District cooling loss waterfall
Every ton-hour of cooling produced should end up on a bill, or have a cause and an owner. This interactive demonstration shows how Inerra Impact accounts for unbilled cooling, from budget to cooling billed and down to the leak, meter or bill behind each loss, using a fictional four-plant district cooling business in the GCC.
At a glance:
Against budget
Metered export against the budget at actual weather, of expected energy. Weather moved the budget by .
How much is explained
of the shortfall is explained by counted losses. The other , , is unexplained.
of unexplained losses, more than the whole shortfall. The counted losses are net better than budget, so the gap is a data question first.
of unexplained losses, even though this view is ahead of budget.
of unexplained losses, inside the model and meter tolerance on complete data, so this view is on budget.
How much is actionable
worse than allowance across in network faults, low delta T, metering and billing: the losses operations, contractors, customers and the billing team can act on. of it has no contractual owner.
Every controllable category is at or better than its allowance in this view.
Largest variance and next step
at , Main cause: , carried by , and , carried by .
Every category is at or better than its budget allowance in this view, counting paid curtailment as recovered.
Net budget (P50)
Metered against it
Budget at actual weather
Weather
Metered export
against budget at actual weather
Total losses
Expected energy less metered
Unexplained
Not accounted for by any loss
Data completeness
Weighted by expected energy
Battery round trip
against guarantee;
CHP heat delivered
against heat budget at actual demand
From budget to cooling billedFrom cooling produced to cooling billedCHP heat, from budget to heat deliveredWhere the CHP gas wentBattery round tripPlant efficiency against design
Each loss bar shows the result against the allowance in the budget. Up is better than budget, down is worse. Click a bar to see what is inside it.Every ton-hour between the plant meter and the customer bills. Click a loss bar to see what is inside it and who owns it.CHP heat in MWhth, measured inside the energy centre at the CHP heat meters after the dump radiators, so boiler heat and the network beyond the energy centre are outside it. Heat dumped through the radiators is not a bar here, because the network did not need that heat. It burned gas for no heat sale, so it is in the Fuel tab.Every MWh of gas burned, on gross calorific value, split into what came back as electricity and useful heat and what was lost, beside the engine maker's full-load figures converted to gross. A real assessment corrects them to the actual load, ambient conditions and gas quality, and applies the contract tolerance.Every MWh imported to charge the battery and run the site, split into what was exported and what was lost on the way, beside a reference split built from the round-trip efficiency guarantee and the design loss budget.Electricity used per ton-hour of cooling produced, split by system, against the design figures behind the budget. Emicool's published terms let it add 10% to the consumption charge for each degree below 8.9 °C, or lower the supply temperature instead; in Dubai any such surcharge needs Supreme Council of Energy approval. A real assessment checks whether the contracts allow it and whether it is billed.
- Totals
- Weather (degree days), not controllable
- Heat lost
- Unexplained
- Totals
- Weather and design, not controllable
- Better than budget
- Worse than budgetLoss
- Unexplained
- Largest shortfall
Low dataData completeness is here, below . Bars that look better than budget may simply be under-recorded, with the missing losses sitting in unexplained, so read them with care.
The value axis starts above zero so the loss bars stay readable; total bars carry a break mark where they are cut. Source: fictional sample portfolio, full year 2025.
Inside
Allowed ·Actual ·Against allowance
Items and owners
Click an item to see the events or measurements behind it.
Unexplained has no items, and the budget allows nothing for it. It is what is left once every counted loss and the cooling billed are taken away from cooling produced. Below about 1% of cooling produced it is within the uncertainty of the plant meter against the building meters. Gaps in building meter data do not lose billed cooling once the true-up bills it, but they stop the daily reconciliation, so losses on those buildings cannot be attributed. The budget allows nothing for it, so within the ±1% tolerance it is shown as a variance only for completeness. Compare it with data completeness in the site table.
By site
Bars show the actual loss and ticks show what the budget allowed. Click a site to drill into it. In % view each site is measured against its own expected energy.
Source: fictional sample portfolio, full year 2025.
Who owns the loss
Each loss item mapped to the party that carries it. Some unbilled cooling can be recovered by back-billing, within the limits in each customer contract, so a real assessment records what is recoverable as well as who owns it.
- Owned by a party or contract
- No contractual owner
- Unknown (unexplained)
Source: fictional sample portfolio, full year 2025.
When they happened
Each dot is one event, sized by what it lost. Click a dot or a row to open it.
Events, largest first
| Start | Site | Asset | Root cause | Duration | Lost | Status |
|---|
By asset
By month
Click a month to set the period.
How it is measured.
Times are site local time. Source: fictional sample portfolio, full year 2025.
Losses by month
Every loss category, month by month, with the total the budget allowed marked on each bar. Click a month to set the period, and click it again to go back to the whole period. Click a category in the key to open it.
Source: fictional sample portfolio, full year 2025.
Sites
Sorted by result against budget at cooling produced, worst first. Click a row to drill into the plant. Load factor is cooling produced against plant capacity over every hour in the period.
| Site | Plant | Capacity (TR) | Budget at cooling produced (RTh) | Billed (RTh) | Against budget | Losses | Unexplained | Data completeness | Load factor |
|---|
Source: fictional sample portfolio, full year 2025.
Method, definitions and sample data
- Net budget
- Cooling the business plan expected to bill in 2025, after the losses it allows for in each category.
- Production and connections
- The change in budget because the plants produced more or less cooling than planned: hotter or cooler months, buildings connecting earlier or later than the plan assumed, and any network loss or plant meter error above its allowance, which is also shown in its own bar. Cooling produced is what the buildings drew plus what the network lost on the way. It is not an operational loss, so it is shown in grey.
- Cooling produced
- Cooling leaving the plant, measured at the plant export meter on the network side of the storage tank, so charging and discharging are already netted out. Its flow sensor is on the flow pipe, so a leak from a flow pipe shows in this balance at about 2.3 to 2.8 RTh per m³, while a leak from a return pipe barely does; return leaks cost water and treatment and are followed on the make-up meter, not in these bars.
- Cooling billed
- Cooling billed to customers and not in dispute, from the energy meters at each building's energy transfer station, estimated bills included. A back-bill the customer disputes stays a loss until it is settled.
- Unbilled cooling
- The gap between the two, like non-revenue water for a water utility. Some of it is physics: heat gained by buried pipes, and pump work that ends up in the water. The rest is leaks, wet insulation, extra pumping from low delta T, meters reading low, and bills that were estimated, late or wrong.
- Allocation
- Lost cooling goes to the first cause that applies, in the order the bars run: plant meter error, network faults, network heat gain, low delta T, metering, then billing. Whatever remains is unexplained.
- Plant meter error
- A plant export meter that reads high makes cooling produced look bigger than it was. It loses no revenue, because customers are billed from their own meters, so it gets its own bar, nothing is allowed for it and it is valued at nothing. It is booked only after a clamp-on check on the export meter has confirmed it, as at Wahat on 14 October 2025; until then the gap stays in unexplained.
- Heat gain and pump heat
- Ground heat gain depends on pipe size, insulation and ground temperature. It does not scale with cooling load; it follows ground temperature and peaks in late summer. The budget allows the design ground gain in ton-hours for each month, whatever the load, plus pump heat at design as a share of cooling produced. Insulation that has aged past its design heat gain counts with the damaged and wet sections under network faults. About 55% of distribution pump electricity ends up as heat in the water between the plant meter and the building meters. At the design 0.07 kW/TR that is 1.1% of cooling produced, counted with ground gain as design.
- Low delta T
- Pumping above the design 0.07 kW/TR, and the extra heat a colder return pipe picks up from the ground, both caused by water coming back below its design temperature. The cause is at the building, in the customer's secondary system or the provider's ETS heat exchangers and control valves. The provider carries it unless an approved low delta T surcharge is billed.
- Plant view
- Electricity per ton-hour of cooling (kW/TR), split into chillers, condenser pumps and cooling towers, distribution pumps and auxiliaries, against the design figures. Low delta T between supply and return raises distribution pumping and keeps more chillers running. Delta T is flow-weighted: cooling divided by water pumped.
- Value view
- Each RTh at the consumption charge. Metering and billing losses are lost revenue at that charge. Leaks and heat gain are cooling nobody used, so their true cost is the electricity and water to make it; they are shown at the same charge here so the bridge closes. Capacity charges are fixed per ton of contract capacity, so most unbilled cooling does not touch them. The exception is a connected building with no billing account, which misses its capacity charge too. That is not in the value shown here: each of those events notes the capacity charge it missed, about £132.8k in all. A plant meter over-registration is a measurement error with no revenue effect; it is shown at the consumption charge only so the bridge closes. Billing at the wrong rate does not change the ton-hours billed, so it is not in this bridge; a real assessment checks it separately against the tariff schedule.
- Back-billing
- The contracts allow three months of back-billing before the bill date, for every kind of billing error. Cooling that a back-bill recovered and the customer paid within 2025 is not counted.
- Estimates
- An estimated bill is a timing difference: the next actual read from the meter's cumulative register bills the rest, so estimates corrected within 2025 are not counted. What stays is what can no longer be billed, where an estimate ran past the three months the contracts allow to back-bill, plus estimates still waiting for an actual read at year end. For a failed meter, the loss is the consumption the contractual estimate did not bill.
- Billing status
- Open: the error is fixed and the back-bill is still inside the three months, or the actual read is still due. Disputed: the back-bill went out and the customer has not accepted it, so it stays a loss until settled. Closed: written off, beyond the three months or as a concession.
- Events
- Leaks, meter failures and billing errors are listed one at a time with the building or pipe section, dates, root cause, owner and evidence. A building has one event at a time, and a new building has nothing before its billing account opens. An event that runs past a month end is carried into the next month as its own part, so each month holds the loss it had. Events add up exactly to the item above them.
- Response target
- 4 hours from a leak alarm to a crew on site, and 24 hours from a meter alarm to a technician on site with 72 hours to restore the meter, in this sample. A leak repair often waits for a planned shutdown of the branch, because isolating it cuts off customers. Leaks cost more in make-up water, treatment chemicals and corrosion than in cooling, so each leak event also shows the water lost and what it cost. Small air valve leaks, under about half a cubic metre an hour, cannot be separated from the make-up trend; they are found on the monthly chamber inspection, counted from the inspection before, and carry no response target.
- Plant trips
- Not a bar here. With the plant meter on the network side of the storage tank, a chiller trip that the storage cannot cover cuts cooling produced and cooling billed alike, so it shows in production and connections, not between the meters.
- Data completeness
- The share of building meter intervals with a valid reading, weighted by consumption. It falls when meter communications fail or a meter stops.
Sample data. The four plants, their names, tariffs, allowances, events and every number on this page are fictional, generated to show how the waterfall behaves. Meter models are named to make the sample realistic; the faults and figures attached to them are invented. Values are in pounds at the 2025 average rates of about AED 4.84, QAR 4.80 and SAR 4.94 to the pound. The UAE consumption charge of £0.117 per RTh is AED 0.568, the published Empower rate. Qatar and Saudi providers do not publish their tariffs, so £0.100 and £0.090 per RTh are assumptions. Electricity is priced at 2025 DEWA, Kahramaa and SEC commercial rates, with DEWA's fuel surcharge of about 6 fils/kWh. The fuel surcharge that district cooling providers pass on to customers is left out of the consumption charge.