800Watts Savings Estimator

Solar savings estimator

Step 1 of 4 — Location

Where are your panels?

We use your postcode to look up local solar irradiance from satellite data. Only the outward code (first half) is sent to the lookup service.

Please enter a valid UK postcode.

Step 2 of 4 — Panel setup

How are your panels positioned?

The direction your panels face and their tilt angle significantly affect how much energy they generate. South-facing at 35° is optimal for the UK.

2 panels = 800W system (UK legal maximum)

Flat roof: 5–15°  ·  Pitched roof: 30–40°  ·  Wall-mounted: 60–75°

Step 3 of 4 — Energy usage

Connect your Octopus account (optional)

Pull your real smart meter history to calculate exactly what you would have saved. Skip to use UK averages instead.

Your API key is sent directly to Octopus Energy's own servers and is never stored anywhere. It exists only in memory for this session and is gone when you close the tab.

Find this at octopus.energy/dashboard/developer

Results

Your 800W solar estimate

— kWh
Generated per year
£—
Saved per year
—%
Of usage covered
— yr
Payback period
Out all day Working from home Home always

Adjust to reflect how often you're home during daylight hours. This affects how much generated solar you actually use vs. export unused.

— kg CO₂/yr
Carbon offset
£—
10-year cumulative saving
If you'd installed this system 3 years ago
£—

Tariff note

How orientation affects output at your location

Cumulative savings — 20 year projection

Calculation assumptions & methodology
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