The actual solar thermal exploitation in Sicily represents an instance of under utilization a resource widely available and, at the same time, with competitive costs.

The assessment of solar thermal potential carried out in Energy Master Plan has been referred to the sector and end uses listed in the following table.

As an example, a brief description of the methodology for assessment of the potential of energy saving in the residential sector is now reported.

A reference building stock has been defined taking into consideration all the family house buildings and all the apartments located at the top floor of the buildings. Assuming the climate conditions and the building park characteristics, the possible energy production and saving have been assessed comparing different conventional sources.

All the one store buildings and all the apartments located at the top floor of the multi-storey buildings have been considered as suitable for solar thermal plants. Only apartments already equipped with an autonomous heating system have been considered "technical” suitable for a solar integration installation.

The solar fraction has been evaluated with the f-chart method. The economic analysis has been performed considering several fuel for the back-up system.

In addition, the typical user has been assumed to be a family of 4 people.

All these data have been utilised in order to set up a new type of "economic suitable graph”, in which are compared for different investment costs and different conventional sources (variable price of kWh), the annual costs saving and back-up costs using the optimised solar thermal system.

The use of this diagram is explained using the corresponding points indicated on it:

1. plant specific cost [€/m2];

2. cost of conventional fuel curve [€/kg];

3. optimal surface to be installed in this climatic areas for 4 persons [m2];

4. solar fraction;

5. annual costs saving curve [€];

6. annual back-up costs with conventional source [€];

7. pay back time curve;

8. pay back time [year].

Table 5 reports the potential of solar energy utilization in the residential sector together with the set of actions foreseen in the short and in the medium term in Action Plan.

In the residential sector, a program funding 235.000 m2 in the short term and 400.000 m2 in the medium term of solar collectors have been proposed for DHW systems. The primary energy saving and the avoided CO2 are expected to be about 33 ktep and 77,4 ktCO2 (short t.) and 51 ktep and 114,2 ktCO2 (medium t.). The assumed share of capital cost financed is 30% in the short term (about 35 M€ ) and of 15% (about 21 M€) in the medium term when, in addition, a reduction of unitary costs has been hypothesized.

For the tertiary sector a program financing 25.000 m2 (short t.) and 50.000 m2 (medium t.) of solar collectors has been proposed for low temperature systems. The energy saving and the avoided CO2 are about 1,8 ktep and 3,7 ktCO2 (short t.) and 4,5 ktep and 9,0 ktCO2 (medium t.). The share of funding was assumed to be from the 30% (about 3,5 M€ ) to the 20% (about 4 M€). The sectors that have to be privileged are the ones in which the demand shows a summer peak load or alternatively the users characterized by steady and substantial consumptions during the course of years. The most interested users to be considered are: swimming pools, camping, barracks, prisons, sporting plants, hospitals and clinical medicines, bathing establishments.

A program for an extensive demonstration of solar cooling systems in tertiary and public buildings of about 15 M€ has been proposed. The expected energy and CO2 saving up are in the medium term about 5,2 ktep and 10,5 ktCO2 considering a share of financing of 50%. In the short term the funding intensity will be higher (70%) in order to evaluate the technical and economic performances of some configurations user/plant and to promote the diffusion of a local know-how.

Another key issue is the involvement of the Energy Service Companies stimulating the market of "energy saving”. A significant contribution by the private market of "white certificates” is expected to be free of public funding. At the same time, there will be activated measures voted to stimulate the existing economic potential through enterprise support, information, training and cultural activities in order to promote a diffusion of this technology with lower costs.

The voluntary agreement among the system suppliers and a Regional control Body is one of crucial tool to successfully achieve the actions. The supplier has to grant the energy performances of the system installed according to standard contracts. In addition suppliers, installers and technicians must be affiliated in a Regional Register.

Conclusion

The new Energy Action Plan for the Sicily Region will apply measures for the support of PV and solar thermal on the basis of a more "user oriented” approach and a merit strategy for SMEs and public actors.

For PV systems, where the economic efficiency of the last funding policies, resulted very low, particular attention will be dedicated to the "quality” of the project and the system. This will be obtained through new assessment procedures for project funding and a shift from capital cost to produced energy funding. Private enterprises will be supported on the basis of voluntary agreements for the certification of the products quality.

Residential DHW system will be stimulated through direct incentives to the small user such as bonus distributed by sellers and/or installers. A positive factor to be supported is the involvement of energy utilities and Energy Saving Companies in the "energy saving” market created by the new national rules.

The results of these policies might be very relevant in the Regional energy contest: about 4,5% of saving of primary energy in the civil sector (of which 0,5% due to PV system), correspondent to the 1% of the gross internal demand, and about 290 ktCO2 of avoided emission per year, correspondent to 4-5% of the objective of Kyoto Protocol for Sicily.