ELECTRICAL RESILIENCE Emissions per kWh 300g 300 200g 200
Operational carbon footprint per life time of use (8000 cycles)
1 64,000 kg CO2 2 426,667 kg CO2 3 490,667 kg CO2 4 1,930,667 kg CO2
eq
eq eq
eq 100g 100
Total carbon footprint per lifetime of use 1 152,000 kg CO2 2 514,667 kg CO2 3 578,667 kg CO2 4 2,018,667 kg CO2
eq eq eq
eq
Total BESS energy over lifetime
0g 0 10/01/2022 11/04/2022
a diesel generator, due to the differences between the two systems, as previously stated. The carbon emissions associated with the temperature maintenance for the two systems have been disregarded as part of this calculation. A further calculation has been made based on the conversion of a standby diesel generator vs a biodiesel generator, in order to compare the carbon footprint of each. For this calculation, the assumption has been made that the generator consumes the same amount of B100 biodiesel as standard B0 diesel fuel. It should be noted that biodiesel has 7% less energy per volume in comparison to B0. The latter is taken into consideration within the calculations and figures I will now present. For the carbon footprint calculation, it
is assumed that the diesel generator will operate for 200 hours (no. 1 in Figure 5) every two years, in addition to its standard maintenance cycle (no. 4 in Figure 5). The indicated 200 hours of operation are also split into 100% of its rated capacity (daytime no. 2 in Figure 5), and 50% of its rated capacity (night-time no. 3 in Figure 5), for more detailed representation. The comparison does not take into consideration what the longest and shortest intervals of continuous generator operation are, which would help in making a more precise comparison of the two systems. The following four sources of energy
Fuel required for lifetime operations
1 440,000.00 B0 litres 2 220,000.00 B0 litres 3 110,000.00 B0 litres 4 105,600.00 B0 litres
484,000 B100 litres 242,000 B100 litres 121,000 B100 litres 116,160 B100 litres
1 & 4 Total carbon footprint (embodied + use) 2 & 3 & 4 Total actual carbon footprint (embodied + use) 11/07/2022 10/10/2022
have been identified for the BESS unit (in Figure 7): 1 Charging from a wind-generated power source.
2 Charging from a solar-generated power source.
3 Charging from the grid during the best recorded month.
4 Charging from the grid when its carbon footprint is average.
The embodied carbon for each system has been estimated as follows: n Generator – 12,000 kg CO2 on 9,000 kg CO2
eq (based eq for a 500 kW generator)
n BESS – 88,000 kg CO2 55 kg CO2
Aluminium battery).
Carbon footprint lifecycle assessment of BESS The carbon footprint lifecycle assessment for the battery energy storage system has been estimated as follows: a) Estimation of Total BESS energy over a lifetime (TEOL) = ((BESS operational capacity) x (initial energy) x (no. of cycles)) / (efficiency rating).
b) Estimation of operational carbon footprint per lifetime (OCFPL) = (TEOL) x (source of energy carbon footprint).
c) Estimation of total carbon footprint per lifetime of use = (OCFPL) + (embodied carbon of selected BESS).
Generator use
1 1,056,000.00 kg C02 2 528,000.00 kg C02 3 264,000.00 kg C02 4 253,440.00 kg C02 Diesel
1,321,440.00 kg C02 1,057,440.00 kg C02
carbon footprint on diesel eq
eq eq eq
eq eq Figure 9: Diesel generator carbon calculation estimate comparison between B0 and B100 fuel. 56 Health Estate Journal September 2023 eq (based on /kWh for a Lithium-Cobalt-
Carbon footprint lifecycle assessment of a standby generator The generator carbon footprint calculation for the embodied carbon and operational carbon use has been estimated based on the following two scenarios: 1 With the 200-hour generator operation calculated as a 100% rated capacity, plus the carbon footprint of the ongoing maintenance.
2 With the 200-hour generator operation split into 50% of time operating at 100% rated capacity, and 50% at 50% rated capacity, plus the carbon footprint of the ongoing maintenance.
Biodiesel generator carbon footprint (estimated by converting the quantity of traditional diesel fuel used) Based on the defined operational parameters and the two indicated
Generator use
1 302,016.00 kg C02 2 151,008.00 kg C02 3 75,504.00 kg C02 4 72,483.84 kg C02 Biodiesel
carbon footprint on biodiesel eq
eq eq eq
386,499.84 kg C02 310,995.84 kg C02
eq eq 10,666,667 kWh
Figure 7 (left): Indicative grid emissions (source).
Figure 8 (above): An operational BESS carbon footprint estimate.
As is shown via the calculated outputs, the source of charging for the BESS is very important. The total operational carbon figure when a BESS is charged from the electrical grid utilising average carbon values per kWh equates to 1,930.7
tCO2
eq, which is significantly higher when compared with the value achieved when the BESS is charged from the wind- generated source (64 tCO2
eq). Total LCA
values are presented within the ‘Total Carbon footprint per lifetime of use’ table in Figure 8.
Page 1 |
Page 2 |
Page 3 |
Page 4 |
Page 5 |
Page 6 |
Page 7 |
Page 8 |
Page 9 |
Page 10 |
Page 11 |
Page 12 |
Page 13 |
Page 14 |
Page 15 |
Page 16 |
Page 17 |
Page 18 |
Page 19 |
Page 20 |
Page 21 |
Page 22 |
Page 23 |
Page 24 |
Page 25 |
Page 26 |
Page 27 |
Page 28 |
Page 29 |
Page 30 |
Page 31 |
Page 32 |
Page 33 |
Page 34 |
Page 35 |
Page 36 |
Page 37 |
Page 38 |
Page 39 |
Page 40 |
Page 41 |
Page 42 |
Page 43 |
Page 44 |
Page 45 |
Page 46 |
Page 47 |
Page 48 |
Page 49 |
Page 50 |
Page 51 |
Page 52 |
Page 53 |
Page 54 |
Page 55 |
Page 56 |
Page 57 |
Page 58 |
Page 59 |
Page 60 |
Page 61 |
Page 62 |
Page 63 |
Page 64 |
Page 65 |
Page 66 |
Page 67 |
Page 68 |
Page 69 |
Page 70 |
Page 71 |
Page 72 |
Page 73 |
Page 74 |
Page 75 |
Page 76 |
Page 77 |
Page 78 |
Page 79 |
Page 80 |
Page 81 |
Page 82 |
Page 83 |
Page 84 |
Page 85 |
Page 86 |
Page 87 |
Page 88 |
Page 89 |
Page 90 |
Page 91 |
Page 92 |
Page 93 |
Page 94 |
Page 95 |
Page 96 |
Page 97 |
Page 98 |
Page 99 |
Page 100 |
Page 101 |
Page 102 |
Page 103 |
Page 104 |
Page 105 |
Page 106 |
Page 107 |
Page 108 |
Page 109 |
Page 110 |
Page 111 |
Page 112 |
Page 113 |
Page 114 |
Page 115 |
Page 116 |
Page 117 |
Page 118 |
Page 119 |
Page 120
