Using Solar to Generate Electricty & Heat Your House

My first job out of college was at a solar energy firm. I got this job as result of a major research project I did on heating with solar energy. This is also when I first found out how magazines get some of their material. A major science magazine used much of my material without giving me any credit, after I had given them a tour of our company and shared my research paper with them.

In my previous article on generating electricity we discussed how it is much better to use a bike for its mechanical advantage vs using it to generate electricity. Solar energy is similar. Heating your house and domestic hot water is a much better way to use solar than to generate electricity. This is not to say that photovoltaic (using sunshine to generate electricity) is not a good idea but that its pay back is much longer if at all in many cases.

Someone recently asked me what they thought about using photovoltaic collectors on their house. I told them costs have come way down but first things first. And the first thing before installing collectors is to reduce your electrical consumption considerably. This is a good practice for anyone and realistically saves you so much money that it is not worth putting photovoltaic collectors on the house. Here is why.

As of October 2011  COSTCO has a Coleman 170W crystalline solar kit and comes complete with 2 x 85 W solar panels, 30 A digital charge controller, 200 W inverter, wiring, brackets, screws, and a voltage tester for $800 dollars. You will still need to add a deep cycle battery for a hundred dollars. So for just under a $1,000 you have a 170 watt system that can run three 50 watt light bulbs. THAT'S IT!
Just to run your fridge you would have to spend another thousand dollars or two. To run a whole house we're talking ten to twenty thousand dollars and more.

Instead, you could build a small house correctly oriented to the sun with properly placed windows and good insulation. With little if any more building cost you could keep your house around 55 to 65 degrees even in a cold Wisconsin winter. Done right, a conventional heating system is no longer needed and all you may need for heating your house is your water heater.

So the first thing you can do to save money and prepare to go solar is to reduce your electrical consumption by 50 to 75 percent. (You are going to have to do this anyway if you want to go with solar electricity. This alone could save you so much money that after 10 years you could afford to install solar.)

In spite of all of this there are still good reasons that you might want to install photovoltaic collectors. (Emergency electric if grid is down, you're not near power lines, makes you feel good, etc.)