Standby power generator minimises wastage and can generate risk-free revenue for food processing companies


A D Harvey is a poultry processing company located in Bunwell, Norwich. Established in 1956, the family business has grown steadily. The company deals with approximately 20,000 free-range, end-of-lay hens per day. Once processed, the birds are sold to wholesale markets across the UK.

Processing power

Constant power is vital to A D Harvey’s operations to ensure the birds’ welfare. Chickens are delivered to the site daily but the company doesn’t have the capacity to store 20,000 birds onsite.

RSPCA animal welfare standards require chickens to be slaughtered as soon as possible upon arrival at a processing plant and in any case within four hours. If there’s a power outage and the processing equipment fails, then the birds cannot be returned to their point of origin; they must be killed and disposed of which can lead to a considerable amount of waste. Therefore, it’s essential that the birds are processed on the same day; the only way to guarantee that is to have a reliable source of standby power.

Standby power provides risk-free revenue

A D Harvey’s Centrax turbine generator was old and becoming unreliable, so it needed to upgrade its equipment urgently.

After responding quickly to a request for an initial site survey, UPS Systems delivered a 700kVA open set generator into an existing outbuilding to help A D Harvey maintain its operations in the event of a mains failure. After removing the ageing generator, the new one was connected to the fuel line from the existing tank.

An additional benefit for A D Harvey from having a new generator installed is that it qualifies for National Grid’s short term operating reserve (STOR) programme. Payments are made to companies to use their standby power generators on a regular basis – not just when the power fails – to help even out power usage across the UK by removing load from the Grid. National Grid’s STOR programme helps balance the supply and demand of electricity during times of grid stress. This is known as demand response.

Signing up to the scheme is a long-term commitment; companies are expected to sign up for at least five years. Those wishing to take part must have a generator with a minimum capacity of 100kW and usually be able to switch it on with 20 minutes notice. In return, National Grid will pay the company to make its generator available, and pay for the load it takes off the grid, usually through third-party aggregators.

It’s good practice to run a generator weekly, and ideally under full load. Like a car engine, generators require frequent use to keep them working efficiently. Testing ‘off-load’ can cause poor combustion, soot formation, clogging of injector rings and unburnt fuel creating oil contamination. Fuel kept in storage for extended periods of time can lead to further deterioration and damage. This practice is referred to as resilience testing and should be part of a site’s regular maintenance regime. However, when a generator is used to provide standby power it can be difficult to find a suitable load for testing purposes without switching off the mains and using the actual load that the generator is supposed to be protecting. This would be a huge risk if the generator should subsequently fail.

Demand response allows standby generators to be tested ‘on-load’ and at full capacity, making it an ideal way to prove engine resilience and optimise performance. Generators are most valuable in demand response programmes where they are able to synchronise with the mains grid supply because they can support significant site electrical loads.

The results

Tim Harvey, Partner of A D Harvey, said: “UPS Systems has been fantastic. When we knew we had to replace our old generator we spoke to several companies, but UPS Systems has definitely surpassed our expectations.

“We regularly test our generator to check it is in full working order. But now we will be eligible for STOR and get paid to do it. This risk-free revenue stream could pay for the generator’s maintenance while also helping to offset the initial capital costs. Furthermore, the hours we would be on call to provide power to the Grid are suited to our working day, so being part of the scheme wouldn’t affect our operations.”