How it works · Baseload Renewable Energy Systems
Solar by day. Storage by night
Diesel only as a reserve.
Oversized solar charges a battery with many hours of storage. The battery carries the island through the night, and the existing diesel plant stays on standby for rare extremes. Watch a modelled island grid, hour by hour.
44% | cheaper than diesel power in 2026 · see why
- Solar to island
- Solar to battery
- Battery to island
- Diesel
- Demand
CI-BRO hour-by-hour model of a representative island grid, based on 2023 hourly solar resource. Diesel stays connected as backup.
What about the cloudiest week? →Week fuel: 314,600 L of 1,242,300 L · Spare solar this week: 28 MWh
The whole year · representative island grid, modelled
95–99% renewable
Solar, battery and a small diesel reserve, sized together for each island’s own demand and weather.
The diesel reserve covers the rare extremes: typically 1–5% of the year’s power.
CI-BRO hourly dispatch model
THE ECONOMICS
Solar and storage have been cheaper than diesel since 2021
Since 2010 the cost of power from a 95%-renewable BRES system has fallen 87%, from $1,355 to $175 per MWh. Diesel has no such curve: it rises and falls with the oil price. In 2026 it costs $311, so BRES is 44% cheaper.
Reference island, Caribbean solar resource, 10-year lifetime, 10% WACC (conservative: solar and batteries last longer). Diesel: island fuel prices of each year. Pure BRES converted from euros at 1.15 US$ per €. 2026: costs and prices to date. Source: Charged Islands cost model.
−87%
fall in the cost of BRES power since 2010
$21
a barrel: the only oil price at which diesel would compete. Since 2010 that happened in 2 of 198 months
95–99%
of the power from sun and storage. A small diesel reserve covers the rare extremes.
THE SYSTEM
Four parts, one baseload system
MWp
MW/MWh
Hz - V
24 h
Solar PV
Oversized to cover daytime demand and fill the battery for the night.
Battery Storage
Shifts solar into the evening and night, sized for the cloudiest week of the year.
Energy management
Forecasts sun and demand, dispatches solar, battery and diesel hour by hour, and keeps frequency and voltage stable.
Island Grid
Stable, predictable power for homes, businesses and critical infrastructure.
BACKUP
Existing diesel generators stay connected for rare low-solar stretches, integrated for the lowest overall cost of electricity.
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