Where does my energy come from? The UK's fuel mix

We tend for take for granted the electricity that flows from our sockets and switches, powering our lights and charging our mobile phones, and the gas that runs our boiler and fries our eggs-no matter how much we're paying for those supplies. Pay your utility bills (hopefully on a cheap tariff because you compare energy and shop around) and your television will turn on and your bathwater run hot-just as it did a decade ago and did for your parents in the 1970s.

But behind those sockets and gas mains, a revolution has been taking place in the way Britain powers its buildings. While electricity has stayed electricity-the same stuff that Benjamin Franklin conducted from storm clouds with a kite-and by and large, gas has remained natural gas (although now with increasing percentages of biomethane-more about that later), the way they're sourced has changed, as Britain undertakes a decarbonisation of its economy and infrastructure to meet the growing threat of climate change.

The renewable revolution

The fuel mix of our energy supply-where it comes from, basically-has become a politically charged issue for the nation, and for individual consumers. There are now a range of green energy suppliers offering renewable tariffs, with electricity generated exclusively from renewable resources and gas with a portion of biomethane, and they're a competitively priced option for consumers worried about the environment and their household carbon footprint.

Even if you're not ready to commit to a green energy tariff, when you compare energy you might want to consider the fuel mixes of the various suppliers on the market. Some will be more dependent on fossil fuels than other, which will increase your contribution to climate change and possibly drive up the cost of any variable tariff in the future, as financial penalties for burning fossil fuels increase.

For more information about the fuel mix of the nation's energy supply, and for your own individual supplier, read on:

National fuel mix

Ultimately, the energy that comes out of your sockets and pipes is the same stuff your weird neighbours are using for their lava lamps-no matter what type of electricity supplier and tariff you each have. Your personal electricity and gas aren't funnelled directly from your supplier. Rather, in taking on your contract, they've agreed to offset your annual use by feeding power into National Grid-either what they've purchased wholesale or generated themselves.

Years ago, if you followed the path of electricity upstream from your light bulbs back through the wires of the National Grid, you'd ultimately end up a coal-fired plant-belching smoke into our skies and carbon dioxide into our atmosphere. Today you're as likely to end up in an offshore wind farm and or a field of solar panels. Travel from your hob through the gas mains and you'll find pipelines from continental Europe, (controversially) fracking projects, but sometimes green gas farms' where domestic and agriculture waste is digested by bacteria to create biomethane.

Our energy infrastructure has dramatically changed: there is now more renewable energy capacity than fossil fuel capacity in the UK. Between July and September 2018, the UK had 41.9 gigawatts of capacity in wind, solar, biomass, and hydropower installations, compared to 41.2GW of capacity in coal, gas, and oil-fired plants-down over the last few years as old-style power plants have been decommissioned. There are now just seven active coal-fired plants in the UK and all are scheduled to be mothballed by 2025. The best way to save money on your bills is to do an energy comparison.

These remaining plants are mostly used during times of peak electricity demand-such as last year during the Beast from the East storm-and for load balancing. In 2018 coal generated just 5% of the UK's electricity, down from 42% in 2012. This has been matched by an increase in the percentage generated from natural gas-from 25% to 39%-but also a dramatic change in the portion generated from renewables, including:

For a total of 27% from renewable resources.

The performance of renewables was even better during the sunny months of the second quarter of last year, when the UK generated nearly a third (31.7%) of its electricity from renewable resources and just 1.3% from coal. In fact, the UK went a record consecutive three days in April without using any coal-generated electricity at all.

If you're curious about what resources are currently generated the UK's electricity, GridWatch provides live updates about the nation's fuel mix.

Progress in developing renewable alternatives to the natural gas that powers our boilers and hobs has lagged behind renewable sources of electricity, but some green energy companies supply natural gas that's around 10% biomethane.

Fuel mix of individual suppliers

Not all suppliers have transformed their individual fuel mixes at the same rate as the industry as a whole. Some suppliers continue to generate just 2.6% of their electricity from renewable resources, relying on gas to meet more than 60% of their demand.

Even among the Big Six which continue to dominate the domestic energy market, fuel mixes aren't created equally. Only British Gas surpasses the national average for share of renewable resources, at 43%. Competitors EDF and Scottish Power generate just 11.7% and 15%, respectively, of their electricity from renewable resources

However, there are now 15 green energy suppliers offering electricity generated only from renewable resources.

Your supplier should publish information about their fuel mix on their websites. You can also consult this list of the electricity sources of the UK's domestic energy suppliers and see how their mix compares to the national average for suppliers.

Most suppliers offer gas that is just natural gas. But several greenenergy providers source or themselves generate biomethane, feeding it into their gas supplies. These include