Keeping their cool

Demand side solutions can help balance the electricity network. By knowing when to increase, decrease or shift their electricity usage, businesses can earn revenue, save on total energy costs and reduce their carbon footprints. Stuart Lloyd, Chief Engineer of Norish, a cold storage and logistics company, explains how it works for them.

Norish is a major energy user because of the nature of our business, especially where it includes temperature controls. We do everything possible to manage our energy use, both for cost reasons as well as environmental ones.

We operate eight storage and distribution centres across England and Wales providing over 75,000 racked pallet spaces of which 60,000 are temperature controlled. Our annual electricity consumption is 21GWh so anything we can do to reduce that is welcome.

Flexitricity manages the demand-response relationship with National Grid on our behalf and provides National Grid with Short-Term Operating Reserve (STOR), an important source of reserve electricity.

Four out of our eight sites are connected to Flexitricity’s smart grid. When there is sudden high demand for electricity, or if a major power station fails, we can help National Grid by reducing plant loading for certain periods.

Hardware installed by Flexitricity automatically turns down our cooling plant for short periods to reduce the stress on the network, and because this automated load management is carried out for short periods and within pre-agreed parameters, it does not affect our product temperatures or freezing cycles at all.


When there is sudden high demand for electricity, or if a major power station fails, we can help National Grid by reducing plant loading for certain periods.


By companies like ours making this extra capacity available, it reduces the need for power stations to be kept on ‘hot standby’ or running inefficiently at part-load as emergency back-up. Indeed, Flextricity’s figures show that their STOR can reduce emissions by between 300 to 750 tonnes of CO2 per megawatt per annum.

Working with National Grid and Flexitricity to help provide extra capacity when it’s needed has been a great success for Norish. It’s led to us lowering our energy consumption and our carbon footprint and allowed us to earn extra revenue, all without disrupting our normal business operations.

A dynamic approach to managing energy

North West water company United Utilities is well on the way to building a “virtual power station.” Energy manager Andy Pennick describes how getting smarter with energy use can pay dividends and boost green credentials.

We know that energy is one of our biggest costs so our mantra is to use less, generate more and use our assets smarter. We’ve done a lot of work already on installing more energy-efficient equipment and we’re generating some 18 per cent of our own electricity through biogas and other renewable sources. But it was the “getting smarter” that led us to trialling Dynamic Demand, a dynamic frequency response solution offered by Open Energi.  

Water companies are ideally placed to make use of frequency response. Certainly we use a lot of power, but often we can be flexible about when we need to use it thanks to the storage available in our assets.

Take clean water pumps for example. Some service reservoirs have many hours of storage and the pumps don’t necessarily have to operate immediately when water levels start to fall.  Another good example for wastewater is the air blowers on activated sludge plants. When managed, there’s headroom available in the process that allows for flexibility in precisely when the air blowers need to cut in, especially suitable for those with variable speed drives.

In 2014 we decided to trial Dynamic Demand at three sites, Hoghton water pumping station, Bolton Wastewater Treatment Works and Birkenhead Wastewater Treatment Works.

What are the challenges?

It was easy enough to identify the types of site and process that would lend themselves to Dynamic Demand, but one of the biggest challenges we faced was persuading our operational teams that it was a good idea!

The top priority for our employees is maintaining compliance.  We had to create a cultural shift so they were prepared to accept handing over some control of our processes.  We did that by sitting down with the operators involved and working through the numbers in extreme detail.

HazOp is a risk-based analysis tool we use to brainstorm all the things that could possibly go wrong on each site where we planned to trial the technology.

This allowed us to set safety margins within which the equipment could respond to changes in frequency. Once outside those margins, the process takes priority again.  It does require a certain trust in the solution and that was the most difficult obstacle for us to overcome.

 We know that energy is one of our biggest costs so our mantra is to use less, generate more and use our assets smarter.

What’s next?

To date we have installed the technology at 10 of our larger activated sludge plants, (biological wastewater treatment) including Davyhulme in Manchester, St Helens, Preston, Runcorn, Warrington and Widnes. We have also successfully integrated Dynamic Demand onto other sites, for example a water pumping station. Over the coming months we are targeting a further 10 activated sludge plants and have started to evaluate new waste and fresh water processes that we feel would work with the technology.

We are also embarking on a programme with Kiwi Power to automate our back up diesel generators for deployment in the STOR market alongside working on DSR trials with our local DNO, Electricity North West.

Our aim, by 2020, is to provide access to 50MW of Demand Side Response for National Grid – enough to displace a peaking power station. I think that’s a very tangible ambition, and it shows there’s real potential for the water industry to help build a sustainable future UK energy market.