Solar Panels For Agricultural
Almost every form of agriculture involves the use of the sun to efficiently convert its solar energy to produce forms of energy we need for life; farmers have been harnessing this power for centuries and in more modern times greenhouses have become a commonplace method of converting solar light to heat, enabling year-round production and the growth of specialty crops and other plants not naturally suited to the local climate.
Increasing electricity costs and other factors have made farmers look at ways of reducing their overheads and improving their profitability of their businesses. So farmers and landholders are now realising the value of using unused roof space or parcels of relatively unproductive land to install solar panels.
Comparing a standard grid supplied unit cost of 15p; getting a subsidy free rate of 4.85p per unit together with little maintenance cost and a return on investment of 17.5% is one of the main reasons that more and more farms are getting into solar panels.
Applications of solar energy in agriculture include pumping water, drying crops, brooding chicks and drying chicken manure. An increasing number of vintners now use the energy generated by solar panels to power grape presses.
Using Solar Panels on a Farm
It has become easier and more affordable to use solar power on a farm owing to the rapid advancements in technology and the increasing awareness about renewable energy sources. Although many farms would find it difficult to become completely solar powered, natural methods of harnessing solar energy and installing solar panels are some basic techniques that can be adapted by almost any farmer.
A professional site survey is crucial in order to find the areas that receive direct sunlight during most part of the day without any obstructions and also to determine what other work is required, such as the steps needed to commission a three-phase system. Ideal locations include open land as well as buildings with glass or open rooftops.
The initial set-up cost of a photovoltaic system is determined by the size of the installation and the overall quality of the system. The main outcomes are a dramatic reduction in electricity bills together with possible income from the export of any surplus electricity to the grid.
In order to benefit the health and growth of farm animals many farm buildings need to be maintained at a certain temperature and humidity level. A solar space heating system would monitor the internal conditions of the building and activate the sunscreen and ventilation systems to keep the temperature and humidity at optimum levels.
Using solar panels on a farm to heat water is an excellent way to reduce your running costs. The heated water can then be stored in properly insulated storage tanks for later use.
Arable Farm
A ground-mounted solar tracking system was installed on a farm in the rural countryside to provide electricity for a grain store and drying facility. The ability to track the sun makes the system 35% more effective than roof mounted panels. The owner said that solar suits his arable business as he uses most energy for grain storage and drying during the summer months when there is the most sun, unlike many businesses which use more electricity during the winter.
Grain stores
The farm owners built a new grain store with a 26,500-tonne capacity. They had been considering installing solar panels on the roofs, but decided to go with a free-standing tracker system instead. The owners said that they cost 15% more than roof panels, but that cost has been absorbed by the cost of reinforcing the roof to withstand the panels. Because the tracker system produces 35% more energy it meant it was a simple choice. In this particular case, by installing panels on a roof there is the danger it could create some water leakage and with £4 million of grain in the shed it was a risk they were not prepared to take. The solar panels have been erected on what was a ‘dead space’ behind the grain store, which will be grassed down and they are high enough for it to be grazed by sheep and other small animals. They were pleased about the easy access for any engineering and maintenance work and it doesn’t have all the health and safety issues which could arise with panels on that particular type of roof. The tracker system has its own protection systems, so that if it is very windy they automatically go into flat mode and if it snows they move to a vertical position.
Other Developments
Using farmland for solar does not prevent the land being used for agriculture. Moves are being made to create hybrid systems called agrophotovoltaics that puts solar panels and vegetable farming in the same fields. This is where solar panels are installed 12m off the ground allowing tractors and harvesters to continue working below the system so crops can be grown underneath. The system doesn’t completely cover the canopy, so there is still some light coming through. A pilot project was run on a farm in India, where they grow cotton and tomatoes. The shade from the panels not only protected the tomatoes and cotton from the heat, but also prevented water from evaporating, and led to a 40 per cent higher yield of both crops.
Planning
Planning permission will only be granted to lower-yield fields or grass used for grazing, so the most fertile land cannot be covered with solar panels. When the solar panels are installed, the fields can still be used, either by filling them with bumblebee-friendly flowers or using them to graze small animals like sheep or goats. So, any loss to food production would be minimal.
