Looking at the energy consumption of every part of your farm and then trimming it back sounds like an obvious way to cut power bills. But it’s a fair bet that few farmers have ever done it.
So it’s all the more impressive that one farming organisation that is doing just that should also happen to be one of Britain’s biggest farmers – The Co-operative. The Co-op farms 70,000 acres across Britain and has set a target to cut its energy use by 25% by 2012, whether it is on its farms, in its shops or in its distribution centres.
At Coldham Estate near Wisbech, Cambridgeshire, farm manager Russell Armstrong is going about the task with gusto. It is a big project because it is a big farm – 1523ha (3760 acres) of grade-one and two silts (two-thirds of it irrigated) that grow potatoes, onions, shallots, broccoli and sweetcorn, as well as more mundane crops: wheat, sugar beet and oilseed rape.
But the first things you see as you approach the farm are related to energy production rather than saving. Eight 2MW turbines stand proudly on the flat fenland landscape and seven more are due to join them next year. Each cost £2m to build, but payback is expected in just 6-7 years. They are connected to the local grid so the power is used locally.
While the turbines are the glamorous, highly-visible end of The Co-operative’s energy plan, it is the energy-saving measures that are mostly exercising Mr Armstrong and his staff’s time. In fact, changes have been made to almost every aspect of running the farm.
Electricity to power the irrigation pumps, for example, is a major expense and it has been priority to rein that back. The motors powering the pumps have been fitted with inverters so, rather than spinning at full speed all the time, they run at lower rpm.
Rain guns have been changed for booms, which run at lower pressures and boost pumping efficiency and pipe diameters have been changed from 4in to 5in to cut friction losses and increase efficiency.
Pumps will soon be switched on and off by a mobile phone rather than manually, saving vehicle mileage and fuel. And there are plans to fit energy-saving inverters to the two giant pumps that help drain this close-to-sea-level farm.
Things are changing in the potato and grain stores too, both areas of traditionally high energy use. “Our old system involved tipping corn in the yard, bucketing it into a mobile drier, then trailering it to off-site stores,” he says. “So we were triple-handling everything.”
That has been ditched for an on-floor system with cheaper-to-run modulating gas burners, an energy-saving differential thermostat and lighting that can be switched on and off in sections. This should cut energy use by 60%, says Mr Armstrong.
Likewise, the not-very-airtight converted barn that was used to store potatoes has been replaced with an efficient one, with inverter drives on fans and fridges and thick insulation.
In the field, previous plough-based cultivation systems that involved seven passes have been replaced with a three-pass min-till system. GPS autosteer systems are used to save diesel (and time) by cutting down overlaps and reducing the number of passes.
Will he hit the 25% target? Mr Armstrong is confident he will – and even if he doesn’t, it won’t be for want of trying.
What the judges liked
- Challenging energy-reduction targets the farm is determined to meet
- Carrying out large-scale farming but with a sensitive touch
- Good at concentrating on the small things, despite the size of the business
- Staff are motivated to cut energy costs
- Coldham Estate is 1523ha (3760 acres), growing wheat, beans, potatoes, salad vegetables, onions, shallots, broccoli, runner beans and sweetcorn
- Two-thirds of the farm is served by an irrigation system
- Target is to cut energy use by 25% by 2012
- Eight 2MW wind turbines produce enough power to each supply 9000 homes, with seven more due to be erected in 2010
- Changes to irrigation pump motors, and grain and potato stores result in significant cuts in energy usage