Planning a carbon-neutral district heating system for UC Davis July 2018

campus carbon footprint Existing Steam System 27 miles of underground pipe 50+ years old 32% campus carbon footprint 8M square feet served

Davis Main Campus CY 2017 Energy Use Additional Context Davis Main Campus CY 2017 Energy Use UC Policy Drivers: Climate Protection: Reduce GHG emissions to 1990 levels by 2020 Climate neutrality by 2025 for business operations Climate neutrality by 2050 or sooner for commuting & business air travel Clean Energy: 100% clean electricity by 2025, to be met through a campus-determined mix of on-site and off-site renewables; implementation of energy efficiency actions to reduce the campus’ energy use intensity by an average of at least 2 percent annually; and by 2025, at least 40% of the natural gas combusted on-site at each location will be biogas. Commodity Units Annual Use Total Electricity GWh 227.2 Solar Farm 29.2 Other Renewable 1.3 Total Gas MM Therm 10.3 CHCP 8.3 Chilled Water MM Ton-hr 39.1 Steam MM lb 763.1

Heating System Impact on Campus Climate Goals Camille to present

Heating System Analysis Demand Heat Recovery Potential Cooling Demand Diverse campus activities necessitate some heating and cooling year-round

Steam Heating: A Losing Proposition Aging system, needs extensive repairs/renewal Expensive to operate & maintain, safety concerns Over 30% energy loss in distribution piping Will require additional capacity in next 5 years $141M total on map

Heating System Analysis Goals for Heating System Investment: Leverage advantages of district systems Provide infrastructure modernization and renewal Provide a safe and reliable heating system Lowest life cycle cost (capital, energy, & maintenance) Help campus reach sustainability and carbon goals

Heating System Analysis The Process: Incorporates large Stakeholder group and smaller Working Group Big Sky ideation charrette Qualitative (criteria and weighting) short listing of options Quantitative (approx. 80 assumptions and inputs) Cost Carbon Energy Water Sensitivity analysis on assumptions and inputs

Heating System Analysis Life Cycle Cost Modeling 60 year horizon Costs included: Capital (initial & future) Operational (maint., energy & carbon) Evaluated existing system vs 5 alternatives Included escalation and sensitivity analysis Most of campus heating can be met w/ heat recovery Can reduce operational costs by 90% Can reduce distribution energy losses by 80% Existing steam system is the most expensive Hot water with heat recovery is the lowest cost Centralized heat recovery is less expensive than distributed

Heating System Analysis Findings: New distribution system would address both renewal and capacity needs Comparable capital investment would replace entire steam system with innovative hot water system and operational savings Provides a pathway to carbon neutrality via full electrification Most of campus heating can be met w/ heat recovery Can reduce operational costs by 90% Can reduce distribution energy losses by 80% Existing steam system is the most expensive Hot water with heat recovery is the lowest cost Centralized heat recovery is less expensive than distributed

Central Combined Heating and Cooling (CHC) with Building Heat Recovery (HR) is the lowest NPC option for 82% of the sensitivity testing.

Central Combined Heating and Cooling Recommendation Central Combined Heating and Cooling Least cost option, yet sustainable, innovative & resilient Potential for incremental investment to full electrification and carbon neutrality by 2025 Campus districts identified for conversion plan Tercero District already operational since 2010 Building on experience from similar projects on other campuses (ie, Stanford, UBC Vancouver, Ball State, Univ of Rochester, UVA)

1 good (meets emission standards) 1 okay (requires emissions upgrades) Existing Steam Heating NG fired steam boilers 1 good (meets emission standards) 1 okay (requires emissions upgrades) 2 at end of life (require replacement) Aging steam distribution Core distribution requires near-term replacement Steam to Water HX in building level mechanical rooms Cooling Central, conventional chillers Chilled water TES (5M gal.)

Central CHC +HW Dist. +Boiler +Heat Recovery +Heat Pump System Future Enhancement Full electrification

Existing District Steam Boundary Chilled Water & Steam Plant Chilled Water TES Plant 1 MILE

Campus Districts for Implementation

45% of Waste Cooling Heat can Provide 60% of Heating Capacity

Recommended Option Cooling Demand: 45% CHC 55% Conventional 15% False Cooling Recommended Option Heating Demand: 60% CHC 20% Building Airside Heat Recovery 20% Boiler Heating (Replaced by geo-exchange/air-source heat pump system with future enhancement)

Proposed Hutchison-Quad District Hot Water Conversion Cost effective solution to address the Quad underground steam piping deficiencies Convert 2.8M sf (30%) of campus buildings from steam to hot water (40 buildings) New underground hot water distribution New building heat exchangers for domestic and industrial water and the building heating system Allows for LRDP growth/expansion

Hutch - Quad Hot Water Conversion Quad Steam Renewal Hutch - Quad Hot Water Conversion

Achieving Our Goals: Heating System Analysis Leverage advantages of district systems Provide infrastructure modernization and renewal Provide a safe and reliable heating system Lowest life cycle cost (capital, energy, & maintenance) Help campus reach sustainability and carbon goals Implement in groups to align with available funding

Lessons Learned Understand your system: data gathering is a big effort Acknowledge the importance of process to help build consensus among stakeholders Fluently know the various assumptions in your model; be able to explain them to leadership and stakeholders Go where it leads you: be open to surprising results agenda

Discussion Presenters: Michael BOVE, Affiliated Engineers, Inc., mbove@aeieng.com Camille KIRK, UC Davis, Office of Sustainability, cmkirk@ucdavis.edu Joshua MOREJOHN, UC Davis, Facilities Management, jdmorejohn@ucdavis.edu