December 3, 2014

Most Solar Panels Are Facing the Wrong Way

Alpenglow Solar’s Notes:

Admittedly, it’s confusing. Regionally, some installers reccommend a south facing pitch to your solar panel installation, and some suggest a west facing pitch. Who are you as the consumer to believe?

Trust the professionals at the time of inspection. They will take into account landscaping, your specific homes position on the globe and its time of peak performance for full sun exposure.

Most Solar Panels Are Facing the Wrong Way

Originally posted on
Written By Todd Woody

Does your roof face south?

That’s one of the first questions you’ll be asked if you’re considering installing solar panels on your home.

For good reason: Photovoltaic panels that capture the southern sun generate the most electricity—as much as 20 percent more power than west-facing panels—and the best return on your investment.

So homeowners whose roofs face west may decide it just doesn’t make economic sense to go solar. Only 9 percent of 110,000 residential solar arrays in California look toward the Pacific Ocean, according to a new study by Opower, an Arlington, Virginia, company that analyzes consumer energy use for utilities.

There’s just one problem: South-facing panels produce power at the wrong time of day. Electricity production peaks around noon, when no one is typically at home and demand is low. As the sun moves lower in the sky, the amount of electricity generated by south-facing solar panels plummets after 3 p.m. and flatlines in the late afternoon, when people arrive home and crank up big-screen televisions and other appliances.

Panels facing the setting sun, on the other hand, continue to generate electricity until late in the afternoon, just when demand peaks. That means putting more solar panels on west-facing roofs could eliminate the need for carbon-spewing fossil fuel “peaker” plants that are fired up to meet spikes in electricity demand.

“A region with 25,000 solar rooftops, especially if strategically oriented, could send as much late-afternoon power back to the grid as a 50 megawatt natural-gas peaker plant,” Barry Fischer and Ben Harack, the study’s authors, wrote in an email. “While it’s not possible to state the ‘optimal’ percentage of solar installations that should be west-facing, we do have good reason to believe that a substantially higher percentage is warranted.”..

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