Our client, as owner of a solar power plant, filed suit against the Spanish Government alleging that changes in government subsidy rules led to unfair disadvantages for his enterprise. Fichtner provides support by preparing an expert technical and economic opinion paper. This includes investigations into the construction costs of solar power plants and of a legally defined reference power plant. Further, a comparison is made of the Spanish market model for remunerating solar plants with those of other countries. Research into details of the legislative procedure was conducted locally by expert staff from our Spanish subsidiary. The conclusions of the expert opinion are drawn on by our client in the arbitration proceedings.