Solar panels for farms in Lincolnshire

Which farm loads suit solar

Solar pays best on a farm that uses power while the sun is up. Poultry houses are a good example, with ventilation, lighting, feeding systems and environmental controls running through the day, and so is irrigation, which peaks in exactly the dry, bright weeks when an array produces most. Cold stores and grain stores that run fans and refrigeration day after day give an array a steady load to work against.

Loads that fall outside daylight are where storage comes in. Early morning and evening demand on a livestock unit can be carried by a battery charged from the day's surplus, which is how the Friskney system is set up. The starting point is a year of half hourly data from your supplier, because it shows when the farm really draws power, not just how much.

Ground mounted or on the roof

A field array can face due south at the best angle and sits clear of anything the farm does to its buildings, which is why we often recommend one. On the Friskney job the frame went in on ground anchor bolts, avoiding large concrete bases and keeping disturbance to the land down. We space the rows for the low winter sun and leave room for mowing and for machinery to get round.

Farm roofs can work too, but they need a survey first. Plenty of older agricultural buildings are roofed in asbestos cement sheet, which cannot simply be drilled and walked on, and the roof has to carry the extra load for the life of the array. Sometimes the right answer is to re-sheet the building first, and often it is simply to put the panels on the ground instead.

The Friskney poultry farm in figures

For M Holmes Ltd we designed and installed 72 panels of 420 watts each, 30.24kW in total, on a ground anchor framework. Cable trenches carry armoured SWA cable from the array to the main distribution point, and we installed a new three phase distribution board to take the solar and the battery.

Three phase hybrid inverters manage the panels, the battery and the site demand together, set up to use the farm's own generation before anything is exported. The 30kW battery system stores the daytime surplus and carries the early morning and evening loads. Every AC and DC circuit was tested, and the earthing and protection verified, before the system was commissioned.

Grid connection and planning

Many farms already have a three phase supply, as Friskney did, and a system of this size needs a G99 application to the distribution network operator before it is connected. Rural networks can be short of capacity, so the operator may approve the connection with a limit on what you export. That is usually workable, because a limited system still saves exactly the same on every unit the farm no longer buys.

Panels on the roof of a farm building can often go up under permitted development, provided they stay within limits on how far they stand off the roof and how close they come to its edge. A ground mounted array of any useful size usually needs a planning application or prior approval from the district council, so we raise it at the start. Solar on a farm is a business asset, so ask your accountant how capital allowances apply to it.