Selgars House — Energy Dashboard

Cosy Octopus live since 8 Aug 2026 · Region L (South West England) · based on 8,089 kWh of real 2025 usage

Data to 7 Aug 2026 · 27,961 half-hourly readings · refreshed 8 Aug 2026

Now: net annual position
£1,507
actual tariffs + FiT
Recommended: Cosy + Outgoing
£1,032
keep generation tariff
Annual saving
£475
31% lower
Peak-time habit costs
£296/yr
≈ £25/mo

Is Cosy actually cheaper? The honest answer

On import alone, a straight swap to Cosy would have cost about £142/yr more than the tariffs you were actually on in 2025 (a mix of Agile at 19.89p and Cosy). But Agile has climbed recently: over your last 30 days it averaged 27.25p versus Cosy's 23.38p, so Cosy is now the cheaper import for you.

The durable saving is the export switch: moving from Good Energy FiT deemed export (~£200/yr) to Octopus Outgoing (~£600/yr) adds roughly £400/yr, and shifting load into the cheap windows adds more on top.

Agile vs Cosy, right now

Your real recent usage priced on the Agile rates you were paying versus Cosy. Annualised.

WindowAgileCosyCosy saves (annualised)
Last 30 days27.25p · £1,565/yr23.38p · £1,342/yr£223/yr
Last 60 days25.27p · £1,522/yr23.49p · £1,415/yr£107/yr
Last 90 days24.54p · £1,705/yr23.68p · £1,646/yr£60/yr

Heating (Viessmann Vitodens 100-W)

not configured

Connect your Viessmann account to pull gas and boiler-electricity use and outdoor temperature. You will be sent to Viessmann to log in, then returned here automatically. (Set VIESSMANN_CLIENT_ID in .env first.)

Gas figures are the boiler's own metering (kWh). The Vitodens is a gas boiler, so your space heating is gas, not electricity.

Suggested monthly direct debit (Octopus)

Annual Cosy import cost minus Outgoing export credit, averaged over 12 months. Your FiT generation payment (~£280/yr) arrives separately from Good Energy and is not part of this.

Now (actual Agile)
£166/mo
Your actual recent import, no export credit.
Cosy — no change
£127/mo
Net of £600/yr export. £NaN/yr.
Cosy — Octopus projection
£109/mo
If you shift load as Octopus expects. £NaN/yr.
Cosy — optimised
£100/mo
With active load-shifting (illustrative).

When you use electricity — and what Cosy charges for it

Average day across 2025. Green = cheap 13.1p (4–7am, 1–4pm, 10pm–12am) · amber = day 26.7p · red = peak 40.1p (4–7pm).

You used 1,097 kWh in the 4–7pm peak last year. On Cosy that costs about £296/yr more than running the same washing, cooking and heating in a cheap window (£25/month).

What the solar is for

The solar offsets your 26.7p day-rate usage and earns export income that pays for the expensive peak and winter heating. Export/generation figures are estimates until the export MPAN and smart export reads are in place.

Self-consumption value
£534/yr
~2,000 kWh of solar used in the house, mostly offsetting the 26.7p day rate.
Export income (Outgoing 12p)
£600/yr
~5,000 kWh exported at 12p. This is the money that offsets peak + heating.
Export vs peak-time spend
Covered ✓
Peak spend £439/yr; export income £600/yr — a £161 surplus toward winter heating (£782/yr).

Note: in the 1–4pm cheap window, self-consuming solar only saves ~13p, about the same as exporting at 12p — so in that window it is roughly even whether you use or export it.

Monthly import: what you paid vs Cosy

Actual tariffs (Agile/Cosy) vs Cosy, unit cost only, 2025 real usage. Winter (heat pump) dominates.

Where your usage falls: actual vs target

Your 2025 shape vs Octopus's Cosy projection. Moving more load into cheap windows (and out of peak) is the opportunity.

Combined net annual position

Import cost minus export income. Lower is better. Export figures estimated.

ScenarioNet £/yrSaving vs now
Now: actual tariffs (Agile/Cosy) + Good Energy FiT£1,507
Cosy (no change) + Outgoing, keep generation tariff£1,249£258
Cosy (Octopus projection) + Outgoing, keep generation tariffrecommended£1,032£475
Cosy (optimised) + Outgoing, keep generation tariff£924£583
Cosy (no change) + Outgoing, generation tariff LOSTavoid£1,529-£22

Key decision: keep the FiT generation payment (~£280/yr, guaranteed to ~2038) and move only the export element to Octopus Outgoing. Leaving FiT entirely throws away the generation payment — the “avoid” row shows the cost.

LPG (Propane) — Calor Tank

Days left in tank
369 days
at 3.22 L/day current rate
Daily gas cost
£2
3.22 L/day · 60p/L
Seasonal reorder
26 Dec 2026
140 days (winter rate)
Annual LPG (seasonal est)
£2,076
3,078.92 L/yr · £169/mo DD

Tank status — 0232-308648

Empty63% gauge · 71.9% of full · 1327 L87% (full)
2000 L cylinder · max fill 1847 L at 87% gauge▲ reorder at 12% gauge
Last fill
28 Mar 2026 · 1574 L
Consumed since fill
428 L in 133 days
Avg since fill
3.22 L/day · £2/day
Viessmann last 7d
0.91 L/day · £1/day

Seasonal reorder: 26 Dec 2026

Winter rate ~16.7 L/day (Nov–Mar). Order by Nov for guaranteed delivery.

Annual LPG cost (seasonal estimate)

Normal winter (3,078.92 L est)£2,076/yr
Warm El Niño winter (−12% heating)£1,855/yr
Monthly direct debit£169/mo

52p/L base + 8p/L Trump-tariff surcharge = 60p/L effective

Standing/service charge ~£229/yr · estimate based on seasonal model (partial 2025 data excluded)

Turn the boiler off in summer — use the 3kW immersion instead

All summer gas (DHW only) is logged as space heating in the Viessmann circuit — there is no separate DHW reading. The boiler is burning ~0.91 L/day in summer. Switching it off May–Sep and using solar excess (or the 13.1p Cosy cheap window) for the 290 L immersion saves significantly.

Keep boiler on all summer
£296
153 days × 0.91 L/day at 60p/L
Switch off + immersion on Cosy cheap
£237
11.8 kWh/day × 13.1p. Saves £59/summer.
Switch off + immersion on solar
Free
Excess solar → immersion = £0. Saves £296/summer vs keeping boiler on.
Immersion specs
Thermowatt 3kW · 290 L cylinder
Set to 45°C · 11.8 kWh to heat from 10°C
Cost per DHW cycle
Solar (excess)Free
Cosy cheap (13.1p)£2
Gas boiler equiv£1
Optimal strategy
  1. Run immersion on solar excess first (1–4pm)
  2. Top up in 10pm–midnight cheap window
  3. Keep boiler off May–Sep entirely
  4. Restart boiler Oct when morning temps drop