Chapter 1/3: How we’re slashing up to 450 tons of CO2 per year with only 2000+ laundries and no budget

Adrien de Vriendt
7 min readFeb 13, 2023


This post belongs to a 3-post series gathering my learnings after 18 months as a ClimateTech founder at adapt. I hope sharing my experience will help others trying to avoid climate chaos.


  • We can forecast when electricity will have the lowest carbon footprint, for every ‘grid’ (or electricity system) on the planet
  • The ClimateTech adapt shows the ‘low-carbon hours’ forecast in various areas in a user-friendly tool used by 2,000+ adapters (adapt users) to plan and postpone the consumption of energy-intensive electric devices (mostly laundry, dishwasher & EV charging)
  • Depending on the methodology used, adapters collectively reduce between 50 and 450 tons of CO2 per year

Introduction: how is electricity produced?

Art, or the backbone of our industrial civilisation?

To simplify it, there are three main ways of producing electricity, each with a significantly different impact on the environment:

  • Variable low-carbon: produces electricity out of the sun and the wind (~8% of world electricity)
  • Base-load low-carbon: produces electricity from renewables sources (deep geothermal, hydro & biomass) or nuclear fission (~28% of world electricity)
  • Fossil: produces electricity out of the combustion of fossil energy, representing the main source of electricity worldwide (~63% of world electricity)
The three main types of electricity

In most world electrical systems, electricity is produced out of a mix of these 3 types, resulting in different shares of fossil electricity (except in a few places very rich in renewable energy sources, like Quebec, Norway or Iceland that produce +95% of their electricity from hydro & geothermal).

Getting rid of fossil energy asap, in electricity (which represents ~25% of anthropogenic greenhouse gases (GHG) emissions with heat), and in energy in general (which represents ~80% of anthropogenic GHG emissions), is humankind’s #1 priority.

Snap back to (physics) reality: 100% renewable electricity does NOT exist in most areas

Despite numerous claims by energy retailers (here or here), 100% renewable electricity is not a physical reality in most electrical grids (these claims only exist thanks to an accounting system that allows the purchase of renewable energy certificates without any time or geographical correspondence).

Why? For two reasons:

  1. Electricity production and consumption must always be balanced to avoid a black-out
  2. There’s no large-scale solution for energy storage yet

The consequence of these two truths is when there’s not enough low-carbon electricity (e.g. no wind at night), the share of fossil electricity increases because fossil-fuel back up power plants are asked to produce the ‘marginal’ extra electricity by the electrical system operator.

Everything is balanced, including the electrical grid

Carbon intensity of electricity varies from one hour to another

Carbon intensity is a measure of how clean our electricity is. It refers to how many grams of carbon dioxide (CO2) are released to produce a kilowatt hour (kWh) of electricity. (National Grid)

The share of fossil electricity impacts carbon intensity: the more dirty fossil energy we need to meet demand, the dirtier electricity will be. As a result, carbon intensity changes from one hour to the next.

There are 2 methods to calculate carbon intensity:

  1. The average carbon intensity: what’s the difference in the average carbon intensity (weighted average of the different electricity sources) in a specific electrical grid?
  2. The marginal carbon intensity: what’s the climate impact of the last marginal fossil power plant used to produce extra electricity to balance the grid? As most of European national electrical grids are ‘interconnected’, the marginal power plant could be in a neighbouring country exporting electricity.

Both methods to calculate carbon intensity have their pros and cons (sparking an intense debate among a few carbon intensity ayatollahs) that I’ll refrain from detailing here to keep my post accessible. This article gives some insights on this topic.

Good news: we can predict when electricity will be the cleanest

The idea of adapt came to me as I was riding my kite-surf board. Similar to how weather apps provide wind & weather forecasts at every kite-surf spot of the world (like windguru or windy), we can forecast everywhere (or, in every electrical system) when electricity will be the cleanest.

Why? Because weather forecasts have a huge impact on both electricity consumption AND variable low-carbon electricity production, and hence on the carbon intensity of electricity.

Plan your electricity consumption when electricity is least carbon-intense

At adapt, we connect to various datasets to estimate when the share of fossil energy (carbon intensity) will be the lowest in the next hours / days in various electrical grids in Europe and in the Caribbeans. We invite our end-users to adapt their electricity consumption accordingly.

Our objective is to shift the electricity consumption of our adapters to hours when electricity has the lowest carbon intensity. By doing so, we can avoid firing up the world’s most polluting and deadly power plants, like coal power plants in Europe.

The collective direct climate impact of adapters

Our collective direct impact on CO2 reduction is the sum of every single action of postponed electricity consumption (e.g. the laundries planned when carbon intensity was the lowest within the next hours / days).

As we don’t precisely track when adapters consume (and don’t consume) electricity (technically feasible with smart-meters as we’ve done in continental France), we must estimate our impact.

The number of adapters who’ve changed their electricity consumption behaviour

Since September 2022, approximately 2,000+ different people have visited adapt on a weekly basis to plan their electricity consumption.

Daily traffic (couldn’t import weekly report sorry)

The electricity-reliant tasks planned and postponed by an adapter

Each household has a different energy consumption profile, and a different potential for electricity consumption potential. These parameters depend on a large number of factors (geographical, physical, social, economic etc.).

How much electricity can you consume when electricity is least carbon-intense?

Based on registered members’ data and adapters feedback, we assume the following:

  • >95% of adapters have one laundry and one dishwasher at home
  • >20% of adapters that own a car have an EV or a plug-in hybrid EV
  • ~75% of yearly laundries/dishwashers and EV charging sessions are planned with adapt

As a result, we estimate that the average adapter postpones ~750 kWh/y. This represents ~12% of EU average electricity consumption for a 4-person household (Eurostat, 2020).

NB: under-estimate factor: other devices (e.g. e-scooters, e-bikes, etc.) are not counted ; over-estimate factor: since EV charging tends to take multiple hours (and therefore experiences varying degrees of electricity cleanliness), the potential carbon intensity delta could be lower compared to a postponed laundry/dishwasher run.

The carbon intensity variation potential

To estimate how much CO2 could be saved by starting a dishwasher at the right time instead of the worst time, we must estimate how much carbon intensity could diverge within a specific period : the carbon intensity variation.

Below are the values we used to estimate the impact of postponing electricity consumption by a few hours/days (in gCO2e/kWh) in selected electrical grids, for the 2 carbon intensity calculation methods.

This is an estimate obviously

Regarding the geographic distribution of adapters, we assume the following:

  • ~80% of adapters are based in continental France
  • ~20% of adapters reside elsewhere, with Belgium and Germany representing the majority of these users (50%), followed by Switzerland, Guadeloupe, Great Britain, Spain and Italy (+ other locations)

The result of our collective action

Based on the previous assumptions, we assume our direct climate impact is about 50–450 tCO2e/y.

Thanks to our community, we directly reduce GHG emissions from electricity consumption! Furthermore, we know exactly how to achieve a massive impact (e.g. at a ~MtCO2e/y):

  1. By growing the community
  2. By increasing the electricity consumption postponed, with automatic smart charging of EVs or electric boilers automation for instance
  3. By extending our service to carbon-intensive electrical grids (most countries unfortunately) and targeting the most polluting coal power plants: lignite power plants

The question then becomes: how to build a sustainable business out of it? Answer in the next chapter!



Adrien de Vriendt

I write about energy & climate. Founder of adapt, the live & forecast climate impact of electricity.