Sunday, August 9, 2009
As part of my crazy, OCD-like planning for the "zombiepocalypse" I did a very sane thing: I made an appointment to go down to Western Solar in Bellingham and learn as much as I can about solar electricity. Prior to the appointment, I read an entire issue of "Home Power" magazine, so I felt prepared.
So how about I tell you what I learned about solar electricity. First I learned that we use a lot of electricity, even though I go around turning things off all day and night. We use approximately 12,000 KwH/year. Buying an installed system that generates one third of that would cost - today, from these guys I went to see - $31,000. What is that, like 100 years of electricity bills?
However, here are some more facts that make it cheaper:
1. federal rebate: 30% of installed cost. Bing, we're down to $22,000.
2. Since the system is grid-tied without battery back-up (more on this later) we'd be selling surplus electricity to the grid. The grid has to buy it from us at an artificially high rate - whereas we pay $.08/watt when we buy from them, they have to pay us $.15/watt when they buy from us. The law says they have to do that at least until 2020, and it might even go up.
2.a) What surplus energy? I thought this system only produced one third of your energy? Right, but that usage is concentrated at certain times of the day/year. And our system would produce most of it's energy at different times of the day/year. We use most of our energy in the winter. The sun gives us most of our energy in the summer. We use at night; it produces during the day. So, on any given sunny summer day when we aren't at home or are outside doing something that doesn't use electricity, our system is spinning our meter backward. We save the nine cents we pay for each watt, plus, when the meter goes back to zero for that month, they pay us fifteen cents. So theoretically, each watt we produce is actually worth 24 cents to us. Some of them, anyway. The piled up surplus from the summer months will lower our bill in the winter. Some people with big systems actually get checks from the utility.
But wait a minute. I though independence was the goal here. How does a grid tied system give you that?
It doesn't. The power goes out, it goes out for us too. But batteries are WAY more expensive than I thought. And the system requires more maintenance. And the batteries need replacing every five, ten, or fifteen years depending on how much money you spend on them in the first place. And an off-grid system is totally incapable of producing anything like the amount of power we actually use unless we literally stuff the attic with a hundred thousand dollars worth of batteries. I'm not worried about the occasional one or two day outage. I'm worried about the day the grid goes down for good. And I doubt that day will come within twenty years. I think electricity will get much more expensive fairly quickly, but I doubt it will become unavailable that soon.
So my thinking is, it makes sense to save money on the batteries and maintenance now, and worry about adding that expense in ten or fifteen years, or twenty, when the shit can be seen from the fan. Or alternatively, when it becomes clear that I was wrong and the shit isn't headed this way at all, I will have saved a huge amount of cash and hassle.
Now I know I'm going to hear from a fair number of smart, handy people who understand electricity and like to build stuff. You guys are going to say "$30,000 my ass. I can build that system for $242 and a mile of string." Well bully for you. You should go into business then. I can't, and I'm not interested in spending the next few years of my life learning how. I have other stuff to do.
Like go milk the goats, which I have to do right now.