The shortage is not software engineers. It is the people who install things.

Every energy transition timeline and every datacentre buildout schedule contains an assumption about installation labour, and in most countries that assumption is wrong.

High voltage jointers, refrigeration engineers, controls technicians, medical equipment engineers and commissioning specialists are all in shortage across northern Europe and much of the United States, with an age profile that makes the next decade worse before it improves.

Why training has not responded

Apprenticeship capacity is limited by qualified supervisors, not by candidate interest. A firm that takes an apprentice loses productive time from its most experienced engineer, and in a market where that engineer is already oversubscribed, the firm rationally declines.

What has worked

Shared training centres funded by groups of employers, which pool the supervisory cost. Manufacturer academies tied to specific equipment lines. And, in Denmark and parts of Germany, subsidy structures that pay for the supervisor's lost hours rather than the apprentice's wage.

That last design detail matters more than the headline funding number, because it addresses the actual constraint.

The forecasting implication

Any national decarbonisation plan that does not publish an installer workforce number alongside its equipment number is publishing half a plan.