EXPRESS #4 - July 10, 2018
The German research institute Fraunhofer ISE reports that it has demonstrated the feasibility of what it calls agrophotovoltaics (APV) in two projects in Chile and Vietnam. Earlier Fraunhofer had done successful tests in Europe.
The results from the first experimental program near Lake Constance in southwestern Germany found combining agriculture and solar increased the output of the land by 60% over what it would be if the same land was devoted 100% to farming or 100% to solar panels, writes Steve Hanley on Cleantechnica.
“From the perspective of agricultural science, agrophotovoltaics is a promising solution for increasing both the land use efficiency and the share of renewable energy provided by the agricultural sector,” professor Iris Lewandowski, who heads up the department of biobased products and energy crops at the University of Hohenheim, told Cleantechnica.
Since last year, Fraunhofer has applied the lessons learned from the Lake Constance experiment to three agricultural environments in Chile and a shrimp farm in Vietnam. In all cases, the benefits suggested by the first pilot project in Germany have been confirmed, Fraunhofer has reported.
“Three identical 13 kWp APV systems were constructed in various locations in Chile. Researchers were interested in finding out which plants benefited from the shading from the APV array. Sensors measured meteorological data like solar radiation, humidity, soil moisture, and ground temperature.”
The partial shading of crops planted beneath the APV scaffolding can reduce the need for irrigation, notes Cleantechnica. “Various fruits which normally do not grow well in dry climates with high solar radiation can flourish when shaded by an APV system and livestock can benefit from less exposure to the sun. The electricity generated can power water pumps or desalination systems. In addition, it can be used for cooling and processing crops, making them preservable and therefore more profitable.”
The results of another pilot project, in Vietnam, “indicate that APV can significantly reduce carbon emissions while slashing water usage by up to 75%.”
“By combining aquaculture and photovoltaics, the land use rate increases by at least 65 percent compared to an open field PV plant,” says Max Trommsdorff of Fraunhofer ISE. The APV system provides other benefits, particularly improved working conditions due to the shading provided by the solar panels together with a stable, lower water temperature that helps the shrimp grow faster and healthier.
If APV technology and techniques are expanded to developing countries around the world, it could make “a lasting contribution to improving resource-efficient land use and regenerating parched soil,” claims Stephan Schindele of Fraunhofer ISE. “Lower emissions, site specific electrical power, more efficient and profitable farming — APV systems could be the answer to the need for renewable energy in many parts of the world.”