Pictured above: David Lewis, Chris Allwood and Howard Hughes

Seeing is believing and for farmers considering renewables the sight of the solar photovoltaic panels on the grain store roof at Park Farm Crewe Green Crewe in Cheshire and the meters whirring as the energy is fed back into the grid should help remove any shadows of doubt hanging over the investment potential of roof top solar.

The day was dull and showery when clients of Cheshire agricultural consultants HarveyHughes Limited visited the livestock and arable farm but still the 15kWp system atop a south facing roof were soaking up she sun rays to produce energy sufficient to power the lighting and heat up the tea urn for the meeting.

David Lewis, his wife Carolyn and son, Simon, farm 120 ha on the Duchy of Lancaster's Crewe Estate and their 15kWp PV installation has been up and running since March 5. With nearly two months of exceptional sunshine the system has already notched up a quarter of its design output for the first 12 months and has reached a peak output of 15.4kW on several occasions.

David is now a solar energy convert.  From running his farm electricity system geared around cheaper night time tariff he has turned things on their head and is now switching on equipment in the day when energy production is at its highest. 

Having gone out of milk five years ago, the family now grows arable crops, contract rear heifers for their neighbour and rear and finish beef cattle.

"We now use our home produced energy to warm the water for calf feeding, run the feed roller and in the summer we will power the grain drying and handling equipment," he said. "As soon as I see the meter's recording 3kw we switch on the roller mill to make sure we utilise as much of our power as possible."

Having researched the subject thoroughly at the end of last year, David decided to use the services of Phoenix Renewable Technologies ,  a Newcastle under Lyme, Staffordshire-based company whose consultant Chris Allwood,  Simon had met at Weston Discussion Group,  and seemed to have the necessary knowledge, honesty and experience to come up with the goods.

Finding someone with this understanding of the range of products and the role they have to play is vital according to Howard Hughes of Harvey Hughes Limited, if farmers are to make optimum benefit from renewables. 

Eighteen months ago there were only about three companies involved in solar energy now, on the back of the promised benefits and rewards, there are more than 13,000 companies offering to put up solar panels.

"With Feed in Tariffs in place farmers can reduce carbon emissions, reduce electricity bills and their reliance on external power providers and gain a good return  on their investment," said Chris Allwood of Phoenix Renewable Technologies.

"You'll find it hard to get a better return on your money. With FiTs guaranteed for 25 years we reckon you will get around a 10 per cent return on investment in real terms and with index linking this return will increase year on year."

The FiT  is funded by the government and paid back through the major energy companies. It varies depending on the size of the system and at Park Farm the 15kW scheme is classified as a medium industrial application eligible to the 32.9p/kW rate for all electricity produced with a further 3.1p paid if the power is not used on the farm and exported back into the grid.

The FiT is generous but the installation cost is high. David is budgeting on a 10 year payback time for the 84 panel system, which is installed on a south-facing 30 degree roof. The fact that the FiT is guaranteed for 25 years and index linked helped him swallow the pill.

"Since signing up there has been a Retail Price Index increase of 4.8 per cent since April 1. You don't put any labour in so you won't be getting the return of some better farm enterprises but an index linked return of eight to 10 per cent is good," David said.

"As well as the income from the tariff you also have to calculate the saving of energy used directly and the income from the export tariff which is paid on half of our production."

The panels were installed on an existing grain store which was a tenant's building. Phoenix calculated it would accept an 84 panel system producing a 15.54 kWp output. The system is designed to balance the feed of energy generated into the 3-phase electricity supply by sub-dividing the array of panels into three equal parts each of which connects to the national grid through its own dedicated inverter.

Shading is another factor that has to be considered when choosing a site and this can be a bigger problem when panels are at ground level. 

"Shading of part or all of a string of panels will stop electricity production in that string. This can be caused by neighbouring buildings, trees and other vegetation and dirt build up," Chris said.

"Obviously a site inspection is required to help ascertain the site with least shading and then we arrange the panel strings so that fewest are affected. Trim trees and regular (annual) cleaning is essential."

A monitoring system has been installed which allows David and Chris to view production data on their computers via an internet portal and see how the system is performing day by day.

"The best production days are not necessarily the hot sunny ones. Best output comes when the sun comes out after a shower and the sky is bright blue," David said.

"The more of our own electricity we can use, the better and sometimes I'm thinking what else can I use the power for," he added.

For further details contact Howard Hughes on 0161 9277562 or Chris Allwood on 01782 562038.