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Measuring energy use is first step to reducing costs

18 January 2012

Closer monitoring of electricity use in potato stores can significantly reduce bills, AHDB Potatoes research has revealed. It will also help meet increasingly tight carbon footprint requirements being introduced by multinational buyers and supermarkets. 

Electricity is a key storage cost, typically varying from £3.50 to £6/t for processing potatoes and £5 to £9/t on prepacks, says Adrian Cunnington, head of Sutton Bridge Crop Storage Research. “But some of our monitoring work has shown a three-times difference between the worst and the best stores. Operators at the higher end of the spectrum could potentially halve their electricity costs.”
Most growers only have one meter for each farm. But individual metering of stores gives a much better picture of where and how efficiently electricity is being used, he adds. “There is plenty of scope for growers to learn more about the true cost of running their stores.”
Smart meters can monitor and record electricity as often as users require, from monthly to near real-time. Results can be accessed online or increasingly through mobile phone technology. 
Even relatively efficient operators stand to save by fitting a smart meter, he adds. “It costs about £7000 a year to run a 1000t potato store. Assuming a smart meter costs about £500 installed and £7-8 a month to run, then even a 10 per cent saving will more than cover that outlay.
“Given that energy costs have risen 40 per cent in the past three years, this is definitely an area that people need to be getting a better handle on.”
Growers can find out how their stores compare in terms of energy cost and use with others by going to They can then undertake an energy use audit to guide improvements, says Adrian. 
Improving the energy efficiency of a store will also help growers meet the tighter supply chain carbon targets being introduced by an increasing number of forward-thinking companies, he notes. 
“Although storage only accounts for about 15 per cent of the carbon from potato production, there are still gains to be had. We want growers to be prepared rather than being on the back foot.”
Several companies offer services to help growers reduce energy costs through better metering. Tim Pratt, technical director of energy service provider Farm Energy emphasises the need to meter each store separately to pinpoint areas of improvement.
“Even ‘dumb meters' installed on individual stores and read manually each week can be very revealing. On one farm we monitored for the AHDB Potatoes project, one store was using twice as much electricity as its neighbour. It was refurbished and now runs nearly as efficiently as the other.”
Smart meters can be more convenient in terms of data collection, provided information is easily interpreted, he advises. “Before buying, get a 'demo login' to see how easy it is to view the data. Look for good graphing functionality rather than tables of numbers.
“Check also how often data is downloaded - it will be priced accordingly. And if an electricity supplier offers you a free smart meter check the small print. You may only be able to access data as long as you buy electricity from them and/or pay a leavers fee.
“Finally, don't forget the extra benefits. An energy-efficient store means less weight loss and better crop quality - often worth as much or more than the energy saving.”
Leasing meters is by far the most popular choice, points out Rob Weaver of energy consultancy BCR Associates. “This currently costs about £115 a year plus VAT over five years.
“And once a smart meter is installed, it is possible on future energy contracts to have a reduced standing charge, typically by £60-80 per year.”
The company also offers data management to help reduce bills, says Rob. “Typical savings of over 10 per cent can be achieved. We also offer preferential terms on installing smart meters through a cash rebate scheme when we buy the energy for AHDB Potatoes farmers. This will be scaled according to use, from £40 for a 40,000 kWh user to £120 for a 120,000 kWh user.”
For more information please see
Are you an energy consultancy business? Contact AHDB Potatoes and we will add you to our business list. 
Printable Version Grower Gateway - Issue 1, 2012
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