or efficiency of solar panels
. It is measured in percentage and shows how much of the sunlight hitting the panel can be converted into electricity. Normally, a single solar panel can convert about 20% of the received sunlight into electricity.
Solar panel efficiency is determined under Standard Test Conditions (STC): cell temperature of 25°C and irradiance of 1,000 W/m². It means that a 1 m² PV module with an efficiency of 15% would produce 150 W. You will find the panel's efficiency as well as its power output on the specification sheet. However, be ready to see a slightly lower performance, as there are lots of factors which reduce
solar panel efficiency. 2. Durability
. Most solar panels for homes can withstand various climates: cold winters, hot summers, heavy rains. However, if you live in a region where hail storms
are frequent, you need to carefully check the panel specification sheet for information regarding the temperature range the panel can endure, and whether it has undergone a hail impact test. 3. Size
. The dimensions of your panels should fit the side of the roof where you want to install them. In the USA, it is best to place all solar panels on the southern side. If there isn't much space available, you may need to go for more powerful and efficient panels, which won't take up a lot of space while producing the necessary amount of electricity. 4. Warranty
. Make sure the solar panel manufacturer you have chosen offers both product and performance warranty
. Product warranty typically guarantees 10-12 years without failing. Performance warranty ensures that the panels will produce at least 90% of their rated output in year 10 and at least 80% in year 25 or 30.5. Price
matters, but doesn't always reflect quality. Usually, when buying solar panels for home from premium manufacturers, you pay 10-30% more just for the brand. We recommend you to check the panel's characteristics and reviews before purchasing.