Most small-scale gasifiers are built for clean wood chip 1 , because the ash in fuels like straw, household waste and sewage sludge melts into slag that can block the reactor and stop the plant. 2 That leaves crop residues and household rubbish to the cheapest routes: dumping, landfilling or burning in the open. 3 These add to greenhouse gas emissions and harm the environment and people's health. 4
Jenja is a machine designed to turn difficult waste into energy.
Crop residues, household waste and sewage sludge are hard to turn into energy: their ash melts into slag, so most small gasifiers only run on clean wood chip. 5 The waste goes the cheapest way instead. 6 An estimated 41 % of the waste generated worldwide is burned in the open, releasing pollutants that harm people's health. 7 At the same time, 655 million people still had no electricity in 2024, most of them in Sub-Saharan Africa. 8 Off the grid, the usual answer is a diesel generator, with fuel that is costly to transport 9 and exhaust that causes lung cancer. 10 Jenja is designed to bring the two together: local energy from local waste.
In the Paris region, two public bodies deal with what millions of people leave behind: Syctom handles household waste, and SIAAP treats wastewater. Together they set up COMETHA, a programme to find better ways to turn sewage sludge and the organic part of household waste into energy. 11
Our earlier, smaller test unit, the X10, took part. It was fed digestate pellets, the material that remains after waste has been turned into biogas, and turned them into a fuel gas. That means even the leftovers of biogas production can become a source of energy. Jenja is designed to take that work further, at a larger scale.
One feedstock can create several potential pathways, but they compete for the same carbon and energy. More carbon directed to char means less carbon available as gas. More gas sent to hydrogen means less gas burned for power.
Each pathway follows the chain from what Jenja is designed to produce to the change it could make on the ground.
Jenja is designed to turn residue a site already holds into its own electricity and heat, so supply no longer waits for a fuel delivery.
Explore the impact →Heat that would otherwise be lost could drive cooling and pasteurise water, so cold and safe water need no extra fuel.
Explore the impact →A suitable site could cut what it spends on diesel, grid power or coal, and with it the exposure to a price it does not set.
Explore the impact →The material becomes the input instead of a disposal bill. What that is worth depends on what happens to it today.
Explore the impact →Part of the carbon leaves as a solid rather than as gas. Whether it stays locked away depends on tests we have not run yet.
Explore the impact →We separate what we have shown from what could happen.
An avoided emission is not something you can measure in a pipe. It is the difference between what happened and what would have happened instead. Unless the second half of that sentence is written down, the first half cannot be claimed. So we do not publish a single overall impact number, and we do not add these pathways together.
We show a pathway only if it names what it replaces. Method source: WBCSD, Guidance on Avoided Emissions , which requires what would have happened otherwise to be defined before an avoided emission is reported.
Nothing in the evidence centre is a sales document. Where a data sheet is not yet published, the entry says so, and the claim that depends on it carries a state rather than a number.
If you are a researcher, an investor doing diligence or a grant reviewer, the methodology page is written for you: ten steps, in order, with the uncertainty published rather than smoothed.
Open the evidence centreUnderstand the impact pathways and where the commercial potential sits.
Explore potential applications in energy access, water, waste and local resilience, with the deployment dependencies named rather than hidden.
Explore difficult feedstocks, energy substitution and waste-management pathways, and see which of them we have actually processed.
Access the assumptions, the methodology and the sources, including the parts that are not finished.
Every real impact claim starts with a real baseline.
A global figure tells you nothing about your operation. What decides your number is the residue you hold, what you pay for energy today and what would otherwise happen to that material. Tell us those three things and we will tell you whether the pathway is one we can support.