UK Data Centre

Site and Targets

Data centres are expanding at a pace that frequently outstrips grid capacity expansion, forcing operators to pursue creative solutions to meet demand and grow their operations. Given the complexity of integrating existing grid capacity with future expansion plans while maintaining the site's critical reliability requirements, Encast was selected as the modelling platform.

A tier 2 facility certification required the site to achieve N+1 redundancy with 99.74% uptime, a demanding standard compared to a typical industrial site. This necessitated integrating an existing battery backup system with new biodiesel generator systems, all while advancing the group's ESG commitments.

Project Challenges

The facility's energy profile presented distinct challenges. Compute usage remained relatively constant at 100MW with only 8% variation across the day, supplemented by office and facilities consumption of 250kW. The site currently relied on mains gas for baseload power, following typical UK grid usage patterns in its location in southern England.

The operational goals were ambitious and multifaceted. Energy resiliency required desensitizing the site from wholesale gas price volatility while diversifying energy sources. The facility needed to reduce outages, meet green energy targets for ESG compliance, and maintain critical uptime with zero dependence on the grid during energy outages. A 10-year plan called for midlife expansion to 150MW capacity; yet grid connection expansion from the current 105MW was infeasible, as upgrading would require a five-year application process and cost an eight-figure sum in GBP.

Technical barriers compounded these challenges. The existing energy model proved unreliable when modified, operated slowly, and contained numerous errors. Battery load shifting was unfeasible given the facility's constant demand profile. While grid upgrades were impossible, the site had secured approval for a feed-in tariff arrangement. Perhaps most critically, the very high uptime requirements left no margin for error.

Solutions

Encast enabled a sophisticated, multi-layered energy strategy. The solution leveraged an existing UPS battery system for seamless generator startup and switchover. Biodiesel backup generation was introduced gradually; by year five, both load and backup gensets transitioned to biodiesel to meet sustainability targets. Rooftop solar deployment began in year two, covering the facility's entire roof. A private wire connection to wind generation, capable of delivering 150MW, was established in year one, providing immediate clean energy access.

The platform's strength lay in its ability to rapidly evaluate numerous scenarios and potential solutions against one another. Real-time iteration enabled comprehensive sensitivity studies examining fuel and grid pricing impacts, allowing the team to stress-test different generator configurations and maintenance schedules. This granular analysis helped rule out suboptimal approaches early in the planning process.

For financing purposes, the model underwent intense scrutiny. Supply chain concerns were systematically evaluated through investigation of multiple equipment options. Financial backers gained confidence through detailed analysis using five-minute resolution views of critical model points, drilling down to understand the system's behaviour during peak stress periods. The combination of an inexpensive power purchase agreement with full-site generator backup and energy export capability delivered exceptional operational flexibility, ultimately improving financing terms and demonstrating robust risk management to investors.

Summary

This case illustrates how Encast transformed a complex data centre expansion challenge into a strategically sound, financially viable investment. Facing the practical impossibility of grid expansion, the platform enabled the team to design a resilient, multi-source energy system that would support both current operations and future growth while advancing ESG objectives. By facilitating rapid scenario evaluation, detailed sensitivity analysis, and granular financial modelling, Encast allowed stakeholders to confidently navigate competing priorities: cost minimization, reliability maximization, sustainability advancement, and supply chain risk management. The result was a 10-year roadmap that decouples the facility from grid constraints, provides multiple redundancy pathways, and delivers operational flexibility that strengthens both project economics and long-term resilience. All critical for a mission-critical infrastructure asset where downtime is not an option.