asked the Secretary of State for Energy what percentage of the energy used for illumination of public places is consumed between midnight and 6.30 a.m.

There is no accurate or reliable information available, since the control of street lighting is a matter for the local authorities, whose practices vary widely. An estimate made by the Electricity Council and based on information collected a few years ago suggests that the proportion might be rather more than one-third of the total consumption for public lighting purposes.