A look at

Battery-based energy storage has huge scope for decarbonising our power system. Rising electricity prices and decreasing technology costs are driving this market, while businesses and homeowners are becoming more aware of the environmental impact of their energy use.

Battery storage is fl exible, can be deployed quickly, has multiple applications and is expected to grow signifi cantly in the coming years. According to the Bloomberg New Energy Finance (BNEF) report, the global energy storage market will grow to 125GW between 2016-30. Policy Exchange has stated that a smarter power system that takes advantage of innovations such as battery storage could create savings of around £8 billion for the UK by 2030.

“Self-generation, buff ered through storage, is now achievable for homeowners – at a cost,” says Luke Osborne, energy and emerging technologies solutions advisor at the Electrical Contractors’ Association (ECA). “In the commercial arena, signifi cant savings can be made through the use of energy storage by reducing the periods when companies enter higher pricing regimes.”

Frank Gordon, head of policy at the Renewable Energy Association (REA), says opportunities to make savings already exist. “Th e two main applications at present are behind the meter in combination with solar and other on-site renewables, and large gridconnected applications at multi-MW scales,” he says.

Although there was a lot of talk about battery storage at the NICEIC & ELECSA Live South 2019 event, none of those questioned had installed DC equipment – and only one had any kind of storage device. “Cost is a barrier to entry,” says Paul Collins, Certsure technical services manager. “Once prices decrease, we will see greater adoption – but there also needs to be more awareness of the benefi ts to consumers in using battery storage, especially for the one million homeowners who have already invested in solar PV.”

POWER-PACKED

Batteries have management systems that off er a range of potential applications, such as storing excess energy generation from solar PV, purchasing cheap electricity at night and storing it for later, providing grid-balancing services and wholesale electricity trading, and providing back-up during a power cut. Solarcentury claims that the combination of solar, battery storage and a grid service tariff could cut the average electricity bill by 70 per cent.

BNEF’s ninth Battery Price Survey found that the average lithium ion (Li-ion) battery pack fell in price by 85 per cent from 2010-18 – a key factor in the growth of energy storage. “Th is has meant that storage has become economically viable in many areas,” says Richard Molloy, business development manager for energy storage at Eaton.

Flow batteries are increasingly used for large-scale installations. “Th e chemicals in a fl ow battery can be replaced, so their eff ectiveness can be maintained,” says Osborne. “Th ey also have the ability to be completely discharged and charged without long-term degradation, which isn’t the case with Li-ion.”

Th e challenge to create more eff ective battery technology is global. Th e UK government’s Faraday Challenge will invest £248 million into battery development initiatives, while the French government is putting £597 million into the manufacture of battery cells. Meanwhile, the German government has set aside around £900,000 to support battery cell production.

However, for Lior Handelsman, SolarEdge’s vice president of marketing and product strategy, more attention should be paid to inverters. “Th e inverter acts as the brain of the local energy system and as a facilitator between the local energy system and the grid,” he says. “An inverter’s ability to manage a battery for diff erent purposes, such as time of use, self-consumption, back-up and grid stability, has allowed batteries to become more functional and useful.”

125GW: THE EXPECTED SIZE OF THE GLOBAL ENERGY STORAGE MARKET BY 2030

BY ROB SHEPHERD

Locked up

Storing electricity and heat when it’s cheap and plentiful, then using it afterwards when supply is scarce or expensive, makes sense for householders, businesses and society

ONWARDS AND UPWARDS

For almost a decade, the government-backed Feed-in Tariff (FiT) scheme promoted renewable electricity generation and required participating electricity suppliers to make payments on generation and export from eligible installations. Th e scheme was closed in April 2019; while this is lamented by some, for others it means the government can focus on energy storage technology.

Th e link between renewables and energy storage can create a virtuous circle, says Delphine Clement, commercial and industrial building segment manager at Eaton. “Th e accessibility of energy storage technologies makes renewables a more viable option,” she says. “Businesses can save on energy costs, generate additional revenue and ensure greater power resilience. As more commercial organisations invest in energy storage, we’ll see increased fl exibility for the grid and a boost to the renewables sector.’

Solar Trade Association chief executive Chris Hewett is upbeat about what’s been achieved and what’s in store. “Solar technology is now well established in people’s hearts and minds, while related technologies like battery storage and electric vehicles (EVs) are generating fresh excitement,” he says.

HIT THE ROAD

Electric vehicles are becoming more common, and will soon require

Home help

SolarEdge off ers seven key pointers for specifying and installing residential battery storage:

• • The battery’s capacity needs to meet energy demands • • The battery’s charging and discharge rate needs to meet additional power generation. Th e transmission and distribution infrastructure may have to be upgraded by adding more capacity to transmit and deliver additional electricity during peak times.

Attention is turning to ways that battery storage can be used to power EVs, rather than feeding power back into the grid – both in domestic and commercial premises, and by placing battery storage at charging stations to reduce the capacity needed during on-peak periods.

Gordon believes the energy storage and EV sectors have much to gain from working together. “Energy storage will improve EV infrastructure, and be benefi cial in areas of the grid where constraints exist and users want to maximise the use of electricity they have generated themselves.”

But installing EV charging stations is expensive and, in addition to the cost of the charger itself, an upgrade to the grid connection may be required to accommodate the increase of a site’s capacity to manage peaks when cars are charging. “Using energy storage to support EV charger integration is a good way to mitigate costs by enabling peak shaving, cutting energy and reducing or even avoiding the need for grid connection upgrades,” says Clement. “Energy storage is fundamental to the proliferation of EV chargers, as it limits their impact on the grid.’

It is also interesting to note that ‘second use’ EV batteries are being deployed as storage devices in buildings, becoming a key part of the energy storage cycle.

MAKING A MOVE

Energy storage is opening up new opportunities for electrical contractors, who can combine it with renewables work. “Do your research,” says Osborne. “Although most manufacturers have installation guides and specifi cations on their websites, it’s worth speaking to them and arranging product-specifi c training.

“Manufacturers will sometimes off er enhanced warranties for trained installers and will often add them to their preferred installer lists. Th e Institution of Engineering and Technology (IET) also has a Code of Practice for Electrical Energy Storage (ISBN 978-1-78561-278-7), which off ers useful information.”

It is estimated that the National Grid spends £1 billion a year on balancing and managing energy demand and supply, so it is no surprise that combining renewables and energy storage is being explored so vigorously. Likewise, the International Energy Agency claims that heat accounts for around 50 per cent of world energy consumption, so storing solar-generated electricity as heat energy could lower carbon emissions. Th is is likely to be a prominent area during the coming years – and one that savvy electrical contractors can benefi t from.

owner demand • • The battery should have a high power rating • • The battery and inverter should have fl exible installation, warranted for both indoor and outdoor installation • • Both the battery and inverter should have longterm warranties

‘There also needs to be more awareness of the benefits to consumers in using battery storage’

£248M: THE AMOUNT THE UK GOVERNMENT IS INVESTING IN BATTERY DEVELOPMENT

£8BN: THE AMOUNT THAT COULD BE SAVED THROUGH HAVING A SMARTER POWER SYSTEM, INCLUDING BATTERY STORAGE, BY 2030

• • Select a DC-coupled battery system. This minimises energy loss as there are no additional energy conversions. In addition, it increases the amount of energy that can potentially be routed to the battery since the inverter does not act as a bottleneck • • Select a high quality inverter

Rob Shepherd is a freelance business journalist who specialises in the building services industry