Solar Panels that Produce Energy and Help Promote Crop Growth
Funded through Round 7: Renewable Energy in 2013, this project allowed farmland to simultaneously generate food and electricity with the use of a low cost and highly durable power generating greenhouse-mounted solar panel that simultaneously generates electricity and facilitates plant growth. The ability to reduce energy costs with an integrated renewable energy source presents a great benefit to Alberta greenhouse growers.
The Wavelength-Selective Solar Collectors (WSSCs) Soliculture deployed in this project are composed of a glowing red glass panel that absorbs green light unutilized by plants and emits red light. The red light is concentrated onto a low density of solar cell strips attached to the glass panel, which enhances the solar power generation by 50%. The WSSCs also increase red light, the most photosynthetically active light wavelength, on the plants; this reduces plant stress and facilitates plant growth. If all the greenhouse space in Alberta was converted to Soliculture greenhouse panels, there would be 70MW of potential power and 70,000 tonnes of CO2 savings each year. Emission reductions occur by replacing fossil fuel generation power with solar-generated power. Further reductions come from plants grown within the greenhouses converting CO2 exhaust and heat from fossil fuel power sources into O2 and biomass. Additionally, utilizing the 70 MW of potential power would reduce the amount of energy greenhouse growers spend on electricity.
Innovations Made to Assist in Manufacturing
During the project, Soliculture made great strides in improving the reliability, manufacturability and cost of their greenhouse integrated photovoltaic panel. The initial panel materials allowed Soliculture to install demonstrations at several greenhouses in Vegreville, Alberta and California. However, the project found that these materials were not scalable to high volume manufacturing, so further adjustments would be necessary to enable expanded commercialization. As a result, Soliculture developed a highly stable luminescent back sheet to replace the original brittle and tedious acrylic backing. Furthermore, Soliculture has partnered with Solaria Inc. to incorporate their solar cell singulation technology with Soliculture’s own light tuning technology. Solaria has the tool set to dice cells into 3mm strips and provide the interconnection into strings. The ability to dice and string these cells with an automated tool significantly reduces the cost of building Soliculture panels.
What’s next?
The solar panels have reached commercial status with several retrofit sales to existing greenhouses and third party certification from Underwriters Laboratories in progress. Soliculture signed a license agreement with Solaria to grant Soliculture exclusive rights to Solaria technology for greenhouse products sold in North America Solaria and has since issued seven patents that collectively cover the cell dicing and singulation process. Soliculture is the first company to fully develop and commercialize a viable LSC technology for large scale installations. Soliculture’s greenhouses have been generating power internationally for over 4 years.