Have you ever wondered if it is practical to consider powering your house with solar

electricity? Well, in a recent article at <a

href=”http://home.howstuffworks.com/home-improvement/energyefficiency/

question418.htm”>How Stuff Works</a> they asked the question “How

many solar cells would I need in order to provide all of the electricity that my house

needs?”

Making a series of assumptions about electricity use and basing the hardware costs

on today’s rates, the writers concluded that it would cost at least $30,000 to

generate enough to provide the electrical requirements of a typical home. And that

doesn’t even include the cost of space heating, water heating, cooking, and clothes

drying – all of which it was assumed would be done by natural gas.

The numbers go like this. A “typical” home in the US requires an average of 600

watts per hour every 24 hours to run the lights, appliances, computers, refrigerators,

TVs, and fans and motors on other appliances such as the furnace, clothes washer

and dryer, and so on. That is approximately 14,400 watt-hours per day.

To generate that much electricity using solar cells you would need about 41,000

square inches or 285 sq. ft. of solar panels. At today’s prices that would come to

about $16,000. And then, because the sun is not available for parts of some days or

at all on other days you would need a battery storage system that would cost at

least the same – roughly another $16,000. So that puts the price at about $32,000

for the system.

At today’s cost of electricity off the grid that much electricity would cost roughly

$525 per year. At these rates, to recover the up-front costs would take more than 50

years. Long before that time had passed the entire system would have to be. In fact

with today’s technology the battery system would probably have to be replaced

several times over that time period. So it is no wonder that not very many “solar

houses” are being built.

Even if we accept these numbers at face value it does not mean that solar energy

has no place in the energy mix of the future. It just means that it is important to

think long and hard about where it is practical to use it.