Our daily energy production since September, 2010, when the panels were installed. Some days are missed because no one was home to record the data. The red curve is the expectation from a very simplified model. The points above the curve were relatively cool days when the panels were most efficient; low production occurred on cloudy days. The green points are for the second year. During the first year, our total annual production was 4150 kilowatt hours.

    Embracing the future, my wife and I decided to install solar panels on the roof of our three bedroom house in West Los Angeles. Our successful self-experiment may be instructive to those with an interest in energy and energy policy.

    The first step was to decide how big a system we needed. We were paying annually about $500 for 4000 kilowatt hours, a typical residential usage in California for a two-person household. However, there was a lot of waste. For example, we left the two boxes for the cable TV's on all the time. Since our son has graduated college, married and is on his own, we could certainly shut off the cable TV box in his room. Without any loss of comfort and just a tiny effort -- we still operate a large screen TV, two laptops and various appliances and gadgets, we have reduced our usage to about 2700 kilowatt hours/year.

    Thinking that we would want to operate an electric car, we chose a system which provides about 4000 kilowatt hours/year.This required about 20 square meters of panels -- about 1/8 of the total area of our roof. The contractor who installed the panel negotiated with the Los Angeles Department of Water and Power which then directly paid him about $7,000 of the total cost of nearly $17,500. Our immediate cost was about $10,500, but,
because of the 30% federal income tax credit, our final out-of-pocket cost was slightly more than $7,000.

    We are getting a return on our investment that is hedged against inflation and vastly superior to the interest we would get by putting the money in the bank. Installing the panels was a sensible financial diversification. Our house was built in 1928 and requires upkeep. The cost of the panels was about the average amount we spend per year on maintenance and upgrades.

    We are of course happy to have gotten the tax credit for the installation of panels. For comparison, the $1,000 a year I pay for a parking permit at UCLA is not subject to federal income tax. Consequently, I receive a tax subsidy of somewhat more than $300/year for parking. In 25 years, the expected lifetime of the panels, the extrapolated tax subsidy for my UCLA parking permit will be much larger than for my solar panels and, in fact, be comparable to the subsidy I received from the Department of Water and Power.

    My wife felt very strongly that the panels should not be visible from the street, and therefore they were probably not quite as tilted as required to fully optimize their production over the course of a year. Domestic tranquillity was assured at the cost of a few hundred kilowatt hours/year.

    There was a slight leak in the roof after the panels were installed. However, the contractor resealed the system, and there are no longer any problems --even during torrential rains.

    When we replace our 18 year old energy-gobbling refrigerator, we will be closer to using 2000 kilowatt hours/year. However, even now, our panels provide enough energy both for our house and electric car; the end of gasoline and electricity bills for a lifetime. This home experiment suggests that transition to a sustainable, modern economy is within technical and financial reach. It is most pleasing to have an inexhaustible supply of energy from the Sun.



















The rooftop array. The peak production has been about 2400 W from these commercial SolarWorld crystalline silicon panels.