On Friday, April 29, the public was invited to The Fess Parker Hotel in downtown Santa Barbara to watch graduating University of California, Santa Barbara students of the Bren School of Environmental Science and Management give their master’s project presentations. Twenty groups of students lectured on topics ranging from water management solutions in Santa Barbara County to the alteration of the zones of the Galápagos Marine Reserve.
The presentations were split between groups working with clients and groups starting new businesses. One of the groups included Bren School master’s student James Hansen and his team, Andy Bilich, Kevin Langham, Love Goyal and Anjana Krishnan. The team partnered with First Solar, an Arizona-based company that constructs photovoltaic (PV) panels.
Approximately 1.3 billion people lack access to electricity, the majority of whom live in off-grid communities in developing nations. Providing electricity to these people can be done with home diesel generators, grid extensions or microgrids. Microgrids are typically powered by renewable energy and are the greenest option of the three. Hansen’s team’s task was to analyze different microgrid system designs to determine their relative environmental impacts, so as to advise First Solar on their pilot projects in Kenya.
PV is a form of solar energy technology that takes incident light and directly produces electricity, as opposed to solar thermal technology that uses light to heat water, which then powers a steam-turbine. PV cells, also called solar cells, are constructed of a thin material that displays the photoelectric effect, cadmium telluride in the case of First Solar. These materials can take in photons and emit electrons that will create an electric current.
The downside to certain renewables such as solar energy is their intermittency. At nighttime and during cloudy days, for example, the PV cells will be idle. The demand for electricity however is ceaseless. To counter this issue, the PV panels are paired with either a battery backup or a diesel generator.
Hansen’s team conducted a full life cycle assessment of three designs: the PV-battery system, the PV-diesel system and a combination of the two, the PV-hybrid system.
The PV-battery system was found to have the least amount of environmental impacts regarding climate change, particulate matter formation, photochemical oxidants and acidification, but for the freshwater eutrophication category it came up short.
“The eutrophication, or chemical inundation, is caused by the primary metals used in the batteries themselves,” said Hansen in an interview with The Bottom Line. “The primary metals end up getting into the water stream. It is not in the rural communities where the microgrids [are located], but rather in the location were the battery is built.”
This impact can be diminished with acute selection for the manufacturing location. Countries differ in the severity of their regulations for their facilities. Sourcing a battery from a European country with firm restrictions on effluence would insure less metal waste would make its way into the watershed.
PV-battery-based microgrids are made even cleaner when recycling and takeback programs are included for when the system ends its lifespan. Hansen’s motivation stemmed from tackling anthropogenic climate change.
“The developing world is going to produce the majority of our CO2 emissions in the future as they grow, and providing energy access in an environmentally friendly way can have huge impacts on meeting global climate change goals,” said Hansen.
By implementing PV-battery-based microgrids with a recycling program into off-grid communities, companies like First Solar can provide electricity to those without it in a green, sustainable manner.