Is Solar Heating For You? Analysis Method

This analysis can be used to estimate solar performance on a monthly and annual basis. Please understand that the analysis is based upon average solar energy values and that actual performance may be more or less. Feel free to print out the worksheets that follow.

Choose Solar Heat for your new home… It may just be the brightest thing you have done in a long time!!

STEP ONE: CALCULATE S (YOUR SOLAR RESOURCE) PER MONTH.

STEP ONE A

You are looking to find out how much solar energy shines upon a square foot (or square meter) of surface area on a monthly basis.

First open a new tab to https://globalsolaratlas.info/ (A free service* of The World Bank Group) Enter your address and the map will zero in on your solar data.

STEP ONE B

 Scroll down to the type of installation and choose small residential, or any of the others if that’s your installation plan.

(This worksheet is set up for PV systems but it will still provide the number we need.)

STEP ONE C

If you will be installing at the optimum angle and azimuth, skip this step.

If you’ll be installing at the angle and azimuth of your roof, click change PV system.

Then, change the Azimuth and Tilt to match your roof, ignore System size, and click Apply.

STEP ONE D

Finally, click on the default kWh/m2 per year setting beside the green number, and change it to MJ/m2 per year.

This green number is your yearly solar resource in milliJoules per square meter. 

Divide this number by 12 to get S, your average solar resource per month.

*[Data/information/map] obtained from the “Global Solar Atlas 2.0, a free, web-based application is developed and operated by the company Solargis s.r.o. on behalf of the World Bank Group, utilizing Solargis data, with funding provided by the Energy Sector Management Assistance Program (ESMAP). For additional information: https://globalsolaratlas.info

STEP TWO: CALCULATE S', YOUR SYSTEM'S SOLAR EFFICIENCY

For Step Two, we want to figure out how much of this solar resource will actually be harvested by your solar energy system (S’). This is function of collector efficiency and the system operating temperature. Higher temperatures lower efficiency. Efficiency can range from as low as 20% to as high as 80%. (0.20 to 0.80)

If you will be using our solar collectors, their efficiency number is very good, so you can use (0.75) for the energy factor.

Multiply (S) From STEP ONE by the known energy factor of the particular system to calculate (S’).

STEP THREE: CALCULATE HOW MUCH HEAT YOU NEED

We invite you to explore this website and to click on Next Step if you would like more information.

Our solar technicians are always ready to answer questions.

Call 1-800-451-7593