Your energy consultant will look at your last year’s worth of electric bills, talk to you about any upcoming changes like the purchase of an electric vehicle, and then calculate how many panels it will take to provide the same amount of energy in a year. Depending on the amount of wattage your selected panel will provide, a total number of panels will be proposed, and then priced accordingly.
Because different panels produce different amounts of energy, you’ll need to take the total number of panels and multiply it by the amount of energy they produce. For example, 24 panels x 325 watts would equal 7,800 kW. Another company might propose 22 panels that each produce 360 watts of power, so that would be a total of 7,920 kW. Then it’s easy to take the total installed price and divide it by the amount of power the system will produce to get a number that can be compared.
Of course price is a consideration – but so is value. What is the term of the warranty? How long is it for? Is it for the product itself and the production, or how much energy the panel is guaranteed to produce? Another factor to consider is degradation – how much energy will the panels be producing after five years? After 10? If a panel is too inexpensive, it may be beause it will lose a lot of its ability to produce power each year.
After the materials have been ordered, and the proper permits are gathered from your city and your HOA (if applicable), the installation itself is generally only two to three days for most systems.