By PB Floyd
I’ve been fascinated by solar energy as a futuristic technology since I was 7 years old. Solar energy is locally produced, makes people independent from huge centralized oil and power companies and avoids burning fossil fuels. When I started a group house in 1998, I looked into putting solar power on the house right away because I hated the idea of our house contributing to the pollution and corporate domination that we are trying to stop. Unfortunately, at the time, it wasn’t financially realistic. This spring, I finally had time and money to install a professional quality solar hot water system on the house. But putting in the long-desired solar system didn’t turn out how I expected it to.
Do It Yourself (DIY)
Over the past 10 or 12 years, I’ve become increasingly personally worried on a day-to-day, psychological level about climate change caused by burning fossil fuels. At this point, I talk about it in therapy. As a result, I’ve tried to reduce my personal consumption of fossil fuels in various ways — biking not driving, using a clothes line not the drier, bundling up in the winter instead of using a heater, and keeping lights off when no one is in a room, etc.
Five years ago, I decided that I could use a camping solar shower to heat my shower water during the summer. You’ve seen these things: they’re a plastic bag that is black on one side with a nozzle on one end. You fill them with water, set them in the sun, they get hot, and then you hang them from a tree and take a shower from the nozzle. I started using one at home — heating it on the front porch and hanging it in my bathroom’s shower stall.
I quickly fell in love with it. It got me in touch with the natural rhythm of the sun. When it was cloudy, I wouldn’t shower. I originally intended to use it just during the summer, but I ended up using it all year long for the last 5 or so years. I became fanatical about it, absolutely refusing to take a fossil fueled shower. If it was cloudy for more time than I could tolerate not bathing, I would take a cold shower. After a couple of years, I got tired of the flimsy, expensive camping solar showers so I designed and built a permanent one out of ABS plumbing pipe for about $25. (See the design in Slingshot issue #80.)
My personal solar shower was simple, cheap and cut fossil fuel use, but it had a fatal flaw: I couldn’t convince anyone other than me to use it — or rather it wasn’t practical for other people. The main problem is that five gallons of water — about a 5 minute shower — weighs 45 pounds and is quite bulky. Once the water gets hot in the sun, you have to lift the heavy water over your head to hang it on hooks in the shower stall. My housemates said they weren’t strong enough to lift it and carry it up two flights of stairs. Also, the DIY shower is only hot when the sun shines so you have to time your day around the shower to some extent and you can never shower in the morning, only the afternoon or early evening. (In the winter it will be hot on a sunny day at 3 p.m. – in the summer it can be hot anytime between 1 – 6 p.m., and it can easily get too hot to use if you don’t watch it.) These restrictive hours are okay for me now since I work at home, but before this gig I worked 9-5 and I had to shower before going to work.
Despite the problems with my DIY solar shower, it did prove that solar power is a fantastic way to heat water for home use. On a psychological level, this started eating away at me. Someone would take a fossil fueled shower on a hot sunny day and I just knew that those CO2 emissions were unnecessary. I learned that in some areas (Israel for example) all domestic hot water was solar heated.
When we started the house, I got a bid for installing solar hot water: $12,000. That was too much money when you consider that our annual bill for natural gas (used for cooking and heating water) is only about $400 a year. So the key to installing solar now, in 2007, would be to do the labor myself to save money.
Basic solar hot water heating
Heating water with solar energy is fairly simple. You install panels on your roof, pass cold water through them, and then store the resulting hot water in an insulated tank so that when you need hot water when the sun isn’t shinning, you’ll have it. In the panels, water pipes are connected to metal fins that are painted black. The black metal absorbs the light and gets very hot and transfers the heat to the tubes of water. The panels have insulation on the bottom and glass on the top to keep the heat in.
The kind of system I just installed is called an open loop system. (If you aren’t interested in technical details, skip down 2 paragraphs.) That means that cold water from the city water supply flows into the storage tank and directly up into the solar panels on the roof. The system has a differential controller which means that when a thermometer in the solar panel detects a temperature that is 16 degrees F higher than the temperature detected by another thermometer in the storage tank, a circulating pump turns on to move water from the storage tank up through the panels. The differential controller and the pump work on grid power, but they only consume about 15 watts of electricity when the pump is running or about half a watt when the controller is on. So for all practical purposes, running the system doesn’t consume fossil fuels.
There is a fossil fueled hot water back up for periods when there is no sun. After water leaves the storage tank, it passes through a standard gas hot water heater that will heat the water unless it is already hot going in. To prevent the solar hot water (which can reach temperatures of 200 degrees) from burning people, there is a mixing valve to mix cold water in whenever the solar hot water exceeds 130 degrees.
While the basic design of the system is simple, actually manufacturing and installing such a system is not such an easy matter. First, even though I did all of the work to install the system myself (and thus for free) the components I had to buy for the system were damn expensive. The 120 gallon storage tank, three 4X8 foot solar panels, circulating pump, differential controller, valves, plus 150 feet of cooper pipe and fittings and insulation cost about $8,000. That $8,000 actually represents . . . burning fossil fuels. Ironically, in my attempt to avoid burning fossil fuels, I had just purchased huge amounts of copper, aluminum, glass, plastic foam insulation — even some high tech microchips to run the differential controller. These are all items I generally try to avoid. The environmental damage associated with mining and smelting copper and aluminum and glass and making foam insulation are striking — what was I doing?!?
And then there was installing it. It took me pretty much every waking moment for 2 weeks. Our roof is at a 45 degree angle so a nice guy who is working on our local tree-sit trained me on using ropes and harnesses so I wouldn’t fall and kill myself. The three 4X8 foot solar panels each weighed 125 pounds and they had to be lifted up 35 feet to the top of our 45 degree angled roof! I lost a number of nights of sleep thinking “how can it be done?” It took 4 of us and a lot of creativity, but we got those panels up there. Once the panels were on the roof, the work had only in a sense started. I had to install pipe from the storage tank up to the panels and back, install the pump, valves, etc. Because I’m not the greatest plumber, after I was all done there were some leaks. I would fill the system to test it, find a leak, have to drain the system, go up on the roof to fix the leak, and repeat. (It finally worked!)
The fallacy of Solar energy
At some point during this extremely difficult and sometimes dangerous process, I was sitting on the top of the roof and I realized that I had made a mistake:
I had spent $8,000, used a lot of environmentally d
amaging resources and a bunch of time and energy to accomplish what I had been doing simply, cheaply, locally and easily with my $25 DIY solar shower for the last 5 years.
I had fallen into a very classic human mental trap. In the US, we grow up with hot water flowing out of the tap — and we don’t have to think about how that happens. We don’t have to see the gas fields or all of the environmental destruction that makes that possible. So we think that hot tap water is in some way “normal” and “natural” and we get stubborn and feel entitled to that convenience. When our society runs up against the reality that the ways we’ve been living are not sustainable — that having all this convenience was never normal but instead was always the exception to how people have lived and evolved over the ages — and that this convenience has been bought by burning fossil fuels, oppressing people and destroying the environment — it is hard to give up the conveniences we’ve grown up with and change.
So to avoid change — to avoid having to admit that the way we’ve been living is out of balance with the earth — human beings think of all kinds of fancy ways to achieve the end result of having things operate “the way we’ve been living” by using a different technology. But this is like a cat chasing its tail. Just because you’re not directly burning fossil fuels everyday to heat your water doesn’t mean you’ve stepped outside of our society’s earth killing machine. High technology has extreme environmental costs. And most “alternative green” technologies currently being promoted are high technology. Hybrid cars, ethanol and biodiesel — these are very centralized, high tech solutions designed to permit continuation of an unsustainable, car based existence. Living local and riding a bike or walking is how you reduce your impact — switching one type of high tech for another just trades one problem for another.
In the end, we need to look beyond how a particular technology is powered and instead recognize that global warming is caused not just by the wrong fuel, but by the wrong type of thinking — lifestyles that are too convenient, too speedy, too dependent on technology.
Taking a bath
So now that I’ve put in the solar hot water system, I still think it is a good thing within the context of the very unsustainable society within which we live. There is a cool little read-out that shows how hot the water in the storage tank is, and I feel good when it is 160 degrees — that means the morning showers the next day are covered. But I’m going to keep using my $25 low tech solar shower even though it is a little more work and sometimes I don’t get a shower when it rains. I’m still looking for a better balance between DIY solar and high tech solar. After all, I’m a fanatic.