An initial design for Solar on the Roof

etiennes-house-pptxSo, a friend has gotten the $150 CDN survey done on his house, but I wanted to take a crack at it on my own being an engineer. However, I have already booked a master electrician doing an analysis of how large or small a system I can put in and he will look at my Electrical Panel and do the fnal tie-in (see my city’s permit checklist). This will help me know how many solar panels I can get, even if I don’t buy them all but buy a few a year. Using the Solar Handbook from my previous article, I used those formula and tables to calculate a real live solar installation on MY HOUSE. Here a pdf with all the math and discussion – my own engineering analysis.I am publishing a draft of it as it is the discussion point and my notes to write on tomorrow with the electrician..

There was a calculation missing from the handbook, that is the efficiency based on roof slope. I have heard it said from our in-store tech discussion that inefficiencies can be made up by a larger solar array and mount them flat on ANY roof. Even at a horizontal angle (flat) the solar array picks up lots of energy. So I took their tables and curve fit them an included a formula to use instead of wet finger guessing based on tables of solar panels that mount no where close to your situation. I will post that in my next article. My 18.5 degree roof has a 70% efficiency in the winter months.etiennes-house-google

The program I used for the math calcs is sMath – a great substitute for MathCad.