It's highly significant that demand side response is to be included in auctions for the capacity market, as announced by Decc last Thursday, because it marks once and for all a move away from the principle that has dominated energy policy since the national grid began: of satisfying peak demand at any price.

Capacity market auctions will commence in 2014, subject to European state aide approval, and will embrace new and existing generation capacity including combined heat and power (CHP), embedded generation, energy storage, and permanent reductions in electricity demand.

Demand side response (DSR) means that small, decentralised generators and owners of stand-by generators experiencing reduced demand, or a combination of both, will be able to gain an income by selling the energy they don't need.

The UK‟s electricity system is currently sized to meet peak demands that only occur infrequently, which leads to generating plant and transmission and distribution networks being under-utilised for much of the time.

This is expensive and wasteful.

DSR will open up a huge new market, which will grow even more as the 'smart grid' spreads, by letting energy consumers become active participants in a more local and efficient energy system.

It will embrace many different kinds of energy consumers, such as businesses, farms, hospitals, hotels, universities, local authorities and commercial buildings.

As a result of this policy such enterprises will have greater confidence to invest in their own generation plant, and will have the ability to create income for themselves on a sustainable, predictable basis.

Any facility that collects real-time consumption data and is sometimes on standby to reduce energy use, or that runs standby generation that can start up upon a signal from the electricity system, will be able to participate.

Participants will be able to bid both one and four years ahead in the auctions, giving them flexibility and confidence to invest in the future.

It's also good news for combined heat and power, since much small-scale generation is CHP, producing heat and power for local networks.

The other benefits of demand side response include:

  • addressing the threat to electricity supply caused by the imminent closure of coal-fired power stations;
  • reducing the need to build new power stations and transmission lines;
  • reducing greenhouse gas emissions by allowing power stations to operate closer to the maximum efficiency;
  • avoiding transmission losses by using electricity locally;
  • and reducing the need to keep power stations warm as a spinning contingency reserve.

If we compare the consumption pattern of electricity from the commercial and public sector to the demand profile for all sectors, we see that the peak demands for non-domestic buildings occur at around 11am on weekdays, whereas the total peak is between 4 and 6pm.

This is where the potential for spreading out supply and demand lies.

The potential for DSR to reduce peak demands depends on the flexibility of electricity capacity and the uses to which it is put.

The greatest flexibility is related to load with storage or inbuilt inertia, such as hot water, heating and air conditioning. Some loads, such as computing, exhibit limited flexibility, unless they are in data centres operating unused standby.

Assessments by Element Energy and the Montford University for Ofgem a year ago of the technical potential suggest that DSR measures could reduce winter peak demands in Britain due to non-domestic buildings from 1–4.5GW, but the eventual potential is likely to be much more.

There is work to be done to develop detailed policy implementation that will work well for smaller operators and ensure that the cost effectiveness of DSR is harnessed for the benefit of consumers and the wider UK economy.

A consultation by Ofgem on the subject finished on 28 June. It's probable that the results of the consultation will feed into the practical arrangements under which the capacity mechanism will operate.

Sensibly, there will be a transition period for demand side reduction and small-scale storage within the capacity market.

To this end, Ofgem and the National Grid have just launched a new consultation on transitional products aimed at paving the way for DSR.

The first potential product, Demand Side Balancing Reserve, offers a new opportunity for the demand side to participate in the provision of demand and supply balancing services.

The second, Supplemental Balancing Reserve, is aimed at generators and large users.

Of the first, National Grid is suggesting that it could buy a quantity of demand reduction capability at peak times on non-holiday weekdays during the winter for a set-up payment of between £5-10/kW per year, and utilisation payments for delivery ranging from £500/MWh to £15,000/MWh.

It's also consulting on a second product that would be the same but without the setup payment.

The idea is that this will promote significant growth in the provision of demand-side services ahead of DSR participation in the capacity market.

No one should underestimate the significance of this development: it marks the first time that Britain has moved away from an energy policy of having to supply peak demand whatever it is.

This policy has proved inefficient, insecure, expensive and impractical; the more so as energy and plant construction prices rise and we are constrained by the need to reduce carbon emissions.

It's a fabulous opportunity, and the more organisations and businesses wake up to its potential benefits for them, as well as to the effect on reducing prices for all energy consumers, the better it will be for the whole country.