PARIS (Reuters) - For two straight months this winter, France was a net importer of electricity for the first time in five years, a trend that could continue during periods of peak demand no matter who wins the April-May presidential election.
France, usually a net exporter of electricity, imported a record 950 gigawatt-hours of power on a net basis in January, the highest level since 1980, as a cold snap increased demand for heating amid a series of prolonged nuclear outages.
Dependence on its neighbors during peak winter demand could accelerate if France fails to develop renewables further or extend the lifespan of its 58 nuclear reactors, while cross-border exchange capacity continues to grow.
France's capacity to import electricity from its neighbors increased by 30 percent to 12.2 gigawatts (GW) in the 2016/2017 winter period, compared with winter 2015/2016, French grid operator RTE said in its winter outlook.
Data from the finance ministry showed France spent 290 million euros ($307 million) on electricity imports in January, compared with 56.5 million euros for the same month in 2016.
France passed an ambitious energy law in 2015 with a target of cutting the share of nuclear in its electricity mix to 50 percent by 2025 from 75 percent currently, while investing in renewables and efficiency to curb consumption and heat loss.
Although the share of renewables has increased to about 16 percent, it lags its peers and is well below the International Energy Agency's (IEA) average of 24 percent, the IEA said in its January review of French energy policies.
"Reaching the (50 percent target) will require careful policy guidance, effective markets and strong measures for renewables and energy efficiency," the IEA said.
Analysts say the situation in December and January was exceptional, blaming prolonged outages of about a dozen nuclear reactors for safety checks and low hydropower output as a lack of rain and snowfall pushed reservoir levels to new lows.
"However, given the high sensitivity of French electricity consumption to cold temperatures and the fact that the French production fleet has fallen due to coal plant closures, this issue will be present every year, maybe not to the extent we saw this winter," said Utomi Odozi of Freepoint Commodities.
While President Francois Hollande has begun implementing some of the measures in the energy bill, tougher decisions such as shutting nuclear plants and increasing investments in renewables would have to be made by the next government after the April-May election.
Independent candidate Emmanuel Macron, the frontrunner to win the presidency, plans to stop coal-power generation by 2022. He would keep the 50 percent nuclear target while launching 26 GW of renewables development.
The cornerstone of Macron's energy plan is 15 billion euros of investments with objectives that include immediate help for low-income earners to renovate about 2 million old homes to cut heat loss and curb consumption.
Far-right leader Marine Le Pen, who is expected to come top in the first round of the election but lose in the decisive second round, wants France to be energy-independent, with state-run utility EDF at the center of energy security.
Le Pen has proposed keeping the French nuclear fleet going as long as watchdog ASN deems the reactors safe. She plans to scrap a plan to privatize French hydropower stations.
According to his election manifesto, conservative Francois Fillon, third in opinion polls, also wants France to be energy-independent. He would scrap the 50 percent nuclear target, which he has described as absurd.
He plans to extend the lifespan of the reactors to between 40 and 60 years with the agreement of ASN, and would halt the planned shutdown of the Fessenheim nuclear plant, France's oldest.
But aiming to make France self-sufficient could be costly, according to Fabien Roques, senior vice president at FTL.CL Energy consultancy. Roques said the focus should instead be on how to include cross-border participation in France's security of supply and capacity mechanism that was launched in January.
Capacity mechanisms are used to fund power plants that may not be cost-effective but can guarantee supply during peak demand.
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Additional reporting by Geert De Clercq; Editing by Dale Hudson