How many solar cells would be need in order to provide all of the electricity that my house requires?

If you have been read the HSW article on "How Solar Yard Lights Work", then you can feel how an unbelievable can be produced by a solar cell. The solar panel shown below contains 4 cells, and believe it, each of them can produce 0.45 volts and 100 milliamps, or up to 45 milliwatts. Each cell is measured 2 inches by 0.5 inches. In other words, with these solar cells it can be generated about 45 milliwatts in one square inch (6.45 square cm),how amazing. As the sake of discussion, let's assume that a panel can generate 70 milliwatts per square inch.


What you need to know for calculating how many square inches of solar panel you need for a house.

* How much power the house consumes as an average.
* Where the house is located ( can calculate the mean solar days, average rainfall for a period of time and etc.). This question may be impossible to answer unless you have a specific location selected in mind. So we can assume that on an average day the solar panels can generate their maximum power possible for 5 hours.


A "typical home" in America can be using either electricity or a specific gas to provide heat needed amount heat for the house, the hot water, the clothes dryer and the stove/oven. If you want to power a house with solar electricity, you would use gas appliances instead, because using solar electricity is so expensive. This means that what you would be with solar electricity are the things like the refrigerator, the lights, the TV, the compute­r, stereo equipment, motors in things like furnace fans, washer and etc. Let's say that all of previously mentioned things is out to 600 watts on average. For the course of 24 hours, you will need about 600 watts * 24 hours = 14,400 watt hours will be definetely needed per day.

From the relevant calculations mentioned abo­ve, we should be known that a solar panel can generate up to 70 milliwatts per square inch * 5 hours which is equal to 350 milliwatt hours per day. Therefore you will be actually needed about 41,000 square inches solar cell for the house. That is a solar panel that is measured about 285 square feet (it is about 26 square meters). That is costed around $16,000. Then, because we know that the sun only shines part of the time, not the whole day, you would need to purchase a battery, an inverter and etc., and that definitely often doubles the cost of the installation.

If you want to have a small room air conditioner in your bedroom,what you have to do is double everything.

Because for the reason - solar electricity is so expensive, you would normally prefer at great lengths to reduce your electricity consumption. You may use a portable laptop instead of a desktop computer with a big monitor. You would use fluorescent lights[FLV bulbs] instead of incandescent. You would use a small LCD TV instead of a large color set. You would prefer to a small, extremely efficient refrigerator­. By doing above things you might be able to reduce your average power consumption to at-least 100 watts. This would reduce the size of your solar panel and its cost, and this might bring it into the range of possibility.

The most important thing to remember, however is that about 100 watts per an hour purchased from the power grid may only cost about 24 cents a day normally, or in other words $91 a year. That's why you are not able to see more solar houses unless they are in a remote locations. When it costs about $100 a year to purchase power from the grid, it is really hard to justify the matter of spending thousands of dollars on a solar system.