Solar calculators, as I am learning, are all about you typing in all available information you have about your own solar home project, then the calculator will return detailed cost estimate information. Some of them are more generalized to just give you a ballpark price. Others are mind-bogglingly complicated, taking into account your area of residence and what rebates/incentives are available to you and how that will impact the price of your project.
Some will tell you the available sunlight in your area based on your latitude and longitude.
Here are a few we found (there are at least 10 really functional and free solar calculators to be found online):
- Solar Water Heating Calculator: Solar water heaters are a great way to get into the solar lifestyle. This tool can tell you how your current heater is performing and whether or not you will save money using solar.
- Solar Position and Intensity Calculator: This crazy creation is brought to you buy the National Renewable Energy Laboratory. Given your location, this calculator can show you everything from the time of sunrise and solar elevation to the solar azimuth angle and about 30 other desired outputs.
- PV Watts Calcualtor: This is for people who’s current photovoltaic systems are tied into the ‘grid’. Dollar value and energy production are the big draws here. But make sure you know your current cost and have all the system details.
- Sun Chart Program: This is from the University of Oregon and can tell you, based on your position, hours of usable daylight for solar power purposes.
- Solar Collector Efficiency Calculator: From Build It Solar, this tool does exactly what it says, but be prepared to know the technical details of your system…
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August 23, 2009 at 8:58 pm
Reginald McCurdy
Thanks for the web site. I need to know how I can find out how long to extend the eaves on the passive solar home I am having built. There must be a builder’s table somewhere that relates the pitch of the roof to the latitude of the lot so as to maximize the solar gain in winter and minimize the solar radiation in the summer. I live in a northern climate lat. N44 04 10 and long 80 50 06. Any help would be greatly appreciated. Thanks. REG
August 23, 2009 at 9:29 pm
indianasolar
I am going to have some posts about passive solar design. I don’t know when but some time anyway.
I have a few older books that do a great job explaining passive solar. If I were you I would go on-line to a used book store. ( I use http://www.alibris.com/ all the time. They always have coupons too. Just Google for them.)
Latitude is only one part of the design calculation. You also need to know the height from the bottom of the window to the eave and the bottom of the window to the floor. Then you need to figure out how much sun to let in during the spring and fall.
November 5, 2009 at 5:05 am
ecowho
We have an online calculator for this, see
http://www.ecowho.com/tools/passive_solar_eaves_calculator.php
works on the assumption that during summer you want to achieve complete window shading for the 4 hottest hours of the day. Input your location (latitude or nearest city worldwide) and height of the window from bottom of the glass pane to the eave height and the calculator will do the rest. It will also tell you how much at the top of the window is mostly in shade during winter (so shouldn’t really be a window as such).
Also assumes you have perfectly east/west aligned window with similarly aligned eave.
I’ve double checked the maths – so reasonably confident it should be spot on. Seems to tally with the tables in Australia.
We also have several other calculators.. Any comments or suggested improvements most welcome.