The cheapest energy is the energy you do not consume

Faced with surging prices and the climate emergency, the first instinct is to produce energy differently. But there is a faster, cheaper, no-regret lever: consuming less of it for the same service. That is energy efficiency. A saved kWh costs nothing to produce, emits no CO₂ and wears out no equipment. It is the first move, before any production investment.

Where the losses hide

The reserves are almost always the same from one plant to the next:

• electric motors, ~70% of industrial electricity use, often oversized and without a variable-speed drive — a VSD on a pump or fan commonly saves 20 to 50%;
• compressed air, dragged down by leaks and poor efficiency;
• steam, with its faulty traps and missing insulation;
• waste heat: the thermal energy dumped to the atmosphere — flue gas, condensate, hot water — that could be recovered to preheat an incoming stream.

The hierarchy of actions

There is a common-sense order. First remove the needless demand: switch off what runs for nothing, hunt leaks. Then tune: match motor speed to the real load, lower a network pressure. Then recover: put waste heat to use. Only then invest in higher-performance equipment. You always start with the free or quick actions before the big projects.

Worked example: recovering 300 kW of waste heat from flue gas, 6,000 h/yr, displaces ~1.8 GWh/yr of gas; at €0.06/kWh that is ~€108,000/yr saved, for an exchanger often paid back in 2 to 3 years.

Measure to manage: ISO 50001 and the EnPI

You only manage what you measure. The ISO 50001 standard structures an energy management system: set a baseline, define energy performance indicators (EnPI), set targets and verify progress. Without that measurement, savings “melt” over time, good settings drift away and no one notices. In Europe, the Energy Efficiency Directive (EED) further mandates audits for large companies.

The carbon co-benefit and the payback

Every efficiency action has a double effect: it cuts the bill (OPEX) and the emissions, without changing the process. Many actions have a payback of a few months to two years, and some are supported by energy savings certificates (CEE). That is why efficiency is always the first step of a decarbonisation roadmap: the cheapest, the safest, the one everything starts with.