Figuring out how much power your home uses each day
Even if you’re using solar energy to power most of your home you will probably still be using grid electricity or gas to power large appliances like your water heater or your washer and dryer because solar energy is really not cost effective to use for major appliances. So you will be using solar energy to power things like your lights, TV, computer, phone, cable, refrigerator, microwave, kitchen appliances, and so on.
To figure out how much energy you use to power those things you will need to look at the detailed figures of your electric bill. Most people just take an average of the amount of energy used per hour because it’s easy to find that on the bill. So for the purposes of this example let’s say that an average home uses 800 watts per hour. Multiply 800 watts per hour times 24 hours in a day and you get 19,200. So the average home uses 19,200 watts of energy per day.
Now you have to look at how much energy a solar panel is capable of putting out each day. A typical consumer solar panel is capable of putting out 70 milliwatts of power per square inch every five hours. So multiplying 70 times 5 you get 350 milliwatt hours per day. Dividing 19,200 watts of energy used per day by 350 milliwatts of output by a single solar panel and you will need about 54,000 square inches of solar panel to create enough electricity to provide power for most of the appliances in the house.
Now that’s calculating for just basic appliances. If you want to add one room air conditioner you need to double your power output. So, if you want to use solar energy to power your entire house and you want to keep the initial cost of buying and installing solar panels down you should think about switching to smaller, more energy efficient appliances and learning how to conserve energy as often as possible.
Having this basic information about the size of the solar panel array that you will need will make it a lot easier for you to get accurate quotes from solar panel dealers because most of the time solar power systems are priced per square foot. Every home is different so every home needs a different amount of solar panels in order to get useable solar power.