What’s the typical return on investment (ROI) for solar in Guernsey?
The typical ROI for a solar PV system in Guernsey ranges from 5 to 15 percent, depending on your home, your system size, and your daytime energy use. Solar offers one of the strongest, most stable long-term investments available to island households.
What affects your ROI?
1. How much high-rate electricity you offset
Every kilowatt-hour of solar you use at home instead of buying at the high-rate tariff gives you immediate financial benefit. The more high-rate usage you can shift with solar, the higher your return. As well as this exporting your surplus energy also gives you additional financial benefit. So this combination is what will ultimately give you your return.
2. Rising electricity prices
Each time electricity prices increase, your ROI improves. In recent years prices have risen sharply and are expected to continue that upward trend as infrastructure costs and global energy prices rise.
Solar vs money in the bank
Savings accounts rise and fall, and inflation erodes value. Solar, by contrast, delivers a guaranteed reduction in your living costs for 25–30 years. As grid prices rise, your returns rise automatically. It’s one of the few investments that becomes more profitable the more expensive energy becomes.
What about lifetime financial benefit?
Over 30 years, even a modest solar system can save tens of thousands of pounds in avoided electricity imports. And unlike traditional investments, solar delivers returns every single day — unaffected by markets, interest rates, or global uncertainty.
Your roof becomes a long-term financial asset.
But what’s the payback?
We say payback doesn’t matter so much, it’s the ROI that counts! But looking at systems Renew installed many years ago, clients report to us their payback typically occurring between 8–12 years. And that’s using older, less efficient technology compared to the more efficient and lower cost systems of today.
Some homes experience faster payback, some a little longer, but every system continues producing free energy long after payback is achieved.
And what’s the real payback?
Beyond savings, inflation protection and energy security, there is a return far more valuable than money!
A liveable planet.
Without a stable climate, there is no economy, no infrastructure, no security and no future to build toward. Solar is not just a financial decision, it’s a climate decision — a step toward preserving a world in which homes, businesses and communities can continue to thrive.
Every system installed reduces emissions, strengthens local resilience and contributes to the island’s path toward a zero-carbon future.
Financial ROI is of course important. But the ultimate return is ensuring there is a stable, habitable future at all. Ensuring there is a future worth calculating ROI for!
Climate adaptation will cost us all — mitigation is the path to protection
For islands like Guernsey, climate adaptation isn’t an abstract future issue, it’s a financial one. Rising sea levels, stronger storms, flooding, coastal defences, infrastructure reinforcement and pressure on food and water systems all carry enormous costs that society ultimately pays for. Every year we delay mitigation, those adaptation costs rise — for households, for businesses and for government.
That’s why reducing emissions now is not just environmentally responsible, it’s economically essential. The more we can mitigate today through renewable energy, electrification and efficiency, the less we will have to spend tomorrow on defending against the consequences of a warming world. Every solar panel, every heat pump, every battery and every kilowatt-hour of clean energy generated on-island helps slow the curve, protect our infrastructure and reduce the long-term financial burden on society.
Mitigation is the most cost-effective form of adaptation. The cleaner we become, the more resilient we remain — and the less we all have to pay.
A glimpse into a future powered by 100% Renewables
As solar, batteries and electrification become ubiquitous, the island accelerates toward an economy powered by near-zero-cost energy.
In that world, it goes beyond ROI, it becomes a societal shift.
Sunlight is free, and once the infrastructure exists, the cost of producing each new unit of electricity falls away. Over time this makes energy super cheap, near zero for everyone, strengthens the local economy, boosts competitiveness, reduces household living costs and increases resilience across the island.
The cost of everything powered by that energy becomes cheaper for everyone — and your decision to install solar helps bring that future closer.
