Maximum Power or Power At STC
Maximum Power is measured in kWpk – kilowatt peak (sometimes kWp). In the context of energy generation - the useful power that a piece of equipment will generate under standard, close to ideal conditions. The capacity of most renewable technologies to generate electricity is specified in kWpk. Of course in reality over a year a given installation will produce energy at an average rate that is much lower than this as conditions are not always ideal.
There is an obvious need to compare solar panels and solar panel installations, so that consumers, suppliers and installers can determine how systems, manufacturers, etc are performing. A would be purchaser might ask a supplier, “How many kilowatts of power do your solar panels produce?” Similarly, once an installation has been completed, it would be a useful to be able to specify the power level that you would expect from such a system. Of course the answer to the question depends on a number of parameters: how sunny is it?, what temperature is it?, how much area of solar panels do you have in your system? kWpk is a unit the solar PV industry uses to provide standardisation. The industry has settled on a set of standard test conditions (STC) that pretty well everybody uses. The test conditions basically represent good generating conditions that you might reasonably come across in the field. For example the STC specifies usable sunlight landing on the solar panels at a power level of 1000 Watts per m2 (equivalent to a clear sunny day), and the temperature of the panels being 25 degrees Celsius (note that PV solar panels actually get slightly less efficient as they get hotter). Whatever electrical power a solar panel or a given installation produces under these STC conditions is said to be the maximum power of the system measured in kWpk. Thus someone might refer to a given installation of solar panels as a 4 kWpk system. By this they would mean that whilst exposed to very good conditions you would expect that system to produce 4kW of electrical power.
In practice it is possible for a system to produce slightly more than its official ‘Maximum Power’. For example a 2 kWpk system might, at times that are very sunny but cool, produce a power of 2.2kW whilst those conditions last. This is because the agreed STC, whilst designed to represent excellent practical solar PV generating conditions, do not necessarily represent the very best conditions theoretically possible.
We found your service efficient and enquiries polite and considerate. I would definitely recommend your services to anyone who is looking for solar, in fact we have another farm building which will be sorted after Christmas, and would think we will be contacting you again. Thank you once again.
I have been very pleased with the speedy and efficient service we have received. Everyone in the Geo Green Power team has been pleasant to deal with and all aspects of the installation were carried out in a timely and effective manner. Many thanks for making our lives easier!
Thank you for all your hard work. Everything was completed efficiently and professionally and I’m now saving and making cash thanks to my solar PV system. I like checking my meter just to see how much money I've made! Solar panels are a great investment and I’m recommending Geo Green Power to everyone I meet.