The UK water utility plans to pilot long duration energy storage in the second half of 2018, as part of an ambitious scheme to boost energy self-sufficiency.


As the biggest energy user in the east of England Anglian Water is more exposed than most to the heightened volatility in quality and quantity of energy supply as more renewables are connected to the distribution network. But rather than see this as a negative development, Anglian Water is moving towards increased self-consumption.

In 2017 the utility trialled an energy storage system made from second-life Renault electric vehicle lithium ion batteries at its Cambridge water recycling centre (pictured).

Next Anglian Water wants to explore the potential for long duration energy storage. The company is planning a pilot using flow battery storage, which will contribute to a roadmap it is developing towards energy self-sufficiency, on a 5-15 year horizon.

The second life battery project has shown the potential for energy storage for peak shaving. However, Anglian Water is now looking at how to fully integrate with renewables using longer duration innovative energy storage technologies such as vanadium redox flow batteries.

This will initially entail a small-scale pilot at one site, which will have a solar installation built later this year.


Redox flow batteries are designed to provide energy over several hours, rather than minutes (Image courtesy of Sumitomo Corporation)

Collaborating with an energy supplier and aggregator

The purpose of the pilot is to prepare Anglian Water for the future, so that it will be ready to effectively deliver and operate such a complex asset.

This entails forming a collaborative partnership with the flow battery storage system provider, an aggregator and Anglian Water’s electricity supplier.

The electricity supplier will help the water utility to identify future opportunities and develop a roadmap towards full integration of energy storage at its sites.

The aggregator will optimise energy storage to meet Anglian Water’s objectives and share information with regards to performance.

The energy supplier will also enable Anglian Water to find the best energy contracts to reduce bills and/or increase revenues and will potentially develop new products and contracts to help the water company to get the best of its energy storage asset.

There also plans to work with an electricity utility that overlaps where Anglian Water operates its water network.

Electricity networks used to operate as a simple one-way wire transporting power from the grid to the consumer. Electricity utilities, known as distribution network operators (DNOs), are becoming more strategic in how they manage grid-connected energy assets, including renewables, storage and microgrids, which requires evolving into distribution system operators (DSOs) to do localised grid balancing and other responsibilities that currently lie with the transmission system operator.

Anglian Water will work with a DNO and identify what incentives there are to support the DSO transition.

One DNO that manages electricity distribution in parts of the east of England and which has already embarked on key steps to prepare for its DSO role is UK Power Networks.

Increasing renewables self-consumption will be critical in enabling Anglian Water to reach its 2050 carbon neutrality goal, as well as increase flexibility and resilience against energy volatility and tap future revenue generation opportunities.

Most of the company’s renewable energy supply comes from a network of combined heat and power (CHP) plants fed by biogas generated at various sewage treatment works. However, Anglian Water is investing heavily in expanding its solar capacity so that by 2020, it will generated in excess of 60GWh/y of solar electricity across 150 sites, compared with just over 100GWh/y from its CHP generators.

As well as connecting storage to solar there are opportunities to connect storage to CHP engines that would enable Anglian Water to use more of its self-generated electricity for running sewage treatment works during the night time as well as at times of peak electricity usage, reducing energy costs.