Chinese Xiang Yang Institute (XYI) and US' Focused Sun of Las Cruces, New Mexico are partnering to jointly develop 'solar microgrids', small local electric grids for supplying energy to gated communities, shopping malls, eco-resorts and agricultural projects.
Focused Sun systems harness the sun to provide both thermal energy and electricity by means of concentrating solar system and thermal energy storage.
XYI Dean Jihong Chen said, “Focused Sun has squeezed the cost out of solar concentrators, the key part of the microgrid system that focuses sunlight. Together with thermal storage and Chinese turbogenerators, we can produce small power plants for microgrids.”
According to Focused Sun, the system, when used for both electricity and hot water, can pay for itself in as little as two years. The Focused Sun concentrators are made locally bringing local jobs plus cheap, clean energy. For every dollar spent, four times more solar energy is captured says the company.
“The solar energy peak is at mid-day, but people need heat and electricity in the evening,” says MIT Prof. David Gordon Wilson, an expert on thermal storage and turbomachinery. Wilson believes thermal storage can power generators until the next day. “For microgrids in the 100 kW to 10 MW range, low cost solar concentrators and thermal storage combined with turbo generators make more sense than photovoltaic collectors and battery storage. Thermal storage is the key missing ingredient,” he says.
The system works the same as current large-scale CSP plants, storing thermal energy during the day to release it at night or during cloudy periods.
Small-scale CSP systems have been most often discarded in favour of cheap PV and solar thermal modules. The key benefits of CSP is the higher temperature it reaches for the thermal energy storage system to be dispatched during long periods of no solar radiation.
The project is undergoing a crowdfunding campaign with almost no success as it has raised so far roughly $12,000 out of the $1 million goal.
Dr. Amir Abtahi, Director of the Solar Laboratory at Florida Atlantic University (Boca Raton, FL) has investigated solar microgrids with thermal storage. He says, “The modular approach that Focused Sun uses lets solar energy be customized to various power plant sizes.”