Sweetch img main

Sweetch Energy

Providing fully renewable baseload energy

Sweetch Energy pushes the frontiers of science to develop truly renewable, baseload and competitive electricity.

Sweetch img 2
Sweetch img 3
Their mission
Apply nanotechnology breakthroughs to fight climate change
Challenge
Accelerating sustainable energy
HQ
Rennes, France

Their UVP

Sweetch Energy generates renewable baseload power from osmotic energy, the pressure released where fresh water and saltwater meet. Its INOD technology turns this into continuous electricity that runs day and night, without the intermittency of wind and solar.
Sweetch img 4
Grand challenge

Accelerating sustainable energy

30,000 TWh
Of natural osmotic energy released every year by river deltas and estuaries worldwide, greater than total annual global electricity demand of around 27,000 TWh
20%
of global electricity that osmotic systems could eventually supply, around 5,177 TWh a year (WEF)
500 MW
targeted carbon-free capacity at the Rhône delta, enough to power more than 1.5M people, the size of metropolitan Marseille

Energy is responsible for roughly 75% of global greenhouse gas emissions. As the world population climbs toward 9.7 billion and more people enter the middle class, demand will only grow, potentially doubling or tripling by 2050, exactly as we try to decarbonize our grids and industry. The single most important move to prevent a climate emergency is to power the world with reliable low-carbon, or no-carbon, energy.

Decades of investment have driven the price of solar and wind down sharply, but both carry well-known limits. Seasonal intermittency, combined with storage that remains prohibitively expensive, means a reliable grid still needs another form of baseload generation. Weather and geography shut many countries out entirely. Where sun and wind are abundant, the parks are often far from cities, requiring costly transmission and distribution. And centralized, outdated infrastructure means we waste much of the renewable power we already produce.

Baseload is the missing piece. Solar and wind can supply the energy, but a stable grid needs a source that runs continuously and predictably, day and night, in any season. Today that role falls to fossil fuels and nuclear. Filling it with a renewable alternative is what turns an intermittent grid into a fully decarbonized one. Most candidates fall short: hydro and geothermal depend on specific geography, biomass competes with land and food, and large-scale batteries remain too costly to carry a grid for long. A genuinely scalable, geography-independent baseload renewable has stayed out of reach. This is the gap that matters most, because without it every grid keeps a fossil or nuclear backbone, and the renewables we add only ever displace part of the problem rather than solving it.

As we work toward our climate goals and a more sustainable world, developing new renewable energy sources is no longer optional.

Why did we invest?

First osmotic power station live, €50M raised to date

Sweetch founders
FOUNDERS
Sweetch founder 2
Nicolas Heuzé, co-founder & CEO
Sweetch founder 1
Bruno Mottet, co-founder & CTO
Sweetch founder 3
Pascal Le Melinaire, co-founder & Chairman

We have long been curious about the unexplored potential of oceans, and when we met Sweetch Energy that curiosity met water's potential as a renewable power source. A handful of companies have tried to harness the ocean's mechanical energy through tidal or underwater turbines, but very few have gone after its osmotic energy, the energy naturally released when fresh river water meets seawater.

Unlike most renewables, osmotic energy is base-load, continuous and predictable, a potentially groundbreaking addition to the global energy mix. Lab tests worldwide had proved promising, but no commercial experiment had succeeded: the power density of the membranes at the core of the system was too low to generate electricity at a competitive price.

Sweetch built on breakthroughs in nanotechnology to develop nano-osmotic diffusion, generating immense currents from salinity gradients at the nanometric scale, exceeding incumbent technologies by two orders of magnitude. After years of refinement, its membrane is 20x more powerful and 10x cheaper than existing technologies, enough to project osmotic systems cost-competitive with other renewables. This was made possible by a complementary, experienced team that has built and exited companies in complex, regulated industries.

Sweetch has moved from lab to field, signing agreements with some of the world's largest energy producers to develop the first osmotic power plants. In December 2023 it secured a 25M euro Series A led by Credit Mutuel Impact, with Axeleo Capital joining existing investors EDF Pulse Ventures, Demeter, Go Capital and CNR, taking total funding above 50M euros including a 2.5M euro European Innovation Council grant.

At the end of 2024, the OPUS-1 demonstrator at the Barcarin lock in Port-Saint-Louis-du-Rhone became operational, the first osmotic power station to generate electricity continuously at industrial scale, followed by a first production unit in Rennes in May 2025. In July 2025, the World Economic Forum named Sweetch a Technology Pioneer, recognizing osmotic power as one of ten global emerging technologies.

CO-INVESTORS
  • Y10 Sweetch Go Capital 160px
  • Demeter Logo
  • Cnr Logo
  • Edflogo
  • Y10 Sweetch Axeleo Capital 160px
Hear more
on the company
Push video Sweetch
play video
Close
  • CHALLENGE
  • WHY DID WE INVEST?
Sign up here to receive news & insights