Published on October 15th, 2015 | by Tina Casey13
Thanks To Energy Storage, “Free” Rooftop Solar For Emergencies (CleanTechnica Exclusive Interview)
October 15th, 2015 by Tina Casey
The energy storage field is busting wide open, and an interesting case in point has just come up from a nonprofit called Clean Energy Group. The key elements are affordability, resiliency, and profitability, all of which — in our view — come together to demonstrate that the age of petroleum is rapidly drawing to a close. The organization’s President, Lewis Milford, spoke with CleanTechnica on the phone yesterday to explain what it’s all about.
To be clear, we’re not saying that petroleum will cease to be used, just that it will fall from its dominant position in energy and chemical production.
Solar for low-income housing is something of a trend, which CleanTechnica first noticed back in 2009 when the San Francisco Housing Authority installed a rooftop solar array at a low-income housing project.
Our sister site Sustainablog went back even farther, to 2007, when it picked up on a solar-equipped housing project in Chicago. Affordable housing for middle-income residents is also in on the solar trend.
The big breakthrough came just last summer, when President Obama announced a new job-creating solar initiative aimed at bringing solar to low-income households.
Key elements of the plan include community solar projects that create solar access for renters and residents without adequate roof space, a 300-megawatt goal for installing renewable energy in federally subsidized housing, a commitment from state-based urban and rural stakeholders for 260 solar projects, and more than $520 in committed funding from philanthropies, impact investors and government agencies.
…Solar + Energy Storage Better
The new twist is energy storage. Clean Energy Group (CEG) has hit upon solar with energy storage — solar + storage, as the organization puts it — as the economically sensible way to ensure that residents in income-eligible housing are not left to drift when the next Superstorm Sandy hits.
As the post-storm situation in New York City shows, low-income residents without the financial resources to evacuate or relocate, and in some cases further hampered by age or disability, can spend days, and in some cases weeks, without electricity and other vital services. Without onsite storage, rooftop solar can mitigate the problem but not eliminate it.
“Our interest in solar plus storage is a matter of resiliency,” explained Milford. “Low-income populations suffered greatly in the aftermath of Sandy, and they don’t have to go through that again. Solar plus storage is available and it is actually economical…. These systems pay for themselves.”
The idea of a rooftop solar array paying for itself is no mystery, thanks to power purchase agreements. The difference is when you factor the cost of onsite energy storage into the mix. That’s where the focus on large housing projects comes into play.
Milford brought CEG’s Project Manager, Seth Mullendore, into the conversation to explain how that works:
“Solar plus storage presents opportunities for larger properties with demand charges, in contrast to individual residential property owners. Demand charges can be up to half of an electricity bill in some states.
“The opportunity is both for utility savings and revenue generation, in the frequency regulation market. Systems in housing projects are larger and they can participate individually in that market.”
Talk about having your cake and eating it, too… with ice cream. This is a grid-connected system that will significantly lower monthly electricity bills, seamlessly come into use as a backup during grid outages, and bring revenue in by participating in the grid market.
It’s difficult to see how onsite diesel-powered emergency backup generators can compete with that, so we’re not even going to try.
The Solar + Storage Report
You can get all the details on CEG’s analysis in the organization’s new solar + storage report, Resiliency for Free: Protecting Vulnerable Communities, which takes a close look at the renewable energy potential in Chicago, New York City, and Washington, DC.
The report underscores the role that solar + storage can play in disaster resiliency at critical facilities throughout a community:
“Hospitals, nursing homes, 911 call centers, emergency shelters, and other critical facilities also need reliable, resilient electrical power to deliver emergency services to the community when the supporting power grid is down.
“… Solar photovoltaics (PV) and battery storage systems (“solar+storage”) can help them now. These technologies can provide reliable power for a range of critical facilities and essential building service loads. They can power water booster pumps, lighting, telecommunications, fir e alarms and security cameras, elevators, and climate controls. They can mean the difference between safety and harm, protection and tragedy, dangerous evacuation or sheltering in place when outages occur.”
For housing projects specifically, in our conversation, Milford and his staff emphasized that CEG studied the financials of solar with energy storage in real-world situations, involving certain limitations.
For housing developments, one of those limitations is space. So far, CEG has confined its analysis to rooftop solar with storage, recognizing that playgrounds, parks, and other communal open space would most likely note be given up for renewable energy generation. Parking lots, though, present another potential resource for siting solar arrays.
Mullendore also noted that the space factor and other limitations are also in play for the energy storage system itself:
“The nice thing about storage, especially lithium-ion, is that it doesn’t have to be that big. A 100 kilowatt system is about the size of the fridge…. Fire regulations can have an impact. In California lithium-ion is not a problem, but in New York City you have to use lead-acid storage.”
While we tend to get excited about next-generation energy storage technology, such as flow batteries and renewable hydrogen, Milford and Mullendore emphasized that the focus is on available, proven systems, such as lithium-ion and lead-acid batteries that provide an economical opportunity to strengthen vulnerable communities in the here and now.
Image (screenshot) via Clean Energy Group.