Despite the wide range of home energy storage systems available in the UK, consumers seem to prefer systems that offer performance and value for money over big brand names.
Many solar distributors and installers now cater to interest in residential batteries that can be coupled with solar PV systems.
To meet growing demand the range of available products is expected to increase in 2018 from existing players that are expanding their ranges as well as new brands that will soon be available for installers to get their hands on.
Following entry into the Irish market in 2017, German firm Solarwatt is expanding its UK sales team and is recruiting installation partners for its MyReserve Matrix battery system. The Nissan-Eaton partnership behind the xStorage Home system is also building its installer network over the coming months.
In addition to roll outs of its all-in-one energy storage system in partnership with local authorities in parts of the UK, including London and Yorkshire, Moixa has supplied over a thousand of its smart battery units for installation in private residences. The company’s 3kWh smart battery has proved the most popular system size.
The majority of Moixa battery installations – around 70% – comprise new PV plus storage investments while the rest are retrofits. A typical 4kW solar PV and 3kWh Maslow installation will cost in the region of £7500.00 (€8600.00).
The systems are also available as 2kWh and 4kWh versions. Later this year the company will extend the range to include 2.4kWh and 4.8kWh units.
While there is still the feed-in tariff (FiT), which is expected to come to an end in the first half of 2019 under its next review, customers can expect a Moixa system to pay for itself in year eight or nine.
Further savings on energy costs enabled by solar-plus-storage can be achieved when the home is on a variable rate tariff, so the battery can be programmed to recharge on cheaper off-peak electricity from the grid.
Moixa is unique in the UK as it has developed a virtual power plant (VPP) platform, allowing aggregation of individual units to provide valuable grid services. It passes back some of the revenues to system owners that allow their batteries to be pooled in this way.
Sonnen has also commercialised its own VPP platform, but only in Germany, where it has critical mass of deployed systems in homes.
In the UK market Solarwatt is introducing its latest generation MyReserve storage system, which was launched in Germany in 2017. The system starts at 2.2kWh, which can be expanded in the same increments, to appeal to households of different sizes, as well as small businesses.
According to Solarwatt’s international sales manager Pol Spronk, whereas self-consumption is a key driver for energy storage in Germany, lower retail rates for domestic customers in the UK mean that solar self-consumption, in combination with a variable tariff rate, enables homes to extract the best value from energy storage investments.
In the coming months, Solarwatt will also release an AC-coupled version, which will open up opportunities for solar retrofitting, which will be important for the company as it seeks to address all sales opportunities in the UK.
Like competitors Moixa and Sonnen, the company is looking to social housing landlords as a source of demand. In addition to its modularity and scalable design the system is packed with cell sensors and is protected in robust casing, to meet high levels of safety, all attributes that social landlords, including local councils, should find appealing.
Another new arrival on the UK residential battery storage market is made by Prime, a UK company that imports Chinese military grade lithium ion battery packs. The superior thermal properties of the rugged batteries mean the systems can be installed in lofts too.
The system is warranted to operate for about 12 years. According to one UK distributor, since it started supplying the Prime battery system in October 2017 the product is outperforming a German-made storage system the company has been supplying since 2016.