Fears of overheated IT systems and power outages in France and Europe are lessening this week as temperatures begin to fall.
France's principal power supplier, Electricité de France, announced on Monday that no official shutdowns would be necessary after warning that power cuts were a likely result of several weeks of high temperatures across the country.
The heatwave in France has caused severe difficulties for the country's power industry. The majority of France's energy is produced by nuclear power plants that are kept cool using river water.
The heat of recent weeks has caused this water to become so warm that it could no longer be returned to the river immediately after use without breaking strict environmental laws. Last week, under threat of losing the country's power supply, the French government temporarily relaxed those laws.
That decision by the government, together with lower temperatures across the country and efforts by French industry to cut power use, has prevented any power blackouts, EDF said in a statement. However, it cannot rule out accidental power outages as a result of thunderstorms or other natural incidents.
Not that French hosting companies admit to being concerned. Datacentre managers have shrugged off the threat of power cuts and overheated server rooms, insisting they have the resources to cope with both.
"We were not worried at all," said Eric Matheau, chief information officer of Bull. Bull houses its own and its customers' IT systems in its datacentre in Paris.
"We survey the weather all the time, including the temperature and humidity, and we have two air-conditioning systems where one is running and the other acts as a back-up," he said. The recent hot weather saw the temperature in Bull's server room rise by just one degree, not enough to set off any alerts, Matheau said.
"In terms of continuity of energy, we have independent generators that can run for several days and we often test them," he said.
No experienced IT manager should be caught out by temperature extremes or power cuts, Matheau added, but even in the smallest company the IT manager should be prepared for emergencies of this sort.
Fluxus, owned by BT's Ignite division, runs a large hosting and managed application service centre in Paris for blue chip companies including L'Oréal, La Redoute and Aventis. It cannot afford to lose power and has been designed to cope with both power cuts and extreme weather, chief executive and chief operations officer Nada Faycal said.
"Since last Thursday, when Paris was 40 degrees (Celsius), we tuned the cool air distribution in our datarooms and ran an extra unit from our two spares. We are now back to normal, running two cooling units with two spares. This has had no impact on the platforms," Faycal said.
Fluxus has three uninterruptible power supplies for its power supply from EDF and two power generators. The UPS will maintain power for the 50 seconds or so it takes for the generators to start and the datacentre can then run for several days without refuelling the generators, Faycal said.
Customers demand that sort of protection, said David Thain, analyst relations manager at Cable and Wireless. "Some of our customers stipulate exactly the level of protection they want," he said. All C&W datacentres have two electricity feeds supported by UPSs and diesel generators for when things go wrong. The generators can run for 72 hours.
However, dealing with the heat has not been too much of a problem for C&W because its datacentre is kept at such a cool temperature.
The Netherlands also faced possible loss of power as a result of overheating in its nuclear power stations last week. Like France, the Dutch government temporarily raised the maximum temperature of the water returned to its rivers.
"This measure was only taken for one power plant, which raised in temperature from 30 degrees to 32 degrees," Cor Ruijper, spokesman for Dutch power company Eneco Holding said on Friday.
"There was a lot of fuss about power cuts but we took steps and in the end nothing happened. We had to reduce the maximum electricity supply by 20% to 30% this week, but we do not expect to have to shut down the power now."
The Daily Express newspaper claimed to have discovered that the UK was destined for power cuts this winter as a result of low reserves of energy. However, National Grid Transco spokesman Chris Mostyn said on Monday that the situation is not as dire as the paper suggested.
"We said a few months back that our operating margin is slightly lower than we feel comfortable with. We are not saying there is not enough, just that we are eating into our safety net. There is enough generation in the country to match demand," he said.
Even with a lowered operating margin, the UK has 65,000 megawatts of generating capacity and the highest demand at any point last year was for 54,000 megawatts, Mostyn said.
Gillian Law writes for IDG News Service