National Grid ESO has set a goal of operating a zero-carbon electricity system by 2025. But what does zero carbon actually mean?

When carbon (CO2 or carbon dioxide) and other heat-trapping emissions are released into the air, they act like a blanket, trapping heat in our atmosphere and warming the planet. Conventional energy sources such as coal and gas produce carbon dioxide along with other gasses when burned in power plants.

Carbon-free means that a product or service produces no carbon emissions (e.g., a wind farm that generates electricity or a battery that provides power). Energy sources such as wind power, nuclear power and solar power do not produce carbon emissions when used to generate electricity - we refer to these sources as carbon-free.

This means that if the market only supplies us with electricity generated from carbon-free sources, we can run the system without having to use additional services that produce carbon emissions. So Britain's electricity will be carbon-free. 

Also don't get confuse between net zero and zero carbon, they both are different. Net zero is about offsetting or compensating for the carbon we produce. We reach net zero when the amount of greenhouse gases we produce is no more than the amount we remove.

Zero carbon refers to the emissions produced by a product or service - it means that no carbon is released at all. In the context of energy production, an example would be a wind turbine that generates electricity.

The goal is to run our country electricity system carbon-free, when the market supplies us with electricity exclusively from renewable sources.
Operating a carbon-free grid is an important step toward GB's 2050 net-zero target.