GW Corporate Carbon Pathways for the 2021-31 LTP
Overview
• Background and scenario building
• Officer’s preferred option - B2-R1-P1.5
• Option two - B2-R2-P2
• Option three - B1-R1-P1
• Comparison
Greater Wellington – the path to carbon neutrality and beyond
GW’s corporate targets
• 40% reduction in net emissions in 2025
• 100% reduction in net emissions in 2030
(carbon neutral or net-zero)
• ‘Carbon positive’ by 2035 (units being
generated by GW exceed gross emissions)
• Set five-yearly carbon budgets
Background
• On 29 October Council agreed that there would be at least two
decarbonisations scenarios in the LTP consultation document and one of
these would be B2-R2-P2
• Since then the various scenarios have been investigated further and costs
refined
• The current scenario included in the draft LTP is B2-R1-P1.5
• Following workshop feedback, offsetting assumed not to begin until 2025
at the earliest
Scenario building
• 100% renewable electricity by 2030 (updated
post election)
• All electric light fleet by 2030
• Cuba Street change included
• CentrePort and CCOs removed from footprint
and modelling (total 10,370 tonnes CO2e/year
in 2018-19)
Scenario building - Bus
Level/
Description
GW share of cost
Total cost
label
(2021-30)
(2021-30)
B1
Existing commitment electric buses, plus
$63M
$128M
new EVs at replacement only (‘Organic
Growth)
B2
All bus peak vehicle commitment EV
$83M
$169M
from contract renewal, spares are diesel
(‘Step Change’)
•
Costings are based on existing contractual arrangements. 51% NZTA subsidy.
•
Costs common to both scenarios excluded.
•
B2 achieves a 75% reduction in emissions in 2030 compared to 2019. Scenarios with spare
buses as EV achieve an 82% reduction.
•
~21% of the bus fleet are spares (138 of 663 buses in 2030)
Scenario building - Rail
Level/
Description
GW share of cost
Total cost
label
(2021-30)
(2021-30)
R1
Diesel-electric multiple unit (DEMU) trains on
$118M
$240M
Wairarapa and Manawatu lines from 2025
R2
Battery-electric multiple unit (BEMU) trains
$270M
$550M
on Wairarapa and Manawatu lines from 2025
•
51% NZTA subsidy assumed to calculate GW share of cost
•
Costs common to both scenarios excluded (e.g. station improvements)
•
Note carbon reductions from full electrification of these lines (EMU trains) are the same as R2
Scenario building - Parks
Level/
Description
Cost estimate (total to 2035)
label
P1
1,115Ha grazing phased out over 15 years,
$23.5M
planted in new native forest
P1.5
1,350Ha grazing phased out over 10 years,
$26.4M
planted in new native forest
P2
1,713Ha grazing phased out over 10 years,
$36.3M
planted in new native forest
•
Cost estimate excludes value of emissions units earned from new forest
•
Excludes any contribution from Low Carbon Acceleration Fund (LCAF)
Officer’s preferred scenario - B2-R1-P1.5
• Carbon positive goal achieved
Officer’s preferred scenario - B2-R1-P1.5
tCO2e
Budget
Gross emissions Difference Sequestration Shortfall
2021-25
N/A
140103
0
-32612
-32612
2026-30
38877
85070
46192
-50566
-4374
2031-35
0
55230
55230
-72024
-16794
Total
-53780
Pre-2021 emission unit reserve
-86,129
Net emission unit position
-139,909
Value at $150/tCO2e $ 2
0,986,313
• No external emissions unit purchase needed to maintain carbon
neutral status
• Surplus emissions units available – e.g. for Centreport & CCOs
Why is B2-R1-P1.5 officer’s preferred option?
• This option allows us to meet our carbon positive goals by 2035, while also
optimising costs
• This is a more achievable and affordable option, given we are facing
double digit rates increases for the next five or so years
• Staff have deemed P2 unachievable (more on the next slide)
• R2 seems to be unaffordable, and unnecessary to meet our carbon
positive goals
Why is P2 not achievable? (P1.5 versus P2)
•
Large scale restoration needs to be well-planned, and should align with our master
planning process, which will also identify recreational areas within parks
•
Requires large scale plant procurement, this option will put pressure on existing
suppliers, no time for new suppliers to get into business
•
We can only plant at certain times of the year, which means we would be at risk of not
delivering
•
We need to engage with mana whenua on design, implementation and sites of
significance, this takes time and is reliant on their capacity and capability
•
This option would put staff and contractors under extreme pressure, which is
unnecessary given we can achieve our carbon positive goals with P1.5
Other scenario - B2-R2-P2
• Carbon positive goal achieved
Other scenario - B2-R2-P2
tCO2e
Budget
Gross emissions Difference Sequestration Shortfall
2021-25
N/A
133870
0
-35777
-35777
2026-30
38877
64339
25462
-61083
-35621
2031-35
0
36913
36913
-82469
-45556
Total
-116954
Pre-2021 emission unit reserve
-86,129
Net emission unit position
-203,083
Value at $150/tCO2e $ 3
0,462,514
• No external emissions unit purchase needed to maintain carbon neutral status, surplus
emissions units
• After further consideration we do not think this scenario is achievable for parks, or
affordable for rail
Other scenario - B1-R1-P1
• Carbon positive goal not achieved
Other scenario - B1-R1-P1
tCO2e
Budget
Gross emissions Difference Sequestration Shortfall
2021-25
N/A
142485
0
-27988
-27988
2026-30
38877
130761
91884
-36736
55147
2031-35
0
120026
120026
-52865
67161
Total
94320
Pre-2021 emission unit reserve
-86,129
Net emission unit position
8,191
Value at $150/tCO2 -$ 1
,228,677
• No surplus emissions units
• External emissions unit purchase needed to maintain carbon neutral status
• ~$2.2M/year expense from 2035
• But suggest we include this as a low option in the LTP consultation
Comparison table
Scenario
Carbon positive Spare
Combined cost estimate Total combined cost
goal reached?
emissions units (GW share)
estimate
B1-R1-P1
No
-8,200
$204M
$391M
B2-R1-P1.5
Yes
140,000
$227M
$435M
B2-R2-P2
Yes
203,000
$389M
$755M
Note:
Impact of any potential
LCAF funding not shown
(~$7M left in the fund )
Rates % increase – comparison against LTP budget
18.0%
16.0%
14.0%
12.0%
10.0%
8.0%
6.0%
4.0%
2.0%
0.0%
2021/22
2022/23
2023/24
2024/25
2025/26
2026/27
2027/28
2028/29
2029/30
2030/31
-2.0%
-4.0%
P1.5 B2 R1 Current package
P1 B1 R1
R2 B2 P2
Impact on rates over 10 years
50
s noilliM 45
40
35
30
25
20
15
10
5
-
2021/22
2022/23
2023/24
2024/25
2025/26
2026/27
2027/28
2028/29
2029/30
2030/31
P1.5 B2 R1 Current package
P1 B1 R1
R2 B2 P2
Summary
• B2-R1-P1.5 is an achievable option which optimises cost and achieves our
carbon positive goal
• B2-R2-P2 maximises carbon reduction, but is unachievable for parks and
unaffordable for rail
• B1-R1-P1 minimises costs but is inconsistent with the carbon positive goal,
and creates an ongoing liability for procuring carbon offsets after 2034 to
maintain carbon neutral status
• All three are valid options for the LTP consultation document, officers’
recommend the option currently budgeted, B2-R1-P1.5
Questions?
