Workshop energy costs, and where it actually goes.

Compressed air is the expensive habit

Air feels free because nothing arrives in a tank, and it is one of the most expensive things a workshop produces.

A compressor converting electricity into compressed air is not efficient to begin with, and a system with leaks runs to replace air nobody used. The classic test is to shut everything down at the end of the day and listen: if the compressor cycles overnight, you are paying to fill a leaking system while the building is empty.

Leaks are cheap to find and cheap to fix, mostly at couplings, hose ends and tool connections. Fixing them is usually the single largest reduction in workshop energy costs available, and it takes an afternoon with soapy water and a marker.

Heat leaves through the door you keep opening

A workshop with a large opening cannot be heated the way an office can, and trying is where a lot of money goes.

• Heating the whole volume when only the working level needs to be comfortable.
• A main door open far longer than the vehicle movement requires.
• Destratification, or the absence of it, leaving the warm air at roof height.
• Uninsulated roofs and walls, where heat leaves as fast as it is produced.
• Heating overnight and at weekends by a timer nobody has reviewed since it was set.

The cheapest interventions here are behavioural and set-up rather than capital: close the door between movements, check the timer actually matches your hours, and get the warm air back down to where people are.

Lighting is the easy one, and worth doing properly

Lighting is usually the first thing changed and the change is often half done.

Modern fittings use a fraction of the power of older ones and last far longer, which makes the replacement straightforward arithmetic. What gets missed is control: sensors in areas used intermittently, separate switching so one bay does not light the whole building, and enough light at the working level rather than a general glow.

Better light also has a productivity effect that does not appear on the energy bill. Diagnosis is faster and mistakes are fewer under light that lets someone actually see, so this is one of the few overhead reductions that improves the work as well.

Equipment left running

Every workshop has things that are on because switching them off is a decision nobody made.

Compressors held at pressure overnight, welders and battery chargers left powered, extraction running in an empty bay, screens and computers never shut down, and the kettle that is technically a heater. Individually trivial, and collectively a constant load through every hour the building is empty.

A closing checklist is the fix, and it is the same closing checklist that covers the alarm and the shutter. One habit, several problems.

The tariff and the contract are worth an hour

Everything above reduces what you use, and the other half of a bill is what you pay per unit.

Workshops routinely sit on a rolled-over contract at an out-of-contract rate, which is the most expensive tariff available and the easiest to leave. Knowing your contract end date, and diarising a reminder well before it, is worth more per hour spent than most operational improvements on this page.

It is also worth checking whether your usage pattern suits a different structure. A workshop with heavy daytime load and almost nothing overnight has a very different profile from a business running around the clock, and a tariff designed for the wrong shape quietly costs money regardless of how efficient the building is.

Measure before spending capital

The temptation is to buy something, and the sequence that works is to measure, fix the free things, then decide.

A workshop that knows its base load, meaning the power drawn when nothing is happening, can tell immediately how much of its bill is leaks, standby and timers rather than work. That number frequently surprises people and it is the one that justifies or rejects a capital purchase.

Do the free and cheap things first, then measure again. Deciding on solar, a new compressor or a heating system is a much better decision made against a building that is not already wasting a third of what it uses.