The power rating of solar panels is given in watts.
Watts are a measure of how much electricity is being produced per a second. When you get an energy bill it shows the total energy you use in kWh (kilowatt-hours). So how do you know how much solar you might need? The calculation is actually pretty simple! Take the total energy you used last year (this can be found on your energy bill) and divide it by 1100 and their you go the number of kW that will cover your energy bill.
Yearly Energy Usage (kWh) / 1100 (kW/kWh) = Power of the System You Need (kW)
This calculation is a ball park figure and can vary depending on your roof to find out the exact number get a free solar sight assessment.
The efficiency is another measure of a solar panels. This measure shows how much of the suns incoming energy the solar panel can absorb and turn into electricity. The efficiency of a panel determines how much roof area it will need to take up in order to produce a given amount of power. In other words with a more efficient panel you will need to cover less roof with solar to get the same amount of energy. There can be several factors on efficiency but the most important is if the panel is monocrystalline (more efficient, more expensive) or polycrystalline (less efficient, less expensive).
What is Solar Energy Generation?
Solar energy uses the sun’s visible light to generate heat or electricity. It is infinitely renewable and produces energy in a clean, quiet and consistent way.
How do Solar Photovoltaic Cells Work?
Solar cells are comprised of layers of a semiconductor material such as silicon with either added boron or phosphorous. These layers of “doped” silicon allow for the capture of electrons in the silicon crystal, excited by the solar radiation, to be captured and moved across the cell into the electrical circuit attached to the solar panel.