The storm brewing off Renoir's coast

In Paris, the splendour of the upper Normandy coast was eulogised in paint and in words in the 19th century by, among others, Auguste Renoir, JMW Turner, Victor Hugo and Guy de Maupassant. The cliffs north of Dieppe, where the Norman fields and hills run into the English Channel, remain largely unchanged to this day. But not for long, maybe. If ambitious plans supported by the French government go ahead, the seascapes painted by Renoir and Turner will become part of a giant offshore wind farm by 2015.

The plans, the subject of a bad-tempered public consultation exercise which ended this week, are the test case for a much larger €20bn (£16.7bn) programme to build colossal offshore wind farms in a score of places along the French coast from the Pas de Calais to the Mediterranean by 2020. The first proposed sites should be announced next week.

France, which depends on nuclear energy for 80 per cent of its electricity, has been comparatively slow to join the experiment with wind-power. Although there are already 950 maritime wind-generators in the European Union, none have yet been built off the 5,800km (3,600 miles) of French coastline.

President Nicolas Sarkozy, in an environmental conference early in his presidency, committed France to generating 23 per cent of its electricity from renewable sources by 2020 (including about 8 per cent from land and maritime wind farms). The so-called "two coasts" project – to build 141 immense generators, 500ft tall, off Le Tréport and Mers-lès-Bains where Normandy and Picardy join – is an important step towards this objective.

The plan was initially rejected in 2006 after the area was found to be littered with unexploded mines from the Second World War. The promoters appealed. An independent inquiry, which began in April, has received encouraging comments from national and regional governments and some local politicians, who welcome the new taxes and jobs that the giant wind-farm would generate. The project would produce 700 megawatts of electricity, slightly more than the first phase of the gigantic London Array wind farm off the Essex coast (which will eventually be the largest in the world).

But the French inquiry has also heard vociferous opposition from other local politicians, hotel and shop owners, fishermen and environmental campaigners. They say that the €1.8bn project, due to be completed by 2015, will damage the local fishing and tourist industries and desecrate one of the best loved and least spoiled coastlines in continental Europe.

Pascal Cribier, one of France's most respected rural planning experts, and a native of upper Normandy, says that the intrusion of 150m-high wind turbines eight miles off shore would "destroy a unique and powerful landscape". He added: "The [northern Norman] cliffs are the frontier between a pleasant and productive countryside, created by mankind, and the infinite horizon of an untamed sea. Nowhere else [in France] is this transition so abrupt, so beautiful and so spectacular. This is a natural wealth which belongs to all of us and something that wind turbines would destroy."

Local fishermen and hoteliers have more practical objections. Trawlermen complain that they will lose 70 per cent of their catch if they are barred from the 75sq km of the wind farm. "The company running the project would be given dictatorial control over the best fishing-grounds of the boats from Le Treport and the Bay of the Somme," said Olivier Becquet, director of the local fishermen's co-operative.

Gérard Bilon, president of Sans Offshore à l'horizon, a pressure group created to oppose the project, says that "half of the sea views from Le Treport and Mers-lès-Bains would be blocked by the curtain of turbines". The negative impact on tourism would, he says, cancel the benefits of the promised increased taxes and jobs. Liseline Lavoine, owner of the seafront restaurant Le Comptoir de l'Océan, said that the sunsets at Le Treport were made famous by the novelist and poet Victor Hugo when he visited the town in the 1830s. "What will the sunsets be like when we have the Christmas-tree lights of 141 generators blinking on the horizon?" she asked.

The organisation chosen to build the giant wind-farm, la Compagnie du Vent, a subsidiary of the French energy giant, GDF-Suez, says the wind generators would be more than eight miles offshore. Seen from the shore, even at 150m tall, they will look like "matchsticks seen from one metre away".

But at a final public meeting in Le Treport this week, the company's director of offshore operations, Jean-Mathieu Kolb, made several new concessions. The turbines would, he said, be shifted a fraction towards Britain until they were an average of 18km from the French coast instead of 14km. Fishermen, instead of being banned from the entire zone, would be forbidden to cast their nets only in the "immediate vicinity of each generator".

The independent planning appeal agency, the Commission nationale du débat public, is expected to reach its conclusions by the beginning of next year. With both national and regional governments in favour, local protesters fear that their objections will be drowned by the argument for an overriding national, and global, interest in renewable energy.

But France's off-shore wind wars may be only just beginning. The government is expected to announce in the next few days its first 10 chosen areas for an immense programme of maritime wind-sites from the North Sea to the Mediterranean capable of generating 3,000 megawatts of electricity. Ultimately, it wants to promote a score of sites which will generate 6,000 megawatts by the end of the decade.

Officials at the environment ministry say that they understand the concerns of fishermen, the tourist industry and lovers of landscape. With almost 6,000km of coast, it should be possible, they say, to promote "the greater ecological good" of clean energy and still "respect local environmental needs". But how? And where?

Vague plans for two huge wind farms in Breton coastal waters, off Saint Malo and off Saint-Brieuc, are already almost as contentious as the more advanced project off northern Normandy. Fishermen have suggested one much larger Breton project further off shore. The local prefect (senior national government administrator) will give his opinion on Monday.

There are also plans for a 120-generator offshore wind farm in another part of the French coast much loved by French (and British) tourists: the Vendée between the Ile d'Yeu and Noirmoutier. The local council is fighting the proposal tooth and nail. Mr Cribier, the landscape expert, said: "With wind turbines, we are repeating exactly the same mistakes that we made 50 years ago when we constructed big tower blocks, or 30 years ago when malls and industrial areas were allowed to disfigure the edges of all our cities. These are all huge, technocratic projects which destroy the countryside by selling the illusion of being modern."