Picture Main Street-District Energy-Ben Weill proposal-2021FUTUREPROOFING
DOWNTOWN NORTHAMPTON
Preparing for a district energy system
Ben Weil
Extension Asst. Prof. of Building Science, UMass Amherst
Member, Northampton Energy and Sustainability Commission
Member, Main Street For Everyone
8/26/21
The Context
source: Rewiring America
Main Street Redesign
■First MassDOT Design Submittal (25%) -Target December 2021
■curb placement
■driving lanes
■on-street parking
■subsurface utilities
Prepare now to avoid high costs of
retrofitting.
■Displacing natural gas
■Why air source heat pumps will be sub-optimal for downtown
■District energy system
■The opportunity right now
Massachusetts energy flows
Massachusetts 2050 Decarbonization Roadmap
Natural Gas
■To meet Massachusetts and global climate targets, we will need to phase out the
use of natural gas by the 2030s
■Methane leaks
■Eversource will replace all gas infrastructure as part of Main Street reconstruction
■This equipment will need to be abandoned in place long before its ”lifetime”
■This will be a stranded asset which the remaining utility customers will have to pay
for.
■Northampton needs a natural gas exit strategy
Air source heat pumps are not ideal
■High load buildings require large space devoted to ASHP outdoor units
■High density implies roofs covered with ASHP units. May require expensive structural
retrofits.
■VRF systems cannot take advantage of simultaneous cooling and heating (heat
trading) unless system is shared.
Issues with the current vision approach to heat pumps in New England
Multi-head penalty
reduced benefit of
setbacks
Modularity reduces
economies of scale
simultaneous
peaking
R410A phase-
out requires
equipment
replacement
Common refrigerants have high GWP and will be phased out
What will we want available to
downtown Northampton instead?
■technology neutral
■non-toxic/low GWP/zero ODP
■durable and resilient
■supportive of a renewable grid
■… A District Energy System
District Energy System (DES)
Heating
and
Cooling
center -Hot Water
-Cold Water Supply
-Cold Water Return
Commercial Residential Institutional and
Governmental
12
DES:
A Brief
History
13
Where are DE Systems
Used?
●Over 700 DE Systems
in the United States
14
Future-
Proof
Design
15
Geothermal Options
District energy
hydronics
Temperatures can range:
•Low (50 to 80°F)
requiring heat pumps in
each client
•Medium (100 to 180°F)
allowing some client
buildings to use a simple
heat exchanger only.
•High (over 200°F)… not
recommended
Heat meter
Courtesy of John Siegenthaler
PRECEDENTS:
WEST UNION
IOWA
2013
Richmond, BC
•Committed to reducing greenhouse gas emissions
by 33% by 2020 and 80% by 2050, relative to
2007 levels.
•City incorporated Lulu Island Energy Company in
2013 to implement and operate district energy
utilities on the City’s behalf.
•By July 2012, the construction of the first district
energy system in the City of Richmond—the
Alexandra District Energy Utility (ADEU) —was
completed.
•District energy in Richmond is fully funded by
service fee revenue and has no impact on
property taxes.
Reserve space for DES in Main Street
subsurface plans as part of 25% design
Require new natural gas infrastructure be
designed to be safely abandoned in place
Adjacent
specification:
Sewage Heat
Exchange
Experts
■Who will provide design advice to Toole to assure that sufficient space is reserved at
the right depths?
■HEET
■MEP
Proposal
Recommend district energy systems be supported and
enabled where feasible and appropriate in the City.Recommend
Recommend the City Council develop an ordinance to
enable DES development, financing, and operation.Recommend
Request space for DES piping and connections be reserved
in the design of the subsurface of Main Street.Request
Approve the use of Revolving Fund to pay for the added cost
of this design specification.Approve