Switching to a green energy tariff is one of the easiest ways to reduce the carbon footprint of your home’s energy – but it raises two questions:
- Will it actually cut my bills?
- Does it improve my EPC rating?
This guide explains what green tariffs are, how they work, and how they fit into your overall EPC and energy‑saving strategy.
What is a green tariff?
Broadly, a green tariff is one where:
- The supplier matches your electricity use with renewable generation, or
- Buys certificates that back your supply with low‑carbon sources.
Some tariffs also:
- Offer off‑peak pricing to encourage shifting usage to greener, cheaper times (e.g. overnight or when wind/solar output is high).
- Provide special rates for EV charging or heat pump use.
Do green tariffs change your EPC?
In general, no. EPCs:
- Are based on standardised fuel prices and carbon factors, not your specific tariff.
- Don’t change just because you switch supplier or tariff.
To improve your EPC, you need to change the fabric and systems of your home – insulation, heating, controls, solar, etc. See 27 Ways to Improve Your EPC Rating for a full roadmap.
When can green tariffs still help?
Even if they don’t move your EPC score directly, green tariffs can:
- Reduce carbon emissions associated with your energy use.
- Pair well with heat pumps and EV charging, especially on smart time‑of‑use tariffs.
- Make it more attractive to run appliances like washing machines or dishwashers at cheaper, greener times.
If you’re electrifying heating (see Air Source Heat Pump Costs UK (2025 Guide)) or transport (see EV Charging at Home), choosing the right tariff can have a big impact on running costs.
Types of green tariff
You’ll typically see:
- Standard green tariffs: where the supplier matches your usage with renewable generation or certificates.
- Time‑of‑use tariffs: cheaper rates at set times (often overnight), higher at others – ideal for EVs and heat pumps.
- Dynamic tariffs: prices that change with grid conditions, rewarding you for shifting usage to low‑demand, high‑renewables periods.
The right option depends on your pattern of use and how flexible you can be.
How to choose a green tariff
When comparing deals, look at:
- Your typical electricity consumption and when you use most power.
- Whether you already have or plan to install EV charging, heat pumps or solar.
- Unit rates, standing charges and any exit fees or conditions.
A cheaper unit rate isn’t always the best if it comes with much higher standing charges or restrictive terms.
Next steps
- Use our EPC checker to understand your home’s current efficiency and priority upgrades.
- Focus on fabric and system improvements first (insulation, heating, solar).
- Once your home is efficient, pick a tariff that aligns with your usage pattern, low‑carbon goals and any electrification plans (EVs, heat pumps, etc.).