Conventional wisdom says that if you put solar panels on your roof in the Northern Hemisphere, you should point them within 30 degrees of true south to generate the most energy in the course of a year. But a new study by Pecan Street Research Institute, an Austin, Texas-based research and development organization, suggests that most people may do better at covering their own electrical use and reducing stress on utility grids during summertime peak demand periods if they aim the panels westward instead. (See related quiz: What You Don’t Know About Solar Power.”) 
 
 Though the study has not been released publicly, Pecan Street provided a copy to National Geographic News. It analyzed 50 homes in the Austin area, looking not just at the amount of electricity generated by the panels, but at the impact on homeowners’ electricity use and the utility grid during periods of summer peak electrical demand, which generally occur between 3 p.m. and 7 p.m. (See related post: “Solar Researchers Dig Deeper Into Snow Issue.”) 
 
 The study found that west-facing solar systems reduced the amount of electricity that homeowners needed to draw from the grid during summer peak demand by 65 percent. Homes with the conventional true-south orientation, in comparison, achieved a 54 percent reduction. 
 
 Pecan Street chief executive and study co-author Brewster McCracken explained that west-oriented panels may be more effective for many homeowners because of their lifestyles. West-oriented panels are more effective at capturing solar energy late in the afternoon, which also happens to be the time that most people get home from work and turn on their air conditioning in the summer, he said. So homeowners with panels facing in that direction are optimizing their solar power generation at precisely the time that their own usage surges, and when the utility company needs the most help coping with demand. 
 
 Additionally, McCracken said, using a west orientation for panels means that less electricity will go unused by the homeowners who generated it, and end up as surplus electricity being put back into the grid. That makes things easier for utility companies. “They’re not structured to handle high levels of electricity being sent back to the grid,” he said. “If they have to do that, it becomes a challenge to maintain electric reliability in an area.” (See related story: “New ‘Flexible’ Power Plants Sway to Keep Up With Renewables.”) 
 
 While solar panel installers have known that west-facing panels may be more effective for a while, utility companies still cling to the south-is-best rule-of-thumb, and refuse to give rebates to homeowners unless their panels are facing south, McCracken said. He’s hoping that the study will prompt them to rethink their opposition to west-facing panels. 
 
 The Pecan Street study isn’t the first to show that west-facing panels may be more effective. A California Public Utility Commission study published in 2011 also found that west-facing systems were “significantly better” at offsetting peak load that south-facing ones, even though they had lower annual energy yields. 
 
 Solar Energy Industries Association spokesperson Samantha Page declined comment on the study. A spokesman for Southern California Edison said that the utility continues to recommend a conventional south orientation for solar panels. 
 
 David Mooney, laboratory program manager for solar R&D portfolio at the National Renewable Energy Laboratory in Colorado, said that Pecan Street’s findings weren’t a surprise, but hoped that the more precise quantification would motivate both consumers and utilities to fine-tune their use of solar installations. 
 
 Mooney said that the benefits of tinkering with solar panel orientation would vary, depending upon the region, and that no single prescription necessarily fits all places. “In Colorado, for example, we tend to have clouds rolling in off the mountains in the west in the summer, so west-facing arrays would produce the least electricity,” he said. “You would want to have a southern or eastern orientation here to get the most electricity, and that wouldn’t necessarily align with the utility company’s peak demand.” 
 
 Mooney also noted that the structure of the incentives provided by utility companies figures into how consumers chose to orient their panels. His own utility provider in Colorado, for example, offers incentives that reward optimum output over the year, rather than the amount of electricity generated during periods of peak demand. “I get no benefit from shaving their peak demand, so there’s no motivation to do it,” he said. 
 
 Vote and comment: “What Energy Solution Should We Develop Next?“) ||||| Details Published on November 20, 2013 Written by Amanda H. Miller Hits: 1763 
 
 Facing fixed-mount solar panels west instead of south could produce more electricity during peak demand according to a new study from Pecan Street Research, which debunks the conventional wisdom that solar panels should always face south when installed on homes in the northern hemisphere. 
 
 The research firm, based at the University of Texas's Austin campus, concentrates on testing and developing new technology and business models in advanced energy management systems. The company tested 50 Austin homes with solar panels, some with south-facing installations. Pecan Street used a financial incentive to convince others to install west-facing solar panels for the sake of the study, which is the first of its kind. 
 
 While advanced modeling and research used by installers suggest homeowners could lose up to 30 percent of their energy production by facing solar panels west instead of south, the Pecan Street study found otherwise. 
 
 Austin homes with west-facing solar panels produced 2 percent more electricity during the course of a normal day than homeowners with south-facing panels. Beyond that, they produced 49 percent more electricity during peak demand hours of 3 to 7pm. Homeowners with south-facing solar panels reduced their peak energy usage by 54 percent, while those with west-facing panels cut their power draws by 65 percent. 
 
 “There’s no other residential demand response tool generating 60 percent reductions,” Brewster McCracken, CEO of Pecan Street, told Green Tech Media. “Those are pretty extraordinary peak reductions.” 
 
 This research has the potential to dramatically change the residential solar market. While homeowners with east-west roof pitches have historically thought they would not be good candidates for solar, it turns out their west-facing roof could be an even better spot for solar than their neighbor’s south-facing roof. It essentially opens the solar market up to every homeowner who doesn’t have significant shading issues. 
 
 It also means homeowners might be more inclined to install west-facing solar panels - even if they do have a south-facing roof -especially if their utility offers pricing differentiation between peak demand hours and off-peak hours. 
 
 It's important to note, however, that the Austin study was conducted during the summer months. It’s hard to predict what the overall outcome of the same study would be if winter months, when the sun sets shortly after electricity demand spikes, were included. 
 
 Comments: ||||| Conventional wisdom in the northern hemisphere is to face solar panels south so they get the most light all day. Architects and panel installers implement this approach all the time, especially on homes. But a new study indicates that panels facing west may actually get more juice from the sun, and at more convenient times. 
 
 Researchers at the Pecan Street Research Institute did a study of homes with solar panels in Austin, Texas and found that when homeowners faced solar panels west they were able to generate 2% more electricity in a day. And they also generated more electricity in the afternoon, when power grids experience peak demand. 
 
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 Though a 2% increase in electricity generation isn't enormous, it would certainly add up over the life of solar panels. And the rise in afternoon performance, reducing grid dependance during peak hours by 65% as opposed to 54% for south-facing panels, could have widespread efficiency implications beyond single homes. 
 
 It's only one study so nothing is definitive yet, but if nothing else the research raises a good point about testing solar panel performance in practice instead of just assuming that angling south is always the way to go. [Quartz via Digg]
– If you happen to have solar panels on your house, they might need a change of direction. A new study suggests that the standard industry advice (at least in this hemisphere) of having the panels face south is wrong, reports National Geographic. Try west instead. The study by the Pecan Street Research Institute in Texas found that homes with west-facing panels generate 2% more electricity per day, with the biggest benefit coming in the late afternoon—generally peak usage time for utilities, notes Gizmodo. "Quantifying the way that favoring late-day sunlight helps homeowners save money and utilities flatten out demand could lead to a simple but effective hack for the world’s solar installers," writes Christopher Mims at Quartz. "Simply re-orienting solar panels could shorten the amount of time it takes for them to pay for themselves." It's just one study, however, and it would be interesting to see whether the results hold up in winter as well as summer, writes Amanda Miller at the Clean Energy Authority. Still, she adds, "this research has the potential to dramatically change the residential solar market." (Soon, you might be able to pick some up at IKEA.)