Project: CLASS, or customer load active system services
Cost: £9 million grant from the Lower Carbon Network Fund
Run by: Electricity North West
What’s the idea?
To increase the capacity of the distribution networks by lowering voltage at peak times.
Why would you want to do that?
Demands on the network are rising, with low carbon technology like solar panels and wind turbines springing up. Meanwhile, there is pressure to cut costs. This system will help wring the most out of existing assets before having to upgrade.
How does that work, exactly?
A number of transformers in substations are getting to a point where they need to be replaced to cope with rising demand. Reducing the voltage at peak times curbs demand. ENW estimates they could defer £8 million of investment in 14 substations for three years. If rolled out across the country, networks could defer spending of up to £90 million.
Pretty smart.
Yes, and that’s not all. It can also be used to help National Grid match power supply and demand in real time. If a power station gets a fault and shuts down, for example, National Grid needs to find extra capacity – and fast – to keep the system in balance.
Don’t they have back up generators for that?
Well yes, traditionally it has drawn on a “spinning reserve” – generators kept on standby that can ramp up quickly. That’s still used. But much of it comes from gas-fired plant, which is relatively costly to run and emits carbon dioxide. Increasingly, National Grid is looking at demand response as a cheaper and lower carbon way of managing fluctuations.
And CLASS can cut demand?
Correct. Reducing voltage across several substations at once can deliver a meaningful drop in demand. While it is not a focus of ENW’s trial, networks are likely to be able to benefit commercially too, from selling demand response services to National Grid.
What impact will it have on the customer?
ENW does not expect customers to notice any difference. The reductions are small – no more than 6 per cent and in most cases just 1 to 3 per cent. Kettles might take a couple of seconds longer to boil. A key part of the project is surveying customers, both in the trial zone and a control group, to check they don’t experience any problems.
The project runs until September 2015.