|Figure 1: Google Map|
While it might be a smart strategy to target houses with most promising returns at the beginning of the solar energy industry back a decade ago, the old rules may not hold any longer. With the solar cell efficiency of commercial panels climbing above 20% and, more importantly, the environmental awareness of homeowners increasing, the solar energy market has changed a lot.
Thanks to Google Map, it is just a few mouse clicks away to get an idea about the current status of the market. So I surveyed my neighborhoods in eastern Massachusetts and was surprised to find that a significant amount of rooftop solar panel arrays do not actually face south (Figure 1). This is understandable because a significant percentage of buildings do not have a roof that has a south-facing side. So if homeowners living in those houses want to contribute to solving the environmental problems, they do not have any other choice except putting solar panels wherever they can be mounted. If you take a look at your own neighborhood in Google Map, you should spot a lot of west- and east-facing (or even north-facing!) solar panels.
|Figure 2. Solar simulation in Energy3D|
|Figure 3: South-facing vs. west-facing|
Thanks to the funding from the National Science Foundation, this kind of estimation can be easily done using our Energy3D software, which has a decent crystal ball when it comes to solar modeling and prediction (Figure 2). I have been blogging about this capacity of the software for a while. It is time to finally put this tool into practice to help people evaluate their solar options.
a 5kW solar panel system (Figure 3). The first step is to get a sense of how accurate Energy3D's prediction may be. In situations similar to the standard test conditions (STC), this system -- when oriented to the south -- should generate about 6,000 kWh per year in Boston, Massachusetts and about 8,000 kWh per year in Los Angeles, California. The results from Energy3D agree exactly with these widely-cited numbers, as shown in Figure 4.
|Figure 4: BOS vs. LAX|
|Figure 5: South-facing vs. west-facing outputs|
The results of this study should give you a sense about how simulations may be useful in fostering the growth of the solar energy market. Even better, through years of development, we have made solar simulation in Energy3D so easy that anyone can do it. As an experimental step, we are now collaborating with high schools in Massachusetts to pilot-test the feasibility of engaging students to evaluate the solarization potential of their own houses. Our goal is to create an integrated education-business model that benefits both sides. We hope that the success of this project will help the world reach the goals set by the Paris Agreement.