They also require a warm-up period of 4 - 7 minutes to reach full light output.

The full-scale aggregate operations ran throughout most of the century reaching peak output in the 1960s and 1970s.

However without public sector workers, the private sector cannot reach maximum output - due to the paradox of productivity.

"We are still very short of reaching potential output."

The 1,728 MW Dinorwig pumped power station, though, can reach full output in 16 seconds.

As an emergency reserve power plant, it should reach full output within 10 minutes.

Low pressure sodium lamps are very efficient but they don't render colour well and take several minutes to reach full output.

Some that use a mercury amalgam can take up to three minutes to reach full output.

An HID lamp requires a short warm-up time before it reaches full output.

Production was also slow, not reaching maximum output until 1944.