German agricultural research institute debunks »land grabbing« accuses against wind and solar
Post date: 15/05/2023 - 13:36
The German Federal Research Institute for Rural Areas, Forests and Fisheries (Johann Heinrich von Thünen Institute) has conducted a comparison of the area-related yields of various renewable energies on agricultural land in Germany. In line with numerous comparable scientific publications, the 26-page study, published in the current issue of »Berichte über Landwirtschaft« (Reports on Agriculture), finds wind power and photovoltaics to be many times more area efficient than growing crops for energy production.
The study cites widely diverging expected area yields of between 2.8 and 25.4 megawatt hours per hectare per year (MWh/ha/a) for the use of biogenic energies for electricity production, depending on the type of plant and use; maximum assumptions under optimal conditions range up to around 42 MWh/ha/a. In contrast, for conventional ground-mounted solar power plants, the range is 471 to 1,225 MWh/ha/a. When used for agri-PV, where only a small part of the land is no longer usable for agriculture, the »electricity yield per loss of land for agriculture« is up to eight times higher (10,302 MWh/ha/a), depending on the type of agri-PV system.
For wind turbines, the electricity yield, based on the »wind area requirement,« taking into account the technically necessary distance areas, is 189 to 918 MWh/ha/a, depending on the scenario. In relation to the area sealed by the turbines alone, including crane installation areas and access roads, and thus no longer usable for agriculture, the yields are many times higher and range from 7,500 to a maximum of 60,000 MWh/ha/yr.
Jonas Böhm, lead author of the study, also notes that the results refute the frequent criticism of the »land grabbing« caused by wind and solar: »For 100 percent electricity from wind power and photovoltaics, we need significantly less than half of the area that is currently already being used for the cultivation of energy crops« – although the latter currently covers only a small part of Germany’s energy needs. This would free up large areas that could be used »for food production or biodiversity measures.«
Methane production from biomass and the cultivation of rapeseed for oil production will probably nevertheless be important in the future. However, the methane would then no longer be used for power generation, but as an industrial raw material, and the rapeseed oil would not be used for combustion engines, but »for the lubricant industry and as food.«