Monday, April 25, 2011

Solar Fountains

Every year during the Going Native Garden Tour, I get lots of questions about our solar fountains. We have a lot of water features in our garden. Since the key to making renewable energy practical is to reduce energy consumption, I didn't want to add additional base load to our big solar panels by having fountains that run all the time off of the AC grid. So I've spent the last 6 years or so working with solar fountains, and this post tells you a little about them.

I've found that there are basically three kinds of solar fountains:
  • Fountains in which  the pump, solar panel, and water feature are completely integrated,
  • Fountains in which the panel and pump are provided as a kit, and you simply install them in a water feature,
  • Fountains that are made from bits and pieces that were bought for other purposes and need to be assembled and installed into the water feature.
All these kinds of fountains basically recirculate the same water, and need to be filled periodically because they don't have a connection to a water supply to replace evaporated water. I suppose it is possible to connect a fountain up to the domestic water supply, but it would really be a lot more complicated.

In the first category is what The Lovely Wife calls the "Christmas fountain", because I gave it to her for Christmas a couple years ago. It is basically a plastic birdbath with an integrated solar panel and pump:

These kinds of fountains are really simple to install and use. You just place the fountain out in the sun and fill it with water.

The second kind require you to build some kind of water feature around the fountain. Here you can see a nice little fountain The Lovely Wife built in the front garden, with a blue bowel on top of a column of flat rocks:

The pump and the solar panel come as a kit, you just plug them together and set the solar panel out somewhere where it will get some sun but isn't too obtrusive. That's the solar panel in the background.

The other two solar fountains in our yard are the third type. Here you can see them running full bore on a sunny day. The first picture is the big fountain on the side, the second is the small one in the back:

These started out as the second type, i.e. a kit, but in addition to the solar panel, they had batteries for running at night. Unfortunately, the batteries didn't last very long, so I removed them and wired the panels directly to the pumps. This required some creative wiring as you can see here:

I have the junctions in a couple of plastic Tupperware boxes to  keep it from  getting too  wet. With the big fountain, I can hide the box behind a large fern, but with the small one, I can't. So I bought a fake rock under which I hide the Tupperware box. Here you can see the Tupperware box sticking out when the rock is upside down, and how realistic it looks when the rock is properly positioned:

The fake rock is always a big attention hit during the garden tour. Also, it acts as good habitat for lizards. When I lifted it up recently, there was a big lizard underneath.

The large, 18V fountain on the side has a big pump and a large thin film solar panel:

It's really wonderful, like having a brook in our yard. On sunny days, the sound attracts hummingbirds.

The  smaller, 6V fountain in back has its wiring concealed under the fake rock. It also has a thin film solar panel and runs into a water barrel:

The DC pumps on all the fountains are really  poorly made and usually last between 1-3 years before they burn out. But since they only cost around $20 apiece, it's usually not a problem to replace them, though I had a hard time finding a pump for the 18V fountain. Good, reliable pumps are almost 10x more expensive. Silicon Solar has both the cheap and the reliable pumps, and a line of pump kits including those with battery backup. They have a nice  selection, but sometimes their service isn't so prompt. I had  to cancel an order last year because they still didn't have stock in 6 months after I placed the order. But unless you feel comfortable ordering over the Internet from China or know German (there are some really nice but expensive pump kits from German web sites), Silicon Solar is probably your best bet. I suppose, from an environmental perspective, throwing away a pump every 3 years isn't a particularly good use of resources, but all the parts on the pump can be recycled, and we have especially good recycling in our city, so I've so far favored the cheap pumps despite the hassle factor of having to replace them (and also because until last year, small reliable ones weren't available, at any price).

The latest trend in the cheap pumps is to wire a capacitor across them so that the capacitor slowly charges when there is not enough sun to run the pump continuously. When there is enough charge, the pump turns over once and water spurts out.

Though it is still cold here in northern California, spring is really here now and the wildflowers are spectacular. This double rainbow appeared the other day, perhaps a sign that the mild but wet winter we had this year is finally over:

Friday, April 22, 2011

Earth Day Post: Is E85 Worth It?

Today is Earth Day and so I thought I would post something about what the next step might be in our quest to reduce our carbon footprint to zero. We still need to buy gasoline for our plug-in Prius, especially when we take it out of town, so biofuels seems like one area where we might focus some attention. Our local paper recently had an article about a couple of Silicon Valley companies working on biofuels. One of them is Propel. They're working to get more E85 and biodiesel fuel dispensing pumps installed around the country, and soon will likely be opening a station in our city. Actually, we already have a biodiesel pump at a nearby (less than 5 miles) station, but our plug-in Prius doesn't have a diesel engine and there are, as yet, no diesel hybrids available in America (Citroen makes a limited edition model that they are now selling only in Europe). There are stations with E85 available in San Jose and Redwood City, but they are too far away for regular tanking up, even with our plug-in Prius which we usually fill about once a month and a half, unless we take it out of town.

E85 consists of 85% ethanol made from corn and 15% gasoline  made from oil. Most automotive fuel in the US that is used by "gasoline" engines today consists of 10% ethanol and 90% gasoline. In addition to its value as a renewable,  nonfossil-based fuel, the ethanol serves as an oxygenating agent, which is especially important in California where emissions from automotive combustion contribute to creating smog. Ethanol as an oxygenating agent reduces smog-forming chemicals in exhaust. The EPA wants to increase the percentage of ethanol to 15% in regular gas to reduce the amount of fossil carbon emitted by the transportation network. This is somewhat controversial right now, but most tests have shown the cars manufactured after 2001 can run without any modification and without any negative effect. Of course, this leaves the people with cars manufactured before 2001 with a problem if the entire fuel distribution network switches to 15% ethanol, but we've seen this movie before. When the US switched from leaded to unleaded gas in the 1970's, cars with older engines had to continue using leaded to lubricate the valves, or the driver needed to add something to a tank of unleaded. Retailers continued to sell leaded gas for a while, but have you seen any leaded for sale lately?

In fact, it is possible to fuel any recent vintage car with E85 or even E100 (100% ethanol) without any long term effect on the car. The manufacturers have eliminated rubber and plastic fittings that might be degraded by ethanol from the fuel lines, tank, and other fixtures in the fuel system. Nonmetal fixtures are degraded by gasoline too, just not as quickly, so removing them decreases the probability that the fuel system will experience a failure, which might be quite serious if leaking fuel catches fire. The lower energy content in ethanol does cause problems for the car's engine control computer, though. Because the car ends up using 30% more fuel with E85 than with E10, the engine control computer triggers the Check Engine light (that little light which looks like an oil can on most car dashboards, and comes on usually in rather mysterious and not very critical circumstances). The light stays on until it is cleared on the CAN bus (the car's control system bus) by a computer control plugged into a USB port somewhere in the front of the passenger compartment. So, in theory, we could use E85 without any modification to our plug-in  Prius, if we were willing to drive around with the Check Engine light on all the time. There are also conversion kits for modifying the fuel control system so the  engine computer doesn't report a fault when the car uses more fuel than the engine computer expects, so we could theoretically install such a kit when Propel puts an E85 station within convenient range if we wanted to avoid the Check Engine light problem.

Now, corn-based ethanol is really not the best choice for a renewable transportation fuel. Raising the corn and processing it to ethanol takes so much fossil based  energy that E85 results in only a 20% reduction in life-cycle fossil carbon emission (rather than the immediate carbon emission from just using the fuel). And the ethics of using a food crop for transportation fuel when  the world population is 7 billion and rising - and the amount of agricultural land isn't growing - is pretty questionable in my opinion. With cellulosic ethanol (ethanol made from plant waste and crops such as switchgrass that aren't used for food), the reduction can be much  better, around 86%, according to Propel's website. Production facilities for cellulosic ethanol are gradually starting to come on line, but it will be many years before corn ethanol is completely displaced.

I did a quick calculation to see how much converting our plug-in Prius to E85 would reduce our direct carbon emissions. In the calcuation, I didn't take into account the life-time reduction, but rather just the immediate reduction of substituting fuel which is 85% nonfossil ethanol. My estimate on how much fossil carbon our plug-in Prius and the (as yet undelivered) Nissan Leaf charged from our new solar PV system will generate is  1.11 metric tonnes per year (see this post for more information on how I estimated our projected carbon  footprint),  and our total fossil carbon footprint was estimated at 2.81 metric tonnes per year. If we were to go with E85, we would reduce our transportation contribution by 85% to 0.167 metric tonnes per year, which looks pretty significant, for an overall fossil carbon emissions footprint of 2.417 1.86 metric tonnes per year. But the impact on our percent reduction from our 2002  baseline would be rather small, from a 78% reduction without E85 to a 81% 85% reduction with it. If we factor in the lifetime fossil carbon in E85, the reduction is even less, not even considering the issue of the food v.s. fuel choice.

My conclusion is that between the minimal carbon reduction, the hassle and cost of doing an E85 conversion (if we want to avoid the Check Engine light problem), and the ethical issue, conversion to E85 is not worth it at this time. This might possibly change when cellulosic ethanol becomes the baseline for E85.

Wednesday, April 20, 2011

It's Getting Very Near The End...

We are now in that part of the construction job that feels like Zeno's Paradox. The contractor takes 5 months just to get started on the job, then another 2 1/2 to do the bulk of the work, then another 1 1/4 to do some finishing items, then gets stuck in a phase where every week, a few minor items are done, with the number of minor items completed gradually reducing...

Well, you get the picture. Speaking of pictures, here's one of the urbanite that replaced the concrete sidewalk:

The Lovely Wife filled the cracks with tumbled, recycled shower door glass, looks a little like tiny cubes of ice. Quite nice I think.

The gas fireplace is together, except for the door over the control box:
We tried it out briefly. It puts out an incredible amount of heat, and the fan is a bit loud, but we don't expect to be using it much (we didn't use the old pellet stove at all).

We replaced most of the lighting in the house. Here's what we put in the hallways:
It's nothing special, an Ikea Pult, but we like it and it fits in with our minimalist, more modern decor. The old lights were shiny brass with panes of glass like carriage house lights.

Unfortunately, the chandelier chains were too short, but the electricians hung them anyway:
I can't imagine where their common sense was with this. Also, as you'll note, one of the bulbs I bought didn't work, but still they hung it. This chandelier is a Varaluz Aizen made in the Philippines from recycled iron

The pendant lamp  suffers from the same altitude sickness as the chandelier:
It's a Possini Euro Deco, in brushed nickel.

In two of the upstairs bedrooms which we use as workrooms, we put in sconces. These rooms formerly had spots in them, and were always dark. Now they are filled with light. Here's my office:
The sconces came out the best of our lighting choices.

And on that note, I'll finish this side excursion into interior decorating. I have a couple more posts on more serious topics brewing, but lately I've been so busy at my day job and preparing for the annual Going Native Garden Tour (the high point of the year for The Lovely Wife, who is an avid native gardener) that I haven't had time to post anything.

Sunday, April 10, 2011

How to Get People to Adopt a Low Carbon Lifestyle?

Well, our system remodel - projected to take 4 months but now at 10 months - is slowly grinding to a close. We keep finding odds and ends. The worst one was that someone at the general contractor bought an uninsulated  door for our new HRV chase, which got installed this week. I can't understand why they would think that after paying so much money and suffering through so much disruption to reinsulate our walls, we would be happy with an uninsulated metal door that punches a hole in the thermal envelope of the house. But other items are slowly progressing, and this week we should have the electrical work and baseboards done, which should be sufficient for the inspector to approve the job and for us to move back into the house. The rest of the items - like replacing the door - we can do after we've moved back in.

Anyway, what I really wanted to talk about this week was something else. I got email a few weeks ago about a home visit program run by the local environmental group, Acterra. The email said something about doing home visits to help people reduce the amount of carbon emissions due to energy use. Now that I have been through about 10 years of working on this problem in our own lifestyle, I thought I could help other people too based on our experience. So I signed up for the training.

I'm not sure what I expected but I knew I was in the wrong place when everybody there was either retired, a student, or unemployed. The program requires two home visits a month which are supposed to run for 2 1/2 hours but realistically, it means sacrificing a day a month for the work. Considering that I have a full time job and am usually out of town for a week a month on a business trip, this was a time commitment that I simply don't have. I also didn't find that the program was a good match for my interests and skills. It involves doing stuff I am not good at, like plumbing, and lots and lots of paperwork. So from a personal standpoint, the program doesn't seem like a good match for me.

The program does result in some carbon and water savings, but the per-household  savings are not large, on the order of "change out incandescents for CFLs", better than "unplug the cell phone charger" but not up there with "install solar PV on a power purchase program". The premise of the program seems to be that if people see savings on the order of a couple hundred dollars a year on their utility bills from various conservation measures, they'll become more likely to support larger policy changes to move society to a lower carbon, renewable energy future. There are a couple problems with this premise. First, the program is entirely voluntary, so the people who sign up for it are self-selecting. They are more likely to have environmental concerns to start with, so they probably would support policy changes to move to a low carbon society anyway. Second, the premise that cost savings should be the motivator for adopting energy efficiency and renewable energy is, in my opinion, misleading. There are some very low hanging fruits that are available, but they don't amount to much carbon savings. Once you've harvested those, you quickly come into the much higher branches of the tree, where harvesting the fruits costs money. We are not going to get to 80% carbon reduction by 2050 by saving money. This is one important point I've found out from our efforts over the last 10 years, which have, in fact, reduced our direct carbon footprint (house and car) by an estimated 80%, or will shortly. I can't do anything about my business travel, except quit my job, and we can't do much about purchases that have high embedded carbon content or that use lots of energy, except buy less. Since I enjoy my job, and we already don't spend a lot of money on stuff, we are working on the areas where we can.

To the extent that the environmental community has made this cost saving a major part of their message about carbon  reduction, they have been misleading the public. The amount of money required to build our current, high carbon infrastructure is enormous, and it will take that much, if not more, to replace it. Take, for example, the Interstate highway system. Before 1950, it didn't exist. Now it does. Some huge amount of money went into building it, that came out of a societal consensus about a particular transportation option. In my opinion, rather than trying to sell people on energy efficiency because they can save a few hundred bucks on their utility bill, they should be taking straight:
- That if they don't start using energy more efficiently, it will be impossible to power society with renewables, and we will have to continue using carbon-based energy and nuclear power.
- That if that happens, we will see, every 20 years or so as has been the case up until now, radioactive contamination of large areas of land like around Chernobyl and Fukushima due to reactor malfunctions. These land areas then will need to be sacrificed for thousands of years until the radioactivity decays.
- That the carbon emissions from coal, oil, and natural gas will result in climate changes that will make a large part of the middle latitudes tropical or a desert for at least a thousand years and maybe more, eliminating any agricultural use. The result will be widespread starvation and a population crash.
- That the transition to a low carbon future will require the same amount of investment that we've put into the high carbon infrastructure we have now, but the result will be a world their children can live in with some comfort and prosperity.
The environmental community needs to get in the Tea Party's face about this, and Koch brothers too.

Acterra is a great group, they have lots of excellent programs, including one for training environmental activists, and I fully support them. I also think this program is fine for what it does, though it unfortunately just isn't a very good match for my personal circumstances. It will be especially helpful for low income people, since a couple hundred dollars saved on their utility bill may mean the difference between really making it and not. And it might even help a few middle income people too. But it is not going to convince people who are denying reality about the dangers of carbon-based energy.

Sunday, April 3, 2011

Roof Comparison

If you recall from this post, a picture of the roof after a below-freezing night showed a dense frost pattern, an indication that our insulation job was successful. I mentioned that I did not have a photo from before the closed cell foam insulation. On Friday, I was browsing around looking for a photo of the inside for another reason, and I found a couple of photos of the roof which I took on a cold winter morning in 2008. Here they are:

You can see how the frost is thin and patchy. Some of the patchiness near the top may be from melting but the bottom hasn't had any sun yet. Compare that to this photo, which is from the previous post:

Here the only thinner spots are where the roof rafters are causing thermal bridging. Next winter, I'll try to get some better pictures.

We are now coming into the last week  (hopefully) of our System Remodel, after almost 10 months of work. The solar PV system seems to be functioning well, I've been watching it push the meter backwards. At the peak in the afternoon, it seems to be putting out around 4.5 kw, which is just shy of the 4.7 kw that the panels on the west side of the roof are rated at. The around 5% difference is probably due to the inverter efficiency, possibly also due to some shading on the panels on top of the dormer. We are back on solar thermal hot water, after I discovered that the plumber had removed the temperature probe from the control port in the solar thermal hot water tank. This was why the tank temperature wasn't registering over 74F. Fortunately, it being winter, the tank didn't get hot enough to trigger the overpressure value, though it did cause the solar pumps to be on much longer than they normally would have. The big question right now is: will the Stiebel-Eltron tankless heater handle the extremely high (up to 180F) water temperatures in the summer without triggering the over heat breaker? We have email into Stiebel-Eltron about it. I am also planning on having Sunwater Solar over to check the solar hot water system. It has been two years since we had it installed, and we missed the annual maintenance last year because the house was torn up.

Of course, we won't know how effective the insulation was until next winter when we start heating again. Temperatures here in California were in the 80F's last week, hot for this time of year. Over the weekend, the temperatures cooled down some. Most of our weekend was consumed by working to get the garden in shape for the annual Going Native Garden tour. I'm responsible for the solar fountains, and I can say that as of today, they are all running again. Tune into our sister blog at Town Mouse/Country Mouse for more on the Going Native Garden tour.