How Big Box Retailers Can Go Green and Save 30% on Electricity Bills

Transform Energy Risk into Predictable Savings

This example is a typical use case for Wattstor’s customer success.

Facing strict grid limits and rising electricity costs, a multisite big box retailer needed a way to expand renewable generation without investing in costly infrastructure upgrades. The organisation also wanted to stabilise long-term energy costs and accelerate progress toward net zero.

Wattstor stepped in with an integrated clean-energy system; combining solar generation, battery energy storage, and a smart energy tariff that transformed volatility into predictable, measurable savings.

Project Snapshot

The Challenge

A leading big box retailer with ambitious sustainability commitments set out to decarbonise its entire UK portfolio of 100 sites.

The business needed a solution that would:

• Increase onsite renewable energy use

• Reduce grid dependence and boost resilience

• Prepare sites for scalable onsite solar generation and future energy technologies

• Support carbon neutrality targets by 2030 

At the same time, it faced rising electricity prices, operational pressure from growing demand, and the financial risk of volatile wholesale markets.

Without a smarter energy strategy, the business would remain exposed to unpredictable costs and escalating reliance on the grid.

The Solution

Wattstor engineered a fully integrated onsite energy system tailored to the site’s operational profile and grid constraints.

• Solar PV sized to maximise onsite generation (20 MWp)
• Battery energy storage to capture surplus electricity and discharge during peak demand (10 MWh)
• Intelligent EMS controls to optimise consumption, avoid export limitations, and support continuous operations
• Price Protect, Wattstor’s smart long-term tariff providing cost certainty with a 20 p/kWh cap fixed for 25 years

The Price Protect tariff blends the flexibility of variable market pricing with the certainty of a long-term fixed price cap ensuring the customer benefits from cheaper periods while remaining protected by a fixed 20 p/kWh cap.

Together, this approach delivers stable, low-carbon power without exceeding existing grid limits turning energy volatility into a manageable, strategic advantage.

With this integrated approach, Wattstor created an energy ecosystem that supports both operational performance and long-term sustainability.

Without Wattstor, the business faces unpredictable costs and escalating grid reliance. With Wattstor, they achieve stable budgeting, protect margins and accelerate decarbonisation.

The Results

This project fundamentally changed how the retailer manages and plans its long-term energy strategy. With Wattstor’s integrated system of onsite renewables, battery storage, and the Price Protect tariff, the business secured financial stability and operational resilience that traditional procurement models simply cannot deliver.

With energy costs fixed at 20 p/kWh for 25 years and 0% annual price increases, the organisation now has complete visibility over one of its largest overheads. This price certainty enables leadership teams to plan budgets with confidence, allocate resources more effectively and reinvest capital into core operations instead of defending against market volatility.

The onsite renewable system has also delivered significant environmental and economic impact. The solution generates substantial annual savings of £1.1 million, contributing to £27.4 million in net savings over the full contract term. At the same time, it reduces reliance on the grid and avoids 200,000 tonnes of CO₂ emissions, supporting long-term ESG and sustainability goals.

By combining predictable pricing, operational resilience and measurable carbon reduction, the retailer now benefits from a self-optimising energy ecosystem—designed to lower costs, stabilise operations and futureproof the business for decades to come.

Financial Benefits

Wattstor’s Price Protect solution goes beyond sustainability. It delivers financial resilience and control over one of the largest operational expenditures in any business.

• Budget certainty
  Predictable costs across the full 25-year contract term.
• Margin protection
  Stable energy prices improve profitability.
• ESG compliance
  Measurable CO₂ reductions feed into net-zero reporting.
• Futureproofing
  Insulation from market and policy volatility.
• Smart optimisation
  Automated control between solar, storage, and grid import ensures maximum value.

What This Means for Big Box Retailers

This case clearly demonstrates that big box retailers can achieve around 30% overall savings on electricity costs across the full contract term. At the same time, it enables them to strengthen their sustainability credentials through meaningful carbon reductions and clean onsite generation. By removing exposure to rising and volatile energy prices, retailers gain greater control over their operational budgets and reduce one of their largest financial risks.

The solution also helps retailers increase resilience across multisite portfolios, ensuring stable, reliable power even as operations scale. Ultimately, this approach delivers long-term financial stability and clear operational visibility, allowing retailers to plan confidently and invest in future growth.

By combining onsite renewable generation, intelligent storage, and a smart tariff, Wattstor enables large retailers and multisite operators to turn energy risk into predictability. The result is long-term price stability, carbon reduction, and a proven path toward operational resilience.

Contact our team: [email protected]