Our sustainability and solutions jargon buster

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With climate change and global warming among the biggest challenges we’re facing globally, it seems like everybody's talking about sustainability and renewable energy. And many of us are already trying to do our part to help cut carbon emissions and protect the environment.

But technical jargon can sometimes make it difficult to understand exactly what's being said when discussing how you can become more sustainable.

So we’ve pulled together a helpful jargon buster including common buzzwords relating to sustainability to help you make sense of it all.

We’ve also including some of the solutions that can help you become more sustainable today.

100% renewable electricity

Electricity from renewable sources means it’s been produced from natural sources including the sun, wind and biomass. Powering our homes with renewable electricity has many advantages and, unlike fossil fuels such as coal, has a small carbon footprint.  

At E.ON we provide all our residential customers’ homes with 100% renewable electricity as standard and at no extra cost1.

Air source heat pumps

Air source heat pumps are a cleaner option to other forms of heating. They use the power of air and electricity to create heat. Air source heat pumps are a more efficient, cost effective and sustainable source of heating when compared to traditional heating solutions.

Boilers - combi/regular/system

There are three main types of boilers that can help keep your home warm: combi, regular and system boilers.

  • Combi boilers are ideal for smaller homes, providing hot and cold water while staying small enough to fit in a cupboard. 
  • Regular boilers are designed to serve larger households and are linked to a hot water cylinder and cold storage tank.
  • And system boilers – which provide a constant supply of hot water to multiple taps – are gas boilers designed for properties with more than one bathroom.

You can find out more in our helpful guide on what to look for when picking the right boiler for your home.

Carbon emissions

Carbon emissions are one of the most common types of greenhouse gas and are responsible for the majority of global greenhouse gas emissions. Carbon emissions are released into the atmosphere when we power planes, cars, factories and even our homes and can cause global warming and have a negative impact on the planet.

Carbon footprint

carbon footprint is a measurement of your impact on the planet from the total amount of greenhouse gases you release into the atmosphere by doing common everyday activities such as driving, flying and powering your home. The more you walk, cycle and use less energy, the smaller your carbon footprint will be.

Carbon offsetting

Carbon offsetting provides a way for you to balance out carbon emissions, and your environmental impact on the planet. It does this by funding projects that remove the same amount of carbon dioxide you generate from the atmosphere. For example, you might donate to a non-profit organisation that plants trees, which absorb carbon dioxide and reduce greenhouse gases, when you take an international flight.

Climate crisis (climate change, climate emergency, global warming)

Experts advise that the climate crisis exists because the Earth is warming at an unprecedented pace, fuelled by a growth in carbon emissions and other greenhouse gases created by global industrial activity. This has resulted in extreme heat, floods, droughts, and other challenging environmental conditions that are critically impacting many ecosystems and regions around the world.

Energy efficiency

Energy efficiency refers to using less energy to complete a task, such as turning on a light, cooking your dinner or heating your home, and in turn eliminates excess energy waste. Our customers can use our helpful E.ON See tool to help them better understand their energy use, get personalised energy saving advice and help them become more energy efficient. The more energy efficient you are, the more you can reduce greenhouse gas emissions, lower energy bills, and do your part to support the environment.

Fuel mix

The ratio of different types of fuel an energy supplier uses to generate and supply electricity to customers. At E.ON, we back all our residential customers’ homes with electricity from a renewable source such as wind, solar and biomass.

The electricity supplied to our customers’ homes comes from the National Grid, which operates the distribution of Great Britain’s gas and electricity supply. The National Grid transports energy through a system of pylons and cables around Britain and makes sure that we always have enough power.

Net zero, zero carbon, or carbon neutral

Net zero, zero carbon or carbon neutral are interchangeable terms that describe the target of achieving overall (net) zero emissions and minimising our environmental impact on the planet. The UK is committed to being net zero by 2050 and we can all help in achieving this. What’s more, at E.ON we’ve committed to becoming carbon neutral by 2040.

Simple things we can all do include switching to renewable electricity, considering an electric vehicle or reducing car travel and making your home more energy efficient.


There are three ways you can get renewable power: you can generate it yourself, buy it from an independent generator or you can obtain it through a REGO (Renewable Energy Guarantees of Origin)2. A REGO is a renewable energy certificate which guarantees electricity is generated from a renewable source, matching the amount of electricity supplied to customers with the equivalent amount from renewable sources.

Smart meter

Smart meters are replacing old gas and electricity meters as part of an essential national upgrade to our energy system. A smart meter tracks your gas and electricity use, helps you to see how much energy you’re using and automatically sends your meter readings to your energy supplier. Smart meters give you the power to save money and lower your carbon footprint and help the UK move towards a smarter, cleaner energy grid.

Smart energy grid

Information from smart meters can be used to make more informed decisions about energy production and supply, which means they power a more intelligent (aka smart) UK energy grid. Using this data, energy suppliers can better balance supply and demand for energy to homes and businesses and help reduce energy waste. The smart energy grid also supports the growth of new technologies - from heat pumps to electric cars.

Smart thermostat

smart thermostat is an intelligent thermostat that can track the weather, monitor energy usage patterns, and keep tabs on household consumption, helping you to minimise energy waste and cut costs. With a smart thermostat, you can adjust your heating while you’re out via your smart phone and make use of the energy saving features to heat your home more efficiently.

Solar photovoltaic (PV) panels

Solar PV panels can be installed on your home’s roof allowing you to generate your own renewable electricity and minimise your impact on the environment. Having solar panels allows you to become more independent from the grid, exercise greater control over your household electricity usage, and even sell excess solar electricity that you've generated back to the grid.

Solar battery storage

If you’d like to store excess electricity generated from your solar panels to use later, battery storage makes this possible. It allows you to take any excess electricity generated during the day and use it at night, for example. Doing so means you use less electricity from the grid, helping you to save money and become more self-sufficient.  

1. Electricity backed by 100% renewable sources. E.ON's renewable generation assets, agreements with UK wind generators and the purchase of renewable electricity certificates. The electricity supplied to your home comes from the National Grid and DNOs. eonenergy.com/renewable

2. Ofgem: About the REGO scheme