Image: Centrica

Centrica’s Cornwall Local Energy Market (LEM) flexibility trial has completed, involving over 200 homes and businesses trading stored renewable electricity.

The three-year, £16.7 million ($22.1 million) trial in Britain’s west country saw 310MWh of power traded successfully, with greenhouse gas savings of nearly 10,000 tonnes a year as a result.

The trial was aimed to deliver a market-based solution for flexibility trading at the local level.

As part of the trial, 5MW of low carbon technology, including combined heat and power, solar, wind, battery storage and device level energy monitoring, was installed across more than 100 businesses.

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A further 100 homes received a combination of solar panels and wall mounted battery storage. The stored capacity of the home battery systems was combined to form a virtual power plant and, when aggregated, was able to trade autonomously with the grid operators.

Some businesses saved as much as 35% on energy costs by operating at times more aligned with grid needs.

A major stumbling block on the introduction of a more flexible electricity grid was also overcome when in what is believed a world first, the local distribution system operator Western Power Distribution and the transmission system operator National Grid ESO both procured flexibility simultaneously via the trial’s auction-based marketplace.

This thus paves the way for a smarter grid that is better able to accommodate renewable energy.

“At a national level, the system is managed using flexible demand, battery storage and flexible generation, however, it is becoming increasingly important to manage network constraints at a local level too,” says Jorge Pikunic, Managing Director, Centrica Business Solutions.

“The trial in Cornwall has proved that homes and small businesses can play a role, alongside larger industry, in market-based procurement of flexibility – a genuinely new tool in our low-carbon energy system toolbox.”

Online trading platform

The LEM online platform developed in the trial enables buyers to place bids for flexibility services, which are then matched with offers by sellers, i.e. the participating homes and businesses, through auctions that run from months ahead all the way to same day. The platform manages the process for both sides from contract creation all the way to baselining and settlement, making it easy to trade flexibility.

Other partners in the trial were Exeter University and Imperial College London, with additional support from the Belgian-based advanced energy analytics consultancy N-Side. It was funded by Centrica and the Centrica Energy for Tomorrow Fund, as well as a £11.6 million grant from the European Regional Development Fund.

Centrica has calculated that in order to accommodate the British government’s plans to power every home with offshore wind, as much as 25TWh of electricity will need to be traded flexibly every year – almost double the annual electricity demand of Wales.

Centrica believes that its LEM or a similar technology used across the country would ensure the establishment of local flexibility markets that are “open, transparent and foster competition on a level playing field”.