Fuse Energy finished 2025 on over $400m in ARR, roughly tenfold growth driven mainly by customers after its mid-2025 gas launch.
Alan Chang says growth is constrained by engineering talent rather than capital, and doubling or tripling the engineering team would accelerate it.
Chang says Europe is making it hard to build through bureaucracy and that the median experience raising from a European VC is neutral to negative.
Fuse Energy tops $500m ARR, profitable and short of engineers
Fuse Energy grew roughly tenfold in 2025 after adding gas supply and is now profitable. Its founder says engineers, not money, set the pace. He treats the supplier business as step one toward owning the grid and eventually funding fusion.
Takeaways
Gas launch drove tenfold growth in 2025. Fuse ended 2025 above $400m ARR, up roughly tenfold, mainly from customers won after launching gas supply in mid-2025. About 85% of UK households have gas, a fivefold larger market. Price draws customers in, product and service keep them, and churn is minimal.
Engineering talent, not capital, limits growth. ARR passed $500m in 2026 with about 30% growth so far, which Chang calls not good enough. Headcount doubled from just over 100, with two or three engineering hires a month. Chang wishes the engineering team had tripled last year.
Fuse is profitable and runs lean. Profitable since December 2025 at single-digit millions a month, Fuse treats profit as secondary and takes a view of three to seven years on returns. Chang's costliest mistakes were $10,000 to $20,000. The company has no plans to raise again.
European VCs undervalue outlier outcomes. Chang says the median experience with a European VC is neutral to negative. One top-tier VC could not imagine a UK trillion-dollar company. European funds favour safe B2B SaaS, which pulls top engineers away from hard energy problems.
Chang is cautiously optimistic about Europe. The US has far larger talent markets and wealthier consumers, while European bureaucracy makes building hard. Pros still outweigh cons but the balance is closing. Chang would delete many policies line by line and add none.
Ireland, the US and micro solar next. Fuse expands to Ireland and the US this year but expects no meaningful revenue there in 2026. Micro solar and battery products, costing about $2,000 with a roughly three-year payback, are planned towards the end of the year.
Fuse's plan from supplier to fusion
Build a fully integrated energy company with existing technology.
Move downstream to own and optimise the grid. Recycling is a planned area because it is energy intensive.
Fund a fusion bet from the cash flow of the core business.
Fusion would take at least ten years and no one knows if it works economically. Chang says short-term investor pressure makes fusion companies fragile.
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