Understanding how much energy whether it is diesel, fuel for field work or electricity costs in potato stores, is being used is a vital first step in being able to reduce energy bills, Andrew Kneeshaw of the Farm Energy Centre says.
Tractor diesel costs have risen from 19p/litre in 2001 to 60p/litre in May 2008, he says. “For a 200hp tractor using 35litres/hour that equates to a cost of £21/hour just on fuel. That will have a big effect on a business.”
The first step to reducing energy bills is to log and record use. “That’s easier for diesel fuel, not quite so easy with electricity where there is less immediate connection with what you are doing.”
For fuel use he advises growers to log use so they know where it is going, and to compare use rates for different pieces of equipment.
A 200hp tractor could be costing £21/hour just in fuel to use,
Andrew Kneeshaw of the Farm Energy Centre says
He also suggests growers maximise tractive efficiency by creating optimal set up tables for different combinations of conditions, implements, tractors, ballast and tyre pressures.
All of those factors will affect the efficiency of power transmission, he says. For example, over inflating tyres by 20% can cause a 30% loss in performance, while under inflating by 20% reduces performance by 26%.
“It will take a little bit of research, but the information is available from tractor, implement and tyre manufacturers.”
Monitoring energy use in potato stores is also extremely productive, he continues.
As part of a Potato Council-funded project eight stores have been monitored using SMART metering. “We installed simple logging devices that could monitor store and external temperatures on a 30 minute, daily or weekly basis.”
The information allows the growers to see their usage and compare it against a prediction of what energy should have been used. The data is also benchmarked against other stores in the survey.
One grower in the project had shut down one of his stores on the basis of the information produced, Mr Kneeshaw says. “He was running two stores – a purpose-built new store and a converted grain store. We found the new store was using half the energy of the converted grain store, saving around £2000 in a two-month period.
“The old store is now going to be insulated at a cost of £15,000, with target savings of £5000 a year, giving a three-year payback. Without the monitoring the grower wouldn’t have been able to make this rational decision.”