The global conversation about clean energy is usually about solar panels and wind farms. The countries that have actually reached 100% clean electricity got there almost entirely without either.
According to Ember's yearly electricity data for 2025, Costa Rica, Ethiopia and Paraguay each generate 100% of their electricity from renewable sources, and Norway sits at 99%. (The list covers countries generating at least 5 TWh a year, to filter out very small grids.) For comparison, the world average is just 33.8%.
The catch: it's mostly water
Almost all of that clean electricity comes from hydropower — mountains, rivers and rainfall, not solar panels or wind turbines. Paraguay shares one of the world's biggest hydroelectric dams with its neighbours and produces vastly more power than it consumes. Norway's mountains and heavy rainfall have supported a hydro-based grid for decades. Ethiopia's hydro potential is large enough that the country has been building some of the biggest dams in Africa. Costa Rica combines hydro with geothermal, wind and solar to keep its grid renewable.
These countries didn't primarily get to 100% through ambitious climate policy; they got there because their geography happens to be extraordinarily well suited to hydroelectric dams.
Why that matters for everyone else
The distinction is critical for any country trying to copy the result. A flat, dry country can pass all the renewable-energy legislation in the world and still not have the rivers needed to replicate Costa Rica's number. Geography set the ceiling — policy just decided who reached it.
So the useful question is not "why don't other countries do what Norway did?" It is "what does the equivalent of a mountain-fed river look like in a country without them?" For most of the world the answer is a combination of solar, wind and storage, plus transmission across borders.
The world average, and what it hides
At 33.8%, the world average sounds low — but that figure is a blend of countries with an enormous range. It includes places with near-complete hydro or geothermal grids and places that still run almost entirely on coal or gas. And it is rising as solar and wind become the cheapest new sources of power in many markets.
Hydro isn't free of trade-offs
A grid at 100% renewable electricity does not necessarily mean a low-impact grid. Dams reshape rivers, displace communities and can be vulnerable to drought: when rainfall fails, hydro-dependent countries can face shortages. That is why even the leaders keep diversifying — Costa Rica's mix of geothermal, wind and solar is partly a hedge against a dry year.
What the data tells us
Three things stand out:
- 100% is achievable — but today, only at the scale of small and mid-sized grids with unusually good natural resources.
- The countries that got there did it mostly with one technology, which is not a model most countries can follow.
- The next wave will look different: solar, wind and batteries, not rivers.
Data: Ember — Yearly Electricity Data (CC BY 4.0), data year 2025, countries filtered to those generating 5+ TWh.
