Your array makes more than your plant can use. Keep it.
If your solar outruns your load at midday or at the weekend, the surplus is curtailed and lost, and in the evening you buy the same energy back from the grid at the on-peak rate. CESS puts a battery and a forecast between the two.
Modelled at the 120 kWh / 60 kW system our engine sized for the pilot site, from the site's own metered load.
A site with its own solar, and a bill that still peaks in the evening.
This step is for a single factory or plant that already generates power on its own roof. If all three sound familiar, the battery has work to do before you have spent anything on it.
More than you can take
Over a lunch break, on a light production day or at the weekend, the array makes more than the plant draws. The excess is curtailed, and nothing records it as a loss.
On-peak, after the sun
Your shifts run on after the array has faded, so the evening is bought from the grid at the on-peak rate of a time-of-use tariff, and your highest interval of the month sets a demand charge.
Twelve months of bills
That is all the feasibility model needs to start, plus interval meter data if you have it. It sizes the system from your load, not from a catalogue.
A controller for one site.
At this step CESS runs one battery, behind one meter, against one tariff. Three modules do the work and a fourth looks after the asset.
Your load and your solar, predicted up to 24 hours ahead from your site's own history and live weather.
Leaves space in the battery for the midday surplus rather than filling it from the grid first, and plans the discharge against your tariff.
Captures what the site cannot take and uses it in the evening, in place of grid power at the on-peak rate.
Monitors cell health and degradation continuously, and runs the electro-healing routine built into CESS.
Each module has its own page: Forecast, Dispatch, Recover and Protect.
One site in Bangkok, running since May 2025.
Our pilot is exactly this step: one factory with its own array, losing about 30% of what it generated before CESS connected. What it makes matters less than the shape of its load, and yours will have a shape of its own. It is one site and a pilot, and the figures below say so.
Food manufacturing · Bangkok
Commissioned May 2025 · client anonymised at their request
CESS runs against the site's existing Huawei FusionSolar infrastructure alongside a Deye inverter. Roughly 30% of what the array generated was being curtailed before we connected. The installed battery is a sixth of what our engine sized for this load, so the figures on this page are modelled at full size rather than measured at the pilot's.
Modelled at the 120 kWh / 60 kW system our engine sized for this site, from the site's own metered load. Our fee is a share of measured savings, billed monthly, so the line item only exists in a month where the saving did. Savings do not scale linearly with battery size, so we will not multiply these up for you — your figures come from your own model.
For a solar producer, recovery is the driver that carries the case.
In the pilot model it is worth more each month than peak shaving and arbitrage put together. Your split will be different, because it depends on how far and how often your array outruns your load. The investment case shows how each driver was modelled.It pays back on your bill. It is ready for the network.
Today a CESS battery pays for itself on the bill it sits behind: a lower demand charge, recovered solar, the gap between on-peak and off-peak. From day one, every CESS site is also metered, forecast and dispatched by software, which is what a network needs from each of its members. We are building CESS toward a network in which those sites trade, so the same battery can earn from the grid as well as from the bill.
Find out how much of your solar you are losing.
Twelve months of billing data, and we will model your load, size the system and show you the whole financial case, including when the answer is not to build.
Or reach us at solarbuddies@pjjsolutions.tech