June 30, 2014

Partly Cloudy with a Chance of Solar?

When asked the question if solar panels work when it’s cloudy, the average person may guess the answer is no – how could they work when the sun’s blocked or even at night when the sun’s not even out?

That answer is only partially true (thankfully). True, Solar panels work best during the seasons where sun is more available with longer hours, such as the summer. But ultraviolet light still reaches the earth’s surface in abundance during cloudy days (if you’ve ever gotten a sunburn at the beach on a cloudy day, you’ve experienced this firsthand). On these cloudy days, the production of solar energy could be reduced anywhere from 5-10 percent of what they can produce on sunny days, but they do still actually do their job, even if at a minimally reduced rate. So what then, happens at night?

Net Energy Metering
Think of the grid like a large bank that you can draw power from or even deposit power to from your solar power system. During the day, the extra power that your system produces gets sent back into an electric grid that everyone shares. Your utility will bill you for the “net” consumption for any given period and then provide you with a credit for any excess. This dual path is called net-metering and is just one way to optimize the rate of return on your solar investment.

Battery Bank
Streetlights with solar panels placed above them are examples of how solar power does a great job of absorbing and conserving solar energy throughout the day to be used for power at night. In order to do this, electricity can be drawn from a battery bank, a highly utilized and successful method.
Battery banks shouldn’t be confused with a solar generator which is portable and independent of the grid (generators can be used to run things like a coffee pot at a campsite or power tools at a construction site). Solar battery banks not only store electricity collected by the panels during the day to be utilized at night but even useful to be used if faced with a blackout. They are also a great option for agricultural systems.

So, even though cloudy weather does affect solar electric systems, it doesn’t mean you need ever be without electricity.

KMB Design Group is at the forefront of the escalating solar industry, and is considered a leading consulting firm in the renewable energy field providing photovoltaic design and engineering services. Our Solar engineers will give you full analysis and let you know how much energy can be drawn with considerations such as location, obstructions and orientations. We will also provide you with the best designs that will give you maximum output. Licensed in 49 states, we have the ability to work nationally without limitations.