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F |
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| 1 |
Updated Energy Finanical Model BAWC- 12 Months Operation |
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| 3 |
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Units |
Business as Usual (BAU) Model-
(Gas boiler and chiller)
(March 2021) |
Heat Pump and TES Model (March 2021) |
Actual Operation at 12 months (October 2022- September 2023) |
BAU Reference Scenario (Actual consumption, in the scenario that
the plant was built to BAU specs with gas boiler and chiller) |
Comments- Actual vs BAU comparison Scenarios
For this high-level financial assessment, a BAU reference scenario
with traditional gas boilers was modelled, based on the actual
energy consumption (thermal and electrical) of BAWC. |
| 4 |
Natural Gas Tarrif Rate |
AU$/GJ |
$12 |
$12 |
$28.14 |
$19 |
Brimbank City Council's large site gas contract was $28.14/GJ
in 2023. Contract update for 2024-2026 at Year 1: $16.00GJ, Year
2: $16.83/GJ, Year 3: $16.84/GJ. Beyond this contract the price
is unknown. This models assumes an average of 2023-2026 prices. |
| 5 |
Electrictiy- Off Peak Tarrif Rates |
AU$/kWhe |
0.129 |
0.129 |
0.129 |
|
As per the current electricity bills |
| 6 |
Electrictiy- Peak Tarrif Rates |
AU$/kWhe |
0.227 |
0.227 |
0.227 |
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As per the current electricity bills |
| 7 |
Electricty Blended Tarrif Rate |
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|
0.157 |
The effective rate based on the electricity costs to run the facility
from 10/22 - 9/23. Total Electricity Cost divided by Total Electricity
(kWhe) consumed. The blended rate is used to calculate the eletricity
cost in the BAU Reference Scenario with the assumption that the
ratio of peak to off-peak power is the same in both scenarios. |
| 8 |
Annual Gas Consumption |
kWht |
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|
7179417 |
7,179,417 |
This is the sum of the thermal energy output of all heat pumps,
which would need to be provided via the gas boilers in the BAU
scenario |
| 9 |
|
GJ |
21,501 |
0 |
N/a |
32,307 |
kWht converted to GJ |
| 10 |
Boiler system efficiency |
[-] |
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0.8 |
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| 11 |
Global COP for all Heat Pumps |
kWhe |
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|
3.2 |
The global Coefficient of Performance is the effective annual
average COP representing all heat pumps. As an actual COP is
not available due to metering limitations, this number is used
as a conservative industry average. |
| 12 |
Estimated Electricty input of the heat pumps |
kWhe |
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2,243,567.81 |
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Estimated electricity consumption of all heat pumps in the facility
based on the selected global COP. Annual Gas Consumption [kWht]/COP |
| 13 |
Annual Grid Electricity Consumption |
kWhe |
1,171,789.00 |
2,442,219.00 |
4,048,537.21 |
1,804,969.40 |
BAU Grid Electricity = Actual Grid electricity consumption MINUS
estimated electricity input of the heat pumps |
| 14 |
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| 15 |
Annual Gas Cost |
$ |
$ 258,012.00 |
0 |
$ 9,325.78 |
$628,378 |
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| 16 |
Annural Grid Electicity Cost |
$ |
$ 127,473.00 |
$ 307,957.00 |
$ 633,956.87 |
$ 282,638.57 |
|
| 17 |
Total Annual Energy Costs |
AU$ |
$ 385,485.00 |
$ 307,957.00 |
$ 643,282.65 |
$ 911,017.04 |
|
| 18 |
Difference / Annual Savings |
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$ 267,734.39 |
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This is the annual savings between the Actual Scenario and the
BAU Reference Scenario |
| 19 |
Cost premium (compared to BAU) |
|
N/a |
$ 870,000.00 |
$1,122,000 |
N/a |
$1.1M figure represents the actual centre all-electric plant capital
works cost for of $2.1m - $1m assumed potential cost of a BAU
scenario. |
| 20 |
HP+ TES Simple Payback period (annual energy costs and capital
cost compared to BAU Model) |
Years |
N/a |
11.2 |
4.2 |
N/a |
The original energy financial model provided in 2021 found that
an all-electric centre with heat pumps and thermal energy storage,
would have had a payback period of 11.2 years, compared to a
business as usual design with gas boiler and chiller (BAU). This
updated energy financial model shows the centre actual consumption
after 12 months (Column E) and compares it with the cost of this
actual consumption in the scenario that a BAU centre was built
(Column F). The actual consumption has been influenced by higher
than expected attendance levels (resulting in higher domestic
hot water use and air conditioning needs in the gym) as well
as a rise and then moderate fall in gas prices since 2021, resulting
in a revision to the estimated payback period to 4.2 years. |