Solar power for the farmyard

Since last October solar power has been used to heat the water for the milking parlour wash for the dairy at Greenmount Campus.  The results to date are very encouraging with major savings in electricity costs.

Twenty square meters of solar tubes were installed next to the dairy, facing due south at an angle of 40^o to the horizontal.  The existing water heater was replaced with a new hot water system where the heated fluid from the solar system feeds into a coil at the bottom of a 1200 litre water tank.  The tank also has electric heating to ensure the wash water reaches the required 85⁰C, if necessary. This arrangement maximises the contribution from the solar panels.

The aim of the system is to have half of the total yearly heat requirement produced from the solar system.  The output of heat from the solar tubes over the summer months is especially significant.  The daily electricity consumption in the original system for the twice a day hot wash was 48 kWh, costing around £5.28 at current electricity prices.  Electricity consumption over the summer months was:

Even with the lack of sunshine this summer, this has led to savings of around £4.60 per day over the five months.

Solar systems should last around 25 years and they have a low maintenance cost and low operating costs.  They are especially appropriate for the dairy industry and have other applications in the agricultural and horticultural sectors.

This system is one of the renewable energy technologies at the College that will be on display on 2 November at the “Practical on-farm Renewable Energy” event based at Greenmount Campus, Antrim.

David Trimble CAFRE, at the solar heating panels from the Greenmount Campus dairy which will be on display at the the “Practical on-farm Renewable Energy” event on Tuesday 2 November