Switching Energy Supplier for Greener Electricity

Why Your Tariff Choice Matters More Than You Think

Switching to a greener electricity tariff is one of the simplest steps you can take as a household, but it is also one of the easiest to get wrong. Plenty of deals advertise themselves as "100% renewable" when, in practice, they are doing very little to change how electricity is generated in the UK. Understanding the difference between genuinely green supply and clever marketing will help you pick a tariff that actually supports new wind, solar and hydro capacity rather than simply reshuffling paperwork.

This guide walks you through how to compare renewable tariffs properly, what to look for in contract lengths and exit fees, and how to tell whether your supplier is investing in new generation or just buying certificates.

What "100% Renewable" Really Means on a Bill

Every unit of electricity on the grid is mixed together, so no supplier can literally pipe wind power straight to your home. What they can do is match your usage with renewable generation through one of two routes:

• Own generation or direct power purchase agreements (PPAs) – the supplier buys electricity directly from a specific wind farm, solar array or hydro scheme, often under a long-term contract. This is the gold standard because it supports real assets.
• Renewable Energy Guarantees of Origin (REGOs) – certificates proving a megawatt-hour of renewable electricity was generated somewhere in the UK. These are cheap, tradable and can be bought separately from the actual power.

A tariff can be 100% REGO-backed and still do nothing to build new capacity. If a supplier is buying old certificates from existing hydro schemes, your money is not driving new turbines. Ask the supplier directly: do you buy power directly from generators, or do you rely on REGOs? The good ones will tell you without hesitation.

Comparing Renewable Tariffs Like a Pro

Once you know what to ask, comparison gets clearer. Look at each tariff on these fronts:

• Fuel mix disclosure – Ofgem requires suppliers to publish where their electricity comes from. Check the percentages for renewables, nuclear and fossil fuels.
• Source of green claims – a tariff powered by a named wind farm is stronger than a generic "green" label.
• Price per kWh and standing charge – the greenest tariff in the world is no good if you cannot afford to run your heating.
• Contract length – fixed deals of 12, 24 or even 36 months are common. Longer contracts can lock in lower rates but reduce flexibility.
• Exit fees – typically £25–£60 per fuel, but some suppliers waive them if you switch within a set window or move home.

Run the numbers on your actual annual usage in kWh rather than relying on typical household figures. A 3-bed semi in Leeds and a flat in Bristol will produce very different bills, and the cheapest tariff often shifts once you use real numbers.

The Small Print on Contract Lengths and Exit Fees

Fixed tariffs are not the same as fixed contracts on your mobile phone. In the energy market, "fixed" means the unit rate is fixed, but the contract can still have a set end date. Watch out for these traps:

• Rollover clauses – some suppliers move you onto a more expensive default tariff at the end of a fixed term unless you switch.
• Exit fees applied mid-term – usually £25–£30 per fuel, so £50–£60 for dual fuel. These are waived if you switch within the last 49 days of the contract.
• Green premium pricing – some renewable tariffs cost more per kWh. Compare against a standard variable tariff to see if the premium is worth it.
• Minimum term lock-ins – occasionally suppliers require you to stay 12 months before any green credentials apply.

If flexibility matters more than the lowest rate, look for suppliers with no exit fees at all. Several smaller green suppliers offer rolling monthly contracts, which are handy if you are renting or planning to move.

Checking Whether Your Supplier Builds or Just Buys Certificates

This is the single most important question in green energy, and unfortunately the answer is not always obvious on the marketing page. Here is a practical checklist:

• Look for named generation assets – a supplier that owns or has PPAs with specific wind farms or solar parks is investing in real capacity.
• Check for REGO-only claims – phrases like "we match 100% of your electricity with REGOs" mean certificates, not new build.
• Look for investment commitments – some suppliers pledge a portion of revenue to new renewable projects. That is a stronger signal than certificates alone.
• Check the fuel mix on their website – a high renewable percentage is good, but ask how much comes from sources commissioned in the last five years.

Ofgem's REGO system is not inherently bad, but it has a weakness: certificates are cheap, so suppliers can claim greenness without adding a single new turbine. If your goal is to accelerate the transition, prioritise suppliers that buy directly from generators or fund new projects.

Pairing a Green Tariff with Home Efficiency

Switching supplier is only half the story. The cleanest kilowatt-hour is the one you never use, and UK homes are notoriously leaky. A few practical moves will stretch every green tariff further:

• Loft and cavity wall insulation – still the highest-return upgrade for most British homes, often with grant support.
• Smart thermostat and heating controls – trimming a degree off your thermostat can cut heating bills by around 10%.
• Draught-proofing – cheap, quick and effective on older Victorian and Edwardian properties.
• LED lighting and A-rated appliances – small savings that add up across a year.
• Solar panels and battery storage – increasingly viable, especially if paired with a tariff that pays you for exporting excess power.

Do the efficiency work first if you can. A well-insulated home needs less electricity overall, which means your green tariff pounds go further and your carbon footprint drops faster. Combined with a supplier that genuinely invests in new generation, you will be doing far more than swapping one logo for another on your bill.