What's in store for energy


Dr Scott Steedman FREng

Dr Scott Steedman CBE FREng

After years of anticipation, batteries that can store enough energy to power a house are on the market in the UK. The concept is simple: domestic systems can reduce homeowners’ energy costs by storing energy when there is excess supply and releasing it when grid demand and electricity prices are high. The batteries are charged through domestic solar arrays or some other microgeneration system; smart control systems can take the house off-grid temporarily or moderate its electricity demand to suit grid conditions.

Driven by the development of electric vehicles, battery technology has progressed rapidly in recent years. The new ‘behind the meter’ batteries sit inside the house, with software systems controlling their charge and discharge cycles. Industry interest is growing rapidly. Last year, Tesla Motors announced a ‘Powerwall’ battery for domestic use, with the first UK installation in February this year. A British start-up, Powervault, launched its products in April with units that resemble a dishwasher.

Global players are also taking an increasing interest in electricity storage. Working with three British universities, E.ON is testing a 2 MW battery unit at Western Power Distribution’s Willenhall substation, near Wolverhampton. In May, energy company Total announced the acquisition of Saft, the French company specialising in industrial battery technology. In the same month, car maker Nissan announced plans to pilot its vehicle-to-grid technology in the UK, which will see car owners able to offer stored energy back to the grid.

Managing the peak demand for electricity has long been recognised as an essential element of the future energy mix in the UK. The challenge is moving from a centralised system to a dynamic smart-grid approach and ‘demand side response’, where businesses and consumers can manage their own demand and supply interactively.

Distributed energy storage could not only unlock benefits for the individual consumer but for the entire supply chain. With the right technology, market structures and regulatory framework, supply, generation and distribution companies also stand to benefit. Energy retailers will avoid peak charges by smoothing out demand. Most important of all, with a large enough network of commercial and domestic energy storage, operators will be able to draw on stored energy to cope with unexpected surges. Aggregated together, the nation benefits through the improved efficiency of the whole system.

In the corporate energy market, the focus is on innovative services to manage demand and link storage to the grid. Start-ups such as Open Energi offer their clients technology that enables them to reduce consumption minute by minute, releasing power to be used elsewhere, like a virtual power station.

Green Energy Options, based in Cambridge, is a start-up that develops home energy monitoring and control systems and is pressing for similar innovation in the residential market. The company published a discussion paper on residential battery storage in April that argues that from the consumer perspective alone the business case is weak. The real opportunity lies in finding innovative ways by which batteries can interact with the grid and share benefits.

Regulations will have to change as well. With more than 140,000 new homes being completed each year in England alone, the new house market should be an easy target for the promotion of energy storage. Building regulations in England, Wales and Scotland have been tightened up to encourage, or in many instances, effectively require microgeneration and increasingly high levels of insulation in new houses, but the regulations offer no credit for energy storage as an alternative to microgeneration.

On the engineering side, building trust will require simple interfaces that make it obvious what’s going on and allow consumers to override the system. Batteries need to be integrated with other electrical technology in the home, such as heating, domestic appliances and microgeneration systems. In addition, new control systems are needed that optimise battery use in terms of charge and discharge cycles over the battery’s lifetime.

Widespread roll-out of commercial and domestic energy storage could bring substantial benefits to industry and consumers. The transition to a dynamic grid is just the first step. Rapid development of the market requires an approach incorporating regulation, technology and the supply chain, aimed at building trust and changing behaviour among businesses and consumers if they are to fully embrace these new products and services.

Dr Scott Steedman CBE FREng