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RSAC Meeting 3

Targets and Low-carbon Assumptions

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19 September 2023

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Agenda

Welcome - Arielle + Erica, SSG

Agenda Review - Erica

  • Feedback results from RSAC Meeting 3

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Low-Carbon Assumptions - Camilla

  • Assumptions in GHG emission reduction modeling
  • How assumptions are determined
  • Overview of draft assumptions for Charleston
  • Roundtable discussion and feedback

Target Setting Discussion - Yuill

  • Overview of types of emission reduction targets
  • Recommended targets for Charleston
  • Roundtable discussion and feedback

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Closing - Erica + Team

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Review of Feedback from Meeting 2

  • Heavy emphasis on technical process
  • Interesting information but hard to have input
  • Feel more able to provide input for implementation

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Low-Carbon Assumptions: for the Low-Carbon Scenario (LCS)

Quick Overview

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Low-Carbon Scenarios

Assumptions

Analysis and interpretation of data and information

Data and Information

Data from county and other trusted sources

Targets to drive the speed of the actions.

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Projections

Projections for individual factors modelled together to forecast a future plausible low-carbon scenario for community energy-use and emissions

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What Makes a Good Modeling Assumption?

Projections

Quantified

Time-restricted

Model-able

Detailed

Good Model Assumptions:

  • 4MW of wind generation built in 2035, used to replace grid electricity

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  • 5% of residential buildings retrofit annually to improve thermal efficiency by 50%, starting in 2025

Implementation Actions (not assumptions):

  • Develop a financing program to allow low-income households to retrofit their homes

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  • Install EV charging stations on municipal buildings

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Anatomy of a Decarbonization Pathway

We are here

GHG emissions

Area under the curve = carbon liability (remaining emissions)

Time

We need to get here (net zero)

Reference scenario

Relative importance of actions

Each action results in a greenhouse gas reduction

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Low Carbon Scenario

Draft Model Assumptions

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A Draft Low-Carbon for Charleston

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Demographics and Development

Category

BAP Assumption

LC Assumption

Source

Population

Population growth according to Transportation Modelling projections

provided by BCDCOG

Same

BCDCOG

Employment

Employment growth according to Transportation Modelling projections provided by BCDCOG

Same

BCDCOG

Buildings growth/ Development

29,000 to 36,000 housing units over the next ten years

Same

County of Charleston Housing Needs

Climate Impacts

HDD in 2020: 816 CDD in 2020: 1338 HDD in 2050: 833 CDD in 2050: 1722

Same

The Climate Explorer

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Buildings

Category

BAP Assumption

LC Assumption

Source

New Residential Buildings

2009 IECC building code for new buildings

All new construction is Net-Zero Ready by 2030

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New ICI Buildings

2009 IECC and ASHRAE 90.1-2007

Charleston RISES building code

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Existing Buildings

Current building energy use held constant

100% buildings retrofit to achieve thermal standards of Net-Zero Ready, and 30% electrical by 2050. Retrofits include installing heat pumps for space heating and cooling, and solar PV where appropriate (including storage)

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City of Charleston buildings: Remove 117,080 MtCO2e by 2025

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Space heating/cooling, water heating

No change from current

Heat pumps timed with retrofits/new construction

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Energy Generation

Category

BAP Assumption

LC Assumption

Source

Rooftop Solar PV

30,000 rooftop solar installations in 2022, 5kW average size

Same (for now!)

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Other Renewables

None

None (for now!)

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Transportation

Category

BAP Assumption

LC Assumption

Source

Expanded Transit

Low Country Rapid Transit implemented, opening in 2028

Same

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Electrify Transit

100% EV bus by 2040, 110 busses

Same

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Electrify Personal Vehicles

5% of stock is EV

By 2030, 60% of new personal and commercial vehicles sold will be electric. By 2050, all new vehicles will be electric.

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Electrify Commercial Vehicles

5 % of the Light Duty commercial stock is battery electric by 2050

Light Duty follows personal vehicle trends

Heavy Duty: 50% electric, 50% hydrogen by 2050

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Electrify Municipal Fleet

2 EVs in 2023

All light-duty vehicles are EV by 2030, all others are 50% electric 50% hydrogen by 2050

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Waste

Category

BAP Assumption

LC Assumption

Source

Waste Diversion

40% of solid waste is recycled by 2030

Same

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Waste Treatment

No change from current

Same

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Wastewater Treatment

No change from current

Same

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Industry

Category

BAP Assumption

LC Assumption

Source

Industrial Efficiency

Same as present

Industrial efficiency: mechanical, operational and industrial processes are 20% more efficient by 2035

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Industry

WestRock plant closing in 2023

Same

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Questions?

Anything surprising to you?

Any general comments?

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Roundtable discussion

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Target Setting

A Short Review of the Discussion Paper

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Target Options Summary

This briefing explains net-zero by 2050 as a standard goal, and its alignment with the U.S. federal target, the United Nations Framework Convention on Climate Change (UNFCCC) Paris Agreement, and the Intergovernmental Panel on Climate Change (IPCC) recommendations. It also details four pathways to reach net-zero.

  • A science-based target (general)
  • A science-based target using a carbon budget and fair share approach
  • A target aligning with the United States' federal target
  • An evidence-based target

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Go to menti.com and use the code 8354 4606

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Did you have a chance to review the discussion paper?

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Menti Question

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What questions and observations do you have?

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Roundtable discussion

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Straw poll: which target scenario makes the most sense to you?

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Menti Question

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Link in Chat + Agenda

https://form.typeform.com/to/pwFsgbNZ

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Feedback Form

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THANK YOU

naomi@ssg.coop