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Joulen
Revenue calculator

What could your assets earn?

Drag the sliders to model your portfolio across trading, flexibility and savings. Get an indicative annual figure in seconds, and the full breakdown by email.

What kind of site?

5 kW inverter, matched to the system, the smallest that covers the array.

Electricity use2,700 kWh a year

Every figure comes from full-year, half-hourly modelling of the Joulen Flex dataset. Figures are indicative and depend on your tariff, site and market conditions.

Total annual benefit with Joulen Flex

£1,522/ year

Bill today £688. Grid supply costs covered, with £834 a year in profit.

Solar and battery on their own
£961
Joulen Flex adds (optimisation + trading)
£561
Solar alone
£784
Adding the battery
£177
Smart optimisation
£423
Market access (trading)
£138
Battery cycles (optimiser output)
385/yr · 1.1/day
Solar used on site
69%

Includes solar stored in the battery for later use, not only generation used the moment it is produced.

Modelled demand
2,700 kWh / yr
Get the full breakdown, freeA month-by-month projection for your system, reviewed by our team. No obligation.

Indicative only, not a guarantee of revenue. A Joulen expert validates against live market data for your assets.

Assumptions and sources
  • Every position is a full-year, half-hourly model from the Joulen Flex calculator dataset v3 (2,925 models). Home positions are exact; commercial positions between modelled battery-to-solar ratios are interpolated.
  • Home figures include VAT and use Octopus Flux (region E, August 2026 rates). Commercial figures exclude VAT and use an indicative half-hourly commercial tariff.
  • Trading revenue is settled against observed 2025 GB day-ahead prices.
  • Weather is a PVGIS typical year for Birmingham; demand follows Elexon profile shapes scaled to the chosen level.
  • Standing charges are excluded because they do not change with the system. Battery degradation is not modelled and cycling is not limited.

Model flex-dataset-v3-2026-09-03.

What's in the number

Three streams, one total.

Joulen stacks value across every relevant market, here's where the figure comes from.

  • Trading revenue

    Wholesale, intraday and balancing, value captured by buying low and selling high, every cycle.

  • Flexibility & ancillary

    Payments for keeping capacity available and responding to grid signals.

  • Grid & bill savings

    Avoided network charges and optimised self-consumption that lower your costs.

Precise estimate

Want a precise number?

Book a 30-minute session and we'll model your exact assets and target markets, no obligation.

  • Tailored to your assets & markets
  • Reviewed by our trading desk
  • No obligation
FAQs

Calculator FAQs

  • Flex maximises self-consumption, optimises against weather and tariffs, and unlocks flexibility trading revenue from batteries and EV chargers.
  • Trade captures wholesale, balancing and ancillary market revenue.
  • Grid optimises standalone and co-located utility-scale batteries.

All three run on the same AI optimisation engine.

No. Joulen integrates with the batteries, inverters and platforms you already run. We optimise what you have.

Our tech stack continues to run the same AI decision-making behind every Joulen product, forecasting, optimising and controlling assets in real time. You get the outcomes, just under a different product name.

Optimise to maximise

Turn the estimate into income.

Book a call and we'll show you, with your numbers, how Joulen gets you there.

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