The drain on the electricity supply during the record high
temperatures experienced in July caused the National Grid to
issue two power warnings within a week.
The warnings came as parts of central London
were left without power for a second day after a series of
EDF Energy, which supplies the affected areas,
said that although the failures were not caused by the
weather itself, the system had experienced unusual
demand for air conditioning and extra refrigeration.
The gap between summer and winter usage is large,
A spokesman for National Grid said "last week we informed
the market that we needed them to generate more
electricity or use less because we are getting close to
our safety margin, which we do not disclose".
Demand on the hottest July day had been 44,000 megawatts. This compares
to 42,000 megawatts last year, when the average temperature
Peak demand in winter is 62,000 - 65,000 megawatts.
During this month's heatwave, emergency oil-fired power
stations in Kent and Hampshire were fired up even though the energy
they produce is very expensive - 45p per kWh. The average
householder pays 14p.
The increased costs will be passed on to consumers.
Back to top