If you’re upgrading or thinking about upgrading to a solar power system for your home, you’ll probably see the “WP” designation on certain components. This mark usually has a number next to it and a rating for the system. This has caused a lot of people some confusion as they are not sure what exactly WP stands for.
WP stands for “Peak Watts” and is the rating given for total watt output when the system is operating under perfect conditions. Your system will not always run at this level of performance, as there are too many environmental variables to take into account. However, from time to time you will have that perfect day where everything is calm, quiet and sunny, resulting in your system producing this much power.
Now don’t get excited and start slamming panels with high WP ratings all over your roof. There are other parts of your system involved in converting this energy and if your WP rating is not as high as the panels then the panels can overload them. Let’s say you have 5 panels that are rated at 50 WP each. This is a total of 250 watts in perfect condition.
Now say your converter box only has a 200 WP rating. When your panels are running at full capacity they will put out 50 watts above what the converter can handle and overload it. This can cause all sorts of nasty things to happen and the last thing you want or need is an electrical fire. To avoid this event and prevent your home from going up in smoke, you need to do some math and make smart purchases.
When you purchase your solar panels, be sure to write down your WP rating and then multiply it by the number of panels you purchase. Then when you go shopping for the other electrical support equipment for the system, make sure your WP rating is slightly higher than the total figure you have for your panels. This will ensure that the other components of the system are not overloaded and you will also have a breather to work.
You want to allow this breathing space for your components due to the fact that as electrical systems age, they can’t handle as high a load as when they were new. While not essential, this step can help you get a few more years out of your components before you need to replace them. Even solar panels and their related components have a useful life, and when they reach this useful life, they will need to be replaced.
Fortunately, if the panels and related equipment are made correctly, you won’t have to worry about this for a decade or so. If the panels are very well made, you may not even have to worry about this problem as the system could outlast you.
So when you see the WP mark on your solar power system equipment, remember that that is the maximum power that can be generated under perfect conditions. Also remember that when you purchase your equipment, the support components must have a higher WP rating than all of your panels combined. Failure to do so will lead to overloads on your system, as well as other dangerous side effects.