French law lays out an obligation for energy suppliers to purchase electricity with a feed-in-tariff above the market rate. This extra cost to the supplier is then fully passed on to the energy consumer.
The European court has ruled in favour of the argument presented by 12 anti-wind groups that this amounts to state aid.
Despite the French government's requests to defer the decision, the court ruled that within three months the government must annul the 2008 ministerial decree that introduced the tariffs.
The ruling stems from an appeal to the council by Vent de Colère, an association opposed to industrial-scale wind power, on the grounds that the government had failed to notify the European Commission of the tariff as required for state aid under European law.
The feed-in-tariff for onshore wind has been set by the French government at EUR 0.082/kWh, with EUR 0.13/kWh for offshore windIn March the council's rapporteur called for the decree establishing the tariff to be annulled.
Only in October, the French wind industry was cautiously optimisitic about the prospects of the court finding in favour of the tariff after the government said that it had filed all the paperwork to notify the European Commission of the tariff.
The uncertainty surrounding the tariff, which began in Spring 2012, has led to a severe slowdown in French wind deployment.
Governments and onshore wind developers in other European countries will be eying the decision warily, with many other subsidy programmes operating on a similar system to the French model.