Summary

Lumo uses a simulation framework to estimate bill savings from pairing a residential battery with solar, while also running Lumo’s optimisation engine regularly to plan the best charge and discharge schedule for the battery. Lumo simulates a full year using 1-hour steps and a rolling, audit-friendly loop.

Lumo’s objective is to minimise net energy cost (grid imports minus export revenues) while respecting all equipment limits. In our real-world optimisation, this operation is performed throughout each day and repeated as new real system data becomes available.

In our simulation framework, which is used to calculate the expected value we can achieve for different homes with different hardware configurations, we use real historical data rather than real time system telemetry but then rigorously apply real-world losses to ensure that the result is realistic. 

Savings, both in our real world optimiser and simulator,  are reported against multiple baselines (no solar & battery, solar-only, solar & battery (load-match mode) to ensure fair, comparable outcomes. 

Inputs and configuration

Lumo’s framework ingests measured or estimated time series and configurable device/tariff parameters. The following show some typical default values used

• Home electricity use (kWh per half hour): measured half-hourly consumption from a real system. This real data is used to produce point in time forecasts for the next 48 hours for each iteration.

• Solar generation (kWh per hour): measured or estimated hourly production for the installed system size. We use either real solar output from a system or output calculated from EU GIS irradiance data.

• Import prices (pence per kWh): what the household pays to buy from the grid based on their time of use tariff. 

• Export prices (pence per kWh): what is earned when sending energy to the grid.

• Battery capacity (kWh): Our test system uses a 10.4 kWh battery

• Usable battery range (%): min and max percentages of utilisation, which can each be set between 0 and 100%. A typical utilisation pattern would be 10% to 100%

• Charge/discharge power limits (kW): We default to a 3.6 kW inverter limit

• AC/DC conversion losses: included via inverter paths on charge and discharge.

• Solar system size (kWp):  A typical system will usually be between 3 and 8 kWp , and our standard test system has a 5.4kWp array

Objective and decision logic

We minimize annual net energy cost (imports minus export revenue) while strictly enforcing device limits and applying realistic losses. The optimization produces simple, interpretable actions—charge, hold, or discharge—based on prices, solar availability, and constraints.