Vermont’s largest solar canopy, Encore Renewable Energy’s 156kWp solar carport in Burlington, Vermont, has begun producing electricity at the ECHO Leahy Center for Lake Champlain. The solar power system uses two-sided solar panels to capture direct sunlight and reflected light from nearby surfaces like the parking lot, the lake surface and parked vehicles. ECHO Leahy Center for Lake Champlain is a science and nature center, and it was the first LEED-certified building in Vermont when it was built in 2003. Chad Farrell, Chief Executive Officer of Encore Renewable Energy, answered some questions about the project for CleanTechnica.
1. Where did you source the two-sided solar panels?
The panels are a new product called the Canadian Solar BiKu BiFacial — purchased directly.
2. How much of the electricity generated by the system’s panels comes from reflected light from the parking lot, parked vehicles and nearby lake surface?
We have modeled the system at 5% average increase from reflected light, however manufacturers claim anywhere from 10%-30% depending on conditions.
3. How common are two-sided solar panels, and how much more electricity do they produce?
Bifacial solar panels are considered an emerging technology, gaining significant attention in the market but still considered innovative, with less long-term data to support projected production increases, which have been reported of up to 30%. Most experts / industry players report 5-7% gains. However, it is important to note that the industry has not yet produced peer-reviewed research with long-term data to establish how bifacial modules affect system yield, controlling for various system configurations and locations.
4. Do they cost more, and if so, how much more?
Traditionally bifacial panels have been much more of a boutique product, usually in the form of frameless glass and at near double the typical pricing. Canadian Solar’s BiKu is offered in both Poly and Mono and utilizes existing framing size for a product more suited towards commercial/utility-scale given its compatibility with traditional racking systems. These modules came to us at significantly smaller premiums but have the potential to offer a higher performing yield depending on the underside performance.
5. How much surface area was used for the solar system?
Roughly 10,000 sq. feet of panels, throughout a ~27,000 sq. foot parking lot.
6. How long did it take to install the solar system, and what was the cost?
6 weeks, confidential information.
7. How were the solar panels mounted on the solar canopy?
Traditional method of direct bolt to standard purlins, to be able to utilize standard racking systems with this module.
8. What are some advantages when placing solar panels on canopies rather than the a building roof?
While roof-mounted projects are preferable based on kWh produced per unit capex, urban environments require creativity to maximize locally generated renewable energy (ie. more efficient generation, with future opportunities for energy resiliency through microgrids) given limited available land. There are also the intrinsic benefits for ECHO of having covered parking regarding snow in the winter, shade in the summer and controlled water runoff of hardscapes year round.
Image Credit: Encore Renewable Energy
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