Data Visualisation

My Real Energy Data

Half-hourly import data from Octopus Energy — 25 January 2025 to 2 June 2026. 494 days of real readings, analysed at build time.

Agile rates from public Octopus API · Last CSV export: 2 June 2026

Payback Tracker · £8,500 invested · since 25 January 2025

Recovered so far £1337 of £8,500
£015.7% recovered£8,500
System live since 25 January 2025
Months running 17 months
Estimated payback date January 2034
Saving per month ~£79/mo
CO₂ avoided (est.) 966 kg
Solar self-consumption saving
4145 kWh generated · 2984 kWh self-used · vs 28p standard
£836
Export earnings (SEG ~15p)
1161 kWh exported to grid
£174
Agile smart charging saving
1954 kWh imported · overnight at ~6p vs 28p standard · real data from CSV
£327
Total recovered £1337
+ Axle VPP grid events
~4 events/mo at £1/kWh · now earning, on top of the above
~£144/yr

Solar generation based on Cardiff 3kWp estimates. Will update automatically when real HA lifetime sensor data is available.

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My Tariff Analysis

Based on 1954 kWh imported over 494 days (25 January 2025 – 2 June 2026). Half-hourly Octopus data.

Total imported
1954
kWh over 494 days
Annual est.
1443
kWh/yr (very low — solar working)
Peak import avg
39W
4–7pm (battery covering peaks)
Overnight avg
186W
midnight–6am (Predbat charging)

What your 1954 kWh would have cost on each tariff

Tariff Est. cost vs standard Notes
⚡ Octopus Agile Your tariff ✓ £220 −£327 Overnight charging at ~6p, Predbat optimised
🌙 Octopus Go £291 −£256 7.5p overnight, 24.5p day — less flexible than Agile
🔄 Octopus Flux £290 −£257 Good for battery but Agile beats it with Predbat
📋 Standard fixed £547 baseline 28p flat — Predbat can't exploit cheap slots

Estimates only. Agile figure uses ~6p overnight / ~18p daytime average based on typical Predbat behaviour.

Why Agile is right for this setup
Overnight import is huge
56% of all import happens midnight–6am. That's Predbat loading the battery when Agile is cheapest — often under 5p or negative.
Evening peak nearly zero
4–7pm import averages just 39W. The battery is covering the most expensive Agile slots completely. A standard tariff would waste this advantage.
Annual import is tiny
~1443 kWh/yr imported. UK average is 2,900 kWh. Solar + battery is covering 50% of typical household demand.
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Octopus Agile — Next 24 Hours (live)

Average Import by Hour of Day

Real data from 25 January 2025 – 2 June 2026. Shows Predbat charging pattern clearly.

The midnight spike is Predbat charging the battery at cheap/negative Agile rates. The flat daytime is solar covering load. The small evening rise is household loads after solar ends.

Monthly Grid Import

Higher winter months include more Predbat overnight charging — this is cheap Agile energy, not wasted spend.

Monthly Import — Agile vs Standard

Month kWh On standard (£) On Agile est. (£) Saved (£)
Jan 2025 2.0 £0.56 £0.24 £0.32
Feb 2025 24.7 £6.92 £2.97 £3.96
Mar 2025 24.9 £6.97 £2.99 £3.98
Apr 2025 19.9 £5.56 £2.38 £3.18
May 2025 3.8 £1.07 £0.46 £0.61
Jun 2025 5.6 £1.56 £0.67 £0.89
Jul 2025 26.0 £7.27 £3.12 £4.16
Aug 2025 161.1 £45.09 £19.33 £25.77
Sept 2025 175.7 £49.19 £21.08 £28.11
Oct 2025 185.4 £51.92 £22.25 £29.67
Nov 2025 224.3 £62.80 £26.91 £35.88
Dec 2025 259.2 £72.58 £31.11 £41.48
Jan 2026 245.5 £68.75 £29.46 £39.29
Feb 2026 206.2 £57.75 £24.75 £33.00
Mar 2026 178.5 £49.99 £21.42 £28.56
Apr 2026 132.2 £37.02 £15.87 £21.16
May 2026 77.7 £21.75 £9.32 £12.43
Jun 2026 0.8 £0.24 £0.10 £0.13
Total 1953.6 £547.00 £219.52 £327.48

Agile estimate uses ~12p average. Real cost will vary — Predbat's overnight charging likely achieves lower than this.