The Electric Car Resurrection II: The Hero's Path

While I was researching conversions, I found out that the husband of a friend of my wife's was planning to do a conversion. Steve Schmidt and his son Eric (a high schooler) were well into plans to locate a small junked sports car in good condition and convert from ICE to EV. Now,  Steve's skill with tools is far in excess of mine, and Eric is no slouch himself. Eric recently served as lead engineer on one of the components in his high school robotics team's entry into the national robotics competition. I'd last checked in with Steve two years or so ago, so a few weeks ago I stopped by to see how the project came out.

Steve and Eric started planning the conversion in the spring of 2007. They ordered the batteries in September, 2007 and by February 2008 the batteries had arrived. The conversion work itself followed quickly, by May the car was running.

The "donor" was a 1976 MG midget, located from a junk yard and bought for $800. Here you can see it relaxing in the grass:

The first order of business was restoring the car's gasoline engine. This they did. Here you can see the car with the engine restored, minus the radiator:

Naturally, if you want to get a car relicensed in California, you have to have a smog inspection. Since this car had no pollution controls - catalytic converter, filters on the engine to catch gasoline vapors, etc. - it was labeled a "gross polluter". But they did manage to get it relicensed. The work on the gasoline engine wasn't all lost, they managed to sell the engine on EBay which helped finance the electric components.

After the car was running on gasoline, they removed the engine and started the electric conversion. The most difficult thing about the conversion was connecting the electric motor to the transmission and clutch. Most electric conversions remove the transmission and clutch. Because an electric motor has essentially infinite torque at zero rotation, there is no need for a transmission, unlike a gasoline motor. But Eric really wanted the ability to shift, so they kept the transmission. The connection required them to get a specially machined metal plate to match up the motor to the transmission. This plate is actually a requirement for any electric conversion, but theirs was a bit more tricky because they wanted to keep the transmission.

The most expensive part of any electric conversion is the battery pack. Unlike most hobbyist conversions, the Schmidts decided to go with lithium polymer batteries, having lithium cobalt oxide anodes. They ordered their pack from ABAT, a Chinese company, and the batteries also came with a battery controller for charging. The pack consists of 66 40 amp-hour cells arranged 2x33. The result is 80 amp-hours at 130 volts, or 10 kWh. Here's a picture of the battery box in the front:

There's another battery box in the back where the gas tank used to be.

Shortly after they got the car running, 2 cells went bad and were replaced by ABAT on warranty. They now have two other cells that don't charge up as smoothly as the rest. the line of small dots you see on the front of the battery box are ports they use for balancing the charge across the two strings of batteries. The battery pack cost around $10.5K and weights 200 lbs. though all together, it did not add extra weight to the car. The car is actually slightly lighter than the original but still has the original suspension.

The other electrical components include an Advanced DC 8", 85 hp motor and a Curtis 1221-C controller. The controller is a bottleneck, it will not let the motor draw enough current to get that slapped back into the seat kind of acceleration that electric cars are known for. Steve told me that there is another controller, made by Zilla, which is much better but it is considerably more expensive and also isn't manufactured any more, so it can only be bought used. Because the electrical system is DC, there is no regenerative braking, such as the Prius and other commercial hybrids have.

The range of the car is around 45 miles per charge, top speed probably over 65 mph but they have never tried it. Steve and Eric told me of their adventure with getting the electric car smogged. This sounds like a contradiction, but after they removed the engine, they had to have it retested and certified as not being a polluter. DMV was around 20 miles away,  so they figured they could just make it. On the way back, they almost made it when they realized they were running out of charge. They parked the car at a laundromat and plugged in for a couple hours. After that, they made it home. But the car is mostly used by Eric for commuting 5 miles or so to school and back, so range isn't really a problem.

Eric and Steve split the financing. Eric paid for the ICE components, including a new set of seats from a Mazda Miata and a stereo, and Steve paid for the electric components. In all, the cost came out to $18,266.

After we were done talking, Eric took me out for a spin. The land around their house is hilly, but the car had no problems negotiating the hills. And despite the drawbacks of the Curtis controller, the acceleration seemed just fine.

If you want to find out more about the Schmidt's conversion, check out their Web page at EValbum. com.

More Spark Plugs

Well, if you have been following the saga of the shorting spark plug here and here you'll remember that the high performance spark plugs I got from Enerplus (called Pulstar) shorted and burned out my ignition coil, but the company reimbursed me for the plugs and the coil replacement. My mechanic put stock plugs back into the 2002 Prius, and since then I've been sadly watching as the gas mileage deteriorated by 0.1 mpg per month. And pushing on the steering wheel and saying "come on, come on..." as the car struggled onto the freeway in the morning.

Anyway, I finally broke down a couple weeks ago and bought another set of Pulstar plugs. Enerplus has been working on improving them, and version 2.0 supposedly has a longer lifetime as well as a fix for the occasional high resistance problem that plagued the original plugs I had. Plus they are less expensive.

I recently had the car in for a 75,000 mile checkup and asked my mechanic to put them in again. He looked at me a bit funny and asked if I was sure, but when I told him that the company had made good on their guarantee, he was relieved. I've reset the mileage, hopefully it will get back up to 46 mpg it was before the resistance started creeping up last summer.

System Remodel Coming

My wife and I are in the process of planning a system remodel, or deep energy retrofit, on the house. The idea sprang out of a problem we are having with the cathedral ceiling in the hall that runs the length of the house. The ceiling is cracking along the ridge and on one seam near the north side. According to a structural engineer we had look at the problem, the cracking is happening because the ceiling is spreading. When we moved into the house in 2003, we had the rotting, termite-ridden shake roof removed and replaced with a nice 40 year composite roof. The plywood decking increased the weight of the roof, and since our house was built in the 1970's before they really had the technology of cathedral ceilings down, there is no steel in the ceiling supports. So the weight causes the wood to compress and spread. We had a couple contractors come in last summer and give us bids, and included in the bids was the cost of taking the dry wall off the rest of the ceilings in the house and reinsulating with closed cell foam - a messy job at best - to increase the heat retention in winter. The bids came in around $100K, a lot of money just for some drywall work and insulation.

We decided to think about what more we could do that would move our house closer to our goal of net zero energy. The experience with getting bids on the ceiling showed us that we were about at the limit of what we could do by attacking the problem piecemeal. Most contractors are clueless about how to do good insulation. When we had the kitchen ceiling redone a couple years ago to get rid of leaky can lights, I had to walk the contractor through what he needed to do to get a tight seal, though he is otherwise quite competent and is the most accurate in doing bids that I have found. We decided to work with an architectural firm that has lots of experience with green architecture, Vox Design in downtown Mountain View. Vox is run by Randy Potter and Forrest Linebarger. I know Randy from my time on the Mountain View Sustainability Task Force,  we ended up working with Forrest because he had the most time. We've had four meetings with Forrest since Christmas and are getting close to finalizing the design.

The first order of business before Christmas was to get an "as-built" CAD model of the house, since we had no plans. One Saturday, a guy came over and measured the whole house, checked out all the various kinds of surface (hardwood floor, etc.). Our house has a lot of odd corners here and there, many of the walls don't exactly line up as you might expect, so he had some difficulty getting an accurate plan. This is somewhat of an architectural feature, not a function of sagging over time or anything like that. The house is in a style called "Sea Ranch" after a development along the Mendocino Coast that was built in the 1970's and influenced a lot of the tract architecture in this part of the Peninsula, like the Eichlers did in the 1950's. There are many apartment buildings and townhouses that were built in this style in Mountain View, we owned such a townhouse prior to buying this house, and liked the style so much that we decided to buy another one.

After the "as-built" plans were done, we worked with Forrest to scope the project and define exactly what we wanted. Needless to say, as the planning developed, various odds and ends fell out and a couple of items came in. We have three Hunter ceiling fans that we decided to remove. Ceiling fans are about the worst form of cooling around. They generate more heat than they remove. If you stand right under them, they do generate some cooling but for that they heat up the air around the motor. We never  use them. The ceiling fan electrical connections in the ceiling then are freed up. In the living room and Buddha room, we'll put in light fixtures, since these rooms are dark. In the hall, we'll put in shades that are electrically driven and cover the ridge skylights at night. These skylights radiate lots of heat out of the building on cold winter nights, because they are at the highest point in the house which is where all the warm air collects. And we will  put a skylight in the living room with an electric shade to increase the natural light.

These are actually minor points, though, the major point is that we plan to take off the dry wall and reinsulate the entire upstairs including all the ceilings, and about 80% of the downstairs outer walls, and fix the spreading problem by putting steel in the hall ceiling. The only exceptions are the master bedroom and bath, where we will live during the work, and the kitchen, which we had reinsulated a couple years ago. This will be a messy job, requiring scaffolding through the entire house. All the furniture must come out, and we must essentially move out into the back bedroom. Because the house will be much tighter, we need to install a Heat Recovery Ventilation  (HRV) system. This takes outside air, runs it through a heat exchanger in which the inside air either heats or cools the incoming air depending on the season, and vents the fresh outside air into the building and the stale inside air out. The ventilation ensures that the inside air is always fresh and the heat recovery function ensures that heating or cooling energy isn't wasted.

Other work includes plans to add a geothermal heat pump which will require drilling two wells in the front yard. Geothermal heat pumps are the most efficient HVAC systems around, and will give us some air conditioning in case we get more hot, muggy weeks as the climate changes, like the one we had last August. We will replace our wood pellet stove in the living room with a gas-fired fire place, 88% efficient. I really wanted a new wood pellet stove that was more automated, but Santa Clara County  no longer allows wood burning appliances to be installed due to problems with severe air pollution in winter during inversions. This fireplace will work when the electricity is out (but not of course the gas) and though it will not get us to full net zero energy, we  will buy carbon offsets for it. Yes, I know,  they are like indulgences during the Middle Ages but we still have a gas cooking stove which we don't plan to replace because cooking with gas is much nicer than with electricity. Maybe some day they'll have biogas or someone will come out with a wood stove that doesn't let off any air pollution.

We will also replace our gas backup tank water heater with an on-demand electric water heater to supplement the solar. We decided on an electric backup because we can install solar PV to offset the electricity. We decided on an on-demand heater rather than use the second heat exchanger in the solar tank or an electric coil because any heater that was connected to the solar tank would not take full advantage of solar energy. If you set the tank temperature to 120F, then the electricity will always come on to keep the temperature at that point, even if it is in the middle of the night. With an on-demand heater, the solar collector has an opportunity to add energy during the day, and the on-demand heater only comes on to top off the temperature to 120F when there is demand. So it should use much less electricity, though it will probably be more expensive initially. And it will require that we install a 200 amp electric service from the grid, but we were planning on doing that anyway, since we wanted the extra capacity for the geothermal and maybe another electric car - someday, when our budget recovers from this project.

Finally, we plan on adding more solar PV so that we can offset the geothermal heat pump, the electric hot water heater, and also generate some solar to offset the gas (in addition to the offsets bought from PG&E). Right now, we're looking at a 4 kw system total, but it may go up since there is now no downside to installing as much solar capacity as your pocktbook and roof resource allows. Starting next year, PG&E will pay you back for any extra power you generate above what you use (YAAH!). Over the last 6 years, we've consistently given PG&E something like $70-180 a year back because we've generated more power than we've used, primarily because we've done a lot to reduce our consumption (our solar PV system is actually not very large). This year we gave back much less because of the plug-in hybrid car and the new solar thermal hot water system, which uses a pump.

We're now at the point where we have a preliminary budget (around $200K - expensive!) and are beginning to work on plans to move the furniture out. Forrest is going to start the design of the geothermal system, and we still need to make a few additional decisions. It's going to be pretty disruptive but when we're done, the house will be a lot tighter, more like modern houses, and we should have around 90% of the carbon footprint eliminated (100% if you include offsets).  Stay tuned!