Analisi dell’impatto locale della produzione di idrogeno verde sulla disponibilità di acqua dolce e possibili misure di mitigazione: Il caso di NextHY.

WSI TW /W

= Withdrawal Availability

Commonly used thresholds to interpret WSI are:

WSI < 0.1 (10%): Low water stress

 0.1 ≤ WSI < 0.2 (10%-20%): Moderate water stress

 0.2 ≤ WSI < 0.4 (20%-40%): High water stress

 WSI ≥ 0.4 (40% and above): Critical water stress



III. Percentage of GH2 WCEP on Residual Water Availability calculated as the the Water

Consumption for Energy Production (WCEP), that is the the volume of water

consumed (and not returned to the environment) divided by the residual water

availability. 60

GH2 WCEP on Residual Water Availability WCEP RWA

=( / )

(%) ×100

Where:

 WCEP is the water consumption for energy production (volume of water consumed

and not returned to the environment);

 RWA is the residual water availability after considering the impacts of climate change

and increased demand on water availability.

3.4 Results Scenario 2030

To measure water availability in 2030, it is necessary to start from the estimated figure in

2019, which was 1,285,480,000 m³ of water per year. Beginning with this data, it is possible

to make considerations on how availability varies due to the aforementioned factors.

The increase in demand, which stands at 16% regionally, results in higher withdrawals

compared to the 2019 standards. The effects are attributable to a series of hydrological,

climatic, and economic factors (greater soil evaporation, increased water losses due to poor

maintenance and management of water infrastructure, increased demand from the industrial

sector) (General Report of the PRGA, 2019).

In 2019, we had a total water consumption of 270 million cubic meters per year, with the

following values:

Agricultural Use 2019: 159.4 million cubic meters of water per year;

 Industrial Use 2019: 37.6 million cubic meters of water per year;

 61

Civil Use: 73 million cubic meters of water per year.



In 2030, the consumption will amount to a total of 270 million + 16% increase in demand,

equivalent to 43,200,000 m³, for a total of 313,200,000 m³ of water withdrawals per year.

Based on the estimates previously made for the province of Syracuse, I hypothesized that the

43,200,000 m³ of consumption will be distributed among the three sectors according to the

percentages obtained in 2019 relative to the total withdrawals (59% for the agricultural sector,

13.9% for the industrial sector, and 27% for civil uses), resulting in:

 Agricultural Use 2030: 184.9 million cubic meters of water per year;

 Industrial Use 2030: 43.6 million cubic meters of water per year;

 Civil Use 2030: 84.6 million cubic meters of water per year.

This increase in demand not only translates into higher withdrawals from all sectors—

agricultural, industrial, and civil uses—but also into a substantial reduction in annual water

availability.

We hypothesize a reduction in water availability from 1,285,480,000 m³ of water per year to

1,242,280,000 m³ of water per year.

Availability is further jeopardized by climate change, which affects the conservation of

aquifers. As previously described, the rate of reduction in water availability due to the

decrease in aquifers ranges between 4% and 6%. We therefore hypothesize two scenarios: an

optimistic one characterized by a 4% reduction rate in aquifer availability, and a pessimistic

one characterized by a 6% reduction rate. Subsequently, for each scenario, I analyzed the

impact on water availability and local withdrawals of the Carlentini power plant, using the

two indicators (WSF and WSI). It is worth reiterating that, from the previously conducted

analysis, we derived the Water Withdrawal for Energy Production (WEP) in 2030, which

amounts to 21,293.2 m³, along with the Water Consumption for Energy Production (WCEP)

62

in 2030, which measures the volume of water consumed (and not returned to the environment)

for energy production in a year, amounting to 15,150.4 m³

Optimistic scenario

o

In the optimistic scenario, the reduction in water availability from aquifers due to climate

change decreases by 4%, equivalent to 49,691,200 m³, which does not excessively impact

local water availability. Consequently, the water availability should settle at 1,192,588,800 m³.

With the following data, we then calculate the Water Scarcity Footprint (WSF).

1) WSF

WSF = 21.293,2 m3 / 1.192.588.800 m3

Optimistic

WSF = 1,78×10−5

Optimistic

2) WSI

Subsequently, thanks to the availability of consumption data, we proceed with the

measurement of the Water Stress Index (WSI) to evaluate the ratio between the total water

withdrawal for all uses (including energy production) and the overall renewable water

availability in Syracuse.

The WSI is calculated as follows:

Total Withdrawal =184.900.000 m3+43.600.000 m3+84.600.000 m3+21.293,2 m3

Optimistic

Total Withdrawal = 313.121.293,2 m3

Optimistic

WSI =313.121.293,2 m3/ 1.192.588.800 m3

Optimistic

WSI = 0,262 = (26,2%)

Optimistic 63

3) Percentage of GH2 consumption on Residual Water Availability

Percentage of water consumption = WCEP / Water Availability ×100

Optimistic Optimistic

Percentage of water consumption =15.150,4 m^3 /1.192.588.800 ×100

Optimistic

Percentage of water consumption = 1,27 x 10^-3

Optimistic

Pessimistic Scenario

o

In the pessimistic scenario, the reduction in water availability from aquifers decreases by 6%,

equivalent to 74,536,800 m³, which significantly impacts local water availability.

Consequently, the water availability should settle at 1,167,743,200 m³ per year. With the

following data, we then calculate the Water Scarcity Footprint (WSF).

1) WSF

WSF =1.167.743.200/21.293,2

Pessimistic

WSF =1,82×10^−5 WSF

Pessimistic

2) WSI

Subsequently, thanks to the availability of consumption data, we proceed with the

measurement of the Water Stress Index (WSI) to evaluate the ratio between the total water

64

withdrawal for all uses (including energy production) and the overall renewable water

availability in Syracuse.

Total Withdrawal =184.900.000 m3+43.600.000 m3+84.600.000 m3+21.293,2 m3

Pessimistic

Total Withdrawal =313.121.293,2 m3

Pessimistic

WSI =313.121.293,2/1.167.743.200

Pessimistic

WSI = 0,268 (26,8%)

Pessimistic

3) Percentage of GH2 WCEP on Residual Water Availability

Percentage of water consumption = WCEP / Water Availability ×100

Pessimistic Pessimistic

Percentage of water consumption = 15.150,4 m^3 / 1.167.743.200 m3 ×100

Pessimistic

Percentage of water consumption = 1,3 x 10^-3

Pessimistic

Table 2: Overall results 2030

Index Optimistic scenario Pessimistic scenario

Rate of reduction of groudnwater 4% 6%

Water Scarcity Footprint (WSF) 1,27 x 10^-5 1,82×10^−5

Water Stress Index (WSI) 0,262 0,268

Percentage of GH2 WCEP on Residual Water Availability 1,27 x 10^-3 % 1,3 x 10^-3 %

65

Scenario 2050

To measure water availability in 2050, it is necessary to start from the estimated figure in

2019, which was 1,285,480,000 m³ of water per year. Beginning with this data, it is possible

to make considerations on how availability varies due to the aforementioned factors.

In this case, the increase in demand, which stands at 45% regionally, results in a significant

increase in withdrawals compared to the 2019 standards. In the same year, we had a total

consumption of 270 million cubic meters per year, with the following values:

- Agricultural Use 2019: 159.4 million cubic meters of water per year.

- Industrial Use 2019: 37.6 million cubic meters of water per year.

- Civil Use 2019: 73 million cubic meters of water per year.

In 2050, consumption will amount to a total of 270 million + 45% increase in demand,

equivalent to 121,500,000 m³/year, for a total of 391,500,000 m³ of water withdrawals per

year. Based on the estimates previously made for the province of Syracuse, I hypothesized

that the 121,500,000 m³/year of consumption will be distributed among the three sectors

according to the percentages obtained in 2019 relative to the total withdrawals (59% for the

agricultural sector, 13.9% for the industrial sector, and 27% for civil uses), resulting in:

- Agricultural Use 2050: 231.09 million cubic meters of water per year.

- Industrial Use 2050: 54.49 million cubic meters of water per year.

- Civil Use 2050: 105.8 million cubic meters of water per year.

66

This increase in demand not only translates into higher withdrawals from all sectors—

agricultural, industrial, and civil uses—but also into a substantial reduction in annual water

availability.

We hypothesize a reduction in water availability from 1,285,480,000 m³ of water per year to

1,163,980,000 m³ of water per year.

Availability is further jeopardized by climate change, which affects the conservation of

aquifers. As previously described, I identified in 2050, thanks to a greater availability of data,

4 possible scenarios, in which the rate of reduction in water availability due to the decrease in

aquifers is linked with projections of average temperature increase. The scenarios are as

follows:

- SSP1-1.9: 7-12% reduction of groundwater recharge

- SSP1-2.6: 10-18% reduction of groundwater recharge

- SSP3-7.0: 27-35% reduction of groundwater recharge

We therefore hypothesize for each scenario two sub-scenarios: one optimistic, characterized

by the lower predicted rate of reduction in aquifer availability, and one pessimistic,

characterized by the higher predicted rate in each scenario. Subsequently, for each sub-

scenario, I analyzed the impact on water availability and local withdrawals of the Carlentini

power plant in 2050, where the production capacity is expected to increase from 0.68

KtGH2/year to 18 KtGH2/year, using the two indicators (WSF and WSI). Finally, it is worth

reiterating that, from the previously conducted analysis, we derived the Water Withdrawal for

Energy Production (WEP) in 2050, which amounts to 580,320 m³, along with the Water

Consumption for Energy Production (WCEP) in 2030, which measures the volume of water

consumed (and not returned to the environment) for energy production in a year, amounting to

401,040 m³.

SP1-1.9 Scenario 67

j Optimistic scenario

o

In the optimistic scenario, the reduction in water availability from aquifers due to climate

change decreases by 7%, equivalent to 81,478,600 m³. We will now calculate the necessary

indicators to evaluate the water impact of the GH2 plant.

1) WSF

Water Availability =1.163.980.000 m3−81.478.600 m3 = 1.082.501.400m3

Optimistic

WSF =580.320 m3 / 1.082.501.400 m3

Optimistic

WSF =5,36×10

Optimistic −4

2) WSI

In this scenario, the water availability is 1,082,501,400 m³. Meanwhile, the total withdrawal is

the sum of withdrawals for agricultural, industrial, civil, and energy uses:

Total Wit