What is the grid?

As we all work together to help tackle the climate crisis, you'll hear the term ‘the grid’ more and more often. It's shorthand for ‘electric power grid’, a network of machines, substations, transformers and, of course, wires that links consumers and the electricity generators.

From microgrids to smart grids to the National Grid, grid talk can rapidly get confusing. Here's what the National Grid is, why a smart grid is so important and how microgrids can help the planet.

In most of the UK, the term 'grid' means the National Grid. The National Grid looks after transmission, sending high voltage electricity between substations. It does not generate electricity.

Put simply, electricity is generated using anything from coal to wind to tidal currents. Transmission substations change this electricity to a higher voltage and transmit it along the types of cables you'll see slung between pylons to transformer substations. These transform the electricity into a low voltage for distribution along the sort of wires you'll see on a city street to homes and businesses – overseen by Distribution Network Operators (DNOs).

But despite the name, the National Grid doesn't cover the whole of the UK. It looks after the electricity and gas network in most of Great Britain — meaning mainland England, Scotland, Wales and offshore islands. While Northern Ireland has its own grid, which links closely to the Republic of Ireland's grid.

For a low-carbon future, we don't just need a grid that uses less energy. We need a grid that can balance supply and demand for electricity, enabling us to use more renewables, as wind and solar power generation can vary dramatically depending on the weather and the time of year.

That’s where smart grids come in. A smart grid uses computer technology to monitor and control both electricity generation and electricity demand in real time, as well as minimising disruptions by healing itself when things go wrong.

The smart grid is still a work in progress, but you're already likely a part of it. If you have one of our electric vehicle home charge points, you'll know that your EV charger optimises charging to make the most of off-peak times. You've probably got a smart meter, too. As well as helping you monitor and reduce your own energy use, your smart meter feeds back anonymised data to the grid, enabling the system to predict and plan supply.

As the name suggests, microgrids are small, independent electricity grids. Microgrids are popular because they make homes, and businesses, less reliant on the grid for generating electricity.

They can be as big as a wind turbine farm to power a factory or a hydropower station for a mountain village, or as compact as a rooftop solar panel system with a battery in your home. With solar panels and battery storage, you can save the electricity you generate during the day to use at night. And you can get paid for any extra electricity you generate by sending back excess energy to the grid at times of high demand.

And that does more than save you money. It makes the main grid not just smarter but more resilient. This is essential in a future where, from the air source heat pumps that will warm our homes to the phones we depend on, ever more of our lives will rely on electricity.

At E.ON, we’re committed to helping our customers take action for climate – installing solar panels, air source heat pumps and electric vehicle charging points and providing all our E.ON Next customers’ homes with 100% renewables-backed electricity¹. 

^{1. Electricity backed by 100% renewable sources. Electricity sourced from E.ON's renewable assets, agreements with independent UK generators and the purchase of renewable electricity certificates. The electricity supplied to your home comes from the National Grid. Find out more at eonenergy.com/renewable}