Energy suppliers: flexible assets run on rules of thumb

Heat pumps, home batteries and grid export in a fleet run on simple rules

What happens. Thousands of homes have a heat pump, a battery and solar panels on the roof. Each device follows its own logic: the heat pump holds the room temperature, the battery charges when the sun shines, surplus goes to the grid. The supplier sees the fleet only as a load curve that moves with the weather.

What it costs. Power is bought at expensive hours and exported at cheap ones. Batteries are full before the midday price dip and empty in the evening peak. The flexibility the customers paid for is not turned into money, and the tariff cannot pass any advantage on.

Why the usual fix fails. Time windows and price thresholds work on the days they were set for. A cold week, a cloudy spring or a new tariff structure breaks them, and adjusting thousands of rule sets by hand does not scale.

How a fixed-price remote diagnosis checks it. From metering data, device logs, weather records and the prices of the same period I compare what the fleet did with what a forecast-led plan per home would have done, within comfort and battery limits. The fixed-price remote diagnosis shows how much is at stake and what predictive energy management would need.

Background: Economic predictive control

Spot-market bids are built in spreadsheets, not by optimisation

What happens. Every morning the desk builds day-ahead and intraday bids from forecasts, plant availability and the positions already held. Much of it lives in spreadsheets and in the heads of two or three traders who know which constraint matters on which day.

What it costs. Bids that ignore a minimum run time or a storage limit have to be corrected later in intraday trading at a worse price. Good options stay unused because nobody had time to check them. When one of the experienced traders is away, the quality of the bids drops.

Why the usual fix fails. More spreadsheet logic makes the files slower and harder to check. A bought optimisation tool needs someone who can write the portfolio as a mathematical problem, with on/off decisions and limits, and keep that model correct as assets change. Such people are hard to find.

How a fixed-price remote diagnosis checks it. From past bids, positions, forecasts, prices and the asset limits I rebuild a few trading days as an optimisation problem and compare the result with the bids actually placed. The fixed-price remote diagnosis shows where the current process loses money and what an optimisation model for the desk would take.

Storage, gas plants and renewables are scheduled without ramps and start costs

What happens. A portfolio of batteries, gas engines or turbines and wind and solar parks is scheduled against market prices. The plan treats each unit as if it could jump to any output at any time. Operators then fix the plan by hand when a ramp is too steep or a start comes too soon after a stop.

What it costs. Extra starts burn gas and wear engines. Batteries cycled for every small price spread lose capacity faster than the trade earns. Deviations from the plan end up as balancing costs.

Why the usual fix fails. Fixed rules such as “at most two starts a day” or “only cycle above a certain spread” protect the equipment but leave money on the table on good days and still cost too much on bad ones. Correcting the plan by hand keeps the operators busy.

How a fixed-price remote diagnosis checks it. From dispatch records, start counts, battery cycling data, ramp limits and prices I rebuild past weeks as a schedule that includes start costs, ramps and battery wear, and compare it with what was run. The fixed-price remote diagnosis shows whether economic scheduling would change the plan noticeably and what it would take to set up.

Background: Optimal schedules and setpoint plans

Assets in the portfolio consume, store and feed in at the wrong hours

What happens. A supplier has heat storage, combined heat and power units, batteries, industrial customers with flexible loads and its own solar parks. Each runs on its own timetable or on the operator’s judgement. Nobody decides centrally, hour by hour, which asset should consume, store or feed in.

What it costs. Heat is stored when power is cheap but not needed, and released when power would have been worth more. Flexible loads run in the evening peak. The supplier buys balancing energy it could have avoided with assets it already owns.

Why the usual fix fails. Timetables are set once a season and do not follow prices. Leaving it to the operators works for one or two assets, not for a growing portfolio where every decision affects the others.

How a fixed-price remote diagnosis checks it. From the operating data of the assets, the heat and power demand, the forecasts and the prices of a past period I compute a joint dispatch that keeps every technical limit and compare it with what was run. The fixed-price remote diagnosis shows how large the difference is and what a central economic dispatch would require.

Electric-fleet charging and balancing-market bids do not fit together

What happens. Electric buses, delivery vans or trucks charge at the depot overnight. The aggregator wants to offer their flexibility on the balancing market. But the vehicles leave at different times with different energy needs, and the bid has to be placed long before anyone knows which vehicle will actually be plugged in.

What it costs. Bids that are too cautious earn little. Bids that are too bold cannot be delivered and lead to penalties, or a vehicle leaves the depot without enough charge. Either way, the fleet operator loses trust in the scheme.

Why the usual fix fails. Charging as soon as a vehicle is plugged in leaves no flexibility to sell. A fixed share of the fleet reserved for the market ignores the daily timetable. Writing the decisions as an optimisation with on/off choices and vehicle limits needs specialists that fleet operators rarely have.

How a fixed-price remote diagnosis checks it. From charging logs, arrival and departure times, energy needs, timetables and market prices I compute which flexibility the fleet could have offered with confidence, and compare it with what was bid and delivered. The fixed-price remote diagnosis shows whether combined charging and bidding pays off and what it would take.