Page 17 - Franzitta_et_alii_2017

17 of 19
Sustainability 2017, 9, 106

Sustainability 2017, 9, 106 17 of 19

Sustainability 2017, 9, 106 17 of 19

Figure 15. Discounted cash flow in the two different hypotheses.

For these reasons, we simulate a third hypothesis, characterized by a greater power plant by
renewable sources, in order to sell the electrical surplus and reduce the breakeven time of the project.
In this hypothesis (C), we fixed the installed power by biomass (for reasons of availability of this
resource) and increased the installed power by wind and sea wave. In particular, the power produced
by wave and wind plants was doubled (6.6 MW for the wind farm and 3.2 MW for sea wave).
Thanks to the selling of the electrical energy surplus, in the last hypothesis, the breakeven time
is about 14 years (see Figure 16). Of course, the breakeven time can be further reduced through the
introduction of an incentive [31].
Figure 15. Discounted cash flow in the two different hypotheses.
Figure 15. Discounted cash flow in the two different hypotheses.
For these reasons, we simulate a third hypothesis, characterized by a greater power plant by
renewable sources, in order to sell the electrical surplus and reduce the breakeven time of the project.
In this hypothesis (C), we fixed the installed power by biomass (for reasons of availability of this
resource) and increased the installed power by wind and sea wave. In particular, the power produced
by wave and wind plants was doubled (6.6 MW for the wind farm and 3.2 MW for sea wave).
Thanks to the selling of the electrical energy surplus, in the last hypothesis, the breakeven time
is about 14 years (see Figure 16). Of course, the breakeven time can be further reduced through the
introduction of an incentive [31].

Figure 16. Discount cash flow in the hypotheses A and C.
Figure 16. Discount cash flow in the hypotheses A and C.
5. Conclusions
5. Conclusions
The availability of biomass, wind and sea wave in the province of Trapani shows that the use of
The availability of biomass, wind and sea wave in the province of Trapani shows that the use of
these resources for the electrolytic hydrogen production would allow the replacement of the entire fleet
these resources for the electrolytic hydrogen production would allow the replacement of the entire
of urban buses powered by diesel with an equal number of hydrogen vehicles. From the environmental
fleet of urban buses powered by diesel with an equal number of hydrogen vehicles. From the

point of view, this project allows the abatement of several greenhouse gases, in particular, in the best
environmental point of view, this project allows the abatement of several greenhouse gases, in
Figure 16. Discount cash flow in the hypotheses A and C.
scenario (100% replace of diesel buses), the annual avoided emissions are 1444 tons of CO 2 , 7.64 tons
of CO, 1.12 tons of PM 10 , 2.1 tons of NMVOC and 22.85 tons of NO x .
5. Conclusions
From the economic point of view, the project—in absence of an incentive—presents a very long
breakeven time, incompatible with the lifetime of the plants. A possible solution is the oversizing
The availability of biomass, wind and sea wave in the province of Trapani shows that the use of
of wind and sea wave power plants in relation to the electrical demand for hydrogen production, in
these resources for the electrolytic hydrogen production would allow the replacement of the entire
fleet of urban buses powered by diesel with an equal number of hydrogen vehicles. From the
environmental point of view, this project allows the abatement of several greenhouse gases, in