Energy & Utilities

Green Energy Tariffs UK — Are They Worth It?

What green energy tariffs actually mean, how they work, whether they're truly renewable, and how to choose a genuinely green energy supplier.

Green energy tariffs claim to supply your home with renewable electricity (and sometimes gas). But the reality is more nuanced. Here is what green tariffs actually mean and how to choose a genuinely sustainable option.

How Green Tariffs Work

ConceptReality
Physical electricityAll goes into one National Grid — you can’t choose which electrons reach your home
What suppliers doMatch your usage with renewable energy certificates (REGOs)
REGORenewable Energy Guarantee of Origin — certificate proving 1MWh of renewable generation
The impactSuppliers buy from or invest in renewable generation

Types of Green Tariff

TypeWhat It MeansGenuineness
REGO-backedSupplier buys certificates to match your usageBasic green claim
Direct PPASupplier has Power Purchase Agreements with specific renewable generatorsMore genuine
Own generationSupplier owns wind/solar farmsMost genuine
Green gasIncludes biomethane or renewable gasLook for actual green gas, not just offsets
Carbon offsetOffsets emissions rather than true renewablesLeast genuine (greenwashing risk)

Evaluating Genuineness

Questions to Ask

QuestionGood AnswerRed Flag
Where does the energy come from?Named wind/solar farms, direct PPAs“Various renewable sources”
Do you own any generation?YesJust buy REGOs
What % is backed by PPAs?High (50%+)0% — just certificates
Is gas green?Biomethane or green hydrogen“Carbon offset” only
Investment in new renewables?Yes, X MW being builtNo investment

Rating Scales

Rating SourceTop Rated SuppliersWhat They Measure
Which? Eco ProvidersGood Energy, Ecotricity, OctopusTransparency, investment, fuel mix
Uswitch Green AccreditationVariousMinimum green standards
Your own researchCheck supplier’s fuel mix disclosureAnnual reports, websites

Best Green Energy Suppliers

SupplierOwn GenerationGreen GasRating
Good EnergyYes (solar, wind)BiomethaneTop
EcotricityYes (significant wind)“Green gas”Top
Octopus EnergyGrowing generation + PPAsCarbon offsets (some criticism)Good
Bulb (now Octopus)PPAs, investmentCarbon offsetsGood
EDFNuclear (low carbon, not renewable)Some offsetsMixed
OvoPPAs, tree plantingOffsetsMixed
Big Six on green tariffsMostly REGO-backedOffsetsBasic

Cost Comparison

Tariff TypeCost vs Price Cap
Best green tariffsOften at or below cap
Premium green (small suppliers)Sometimes 5–15% above cap
Big supplier green tariffsUsually at cap level
Standard (non-green)At cap (SVT)

Key point: Being green does not have to cost more. Compare prices — the best green deals compete with any tariff.

Green Gas: The Challenge

IssueDetail
Gas is harder to greenMost UK heating is gas-based
BiomethaneGenuine green gas from organic waste — limited supply
HydrogenFuture potential, not widely available
Carbon offsetsCommon but less genuine
Long-term solutionHeat pumps, insulation, electrification

What “Green Gas” Usually Means

ClaimTypical Reality
“100% green gas”May be offset rather than biomethane
“Carbon neutral”Often includes tree planting or offset projects
“Biomethane backed”Genuine green gas certificates
“Green future”Investment in future solutions

Beyond Green Tariffs

ActionImpact
Reduce energy useBiggest impact regardless of tariff
Home insulationReduces need for any energy
Solar panelsGenerate your own renewable electricity
Heat pumpElectric heating from renewable grid
Switch transportEV charged on green tariff
Demand shiftingUse energy when grid is greenest (wind, solar)

How to Choose

Priorities Guide

Your PriorityLook For
Cheapest green optionPrice compare, green filter
Most genuineGood Energy, Ecotricity, Octopus
Balance of price and greenOctopus, Ovo
Simple switchAny major supplier’s green tariff

Checklist Before Switching

FactorCheck
☐ Price vs price capCompetitive?
☐ Fuel mixWhat % renewables?
☐ Certificate sourcingPPAs or just REGOs?
☐ Own generationDoes supplier own wind/solar?
☐ Green gasBiomethane or just offsets?
☐ Customer reviewsService quality?
☐ InvestmentAdding new renewable capacity?

The Bigger Picture

ActionYour Impact
Sign up for green tariffSignals demand for renewables
Choose genuinely greenSupports suppliers investing in generation
Reduce consumptionBiggest personal impact
Advocate for changePolicy changes have largest effect

Green tariffs are one part of the puzzle. Combined with efficiency measures, they help — but the grid is decarbonising regardless as the UK builds more renewable capacity.

For more on managing energy costs, see our switching energy supplier guide and energy price cap guide.