Solar grazing
Sheep have many virtues, and in the era of renewables a new job! Their eagerness to eat grass provides an almost perfect combination with solar installations located in the countryside.
The agrivoltaics, agriculture combined with solar panels, has several combinations; solar combined with vegetable farming, with olive and almond fields, with grazing lands for animals, etc.
In all cases! the grass that grows under the solar plant is a problem, both in economic and environmental cost, mainly if chemicals are used to eradicate the vegetation.
As a coherent solution, the so-called solar grazing comes into play. In short, using herbivorous farm animal herds to eradicate the weeds that grow under the photovoltaic panel and, sheep are the perfect choice!
Why use sheep instead of goats or cows for solar grazing? Cows are curious and large. They like to rub against things. Goats like to climb and jump on anything. They like to chew on cables. But sheep are relatively small, not very curious, and move with their heads down, in short, they are not interested in the solar panel at all.
The sheep represent the perfect animal for the maintenance of solar panels when we want to control vegetation growth
The grazing of sheep herds in photovoltaic plants provides tangible advantages as noted by the American Solar Grazing Association:
- Reduction in maintenance costs of the installations. The need to mow solar sites is minimized or eliminated.
- Elimination of the environmental impact associated with usual methods to eradicate grass, especially if chemicals are used.
- Extra economic benefits for farms and ranchers; either by having their own panels or by being hired by external companies.
- A stable economy of benefits. Solar farms have an approximate lifespan of 20 to 25 years, which will provide long-term income.
- No need to raise the solar panels higher in the installation. Sheep are small and agile. They can eat the vegetation regardless of the height of the panels.
- With solar grazing, the vegetation of the solar sites becomes a source of nutrition and pasture for the sheep.
- Remembering that the most productive places on Earth to produce solar energy are agricultural and grazing lands. Lands with easy access and plenty of natural light (Abundant solar radiation).
In the following video, we can see an example of professional solar grazing from a photovoltaic farm in the USA.
We refer to “professional solar grazing” as a business, which works and is profitable, and can be clearly seen from the American Solar Grazing Association (ASGA) or from different institutions in the USA.
We could start with the following document “checklist” (In English) about minimum indications that shepherds and renewable energy producing companies must meet if they want to practice solar grazing… What obligations should be considered? From both perspectives, company and shepherd.
- Shepherd…How the sheep will be introduced and removed, what is the movement plan offered, insurance and what type of contract is needed, how water will be provided, etc.
- Company…Is there any type of insurance, is there fencing, what type of grass is there and is it suitable for sheep, when are grazing payments made, costs, what is the herd movement plan on the land, if the first year works well… Is there a long-term plan?, etc.
Including this technique in the initial stages of planning a photovoltaic energy project will allow companies to adapt spaces for optimal management. Solar grazing is more successful when implemented as part of a strategic and rotational plan as noted in this document from CFRA (In Spanish).
In reality, this practice requires a deeper study than it appears… How to know if the pasture has enough nutrition for your animals? How many sheep per hectare are needed?…
The following document already brings us closer to a more detailed reality about the proper balance between forage demand, area, and necessary rotation:
And from the following documentation of the American association. There are different examples in Excel about budgets for solar farms based on solar grazing and its rotation. An example is the Hudson Valley model, located in the state of New York, more than 100 acres (0.40 Km2) with a 25-year solar lease:
In English-speaking countries, most studies report on the cost savings of sheep grazing compared to traditional mechanical mowing and trimming, but few report on profitability for the rancher. In the following document (Mount Morris Agrivoltaic Study) we can see more clarity.
And if you want to delve deeper, the following webinar from YouTube on how to scale a project is recommended…
The conclusion is clear, farm incomes have decreased, and solar grazing allows farmers and ranchers to increase and diversify their income while maintaining their farms and lands.
If you liked the article, rate and share!