A solar farm and a field go together just fine, according to a trial by Germany's Fraunhofer-Institut in southern Germany. The yield of both the solar farm and the farmland is less than usual, but according to the researchers, together they provide a positive sum.
Solar meadows or parks are gaining popularity now that the price of panels has fallen sharply and solar energy is being promoted with subsidies. But a solar farm cannot be combined with agriculture. It is either choose agricultural land or land with solar panels.
A trial by Germany's Fraunhofer-Institut für Solare Energiesysteme and the Universität Hohenheim now shows that the two can be combined, according to a press release on so-called Agrophotovoltaic. In this system, solar panels stand on a frame 5 metres high with a larger gap than usual. This allows enough light to penetrate at the bottom to grow crops.
Two-sided panels
Last year, the combination system was tested at the Heggelbach organic farm in Baden-Württemberg. On the trial fields, winter wheat, potatoes, celeriac and clover were grown for a year in exactly the same way as in fields without solar panels.
The results of the first harvest on the solar field show that the yield is a fifth less than that of the other field, at least for winter wheat, potatoes, celeriac. The clover did 5% less.
The 720 solar panels on the trial farm are two-sided: they also use sunlight reflected from the land. The total peak power is 194 kW. During the year, they produced 1266 kWh per installed kW of power. Because the panels are more widely spaced, the yield is obviously less than for a stand-alone solar farm.
Less yield
In combination, harvest and solar farm therefore have to sacrifice a little yield, but they clearly yield more per area used than a field and a solar meadow separately. After all, less space is needed to both grow crop and extract solar energy.
Fraunhofer now wants to carry out further tests with other crops, different set-ups and types of solar panels to see how further optimisation is possible. There is also the aesthetic aspect: a 5m-high solar farm creates a landscape that will resemble some kind of open greenhouse area. And not every German landscape lover is keen on that either.
By: Kelly Bakker
Source: Fraunhofer/De Ingenieur
