Holmston Farm BESS is a 50MW / 100MWh battery energy storage project located on land north-east of Holmston Roundabout, Ayr, South Ayrshire, Scotland. The site was previously used as a commercial Christmas tree farm.
The project received unanimous planning approval from South Ayrshire Council in June 2023, following a recommendation from the case officer. Construction began in summer 2025, and the project is expected to be fully operational by the end of 2026.
Envision Energy is supplying the containerised lithium iron phosphate (LFP) battery energy storage systems under a 15-year long-term service agreement. The project is being developed by RES (Renewable Energy Systems) and will be operated by Field, a UK-based clean energy company.
Project Overview
Project Name: Holmston Farm BESS
Developer: RES / Field
Equipment Supplier: Envision Energy
Capacity: 50MW / 100MWh
Location: Holmston Farm, near Ayr, South Ayrshire, Scotland
Status: 🔧 Under Construction (started summer 2025)
Expected Completion: Q4 2026
Planning Approval: Unanimously approved by South Ayrshire Council (June 2023)
Battery Type: Lithium Iron Phosphate (LFP)
Service Agreement: 15-year long-term service agreement with Envision Energy
Site History
The Holmston Farm site was previously used as a commercial Christmas tree farm. The project will be located directly adjacent to the existing Ayr substation infrastructure, where the project will connect to the grid. This strategic location minimises new infrastructure requirements and reduces visual impact on the surrounding area.
In its planning application, RES committed to significant biodiversity enhancements, including:
Planting of new native woodland
Creation of species-rich grassland
Creation of a pond for wildlife
Bat and bird boxes
Insect 'hotels' and other habitat enhancement measures
The project is expected to deliver a 15% biodiversity net gain.
Project Significance
Grid Stability: The BESS will provide flexible grid regulation services, helping to alleviate local grid transmission bottlenecks in the South Ayrshire region
Renewable Integration: Supports the acceleration of renewable energy adoption in Scotland
Long-term Partnership: Part of a broader collaboration between Field and Envision Energy in the Scottish market
Sister Project: Drum Farm BESS in Moray is being developed simultaneously under the same partnership
Land Use: Repurposes a commercial Christmas tree farm for critical energy infrastructure, with biodiversity improvements
Developer Background
RES (Renewable Energy Systems) is one of the world's largest independent renewable energy companies, with over 150 employees in Scotland alone. RES has developed and/or constructed 21 wind farms with a total generation capacity of 597MW in Scotland. The company also operates its Global Control Centre providing 24/7/365 monitoring for assets across the planet from its offices in Glasgow.
Field is a UK-based clean energy company focused on developing, building, and operating battery energy storage projects. The company is accelerating the shift toward a cleaner, more secure energy system in Scotland and the wider UK.
Envision Energy is a global leader in green technology, providing smart wind turbines, energy storage systems, and green hydrogen solutions. The company has a strong presence in the European storage market and is committed to delivering safe, reliable, and scalable energy storage technologies.
Project Timeline
June 2023: Planning permission unanimously approved by South Ayrshire Council
July 2025: Envision Energy supply agreement signed
Summer 2025: Construction commenced
Q4 2026: Expected completion and operation
Related Links
Information compiled from RES announcements, South Ayrshire Council planning documents, Envision Energy press releases, and industry reporting. Last updated: 18 April 2026.