Effectiveness and weaknesses of supporting policies for solar thermal systems-A case-study

It is well known that the European Union has pledged to achieve by 2020 a 20% share of renewable sources in final energy consumption and the same share as reduction of final uses. To achieve these goals, the solar thermal sector could provide an important contribution, since the demand for heating and domestic hot water production accounts for 37% of the total energy demand in Europe. In recent years, several supporting policies were actuated in the EU countries and, among these, the Italian Ministry of Environment, in collaboration with Regions, developed several measures for local renewable energies integration in the regional territory, also with the purpose to spread solar thermal water heating (SWH) systems in the built environment. This paper's goal is to evaluate the effectiveness of the supporting strategies to SWH through a comprehensive assessment on the Lombardy Region case-study; to that end, representative indicators were calculated and analyzed. In particular, a so-called Renewables Incentive Paradoxical-Effect (RIPE) was experienced, according to which the greater is the specific amount of subsidy over the years, the higher is the recorded turnkey cost of the specific technology. The results obtained are described in this paper, in order to orient future choices and identify the most promising strategies for improving SWH.