Heating Electrification Strategies to Decarbonize BU’s Charles River Campus: Phase 2 Focus on Decreasing Peak Electrical Demand

Gayatri Sundar Rajan (ENG ‘22)Sabrina Dilig (ENG ‘23)Cathy Cheng (ENG ‘23)

1. Context & Phase 2 Focus2. Strategies to Minimize Peak Loads & Avoid Electrical Service Upgrades3. Financial Analysis of Alternative Electric Heating Strategies4. Cost of Reducing Carbon Emissions

April 20th, 2021

Professor Michael Gevelber (ENG)

Context & Phase 2 Focus

Tradeoff between CapX and OpX?

Cost of reducing GHG emissions ($/ton)?

Evaluate energy efficiency strategies to reduce peak electrical demand.

Compatibility with existing HVAC equipment?

Compare the GHG emissions reduction of each strategy to its cost?

How important is reducing CapX to retrofitting buildings faster?

What equivalent carbon tax is required to make electric heat cost

competitive with fossil systems?Is higher GSHP efficiency worth

a higher CapX?

Environmental

FinancialTechnical

Driving Question: How can we electrify the greatest % of BU’s fossil heating systems in the shortest time given limited capital and operating budgets?

• Phase 1 Results: Hybrid systems of heat pumps and electric boilers significantly reduce CapX and NPV

• MEP Review: Do proposed electric heating retrofits require upgrading a building’s electrical service?

• Phase 2 Focus: How can BU electrify its heating systems without exceeding installed electrical capacity?

Problem: Phase 1 Result Exceeds Max Electrical Capacity• Phase 1 Result: Use a Hybrid ASHP/HT & Electric Boiler system to minimize CapX

• Peak Electrical Demand exceeds existing capacity on coldest days by 50%• When outside temp <40F, greater heating demand & lower ASHP’s COP/heating capacity

Current Summer Peak = 1600 kW

Phase 1 Heating Season Peak = 2400 kW

Current Winter Peak = 1100 kW

50% Increase

Phase 2: Strategies to Avoid Electrical Service Upgrades• Decrease peak heating load with EE measures (airflow optimization) • Use existing fossil-fuel boilers (NG) for supplemental heat on coldest days (only 10% of energy use)

NG boilers also provides backup heating capacity• Lower thermal operating temps (130F) enable more efficient electric heating equipment: low temp ASHPs

Phase 2 Heating Season Peak = 1400 kW

Current Summer Peak = 1600 kW

$ - $ 327K

$ 2.0M

$ 3.4M

$ 1.1M$ 1.8M

$ 2.7M

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$ 207K

$ 372K $ 365K

$ 352K

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$ 203K

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$ 400K

$ -

$ 1.0M

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$ 9.0M

NG Boiler (no BERDOACP, no EE)

NG Boiler (BERDOACP, EE)

ASHP/HT GSHP/HT ASHP/LT & NG BoilerHybrid

GSHP/LT & NG BoilerHybrid

Annu

al O

pera

ting

Cost

($)

NPV

of T

otal

Exp

ense

s & C

apita

l Cos

t ($)

Comparing OpX, OpX, and NPV of Total Expenses (20 yrs, 4.5% interest rate)CapXNPV (20yr, 4.5%)Annual OpX

Financial Analysis of Alternative Electrification Strategies• Validated financial model with Shaun Finn (BU’s VP of Budget, Planning, & Business Affairs)

Capital limitations strategies that minimize CapX important• Consider impact of proposed BERDO ACP cost on GHG emissions ($234/MTon)• Recommendation: ASHP/LT & NG Boiler Hybrid requires lowest CapX and NPV

BERDO's ACP: 234 $/MTCO2e

Cost of Reducing Carbon Emissions• Boston BERDO’s Alternative Compliance Payment (ACP): $234/MTCO2e

• Corresponds to 2.2X NG price ($1.07/therm $2.31/therm)• Insight: Cost-competitive for BU to invest in hybrid electric heating systems vs pay BERDO’s ACP

• Question: Is a 90% carbon emissions reduction acceptable for a lower capX retrofit?

Or: Are we willing to pay 2x the CapX for the last 10% of GHG reduction?

NG Boiler (BERDO ACP, EE)

ASHP/HT

GSHP/HT

ASHP/LT & NG Boiler Hybrid

GSHP/LT & NG Boiler Hybrid

$ -

$ 0.5M

$ 1.0M

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0% 20% 40% 60% 80% 100%

Tota

l Cap

ital($

) per

MTC

O2e

redu

ced

% Reduction in Carbon Emissions

CapX to Reduce Carbon Emissions

ASHP/HT

GSHP/HT

ASHP/LT & NG Boiler Hybrid

GSHP/LT & NG Boiler Hybrid

$200

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80% 85% 90% 95% 100%

NPV

($) p

er M

TCO

2e re

duce

d

% Reduction in Carbon Emissions

Cost of Reducing Carbon Emissions

BERDO's ACP: 234 $/MTCO2e

Retrofit Roadmap: Electrify 14 Key Buildings• 12 yr plan: Electrify 3.8M GSF to reduce 46% of BU CRC’s heating fossil fuel use

• Designed for learning and validating performance

• CapX: $2.0M/yr ($24.9M investment) |Annual OpX: $5.5M/yr• Post-Electrification OpX will be 36% less than NG system with BERDO ACP

$ -

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1 2 3 4 5 6 7 8 9 10 11 12 Post -Retrofit

Projected Implementation Plan for Top 15 Key Buildings & Pilots

Hybrid ASHP/HT Cum OpXHybrid ASHP/HT CapXNatural Gas OpX

Pilot Buildings 1 buildings/yr 2 buildings/yr

Pilot Phase: <100k gsf with AHU,

$370K/year

Initial Phase: $1.7M/year

Main Phase: $3.4M/year

NG

OpX

with

BER

DO A

CP

CapX

OpX

Next Steps1. Steam Loop: Evaluate opportunities to electrify buildings on the steam loop (37% of

fossil use)• Building-by-building evaluation of whether steam loop buildings require high temperature fluids

(>212F) [12 bldgs] • Good news: preliminary investigation indicates that several buildings on steam loop are

compatible with lower temp fluids

2. Energy Efficiency Options that reduce peak loads, CapX, & GHG emissions• Identify & quantify impact of EE measures that are technically/economically feasible

3. Evaluate need for high temp fluid output for AHUs & perimeter heat• Importance: High-Temp Heat pumps (160F) have lower COP than Low-Temp Heat Pumps (130F) &

thus result in higher peak electrical demand and heating energy costs• Develop experimental program for facilities to determine required fluid temp to meet thermal

performance requirements

4. Continue BU Management & Industry Review: Cannon Design, Salas O’Brien, BR+A5. Prepare for 2-Day Heating Electrification conference with ISE in Fall 2021

AcknowledgementsWe’d like to sincerely thank the following individuals for their insight & time:

Understanding Boston University’s Project Planning & ImplementationPaul Rinaldi Assistant VP for Planning, Boston University

Robb DixonBusiness Professor, Boston University, Former Chair, Boston University Faculty Council

Dennis Carlberg Director of Sustainability, Boston University

Understanding Building HVAC Design & Heat PumpsJacob Knowles Director of Sustainable Design, BR+ACris Copley Principal of HVAC & Mechanical Design, BR+AJoshua Michaud Associate Principal of HVAC, BR+ACarolyn Meadows Director of Strategic Initiatives, Boston Arts AcademyJames McQueen Project Manager, Boston Arts AcademyRobert Fisher VP of Facilities, Roxbury Community CollegeBradley Campbell President, Conservation Law FoundationTimothy Simpson AERMEC Product Specialist, Emerson SwanChris Schaffer Founder & President, The Green Engineer Inc.Neetu Siddharth Principal, The Green Engineer Inc.Anthony Hardman Senior BPA, The Green Engineer Inc.Mike Walters Principal & Expert in Distributed Heating Systems, Salas

O’BrienNicholas Conklin Director of Global Product Strategy, Carrier HVACMegan Howard Program Director, MassCEC

Geothermal: Heating & District HeatingTracey Ogden Principal, TAO ConsultingJarred Mullen Skillings and SonsT.J. Bernier Gap Mountain DrillingOwen Brady Manager of Future of Heat Program, National GridErik Pekkala Growth Portfolio Lead of New Energy Products, National GridNathan Phillips Former Project Faculty Advisor & BU Earth & Environment

Professor, Boston UniversityKeeley Bombard Former Student Researcher, BU Earth & Environment (CAS ‘22)

Boston University Student ResearchersAuthor of "BU CRC Electrification" Analysis (Jan 2018)David Staller (ME '18)

Authors of "Energy Efficiency Opportunities on CRC" Analysis (May 2017)Gabriella Henkels, Charles Bradley Miller, Ryan Peters, Carly Baracco, Anthony Graziano, Cole Ashman Paul Chiampa Jr., Jessica Gimbel, Cristian Morales

Estimating Costs & Financing Large CapX ProjectsJudith Judson VP of Distributed Energy Systems, AmerescoPaul Lyons President, Zapotec Energy IncDomenic Armano President, Guardian Energy ManagementMichael Gibbs Former Assistant Executive Officer, CARB;

Former Deputy Secretary of Climate Action, CalEPA;Former Senior Vice-President, ICF International

Robert Kaufmann Founding Partner, First Fuel Software; Earth & Environment Professor, Boston University

Nalin Kulatilaka Founding Partner, First Fuel Software; Business Professor, Boston University

Shaun Finn Assistant VP of Budget, Planning & Business Affairs, Boston University

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