Energy optimisation

Your battery can do more than store solar.

A home battery can charge whenever electricity is available. Getting the best from it means deciding when to charge, when to keep energy for later, when to power the house and when exporting might make more sense.

Rooftop solar panels
The idea

Plan energy around what tomorrow is likely to look like.

An optimisation system can combine changing electricity prices, predicted solar generation, expected household demand and the current state of the battery. It then keeps recalculating a plan as those inputs change.

Weather & solar forecast
Electricity prices
Expected home usage
Battery & inverter limits
Optimisation
Charge
Hold
Power the house
Export
A simplified day

Smarter than a fixed overnight charge.

02:00Electricity is cheap

Charge the battery.

08:00Good solar forecast

Leave room in the battery for free generation.

13:00Solar is producing

Run the house and store the surplus.

17:30Import price rises

Use stored energy rather than buying expensive electricity.

18:30Export is valuable

Where appropriate, exporting some energy may be worthwhile.

23:00Tomorrow's data arrives

Recalculate the plan.

This is an illustrative example. The best strategy depends on tariff, equipment, forecasts and household demand.

What powers this?

PredBat is one tool we can use.

PredBat is an open-source home-energy optimisation system that works with Home Assistant and compatible battery systems. It can calculate charging and discharging plans using tariff prices, predicted solar generation, expected household consumption and the capabilities of the inverter and battery.

Our work is to understand the home, integrate compatible equipment, validate the data, configure the optimisation, commission it properly and make sure the household can understand what it is doing.

Home energy optimisation dashboard
Potential value

Can optimisation pay for itself?

~£267/year

Typical additional annual saving currently reported by PredBat for small-to-medium battery systems.

Up to 29%

Reported bill reduction in its user data. Results vary significantly between homes.

Measure it

Where the system allows it, we prefer actual performance data to heroic savings claims.

Third-party PredBat figures, not a Guildford Home Automation guarantee. Actual results depend on tariff, consumption, solar generation, battery, inverter and other factors.