Energy storage could have saved Britain from some of the economic and environmental impact of National Grid’s shortfall in energy capacity during Wednesday’s evening peak, according to one industry expert.
Owing to factors including the unexpected shutdown of power plants, National Grid had to buy in electricity from abroad and prepare to fire up two out of use thermal generation plants on Wednesday evening. The grid operator had issued a Notification of Inadequate System Margin (NISM), meaning that it needed to procure balancing services at short notice in order to cope with the evening peak in demand.
National Grid also used demand side balancing reserve (DSBR), also known as demand response, calling on heavy users of electricity, such as factories, to quickly reduce or curb their energy use to lower overall demand on the network in return for payment.
Several national media outlets reported the incident with a note of hysteria, describing demand side balancing reserve as a “last resort” available to the National Grid. In fact DSBR is a recognised flexibility resource for power grids worldwide and is increasingly being employed to reduce the network costs of electricity and to balance grids.
Dr Jill Cainey of the Electricity Storage Network also told Next Energy News that in terms of energy security the situation was not as extreme as some reports implied. Cainey said it was unlikely that National Grid would fail to “keep the lights on”. However, there was an economic cost associated with the balancing act, as well as an obvious environmental one.
“…the media is fascinated by the possibility that we’ll all be clustered around candles, and that the lights will go off!” Cainey said.
“It’s unlikely. National Grid is tasked with making the lights stay on and they will do that, I guess the issue is - at what cost?”
An unexpected NISM
National Grid had said a couple of weeks ago in its annual National Winter Outlook report that it had a capacity margin of 1.2%. Adding emergency reserve capacity to that brought the figure up to 5.1%, which Cainey described as “quite comfortable”. While National Grid had said it expected to have to issue NISMs this winter, Cainey said, the fact that Wednesday’s came just a few days into the start of winter was quite unexpected, when usually it would take a more prolonged period of cold weather to cause a shortfall in supply over demand.
The NISM issued Wednesday was the first to hit Britain since 2012, with National Grid requesting up to 500MW of additional capacity between the hours of 16:30 and 20:00 pn Wednesday night, in the end procuring 40MW by 18:00, by which time the situation was resolved.
The Guardian reported that National Grid also bought power from provider Severn Trent for £2,500 per megawatt-hour, when typically it would cost around just £60.
“[National Grid] used their demand side balancing reserve and they also did a system operator to system operator trade with Ireland and that’s how we got through yesterday evening. We had to turn some things down, we bought some electricity from Ireland and we also fired up two old power stations.”
Usually, Ireland would be the off-taker of power from the UK, not the other way around, while capacity also had to be procured yesterday from France and the Netherlands. Buying power through these international interconnections could prove costly, Cainey said.
“Interconnectors are market based. They flow in the direction you can make the most money, [so] they’re not always there to help you for a system problem.”
The two thermal generators switched on as part of the emergency reserve capacity would have produced greenhouse gas (GHG) emissions as well as costs that could have been avoided, had energy storage systems with suitable duration been deployed. Cainey said that pilot projects such as the “Big Battery” in Leighton Buzzard have been deployed by agencies including the government Department of Energy and Climate Change (DECC) to prove the appropriateness of energy storage for this role.
“We, the Electricity Storage Network, would say that yesterday’s incident where they were going to have difficulty meeting peak would be avoided because if they’d had some electricity storage appropriately placed, that’s perfect for getting you over that evening peak, because you’re looking at 2-4 hours [of storage]”.
DECC creates dedicated storage group
More significantly from a long-term perspective, Cainey said that DECC, National Grid and regulator Ofgem have been making serious inroads into recognising the value of energy storage and then putting that into the legislative arena. ESN had advocated for a long time for DECC to create an office charged with looking at the various technologies and possible market framework regulation.
A private meeting of the newly formed Storage Stakeholders’ Steering Group took place on Monday, which was attended by, among others, Lord Adonis, who is tasked with leading the newly created National Infrastructure Commission. Chancellor George Osborne has pledged that the cross-party commission will have up to £100 billion to spend, with energy as a central component and industry figures expecting that storage will be one of its key areas of focus. DECC has also created a two-man “Smart Energy” team to look at “regulatory, market and commercial barriers to storage,” Cainey said, seemingly granting ESN’s wish.
In addition, National Grid is looking at creating a frequency response market, where fast-acting energy storage could play the grid-balancing role traditionally undertaken by gas peaker plants, while Ofgem has been for some time publicly considering the role storage could play in adding flexibility to the network.
So, Cainey said, despite longstanding policy uncertainty in the renewables sector, including expected and severe cuts to the solar feed-in tariff (FiT), “the government is interested in all levels of storage”, from domestic, behind-the-meter systems paired with PV, to long duration storage using, for example, compressed air or giant flywheels, to “intermediate” technologies such as liquid air energy storage.
“We don’t know what the government’s overall energy policy is going to be and we won’t know until the end of this month but we know storage is key to delivering low carbon and reliable electricity system.”