Between closing and opening a facility draws for 15 hours with nobody in it, and the bill carries every one of them. We meter each board for a week, read what is running at 2 am circuit by circuit, and say which of it has to stay.
41 kW through the night: lighting and rooftop units left on, car park fans running, and one unlabelled circuit at 36 A.
The night is the flattest part of the week and the easiest to overlook, because nothing on it looks like a problem. It is also the part that runs every night of the year.
Ashworth House, the specimen office in the scrolled story: 4 floors over a lobby and a car park, open 6 am to 9 pm.
Every kilowatt the facility draws at 2 am it draws at 3 am and at 4 am, and on Sunday as on Tuesday. A load that runs all night costs more over a year than one that runs hard for an hour a day.
The office draws 50 kW at 2 am and needs 9 kW of it. After the changes it draws 16 kW at the same hour, and the week is 4,382 kWh shorter.
A utility bill sees the whole service. A meter on each board sees which circuit is drawing, which is the only way to say what should be switched off.
Each circuit on the specimen office's main board at 2 am on a weekday, and what it reads after its change.
Some of it is needed: the server room, refrigeration, anything life safety. Some was left on: lighting at a fraction of its daytime draw, rooftop units holding a daytime setpoint for empty floors, car park fans running with no cars.
And some nobody can name. Circuit 23 on this board has no label and draws 36 A all night. Finding what it feeds is part of the determination, and it is often the quickest kW on the list.
One change is made once. The rest run every day, on a controller, as rules an engineer wrote.
Ckt 23, no label. Made once by a licensed electrician, and read again at its circuit after.
Floor lighting. A daily rule on the controller, read at its own circuit every month.
Rooftop units. A daily rule on the controller, read at its own circuit every month.
We write down every board and put a meter on each one, reading every 15 minutes for a week.
We split the quietest hour by circuit and sort what is needed from what was left on and what nobody can name.
We specify each change: one made once by your electrician, the rest as daily rules on the controller.
We read the same week again, circuit by circuit, and state the kW and kWh that came off.
What each board draws when the facility is closed, in kW, and which circuits carry it.
From a week on every boardEach after-hours load sorted: needed, left on, or unlabelled, with the kW and the kWh a week it accounts for.
Reviewed by an engineerThe same week read again after the changes, and every month the rules run.
Read on the panelThe peak is the other half of the bill. See Peak Determination.
A week of metering on every board, at 15 minutes, in a normal operating week. The utility's record shows the night exists; only a meter on the board shows which circuit is drawing it.
Any physical change is made by a licensed electrician. The daily rules run on our controller, and what a kWh is worth is read off your own tariff, so nothing here prices it for you.
