Decide before the peak, not after it.
PJJ Dispatch turns the forecast into decisions using model-predictive control. It optimises against the forecast state of your site, not the present one, and that is what separates it from the rule-based controllers shipped with most battery systems.
The rule-based controller aims lower and ends up higher.
Same battery, same load, same day. A fixed rule starts shaving the moment load crosses its threshold, empties the battery on the shoulder of the peak, and has nothing left for the crest. The crest is the interval you are billed on.
One reacts to a reading. The other plans against a forecast.
| Question | Rule-based control | PJJ Dispatch (MPC) |
|---|---|---|
| What it looks at | The reading right now, against fixed thresholds | The next 24 hours of load and solar, from PJJ Forecast |
| When it discharges | Once load has crossed a set line | Before the peak arrives, never after it has already been recorded |
| When it charges | On a fixed schedule, or whenever there is room | When power is cheap, holding charge back for the peak it expects |
| When the day changes | Runs the same rule regardless | Re-plans as new readings arrive, rather than committing to the morning's view |
| Who sets it | Configured once at commissioning | Tuned to your site's own load and tariff |
Rule-based control is not a straw man. It is what ships with most battery systems, and it is what your battery falls back to if you ever stop CESS. It works; it just decides with less information.
Three jobs, one battery, and they compete for the same charge.
Every kilowatt-hour in the battery can do only one of these. Deciding which, hour by hour, is the whole job.
Peak shaving
Holds your monthly billing peak down. A demand charge is set by your single highest interval of the month, so one missed afternoon costs you for thirty days.
Energy arbitrage
Buys power off-peak and uses it on-peak, earning the spread between the two rates. The smallest of the three drivers in our pilot model.
Curtailment recovery
Keeps room in the battery for the solar the site cannot use at midday, then moves it to the hours it is worth most. That is PJJ Recover.
What each of these was worth at our pilot site is modelled separately in the investment case.
Measured against what would have happened without it.
A dispatch claim is only worth the baseline it is measured against. Ours is agreed with you before we start, and it is the same baseline our fee is calculated on.
If you stop paying for CESS, the battery keeps working.
It reverts to conventional rule-based control. What you lose is the forecasting and optimisation layer, which is where most of the return in the model comes from.One module does not run on its own.
PJJ Dispatch is one of four parts of the Cloud Energy Storage System. Each hands something to the next, and the savings come from all four running together.
Find out what CESS would do at your site.
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