that the car needs at least 2 services per year for the 5,000 mile checkups, an ICE vehicle requires around $1600 per year if gas is around $3 per gallon. For an electric, the same miles require only around $300, and the vehicle will most likely require no service. Over a projected ten year lifetime, the electric will save around $13,000, which more than compensates for the after subsidy difference in cost between an ICE vehicle and an electric, but doesn't approach the before subsidy difference. Naturally, the range restriction remains.
There are some companies working on clever ways around the range restriction. Project Better Place is working on a system where the battery is swapped out at charging stations en route if your trip lasts longer than the range of the battery on a single charge. Most likely, cars with swappable batteries will be somewhat cheaper than those with built-in batteries. Since batteries do wear out, having the batteries be easily swappable will also extend the life of the rest of the car. But the requirements for putting in infrastructure for battery swapping are fairly daunting in a country the size of the US. Even proven carbon reduction options such as E85 fuel aren't available everywhere. This is one reason why Better Place is focusing on small countries like Israel and Denmark, or small places like Hawaii and metropolitan areas. But, in the end, Better Place is just one company and unless they can somehow get their system standardized, they are unlikely to make much of a dent in the transportation carbon footprint.
In fact, exactly this could be said for electric cars and plug-in hybrids in general. While the current enthusiasm for electric cars certainly is a hopeful sign, they are really unlikely to make much of a dent in the nation's transportation carbon footprint for some time. They are not priced competitively, and they are only useful for very limited purposes. Even more important, there are millions of ICE vehicles on the road today, and after the financial crisis of the past two years, most people are not even in a position to buy a new car, much less one that costs up to twice as much for a third the range. The only way to really reduce the nation's transportation carbon footprint is to get people to drive less. That option costs essentially nothing, or, if you consider public transit fares, far less than owning and driving a car.
For myself, I've pretty much decided that my next car will probably be a Nissan Leaf, an all electric. The reasons are pretty simple. The after subsidy cost is competitive with a Prius. I can fuel the car free from the electricity generated by my rooftop. And, most importantly, electric cars get to drive in the carpool lane with one driver. I often have meetings I need to go to during the day, and I am invariably pressed for time. If the meetings are near rush hour, the freeways can slow down, so being able to drive in the carpool lane is a really valuable perk. It's a somewhat perverse incentive, but one that I value.
On the other hand, I'm now bicycling to work once a week, which is not near what I was doing a couple years ago. But it is the best I can do with my current work circumstances, and I rarely use the car on the weekend unless it is raining or we're going out of town.
Monday, June 14, 2010
The Electric Car Resurrection V: Charging Stations
The biggest issue with electric cars is "range anxiety". Electric cars have a range that is more limited than ICE cars. That would not be an issue if electric cars could be charged up as quickly as ICE cars can be filled with gas. People are used to being able to wait until they are just about out of gas before stopping at a conveniently located gas station, unless they are cruising through Death Valley. With an electric car, it can take anywhere from 25 minutes to 8 hours to recharge, depending on the voltage and current available from the charging station. Most people aren't going to be able to wait 8 hours after running down their 100 mile range Nissan Leaf to zero charge. This will likely take a level of planning most people are unused to, even with iPhone apps with maps of charging opportunities and apps in the car that tell you how much range you have left and whether you could make it to the nearest charging station if you went somewhere.
The simplest solution to the problem is to recharge the car at home. What I do is to simply plug my PHEV Prius into the 110v socket at night, like a cell phone, and let it recharge on cheap, off-peak power. In the morning, it's ready to go again. This type of recharging also works at other places, like a friend's house or overnight at a bed and breakfast, or even downtown at the public library where there are a couple of 110v electric sockets scattered around the garage. After a while, you get proficient at identifying where there are sockets. My wife's employer has two sockets specifically for electric cars that she uses to recharge the Prius. At my employer, on the other hand, the facilities department sent security after me when I plugged the car into an exterior outlet, then put a small sign on the outlet stating that it was not to be used. Oh well.
While overnight charging at 110v 15 amps works for my 5 kwh battery, with a larger battery, such as the Nissan Leaf or Chevy Volt has, the amount of time to recharge on 110v 15 amp would be prohibitively long. Which is why these cars come with a 220v 30+ amp charging station that is installed in your garage when you buy the car (and for which you pay extra). Note that not all houses can support the current load of a high current recharge of this type. If your grid feed is only 100 amps, as many houses are that were build in the 1970's or before, then you won't be able to get an all-electric car without upgrading your grid connection. With the additional current available, an all-electric car like the Nissan Leaf or an gas-assisted electric PHEV like the Volt should recharge in about 5-8 hours, so, again, overnight charging at home works.
This pattern is fine for commuting. But if we want to get away from just using an electric car for commuting, then charging stations need to be essentially everywhere: parking lots, downtown on the street, you name it. You need to be sure that a station will be available whenever you are in a civilized parking spot (we can leave out Death Valley for now). Not only that, but the car must be able to draw enough current to recharge in a conveniently short time, since people on a 500 mile trip are not going to want to wait 8 hours after driving only part of the way. Making the recharge time the same as it takes to fill a tank with gas is probably too much to hope for, at least initially, but maybe a half hour at most would probably work for many people, especially if the range were high enough, say 200-300 miles like the Tesla. How high would the voltage need to be and how much current are we talking about? Try 400+v at 400 amps, but straight DC instead of AC, and the car would only about half charge in 30 minutes. The conversion to DC happens in the charging station, not the car.
There are a couple startups working on this technology. One is Coulomb Technologies. Their business model is to sell charging stations and the owner then sells the power. Because only utilities, as regulated monopolies, are allowed to sell electricity by the kwh, the charging stations sell power by time. This is a convenient dodge to avoid having the customers of Coulomb be regulated like utilities are. Another startup is 350Green. Their business model is to own the charging stations, install them for free, and cut the property owner in for 5%. Their charging stations also sell power by time, but take time of day and season into account.
Coulomb's model suffers from the chicken and egg problem. As long as there are not lots of electric cars, property owners and municipal governments won't see the economics of buying charging stations. Maybe some gas station owners will install them near areas where there are lots of electric cars, as is the case with E85 fuel. 350Green's model has better economics, though their incentives are a bit slim. Electricity, even during peak times, is about 1/3 the price of gasoline for the same amount of range, so the property owners won't be making much. In any case, there is a technical problem with these fast charging models. Unless the charger contains a large bank of capacitors that charge up slowly to almost the amount of power the car requires, the load on the grid from trying to draw down so much energy over such a short time may cause some failures in transformers and other equipment.
In my opinion, an easier way to solve the problem would be to take advantage of the infrastructure we have. Every street light pole has a small plate near the base the provides access to the wiring. You can see an example here:
What if, instead of installing fancy charging stations, every street light pole was installed with a 110v 15 amp and 220v 30 amp socket? Naturally, this wouldn't take care of drivers going long distances, but it would sure help when you are out driving around on a Saturday afternoon doing errands and need a quick recharge while getting a haircut. The main issue, though, is how to collect money for the power. One obvious way is to put a credit card swipe connected through the cellular network on the pole, and make people swipe their credit cards. Another would be to have some kind of wireless-based recognition system on the car and pole, and have the pole then charge the car owner through a post-paid plan, like a cell phone plan. There are lots of ways to arrange the charging, municipalities could even sell yearly passes to residents for unlimited power use.
There are probably lots more ways that charging stations could be arranged, but initially, home charging looks like it is most likely to be the initial pattern. This isn't actually so bad, since many families have at least one car that they just use for commuting. If a large majority can be convinced to replace that car with an electric, the impact on carbon emissions will be huge and we'll be well on our way to permanently reducing our collective carbon footprint to where it doesn't threaten the planet.
The simplest solution to the problem is to recharge the car at home. What I do is to simply plug my PHEV Prius into the 110v socket at night, like a cell phone, and let it recharge on cheap, off-peak power. In the morning, it's ready to go again. This type of recharging also works at other places, like a friend's house or overnight at a bed and breakfast, or even downtown at the public library where there are a couple of 110v electric sockets scattered around the garage. After a while, you get proficient at identifying where there are sockets. My wife's employer has two sockets specifically for electric cars that she uses to recharge the Prius. At my employer, on the other hand, the facilities department sent security after me when I plugged the car into an exterior outlet, then put a small sign on the outlet stating that it was not to be used. Oh well.
While overnight charging at 110v 15 amps works for my 5 kwh battery, with a larger battery, such as the Nissan Leaf or Chevy Volt has, the amount of time to recharge on 110v 15 amp would be prohibitively long. Which is why these cars come with a 220v 30+ amp charging station that is installed in your garage when you buy the car (and for which you pay extra). Note that not all houses can support the current load of a high current recharge of this type. If your grid feed is only 100 amps, as many houses are that were build in the 1970's or before, then you won't be able to get an all-electric car without upgrading your grid connection. With the additional current available, an all-electric car like the Nissan Leaf or an gas-assisted electric PHEV like the Volt should recharge in about 5-8 hours, so, again, overnight charging at home works.
This pattern is fine for commuting. But if we want to get away from just using an electric car for commuting, then charging stations need to be essentially everywhere: parking lots, downtown on the street, you name it. You need to be sure that a station will be available whenever you are in a civilized parking spot (we can leave out Death Valley for now). Not only that, but the car must be able to draw enough current to recharge in a conveniently short time, since people on a 500 mile trip are not going to want to wait 8 hours after driving only part of the way. Making the recharge time the same as it takes to fill a tank with gas is probably too much to hope for, at least initially, but maybe a half hour at most would probably work for many people, especially if the range were high enough, say 200-300 miles like the Tesla. How high would the voltage need to be and how much current are we talking about? Try 400+v at 400 amps, but straight DC instead of AC, and the car would only about half charge in 30 minutes. The conversion to DC happens in the charging station, not the car.
There are a couple startups working on this technology. One is Coulomb Technologies. Their business model is to sell charging stations and the owner then sells the power. Because only utilities, as regulated monopolies, are allowed to sell electricity by the kwh, the charging stations sell power by time. This is a convenient dodge to avoid having the customers of Coulomb be regulated like utilities are. Another startup is 350Green. Their business model is to own the charging stations, install them for free, and cut the property owner in for 5%. Their charging stations also sell power by time, but take time of day and season into account.
Coulomb's model suffers from the chicken and egg problem. As long as there are not lots of electric cars, property owners and municipal governments won't see the economics of buying charging stations. Maybe some gas station owners will install them near areas where there are lots of electric cars, as is the case with E85 fuel. 350Green's model has better economics, though their incentives are a bit slim. Electricity, even during peak times, is about 1/3 the price of gasoline for the same amount of range, so the property owners won't be making much. In any case, there is a technical problem with these fast charging models. Unless the charger contains a large bank of capacitors that charge up slowly to almost the amount of power the car requires, the load on the grid from trying to draw down so much energy over such a short time may cause some failures in transformers and other equipment.
In my opinion, an easier way to solve the problem would be to take advantage of the infrastructure we have. Every street light pole has a small plate near the base the provides access to the wiring. You can see an example here:
What if, instead of installing fancy charging stations, every street light pole was installed with a 110v 15 amp and 220v 30 amp socket? Naturally, this wouldn't take care of drivers going long distances, but it would sure help when you are out driving around on a Saturday afternoon doing errands and need a quick recharge while getting a haircut. The main issue, though, is how to collect money for the power. One obvious way is to put a credit card swipe connected through the cellular network on the pole, and make people swipe their credit cards. Another would be to have some kind of wireless-based recognition system on the car and pole, and have the pole then charge the car owner through a post-paid plan, like a cell phone plan. There are lots of ways to arrange the charging, municipalities could even sell yearly passes to residents for unlimited power use.
There are probably lots more ways that charging stations could be arranged, but initially, home charging looks like it is most likely to be the initial pattern. This isn't actually so bad, since many families have at least one car that they just use for commuting. If a large majority can be convinced to replace that car with an electric, the impact on carbon emissions will be huge and we'll be well on our way to permanently reducing our collective carbon footprint to where it doesn't threaten the planet.
Sunday, June 13, 2010
The Electric Car Resurrection IV: Plug-in Prius Conversion
As the the Deepwater Horizon sinking slowly destroys the Gulf of Mexico and the consequences of our addiction to carbon-based energy go from being diffuse and hard to see to painful and in our faces, I though I would continue the Electric Car Resurrection series with a post about our plug-in hybrid Prius conversion.
If you've been following the series, you'll remember from this post, admittedly some time ago now, that after studying electric cars for 3 years, I was really ready to go electric. At the time, we had a 2002 Prius that was averaging around 42 mpg and a 1996 Corolla that was averaging around 30 mpg. I was really motivated to replace our 1996 Corolla with something that I could plug in to reduce our carbon footprint. Also, I figured we could get some of the power free from our solar PV since we regularly gave back around $80-$120 per year to PG&E in unused credit (though we did use around 1000 kwh from the grid so we were not 100% carbon free). Despite all my investigation, I hadn't found an electric car option that would really work.
In the spring of 2008, A123 announced their plug-in hybrid conversion package for the 2004-2008 Prius, the L5 plug-in hybrid conversion module. The details of the package looked pretty good. The conversion removes the spare tire and installs a 5 kwh booster battery in the spare tire well, along with a traction battery charger, and a 12v battery charger to handle the increased load on the 12v battery from the electronics in the booster battery. The booster battery uses a technology which A123 calls "lithium nanophosphate", in reality, it is their proprietary development of the lithium iron phosphate technology. This technology is reported to be exceptionally stable and long lasting, unlike the lithium cobalt technology used in laptops. A123 had pictures on their Web site of crash tests in which the batteries simply crushed along with the rest of the car, instead of exploding or anything like that.
The 5 kwh battery is connected in parallel across the 1 kwh OEM battery, and it trickle charges the OEM battery, which means that the 5 kwh battery does not recharge from the regenerative braking. Because the basic drivetrain power equipment is untouched, the warranty for the drivetrain is not voided. In fact, several Toyota dealers in the mid-West offered the A123 plug-in conversion as an option. The battery management system in the booster battery interfaces with the CAN bus, and the state of charge for the booster battery is smoothly integrated into the Energy screen on the car's flat panel display. The booster battery appears as an overlay second battery on top of the OEM battery and the display flashes between the two so you can see the state of charge in both.
While the car ends up not having a spare tire, it isn't a practical problem because the tires are all equipped with slow leak detectors, so as long as you stay on top of any reported leaks, the only problem could occur with a blowout. With that, you of course need to call a tow truck. Alternatively, you could take along a can of the inflator goo that re-inflates the tires and seals the leak, but that also destroys the leak detector, which is somewhat expensive to replace. Other than that, there didn't seem to be any drawbacks or negative impact on the car.
So we decided to do a conversion. The first step was to locate and buy a 2008 Prius. I wanted a model with everything but nav system (I can get that from Google maps on my phone or a paper map), silver in color. If you recall, spring 2008 was the peak of gas prices, where gas was going for $4.00 a gallon here in California, and Priuses were selling like hotcakes. I had a hard time locating a car, most dealers were sold out with 6 weeks to 3 months waiting time. However, I did find one, but unfortunately it had been used by a salesman and had 3,000 miles on it. I tried to argue the sales guy down (it was really used car) but he would have none of it. Priuses were hot items and he knew he could sell it elsewhere for full list price.
I bought the car in May 2008, then we waited. A123 was having some problems with CARB getting the license for the conversion. One little known fact about converting cars to use something other than the fuel they originally come equipped with is that it is illegal without an EPA and, in California, CARB license. The licenses are difficult to obtain, cost upwards of $24,000, and only apply to a specific make and model of car. This is one reason why you don't see many conversions to E85 (in addition of course to the lack of stations selling it). There are very few companies that are licensed to do legal E85 conversions (and most of those do ancient Dodges and such), any others - including those done by hobbyists - are illegal. The ostensible reason is because EPA wants to make sure that the converted car doesn't pollute any more than the original, and that in fact was the holdup with the A123 conversion. EPA was afraid that the catalytic converter wouldn't get hot enough because the engine doesn't go on much and so therefore the car would pollute more. A123 was finally able to satisfy them, and in October 2008, A123 started notifying people who had signed up and paid their deposit when their installation date was.
In November we got a notice saying that our L5 conversion package would be shipped to Pat's Garage in San Francisco shortly. I took the car up to San Francisco when it arrived and they had the L5 conversion installed in about 4 hours. Pat recommended to me that I get a set of sports car shocks installed in addition, because the original squishy shocks that come with the Prius tended to wear out under the additional 200 lbs of battery. I took his advice and, I must say, I am perhaps even more pleased with the shocks than with the electric conversion. Toyota's shocks are almost uniformly squishy, but these shocks make the car feel like a BMW. The shocks cost an extra $1K but they were really worth it. If I ever buy a Toyota again, I'll probably have them replace the shocks. In addition, a few weeks after the conversion, Pat told me about the need for an extra 12v battery charger. If the 12v battery goes out in the Prius, you can't simply jump it like in any other car. You must tow it to the dealer and have them replace it. Since the L5 electronics about double the load on the 12v battery, I thought it prudent to have the 12v battery installed.
Below you can see the back of the car with the electric socket and an extension cord plugged in in our garage.
We had the car decked out with decals on the back bumper and side.
Here's an overview of the booster battery pack:
And this shows more details of the battery pack, including the ventilator that keeps the battery cool:
The ventilator is the black plastic box across the middle of the picture. Normally we also carry a 25 ft. extension cord for "opportunity" charging. Many places will let you plug in for a couple hours, or even overnight if you are traveling longer distances.
The installation also includes a switch on the dashboard for switching the booster battery on and off, and a red light that glows when the booster battery is on and charging the OEM battery:
When the car is plugged in, the back tail lights go on for about a minute, then switch off. Originally, the lights stayed on while the car charged but about a year after the battery was installed, the car got a software upgrade that fixed that and another problem, involving the inability to go into electric mode. If you try to push the acceleration sometimes below 33 mph, the car starts beeping and the display says that it can't go into EV mode. This problem occurred frequently on the original software, especially on steep hills, now it has been improved to where it almost never occurs.
The original specs for the battery pack promised 30 mi. all electric range after maybe 5 min. of standard hybrid drive in order to burn off any evaporated gas vapors and heat up the catalytic converter. A standard 110v 15 amp house current socket is sufficient for charging, so no need to install a specialized 220v recharging station. Recharging takes about 5 hours. While the booster battery still has charge, the car remains in EV mode up to 33 mph (60 kph). In EV mode, the car only switches on the engine if the amount of acceleration needed is large, much larger than causes the motor to cut in in hybrid mode. But above 33 mph, you really need to work to keep the car in EV mode even if there is still sufficient charge in the booster battery because the engine cuts in more often (though not as often as if only the OEM battery is providing power). In practice, the car really only gets around 20-25 mi in all electric range before the booster battery is exhausted but that is enough to get me to work and back with a side trip to the gym for a workout.
You'll also notice the decal for the PulseStar spark plugs on the back of the car. If you read my previous posts (here , here, and here) you'll remember that I had the PulseStar plugs put into my 2002 Prius and that they shorted, destroying the ignition coil. But the company paid for the work on the car and gave me a discount on new plugs, so I bought a new improved set for the 2002 Prius. I also installed them in the 2008 Prius around the time I put the first set in the 2002 Prius. So far, I've not had any problem with them. With no booster battery, the plugs increase the gas mileage around 2 mpg or so.
With mostly around town driving and an occasional trip to San Francisco, Yosemite, or Monterey, the car gets a long term average of around 80 mpg, 30 mpg more than the EPA combined rating. The first six months we had the car, we tried to push the mileage as high as we could, with hypermileing maneuvers like driving slowly to keep it in electric mode, and we never took it out of town. We were able to get the mileage up above 100 mpg (actually, it was around 110 mpg as measured from gas consumption, the in-built meter won't measure higher than 99), but as soon as we took a trip to Yosemite it dropped.
Despite the fact that the car doesn't get the advertised range, I am still more than pleased with it. We don't fill up more than once every month and a half if we just drive it around town, and most of our driving is around town. Assuming we keep the car 10 years and drive about 8,000 miles per year (lower than average, but about what we usually do), the cost of the eliminated carbon is around $1.36 per kg of carbon eliminated. The initial upfront cost of the system is somewhat steep, but during the same 10 year period we end up saving around $8000 in avoided gasoline cost if gasoline is $3.00 per gallon (about what it is now). Since we get the electricity for free from our solar PV system, we don't have to pay for electricity either. This will not pay back the cost of the conversion, but, on the other hand, it will not break our bank account either. We could have chosen to buy a luxury car like a Lexus that cost about the same as the plug-in Prius, but then we would have had to pay for gas on top of the carbon pollution, and we would be contributing to the kind of consumption that leads to incidents like the Deepwater Horizon.
If you've been following the series, you'll remember from this post, admittedly some time ago now, that after studying electric cars for 3 years, I was really ready to go electric. At the time, we had a 2002 Prius that was averaging around 42 mpg and a 1996 Corolla that was averaging around 30 mpg. I was really motivated to replace our 1996 Corolla with something that I could plug in to reduce our carbon footprint. Also, I figured we could get some of the power free from our solar PV since we regularly gave back around $80-$120 per year to PG&E in unused credit (though we did use around 1000 kwh from the grid so we were not 100% carbon free). Despite all my investigation, I hadn't found an electric car option that would really work.
In the spring of 2008, A123 announced their plug-in hybrid conversion package for the 2004-2008 Prius, the L5 plug-in hybrid conversion module. The details of the package looked pretty good. The conversion removes the spare tire and installs a 5 kwh booster battery in the spare tire well, along with a traction battery charger, and a 12v battery charger to handle the increased load on the 12v battery from the electronics in the booster battery. The booster battery uses a technology which A123 calls "lithium nanophosphate", in reality, it is their proprietary development of the lithium iron phosphate technology. This technology is reported to be exceptionally stable and long lasting, unlike the lithium cobalt technology used in laptops. A123 had pictures on their Web site of crash tests in which the batteries simply crushed along with the rest of the car, instead of exploding or anything like that.
The 5 kwh battery is connected in parallel across the 1 kwh OEM battery, and it trickle charges the OEM battery, which means that the 5 kwh battery does not recharge from the regenerative braking. Because the basic drivetrain power equipment is untouched, the warranty for the drivetrain is not voided. In fact, several Toyota dealers in the mid-West offered the A123 plug-in conversion as an option. The battery management system in the booster battery interfaces with the CAN bus, and the state of charge for the booster battery is smoothly integrated into the Energy screen on the car's flat panel display. The booster battery appears as an overlay second battery on top of the OEM battery and the display flashes between the two so you can see the state of charge in both.
While the car ends up not having a spare tire, it isn't a practical problem because the tires are all equipped with slow leak detectors, so as long as you stay on top of any reported leaks, the only problem could occur with a blowout. With that, you of course need to call a tow truck. Alternatively, you could take along a can of the inflator goo that re-inflates the tires and seals the leak, but that also destroys the leak detector, which is somewhat expensive to replace. Other than that, there didn't seem to be any drawbacks or negative impact on the car.
So we decided to do a conversion. The first step was to locate and buy a 2008 Prius. I wanted a model with everything but nav system (I can get that from Google maps on my phone or a paper map), silver in color. If you recall, spring 2008 was the peak of gas prices, where gas was going for $4.00 a gallon here in California, and Priuses were selling like hotcakes. I had a hard time locating a car, most dealers were sold out with 6 weeks to 3 months waiting time. However, I did find one, but unfortunately it had been used by a salesman and had 3,000 miles on it. I tried to argue the sales guy down (it was really used car) but he would have none of it. Priuses were hot items and he knew he could sell it elsewhere for full list price.
I bought the car in May 2008, then we waited. A123 was having some problems with CARB getting the license for the conversion. One little known fact about converting cars to use something other than the fuel they originally come equipped with is that it is illegal without an EPA and, in California, CARB license. The licenses are difficult to obtain, cost upwards of $24,000, and only apply to a specific make and model of car. This is one reason why you don't see many conversions to E85 (in addition of course to the lack of stations selling it). There are very few companies that are licensed to do legal E85 conversions (and most of those do ancient Dodges and such), any others - including those done by hobbyists - are illegal. The ostensible reason is because EPA wants to make sure that the converted car doesn't pollute any more than the original, and that in fact was the holdup with the A123 conversion. EPA was afraid that the catalytic converter wouldn't get hot enough because the engine doesn't go on much and so therefore the car would pollute more. A123 was finally able to satisfy them, and in October 2008, A123 started notifying people who had signed up and paid their deposit when their installation date was.
In November we got a notice saying that our L5 conversion package would be shipped to Pat's Garage in San Francisco shortly. I took the car up to San Francisco when it arrived and they had the L5 conversion installed in about 4 hours. Pat recommended to me that I get a set of sports car shocks installed in addition, because the original squishy shocks that come with the Prius tended to wear out under the additional 200 lbs of battery. I took his advice and, I must say, I am perhaps even more pleased with the shocks than with the electric conversion. Toyota's shocks are almost uniformly squishy, but these shocks make the car feel like a BMW. The shocks cost an extra $1K but they were really worth it. If I ever buy a Toyota again, I'll probably have them replace the shocks. In addition, a few weeks after the conversion, Pat told me about the need for an extra 12v battery charger. If the 12v battery goes out in the Prius, you can't simply jump it like in any other car. You must tow it to the dealer and have them replace it. Since the L5 electronics about double the load on the 12v battery, I thought it prudent to have the 12v battery installed.
Below you can see the back of the car with the electric socket and an extension cord plugged in in our garage.
We had the car decked out with decals on the back bumper and side.
Here's an overview of the booster battery pack:
And this shows more details of the battery pack, including the ventilator that keeps the battery cool:
The ventilator is the black plastic box across the middle of the picture. Normally we also carry a 25 ft. extension cord for "opportunity" charging. Many places will let you plug in for a couple hours, or even overnight if you are traveling longer distances.
The installation also includes a switch on the dashboard for switching the booster battery on and off, and a red light that glows when the booster battery is on and charging the OEM battery:
When the car is plugged in, the back tail lights go on for about a minute, then switch off. Originally, the lights stayed on while the car charged but about a year after the battery was installed, the car got a software upgrade that fixed that and another problem, involving the inability to go into electric mode. If you try to push the acceleration sometimes below 33 mph, the car starts beeping and the display says that it can't go into EV mode. This problem occurred frequently on the original software, especially on steep hills, now it has been improved to where it almost never occurs.
The original specs for the battery pack promised 30 mi. all electric range after maybe 5 min. of standard hybrid drive in order to burn off any evaporated gas vapors and heat up the catalytic converter. A standard 110v 15 amp house current socket is sufficient for charging, so no need to install a specialized 220v recharging station. Recharging takes about 5 hours. While the booster battery still has charge, the car remains in EV mode up to 33 mph (60 kph). In EV mode, the car only switches on the engine if the amount of acceleration needed is large, much larger than causes the motor to cut in in hybrid mode. But above 33 mph, you really need to work to keep the car in EV mode even if there is still sufficient charge in the booster battery because the engine cuts in more often (though not as often as if only the OEM battery is providing power). In practice, the car really only gets around 20-25 mi in all electric range before the booster battery is exhausted but that is enough to get me to work and back with a side trip to the gym for a workout.
You'll also notice the decal for the PulseStar spark plugs on the back of the car. If you read my previous posts (here , here, and here) you'll remember that I had the PulseStar plugs put into my 2002 Prius and that they shorted, destroying the ignition coil. But the company paid for the work on the car and gave me a discount on new plugs, so I bought a new improved set for the 2002 Prius. I also installed them in the 2008 Prius around the time I put the first set in the 2002 Prius. So far, I've not had any problem with them. With no booster battery, the plugs increase the gas mileage around 2 mpg or so.
With mostly around town driving and an occasional trip to San Francisco, Yosemite, or Monterey, the car gets a long term average of around 80 mpg, 30 mpg more than the EPA combined rating. The first six months we had the car, we tried to push the mileage as high as we could, with hypermileing maneuvers like driving slowly to keep it in electric mode, and we never took it out of town. We were able to get the mileage up above 100 mpg (actually, it was around 110 mpg as measured from gas consumption, the in-built meter won't measure higher than 99), but as soon as we took a trip to Yosemite it dropped.
Despite the fact that the car doesn't get the advertised range, I am still more than pleased with it. We don't fill up more than once every month and a half if we just drive it around town, and most of our driving is around town. Assuming we keep the car 10 years and drive about 8,000 miles per year (lower than average, but about what we usually do), the cost of the eliminated carbon is around $1.36 per kg of carbon eliminated. The initial upfront cost of the system is somewhat steep, but during the same 10 year period we end up saving around $8000 in avoided gasoline cost if gasoline is $3.00 per gallon (about what it is now). Since we get the electricity for free from our solar PV system, we don't have to pay for electricity either. This will not pay back the cost of the conversion, but, on the other hand, it will not break our bank account either. We could have chosen to buy a luxury car like a Lexus that cost about the same as the plug-in Prius, but then we would have had to pay for gas on top of the carbon pollution, and we would be contributing to the kind of consumption that leads to incidents like the Deepwater Horizon.
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