We're adding a handicap room to our T era house. It's Spanish style, and has half flat roof and half pitched roof, so we can do either on the new room. Which is better for solar panels: flat roof, or pitched with a south face?
Due to a ChiCom $30 Billion investment in solar panel manufacturing, the price has dropped drastically. It's no longer a ten year payback, especially at our top rate of 30-35 cents/kwh.
We have a 3:12 slope facing south and both the solar hot water and electric generation work very well.
The optimum is to have your solar panels at the same angle as your latitude and facing the equator.
Here's an interesting site that talks about optimum solar panel tilt:
Bonusinfo: We have had an extraordinary sunny July here in Denmark this year. 14% of the country's power consumption was satisfied with solar panel made electricity. As it have also been pretty windy I wonder how much was made by wind.
At 33.7 degrees North, then, they should be at 8:12 pitch.
Here is a link to my panel installation. Payback was a little over three years. They produce more than we use a year. Great getting a check back form the power company at the end of the year.
Any qualified installer can site your property and tell you what the system will produce based on the roof direction and angle.
I just saw that Germany got 24% from renewables.
Thanks for the calculator, Mark. It says my ideal tilt is 29 degrees. That makes more like a 6.6:12 pitch.
Good on ya but i'm surprised a right winger has not suggested a coal fired steam engine on your roof!!!!!!!! Bud.PS,Ran both cars today.Bud.
We have 6 panels on our 30 degree dormer roof at our Black Hills cabin that don't do well in the winter with snow. There is no way to climb up there on a steel roof to sweep it off. We thus have an additional 3 panels on a post we usually leave at 45 degrees in the winter. I can brush them off. Our cabin is off the grid so we can't sell back. We rarely need to start the generator unless the system is covered in snow and dead when we get out there in the winter.
The pitch of the roof is determined by rain and snowfall. The pitch of the solar panels is determined by your latitude.
So you can make your roof whatever you want and then attach the solar panels and pitch them the appropriate degree.
Ralph -- I don't have any personal experience using solar panels, but most of the installations I've seen use a framework to raise the tops of the panels to the desired angle, rather than putting the panels directly on the roof slope.
Here's a picture of mine. They are on the Model T garage and face due south. Interestingly, there is one more row which does not show in the picture and it is on less of an angle than those which are mounted directly on the roof. It provides enough electricity to handle almost every day except yesterday when it was very cloudy and slight rain. Without the air conditioner it just held its own with the meter neither running forward nor backward. On a sunny day, it will still run backward with the air conditioner on.
When you said, "held its own", do you mean that the solar panels keep up with the power requirements of the garage, or are you providing power for your house (& house air conditioner) as well ?
I'm curious about how many square feet of solar panel are required to support a given area of residence. I know climate is a big factor, so you might indicate what part of the country you are in.
Dick, you can click on Norm's name to see his profile. He is 316 miles south of you near San Diego.
The two axis on pipe stands look the best for me in the frozen North? I have doubts about getting any money from [our]power company because they sell at one price and buy at another.There is a place South west of Midland that has a back yard full and i need to ask questions?I'm not sure if my Wind lease will let me install solar? Great link Mark,and thank you! Bud.
Those solar panels serve both the house and the garage. Also the pump in our well. The house is all electric. There is no gas or propane. Most of the year, the solar gives enough for everything and some to spare. The electric company serves us after dark and provides what the solar doesn't provide. The meter has arrows which go either forward when the electric co is providing or backward when the solar is providing more than needed. Yesterday the arrow didn't go either forward or backward, so the solar was providing enough. If we use the oven or the clothes drier, the arrow will go forward, but that only lasts for a short time in the period of one day.
We live in southern California so don't need a furnace on around the clock. We use small space electric heaters in the rooms we are occupying and the wood stove in cold weather gives us enough. We do have the electric furnace set at 55 in the winter so that in the rare occasion of unusual cold weather the pipes won't freeze.