PARIS, June 12 (Reuters) - Electricity produced by onshore wind and solar plants may become more competitive with power generated by upgraded nuclear plants in France by the end of this decade, a study by environmental group Greenpeace showed on Thursday.
The study comes a week before Energy Minister Segolene Royal presents the broad lines of a much-delayed framework energy law that aims to spell out how France will cut the share of atomic energy to 50 percent from the current 75 percent by 2025.
The rising cost of France's nuclear energy is a concern and the government should set up independent expert institutions to help it plan long-term energy investments, a parliamentary committee said in a report published on Tuesday.
According to the Greenpeace study, the investment needed to upgrade French utility EDF's 58 nuclear reactors to bring them close to the safety level of a new-generation EPR reactor would raise median production costs to 133 euros ($180) per megawatt-hour (MWh).
That estimate, based on an extension of the lifespan of current reactors by 10 years to 50 years and 4.4 billion euros worth of work per reactor, would make nuclear energy less competitive than onshore wind power around 2015, the study said.
Greenpeace also sees the cost of photovoltaic power falling to less than 134 euros/MWh around 2019 from more than 250 euros/MWh today, making it competitive with the renovated French nuclear plants by that time.
Photovoltaic solar panels turn sunlight directly into electricity, from concentrating solar power.
State-owned utility EDF has said it expected investment of about 55 billion euros by 2025, less than 1 billion euros per reactor, to upgrade the plants in the light of lessons learnt from the Fukushima disaster in Japan and prepare them for an extension of their lifespan. But the state auditor raised that estimate to 62.5 billion euros last month.
Greenpeace's 4.4 billion-euro price tag per reactor is based on calculations by Wise-Paris and Global Chance, associations close to anti-nuclear groups, reported earlier this year.
EDF has also said the reactors' lifespan could be extended by 20 years, arguing that their design was based on similar models built by Westinghouse in the United States, where many were granted 60-year licences.
French regulator ASN is expected to give a first opinion on whether reactors can be granted life extensions in 2015 and decide reactor by reactor in 2018-2019.
($1 = 0.7345 Euros)
(Reporting by Michel Rose; Editing by James Macharia, Larry King)