Plug-In Solar vs Green Energy Tariff: Which Is Greener?
Is generating your own solar power greener than paying for a 100% renewable tariff? We compare the carbon impact.
The Green Tariff Question
Many UK energy suppliers offer "100% renewable" tariffs. Does paying extra for green electricity achieve the same environmental benefit as generating your own?
How Green Tariffs Work
Most "100% renewable" tariffs use REGO certificates (Renewable Energy Guarantees of Origin). The supplier buys REGOs from renewable generators to match your consumption. This means:
- You're not necessarily using renewable electricity physically
- You're supporting the renewable energy market financially
- The actual electrons you receive are from the general grid mix
How Plug-In Solar Compares
With plug-in solar:
- You physically generate renewable electricity on-site
- Each kWh you self-consume directly displaces a grid kWh
- No transmission losses (grid electricity loses ~8% in transmission)
- No REGO certificate system — the generation is real and physical
Carbon Comparison
| Source | Carbon intensity (gCO2/kWh) |
|---|---|
| UK grid average (2026) | 150-200 |
| Green tariff (REGO-backed) | ~50-80 (accounting method) |
| Plug-in solar (direct use) | 0 (operational) |
| Plug-in solar (lifecycle) | ~25-40 (manufacturing) |
Plug-in solar has a lower lifecycle carbon footprint than even REGO-backed green tariffs.
The Financial Comparison
| Option | Cost/kWh | Annual premium |
|---|---|---|
| Standard tariff | 24.5p | — |
| Green tariff | 25-28p | £15-85/yr |
| Plug-in solar (self-consumed) | ~4.4p (LCOE) | Capital cost |
Plug-in solar is both greener and cheaper per kWh over its lifetime.
The Best Approach: Both
The greenest strategy is:
- Install plug-in solar to cover daytime consumption
- Use a green tariff for remaining grid imports
- Choose a time-of-use tariff to minimise carbon-intensive peak imports
- 800W dual-panel plug-in solar kit
- 600Wh battery with smart scheduling
- App monitoring with real-time generation data
- Balcony, garden & flat-roof mounts available
Are green tariffs greenwashing?
Not exactly, but they're less impactful than often claimed. REGOs support the renewable energy market but don't guarantee your specific electricity is renewable.
Does plug-in solar reduce my carbon footprint?
Yes — directly. Each kWh you self-consume avoids ~150-200g CO2 from grid electricity. An 800W system avoids roughly 280-350 kg CO2 per year.
Related reading
See how much plug-in solar could save you — with real data for your postcode.