Our solar panel installation section has detailed information on how to calculate your energy needs...but how much will the solar panel array cost you? Market prices for residential installations have been dropping, but vary seasonally. For illustrative purposes, we will use some sample data to help you calculate how much your installation will cost.
You've determined that your energy needs, let's look at how you're approaching the problem. If you know your solar panel needs in raw surface area, then you can simply multiply cost/area by area to get cost. For example, if your cost per area is $300/m2, then your cost for a 15 square meter solar panel installation will cost $300 * 15 or $4,500.
If, however, you have only your needs in watts and have no idea how many panels you will need, you can buy panels at unit price until your needs are met. If you sum up the wattage needs of all your household appliances, cooling, lighting, and heating systems, you can come up with a good approximation for your maximal wattage needs. Let's assume a wattage need of 5,000. Solar panels typically cost approximately $4-6/watt before installation, so assuming $5/watt, you will need 5000 watts * $5 / 1 watt = $25,000.
Installation cost varies by contractor. If you need help finding solar panel contractors in your area, we may be able to help. Professional installation is recommended for inexperienced users or for larger installations.