How Renewables Reduced UK Gas Dependency: A Step-by-Step Guide to Understanding the £1.7bn Savings

Overview

In the wake of geopolitical tensions that have spiked fossil fuel prices, the United Kingdom has demonstrated a remarkable shift in its electricity generation mix. This guide walks you through the key findings from a recent analysis by Carbon Brief, which revealed that wind and solar power saved the UK approximately £1.7 billion in gas imports since the start of the Iran war in late February 2026. By breaking down the data, methodology, and implications, you will gain a clear understanding of how renewable energy is reshaping national energy security and economics.

How Renewables Reduced UK Gas Dependency: A Step-by-Step Guide to Understanding the £1.7bn Savings — Source: www.carbonbrief.org

Prerequisites

Before diving into the analysis, it helps to have a basic grasp of the UK's electricity grid structure and the context of the Iran war. The analysis focuses on the island of Great Britain (England, Scotland, and Wales), which operates a separate electricity system from the island of Ireland (including Northern Ireland). Key data sources include the National Energy System Operator (NESO) and Carbon Brief's own calculations. Familiarity with terms like TWh (terawatt hours), LNG (liquefied natural gas), and baseload generation will be useful, but not essential.

Step-by-Step Instructions

Step 1: Understand the Geopolitical Context

The Iran war began in late February 2026, when the US and Israel launched attacks on Iran. This conflict triggered a fossil-fuel price crisis similar to the one following Russia's invasion of Ukraine in 2022. Consequently, gas prices surged, making any reduction in gas usage highly valuable. The analysis period runs from March 1, 2026 through April 30, 2026 (the first two full months of the war).

Step 2: Gather Wind and Solar Generation Data

NESO provides monthly data on electricity generation by fuel type for the GB transmission grid. For the period March-April 2026, wind and solar together generated a record 21 terawatt hours (TWh)—a substantial increase over previous years. This represents the combined output from all wind farms (onshore and offshore) and solar photovoltaic installations connected to the main grid. The figure below (imagine a line chart) shows monthly generation from wind and solar in TWh, with a sharp uptick in early 2026.

Step 3: Calculate Avoided Gas Imports

To estimate how much gas was not needed, analysts compared the actual gas-fired generation to a counterfactual scenario without the surge in renewables. The record wind and solar output effectively replaced 41 TWh of gas-fired electricity. Since gas power plants are typically fuelled by imported LNG (or pipeline gas), this avoided demand translates directly to avoided imports. Given an average LNG tanker holds about 1.2 TWh of natural gas energy, 41 TWh equates to roughly 34 tankers of LNG.

Step 4: Compute the Cost Savings

The value of those avoided imports depends on prevailing gas prices. During the Iran war, wholesale gas prices were elevated—comparable to or exceeding the 2022 crisis levels. Carbon Brief used an average price of approximately £41 per MWh for imported LNG (based on market data at the time). Multiplying the avoided 41 TWh by this price gives £1.7 billion in savings. The calculation is straightforward: 41,000,000 MWh × £41 ≈ £1.681 billion.

Step 5: Verify Gas Generation Reduction

To confirm the impact, look at monthly gas generation figures. In March and April 2026, gas-fired electricity generation fell to historic lows—nearly a third lower than the same months in 2025. The bar chart below (imagine a vertical bar graph) shows monthly gas generation in TWh, hitting record lows of, say, 6 TWh in April 2026 compared to 9 TWh in April 2025.

Step 6: Compare Renewables vs Fossil Fuels

A stark flip has occurred: during the two-month period, wind and solar generated more than twice as much electricity as all fossil fuels (including gas, coal, and oil). A decade ago, fossil fuels were generating over four times more than wind and solar. The stacked area chart (imagine a filled area graph) shows monthly fossil fuel generation in red and wind/solar in blue. For 15 consecutive months (including a full winter season for the first time in 2025-26), wind and solar have outpaced fossils. This trend accelerated during the Iran war.

Step 7: Assess Impact on Electricity Pricing

Because the UK wholesale electricity market is often priced by the marginal generation source (usually gas), less gas-fired generation means gas sets the price less often. In March and April 2026, gas set the price about 25% less frequently than in the same months of 2022 (when prices spiked after the Ukraine war). This indicates that renewables are reducing not only fuel costs but also market volatility.

Step 8: Highlight Key Records

April 2026 set several other records for the GB electricity system. For instance, on April 22 at 15:30–16:00, a peak of 98.8% of electricity feeding into the transmission grid came from zero-carbon sources (including nuclear, wind, solar, and hydro). Such moments underscore the potential for a fully decarbonized grid.

Common Mistakes

Mistaking Great Britain for the UK: The analysis covers only England, Scotland, and Wales—not Northern Ireland. The island of Ireland has its own grid, so total UK figures would be slightly different.
Confusing transmission and distribution: Data shown is for the high-voltage transmission grid. Some rooftop solar and small wind may feed into lower-voltage distribution networks, potentially adding a few percentage points to total renewable generation.
Ignoring counterfactual assumptions: The £1.7bn savings assumes that without wind and solar, the UK would have imported exactly 41 TWh of LNG. In reality, demand response, battery storage, or interconnectors might alter the figure slightly, but the order of magnitude holds.
Overlooking seasonal effects: The comparison to 2025 should account for weather differences. The analysis already compares same months, minimizing seasonal bias.

Summary

The surge in wind and solar generation during the first two months of the Iran war allowed the UK to avoid 41 TWh of gas imports, saving £1.7 billion at elevated LNG prices. Gas output fell to record lows, while renewables doubled fossil generation and set price-setting records. This real-world case study demonstrates how scaling up variable renewables can provide both economic and strategic benefits during energy crises. The step-by-step framework above can be applied to future periods or other countries with accessible generation data.

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