Terminology, Calculations, etc.

The other day I had a question that really, at this point I should have been able to answer easily. I couldn't. It involved a really basic principle: if a system is rated as size X, how much power does it produce?

Here's a useful web site developed by people who aren't as clueless as me:

Solar & Wind Energy Calculations: The (very) Basics

This paragraph from that website helped me the most because it explains what a system size rating means over the course of time (which was the concept I proved to be not too bright about):

"One kilowatt-hour (1 kWh) means an energy source supplies 1,000 watts (1 kW) of energy for one hour. Generally, a solar energy system will provide output for about 5 hours per day. So, if you have a 1.8 kW system size and it produces for 5 hours a day, 365 days a year: This solar energy system will produce 3,285 kWh in a year (1.8 kW x 5 hours x 365 days)."

One blog reader says this on June 15: "Actually 1000 kW of DC system produces about 1200 kWh of AC electric."