I'm considering putting a solar PV system on my roof, and I thought that I should be able to calculate most of the numbers myself from first principles. I have searched for so-called online 'calculators', but found that most of them are aimed at idiots. Here's what I expected to find: A formula giving the exact sun position throughout the year, given latitude and longitude, as well as a factor which handles the distance from the sun w.r.t. time. Now this only provides the *input* energy. I now need to overlay this with average *weather* data on a per-hour basis to get the expected net energy. Finally, I need to *integrate* these data over an entire year to get the values for my own house. There may be such an online calculator, but I haven't been able to find it yet. It may be possible to factor the weather info out of the integration, so that I could 'correct' my location sunlight & weather data with my own lat/lon azimuth (angle of my house) and roof angle, but I'd need to see the equations to find out if this factoring is possible. I presume that someone on this list has already done these calculations for their own home?