Scottish Water taps into solar to run wastewater treatment day and night

TECHNOLGY UPDATE

Scottish Water has completed its first large-scale battery storage project as part of a £2 million renewables project which includes the company’s largest single solar energy array to date at the city of Perth's wastewater treatment works.

This installation is the latest investment by the utility’s commercial subsidiary, Scottish Water Horizons, who are developing a programme of opportunities for battery storage across Scottish Water’s asset portfolio.

The storage project comprises four 0.8 MWh vanadium flow batteries. They will be used to store power generated from the 1MW solar array. This will enable the Perth wastewater works to use around 94% of the solar energy generated to be used at any time of the day or night.

The combination of battery storage and solar power will:

• contribute to the utility’s rapid electric vehicle charging points which have been installed at the site;

• reduce energy costs of the treatment works by approximately 40%.; and

• cut the treatment works’ annual carbon footprint by 160 tonnes of carbon dioxide.

The batteries were manufactured by Invinity Energy Systems at it West Lothian facility and delivered by framework contractor, Absolute Solar and Wind. Scottish Water claimed that Invinity’s patented vanadium flow battery technology “is already making its mark in the energy storage market world-wide as a safer, more durable and sustainable alternative to traditional lithium-ion batteries.”

The battery software and control system that coordinates the production, storage and release of the energy generated, was supplied and installed by Open Energi,