The energy arbitration problem
A HALO FastHub generates power from three sources at once: a 19.32 kWp solar canopy, a battery storage system, and a mains connection. At any given second, each source may be available at a different cost and in a different quantity. The job of HALO OS is to decide, second by second, which source charges which vehicle — and when surplus energy goes to the building instead.
That decision engine is the commercially important part of the system. A hub that defaults to grid power when solar is available wastes money. A hub that draws from peak-rate mains when battery has capacity is more expensive than it needs to be. Getting the arbitration right is the difference between a hub that pays for itself and one that doesn’t.
The dispatch hierarchy
HALO OS operates a four-level dispatch hierarchy:
- Solar-first — available solar generation is dispatched directly to active charge sessions before any other source.
- Battery second — if solar output is insufficient, battery state-of-charge is assessed and discharge authorised down to the configured reserve level.
- Mains last — grid power is drawn only when solar and battery cannot meet demand, and only within the tariff windows set by the operator.
- Building offset — at any point where charge sessions are inactive or at low demand, surplus solar is redirected to the building load.
Tariff-aware dispatch
Most commercial operators are on time-of-use tariffs. HALO OS respects client-defined tariff windows when deciding whether to draw from the grid. During peak hours, the system preferentially runs down battery reserve rather than paying peak rates. Overnight, if the battery is not full, it charges from cheap-rate grid power ready for the following day.
What this means for your energy bill
In a typical HALO FastHub deployment, solar and battery together account for 60–70% of the total energy dispensed to vehicles. The remaining 30–40% is drawn from mains at off-peak rates. HALO OS reports the split monthly, to the kilowatt-hour. Every client knows exactly how much energy came from the roof and how much came from the grid.