Down the Path to Better Solar
His brainchild may look like a postmodern sculpture, but Bill Bender is an engineer at heart, not an artist. When he isn’t busy helping his daughter Kristen climb mountains or biking with his younger kids to school, the unassuming Norwich resident is quietly revolutionizing solar energy.
Bill remembers taking a course in solar energy engineering – he’s a ‘78 Dartmouth graduate – but made his career as an economist and internet entrepreneur. When he moved to Norwich over a decade ago, however, he had the opportunity to put his old solar knowledge to good use. Eager to install renewable energy in his house on Turnpike Road, he was dismayed to realize that the payback period for solar energy solutions at the time was around a hundred years or so. He saw the potential for a cheaper, more efficient solar collector, and his backyard became a testing ground for a radical new design for a device known as a heliostat.
A quick note on solar energy terms: A heliostat is an adjustable mirror that tracks and focuses sunlight on a single point; the energy can be used to generate hot water, steam, or even electricity. A photovoltaic (PV) panel can either track the sun or be static, and it converts the sun’s energy to electricity on its surface. Both are tried and true technologies: PV panels are not particularly efficient, but they can be placed pretty much anywhere the sun shines; heliostats, on the other hand, are more involved, and have traditionally required beefy and costly support structures.
Bill’s tinkering with heliostats in his backyard eventually evolved into a business plan, then a company, Solaflect, now based in Norwich and White River Junction and employing a handful of people.
Solaflect’s work attracted the attention of the Department of Energy. They liked Bill’s lightweight heliostat design that uses carefully tensioned cable struts in place of rigid steel beams. The holy grail in renewable energy is to reduce cost to compete with fossil fuels, and the most expensive part of a traditional heliostat is the structural steel. Bill’s design uses less than half as much raw material, and the DoE has twice awarded Solaflect million-dollar grants to further refine the design, aiming to make cost-effective large-scale solar power a reality within a a couple of decades. The heliostat is currently undergoing long-range stress tests in harsh conditions in Wyoming, and a next big step will be for Solaflect to install an array of heliostats “somewhere in Vermont” (Bill can’t yet disclose where). It will deliver hot water on an industrial scale as further proof of concept.
Almost as an afterthought, Bill’s team realized that their heliostat design could also be used for a tracking photovoltaic panel. That version is less demanding and both cheaper and easier to set up than the heliostat. The array that Bill shows me on a field west of downtown Norwich was the first of the dozen or so that Solaflect will have installed for residential use by the end of 2013. The 4-kilowatt module delivers an average of around 100 dollars’ worth of electricity a month, and with a 20- to 25-year life span it’s a solid investment for a homeowner.
Solaflect is working with the Town of Norwich to build an array of 39 collectors that will deliver 150 kilowatts of energy, meeting the needs of most municipal users in town. Issues with the location for the array has pushed back the project’s start date, but Bill hopes to see the array online in the course of 2014.
Solaflect’s rapid progress and continued success may be attributed in part to the progressive rules like net-metering agreements that are intended to promote renewable energy across Vermont. Former State Representative Margaret Cheney has been an ally, streamlining the permitting process for alternative energy projects. Bill has also had help with the development from teams of students from Dartmouth’s Thayer School of Engineering.
More than anything, though, it’s clearly Bill’s perseverance and ingenuity that has brought him along the path from backyard tinkerer to trailblazing pioneer of highly promising next-generation solar solutions.
This story first ran in the Winter 2013 edition of The Norwich Times.
