Modeling Resilience Across a Diversified Energy Portfolio with PLEXOS®

Centrica operates across the UK, European and Nordic energy landscape, from residential supply under British Gas to a global optimization business that trades LNG cargoes and manages a virtual power plant spanning nearly 20 gigawatts. Its infrastructure arm holds a growing mix of gas storage, batteries, combined cycle gas turbines (CCGTs), solar, and a share of the UK's nuclear fleet, alongside a newly acquired LNG import facility. That breadth gives Centrica a genuinely global view of energy markets, and it also means that any single investment decision must hold up against a huge range of possible futures, from UK policy shifts to disruptions in international gas supply.

To make sense of that complexity, Centrica is building a strategic planning framework anchored in PLEXOS®, designed to turn a sprawling, uncertain picture of global energy markets into decisions the company can stand behind, whether it's boosting flexible generation capacity or expanding its LNG footprint.

Building Consensus Before Building Models

Before Centrica could put PLEXOS® to work, it had to answer a harder question.

How does an organization with this many moving parts agree on what the future actually looks like?

Ten years ago, energy scenario planning was a relatively contained exercise. Today, macroeconomic shifts, geopolitical instability, and the diverging pace of decarbonization across regions have made it a genuinely global problem, and Centrica's various business units did not start from a shared set of assumptions.

The goal wasn't simply to purchase modeling software. It was to get every part of the business, from retail to trading to infrastructure, aligned on a consistent set of views about affordability, decarbonization, security of supply, and system flexibility. Without that foundation, any modeling built on top of it would rest on inconsistent assumptions and carry little weight with the board, investors, or lenders.

A Four-Tier Framework Powered by PLEXOS®

Centrica's answer took the shape of a four-tier framework, with PLEXOS® modeling embedded at every level.

At the base sits the Centrica House View, a central repository of the company's positions on the markets it operates in. Rather than relying on external forecasts, Centrica maintains its own consistent narrative on decarbonization, affordability, and system needs, one that ensures a consistent story whether it's being used internally or shared with external stakeholders. That view is organized around four themes, including customer affordability and technology adoption, the pace of decarbonization and dependence on fossil fuels, the security of supply challenges tied to gas storage and an aging CCGT fleet, and system needs such as battery and long-duration energy storage capacity.

Building that view meant looking well beyond the UK. Centrica partnered with Columbia University to map how global macroeconomic power is shifting, grouping countries into petrostates such as the US, the Gulf states, and Russia, electrostates led by China and increasingly India, and energy importers including the UK, the EU, Japan, and Korea. That global lens matters because Centrica's exposure to gas markets is no longer a domestic story. A heatwave in China or a shift in US export policy can move the gas available to the UK just as much as a domestic policy decision can.

From that foundation, Centrica developed six scenarios, including named world views like Global Fragmentation, Net Zero, and Tech Driven Growth, each is being built out into granular PLEXOS® models alongside a complementary tool used to analyze global LNG markets. The two are used together to translate global storylines into their UK power and gas market implications.

The next tier, Portfolio Analysis, uses those scenario outputs to identify which asset classes Centrica should be targeting and to test how the existing portfolio holds up across different futures. A mix that performs well under one scenario might underperform badly in another, and that stress-testing shapes decisions about where to divest or invest further. Strategic Development sits alongside it, using the same scenario library to sharpen Centrica's broader strategic outlook. At the top of the pyramid are the Asset Investments themselves, the point where all the modeling, scenario work, and portfolio analysis translates into actual capital decisions.

From Scenario Analysis to Multi-Million-Pound Investment Decisions 

The framework's clearest payoff shows up in two recent acquisitions. Centrica's purchase of the 850MW Severn Power Station was directly informed by PLEXOS® modeling, with the valuation grounded in scenario-tested projections rather than a single base case. Centrica and ECP's acquisition of the Isle of Grain LNG terminal drew on the same scenario methodology, weighing the wide range of possible outcomes for UK gas throughput and what that variance would mean for the asset's long-term value.

Beyond the individual deals, the framework has changed how Centrica explains its decisions to the people who need convincing. Being able to show a board, a lender, or an investor exactly which scenarios were tested and how an asset performs across each of them is a fundamentally stronger position than presenting a single forecast and hoping it holds. When circumstances shift, whether that's a supply shock or a change in the pace of decarbonization, Centrica can point to the relevant scenario and explain how its strategy adapts, rather than being caught defending a plan that no longer fits reality.

Resilience as a Continuing Discipline 

Centrica's PLEXOS®-powered framework reflects a broader shift in how energy companies need to plan. A single fundamental forecast is no longer good enough in a market shaped by geopolitical shocks, diverging regional decarbonization paths, and increasingly global gas dependence. By grounding its scenarios in a shared house view, stress-testing its portfolio against six distinct futures, and tying its asset investments directly to that modeling, Centrica has built a planning process designed to hold up under pressure rather than one that assumes a stable, predictable path forward.

That process continues to evolve alongside the markets it's built to navigate. As the energy trilemma of affordability, security, and decarbonization keeps shifting, Centrica's PLEXOS®-based framework gives it a way to keep testing its assumptions rather than being locked into ones that were only ever meant to be a starting point.