Is it possible for solar power generation and agriculture to complement each other? Is it feasible to install solar panels on farmland without hindering the production volume and quality of agricultural products? Perhaps we can look at the example in the Netherlands, where the country unfolded the 2.7MW agricultural solar program AgrilPV using a distinctive solar module technology alongside a UK developer.
For Taiwan, the legal model for farmland solar power is divided into farming and non-farming. The former can also be regarded as “agrivoltaic mutualism” and “aquavoltaic mutualism”, where a solar power system can be directly installed on an existing piece of land after the approval of application, though an agricultural volume of 70% must be maintained. As for the latter, a solar power system can only be installed in areas of land subsidence and severe pollution that have been announced by the government as detrimental for farming, or one can apply directly for a relocation.
The solar farm tested by UK power plant developer BayWa r.e. and its subsidiary in the Netherlands, Groen Leven, is more related to “agrivoltaic mutualism”, where the specially produced solar panels are installed above red currants, raspberries, strawberries, blackberries, and blueberries to see if the final results conform to the anticipation.
The most commonly seen solar cells are azure blue crystalline silicone PV cells that blockade and hinder plants from absorbing sunlight if installed above crops in an elevated position, and while it may create substantial results in solar power, it will generate zero agricultural benefits, which is basically putting the cart before the horse. Hence, the team has adopted a specially made solar panel with a power output of 260W that is similar to that of rooftop solar panels on the market, and is made with thicker glass layer weighing at 35kg per piece in order to avoid plants and the solar panel from sustaining climate impacts of rain, gale, and hail.
Willem De Vries, person in charge of Groen Leven AgriPV, commented that the special request proposed by the team is correlated with “transmittance” as plants underneath the solar panels require sunlight to survive, and traditional plantation of this type of crops in the past also needed an installation of aluminum foil above the crops to avoid direct sunlight, rain fall, hailing, and frost. The team currently uses two solar modules with varied degrees of transmittance, and the production volume of crops increases as the transmittance elevates.
The team has also designed a brand new climbing bracket for these vines to help with thermal dissipation during daytime. As commented by De Vries, the team discovered that the temperature and humidity underneath the solar panels are better than that of traditional plastic protective covers, where the temperature is 5°C lower in contrast to the latter, and 2°C lower than the surrounding environment, with better thermal effects during nighttime.
The team also claims that the new structure is relatively more rigid that will not be easily blown away by strong wind, where the traditional aluminum foils and plastic protective covers may crack and fly away under strong wind. However, the two companies have yet to mention the relevant cost and if such approach will introduce economic benefits, though as commented by De Vries, the installation cost during the current phase is unavoidably pricier than ground solar power, yet the accumulation of experience, continuance in optimization, and the cultivation of the supply chain, will eventually reduce the related cost.
- Special solar panels for agrivoltaics
(Cover photo source: Groen Leven)