Developing a Practical
Net Zero Delivery Plan
Produced by James Beiny
Agenda
01
The 2025 carbon footprint
An emissions baseline across scopes 1, 2 and 3
02
Identifying carbon hotspots
The most carbon-intensive areas
03
Building the emissions forecast
Methodology and the assumptions behind it
04
Highest-impact interventions
Prioritising action for cost and speed of impact
05
Measuring and reporting progress
Targets, KPIs and governance
06
Risks and uncertainties
Potential disruptions to the plan
07
Dashboard mock-up
Presenting outputs to senior leadership
The Emissions Baseline
Southern Water's 2025 carbon footprint
| Scope | Emission category | tCO₂e | Share |
|---|---|---|---|
| Scope 1 | Fleet | 15,600 | 16% |
| Scope 1 | On-site combustion | 13,000 | 14% |
| Scope 2 | Purchased electricity | 44,200 | 46% |
| Scope 3 | Capital goods | 13,000 | 13% |
| Scope 3 | Fuel- and energy-related activities | 7,800 | 8% |
| Scope 3 | Business travel | 2,600 | 3% |
Where the Emissions Sit
Identifying carbon hotspots
| Emission category | Scope | Share of footprint | Rationale |
|---|---|---|---|
| Purchased electricity Hotspot 1 | Scope 2 | 46% | Energy-intensive aeration, pumping and treatment processes |
| Fleet Hotspot 2 | Scope 1 | 16% | Tankering, site vehicles and other fossil-fuelled company vehicles |
| On-site combustion Hotspot 3 | Scope 1 | 14% | Gas heating and back-up power generation across sites |
| Capital goods | Scope 3 | 13% | |
| Fuel- and energy-related activities | Scope 3 | 8% | |
| Business travel | Scope 3 | 3% |
From Baseline to 2030
Building the emissions forecast
01
Set the baseline
The 2025 carbon footprint will serve as the baseline against which future changes are measured.
02
Map the drivers
Link each emissions source to a variable that affects its value, such as wastewater volume and fleet mileage.
03
Project business-as-usual
Roll those forward to 2030 with no new action, drawing on key assumptions made.
04
Overlay the interventions
Subtract each intervention's projected emission savings from the BAU scenario.
05
Test the assumptions
Explore low, central and high cases to provide a range.
06
Recalibrate each year
Check the forecast against actual emissions generated each year and update it.
What the Model Depends On
Key assumptions in the forecast
£
Investment growth Quantified in the model
Spending on capital goods grows by ~3% per year, driven mainly by environmental improvements (e.g. storm overflow reduction), asset renewal and customer growth.
⚡︎
Grid decarbonisation Quantified in the model
The National Grid becomes cleaner over time (~8%/yr), so electricity emissions fall even at the same usage.
♟
Customer demand Quantified in the model
A net growth in demand of ~1% per year after accounting for efforts to reduce leakage and help customers use less water.
▤
Policy and regulation
Tighter effluent treatment standards cause energy consumption to increase. Government policy on EVs drives Southern Water's fleet electrification.
☀︎
Technology maturity
Solar, CHP and heat pumps are assumed to be commercially ready and affordable by 2028.
◔
Data quality
The shift away from the use of spend-based estimates to activity data improves the quality of scope 3 emission calculations.
The Abatement Task
Business as usual vs. a 1.5°C-aligned pathway, 2025–2030
Business as usual
Committed plan
1.5°C-aligned pathway
Hover over the chart for more detail.
The pathway is a straight-line 1.5°C-consistent trajectory (−42% by 2030 against the 2025 baseline), which is consistent with net zero by 2050.
Prioritising Action
Highest-impact interventions
| Intervention | Hotspot targeted | Est. 2030 saving (tCO₂e) | Cost profile | Timeframe |
|---|---|---|---|---|
| Renewable self-generation Priority | Purchased electricity | 5,000 | Moderate cost, <7yr payback | Medium-term |
| Energy efficiency programme Priority | Purchased electricity | 4,000 | Low cost, fast payback | Short-term |
| Fleet electrification Priority | Fleet | 4,000 | Higher cost per tonne abated | Medium-term |
| On-site heat decarbonisation | On-site combustion | 3,000 | Moderate cost | Medium-term |
| Low-carbon procurement | Capital goods | 2,000 | Low cost to administer | Ongoing |
| Committed plan — total abatement by 2030 | 18,000 | = the committed line on the forecast | ||
Measuring and Reporting Progress
Quantifiable targets
- 35% reduction in scope 1 and 2 emissions by 2030 vs. the 2025 baseline
- Increase self-generated renewable electricity to 25% of consumption by 2030
- 40% of fleet transitioned to electric vehicles by 2030
- Net zero across scopes 1–3 by 2050
KPIs and reporting cadence
- Monthly: site-level energy and emissions dashboard for operations (e.g. kWh per Ml, tCO₂e by site)
- Quarterly: performance vs. trajectory reported to the Carbon Steering Group (e.g. tCO₂e run-rate vs. target)
- Annually: carbon footprint independently assured and published in line with applicable regulations (e.g. SECR)
What Could Change the Picture
Key risks and uncertainties
| Risk | Why it matters | Mitigation |
|---|---|---|
| Grid decarbonisation slower than assumed High | Scope 2 reductions overstated in the forecast | Monitor National Grid's published scenarios; re-test the forecast each year |
| Capital funding constraints High | Interventions delayed or scaled back | Prioritise by cost-effectiveness and protect the most vital interventions |
| Tighter effluent standards Medium | Increases treatment energy and chemical use | Engage the Environment Agency early, and choose lower-carbon treatment options where possible |
| Technology and supply chain delays Medium | Abatement slips beyond 2030 | Phase delivery, with fallback dates agreed in advance |
| Measurement uncertainty (spend-based capital goods factor) Low | Carbon footprint may be under- or overstated | Move to supplier-specific data as it becomes available |
Net Zero Delivery Dashboard
Carbon and Climate Team · FY 2025/26
On track
Total emissions
92.2k tCO₂e
▼ 4.2% vs. baseline
Progress to 2030 target
12%
of 35% goal delivered
Renewable self-gen
15.8%
vs. 25% target
Fleet EV share
9%
vs. 40% target
Emissions trajectory vs. target (ktCO₂e)
Footprint by scope
Scope 1: 30% · Scope 2: 46% · Scope 3: 24%
Intervention status
| Energy efficiency programme |
| Low-carbon procurement |
| Solar PV expansion |
| Fleet electrification |
Top hotspots this quarter
| Category | Share | Trend | Owner |
|---|---|---|---|
| Purchased electricity | 46% | ▼ improving | Energy Team |
| Fleet | 16% | ▲ slipping | Fleet Team |
| On-site combustion | 14% | → flat | Property and Ops |