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Springhill, NS, Canada, (December 4th, 2023) – Surrette Battery Company Ltd. is pleased to announce Rolls 5000 Series 4-volt 4 KS 25P flooded lead-acid batteries have been selected for a substantial energy storage upgrade at Isle of Eigg.

Nestled in the Inner Hebrides of Scotland, the Isle of Eigg is renowned for its commitment to sustainability and use of renewable energy. A community-owned and maintained utility, Eigg Electric, was formed in 2008 and provides reliable power to island residents that is generated using renewable energy sources.

Prior to the formation of Eigg Electric, island inhabitants relied on diesel generators as their primary form of electricity. The initial off-grid system incorporated wind, sun & hydro power connected into four clusters, each connected to a bank of Rolls 4 KS 25P flooded lead-acid batteries in a 48-volt configuration. 

Reliable electricity has attracted more residents to the island. The number of full-time residents has increased by 70% since the system was installed. Now at 110, and with tourism bringing in more island visitors throughout the year, their energy storage requirements have also grown.

2023 system schematic

Upgrades have taken place over the years with the most recent completed in June 2023, replacing older system components (inverters / chargers) and adding additional storage. The next phase will incorporate 120 new 4-volt 1404Ah 4 KS 25P batteries to the system.

The initial banks of Rolls batteries installed in 2008 are still in operation and, with proper maintenance by the team at Eigg Electric, have well surpassed the 5-year full replacement warranty. However, they’re now nearing end of life and will be replaced as part of the next phase of the system expansion and upgrade in the Spring of 2024.

Eigg Electric tests specific gravity testing to ensure batteries are balanced and charging efficiently

With production and delivery of the batteries set in early Spring, the planned system upgrades and installation are scheduled for completion in March 2024.

Deep cycle lead-acid batteries are an old but proven technology. When properly maintained, flooded models are known to be reliable and continue to be the most economical form of energy storage, mainly due to their simplicity and lower cost of manufacturing when compared with other battery technologies such as lithium. Systems like the one installed at Isle of Eigg demonstrate the capability of lead-acid batteries in the renewable space, as well as the long-term performance and cycle life they offer.


About Surrette Battery Company

Manufactured in Springhill, Nova Scotia, since 1959, Surrette Battery Company Ltd. their premium flooded lead-acid models are distributed around the globe and continue to serve marine, rail & industrial markets and for use in renewable energy applications from small to large-scale off-grid systems and supplying backup power.

Surrette manufactures Rolls-branded batteries for marine and industrial use and the company continues to serve as a leader in the railroad space, supplying locomotive starting batteries to most Class 1 railroads in North America. Renewable energy markets worldwide now make up 50% of their business and models are offered in a variety of voltage and capacity options to suit the energy storage needs of small to large-scale applications.

From basic systems for lighting and refrigeration such as village electrification in developing countries, off-grid and battery backup systems for residential use, and large-scale migrogrid applications like the one at Isle of Eigg, this proven technology continues to offer affordable energy storage options.

For more information on Isle of Eigg and the Eigg Electric project: