If you are thinking of installing photovoltaic panels in your home, this may be the best time to do so. The Government of Spain is offering aid for the energy efficiency of homes that finance this type of action. Self-consumption through renewable sources will help you significantly reduce your energy demand, especially if your heating or water heater works with electricity. But how many solar panels do you need?
Calculating the number of solar panels that your house requires is relatively simple. Each panel has an average power of 330W, so based on the consumption of your home, you can estimate how big your photovoltaic installation should be. However, there are other variables such as the geographical area, the orientation of the house or the shadows on your roof, which you must take into account when requesting a quote.
The first question that the installer has to know is the amount of kW/h that your home consumes and what percentage of that consumption is done during daylight hours. The geographical area in which the house is located is a determining factor, since the performance of an installation, as well as the hours of peak sun (HSP) will vary depending on whether the region is cold, mild or warm. During this time, the increased solar radiation makes the panels work at maximum capacity, with an estimated production of 1,000W/m2.
To calculate the power your installation needs (W), you can divide your home consumption (kWh/year) by the peak sun hours (HSP) in your region. Once you know the total power you need (W), you can divide the unit power of a panel (W) to find out how many you need to install. In this way, if you need 5kW of power to satisfy your energy demand, you must incorporate an average of 15 panels into your installation.
Each of the plates has an average size of 1.7x1 meters, so based on this data you can compare the square meters you have with those required for an installation with optimal power. The orientation of the house and the slope of the roof will also affect the performance of the panels.
An orientation of 35 degrees with a south or southeast orientation constitutes the most favored position to capture solar radiation and optimize your solar panels. The more your roof strays from those parameters, the less kW/h your installation will produce. Pay special attention to shady areas, as small as they may be, they can halve the production of this energy source.