HomeMy WebLinkAbout2017-09-06-ECC2-min.attach (Hastings Geothermal Heat Pump Design Recommendations)Memorandum
To: Alessandro Alessandrini, School Committee Chair
Cc: School Committee, Board of Selectmen
From: Sustainable Lexington Committee - Mark Sandeen
Date: August 24, 2017
Subject: Hastings Geothermal Heat Pump Design Recommendations
On February 27, 2017, the Board of Selectmen and School Committee voted unanimously in
favor of installing a geothermal heat pump system at the new Hasting Elementary School based
on the recommendation of the Department of Public Facilities.
On June 6, 2017, the School Committee unanimously reaffirmed their commitment to the
geothermal heat pump system after discussing new information provided by the design team
regarding a significant increase in the estimated cost of the geothermal system. On June 22,
2017, the Board of Selectmen also unanimously reaffirmed their commitment to the geothermal
heat pump system after reviewing the design team's updated cost numbers.
On August 15, 2017, the Board of Selectmen, School Committee, Permanent Building
Committee (PBC), and Sustainable Lexington Committee met at the request of the PBC to
discuss the geothermal heat pump decision. Following the discussion, the Board of Selectmen
voted unanimously, with the strong support of the School Committee, to reaffirm their decision
made on June 22nd. The discussion covered the following recommendations:
• Maximize Renewable Energy Production
• Achieve Net Zero Energy Design
• Solar + Storage Savings
• Alternative Energy Credit (AEC) Revenue
• Zero Emissions HVAC Design
Bottom Line - The geothermal heat pump + solar + storage solution is expected to provide
annual savings of between $190K and $277K over the first 30 years of operation. The capital
costs of financing the geothermal heating system are expected to range from $61 K to $117K a
year for 20 years, resulting in a net annual savings after bond payments of between $129K and
$160K by going with the geothermal + solar + storage solution. This integrated geothermal heat
pump + solar + storage solution is expected to be cash flow positive from day one and to save
the Town between $4.5M and $6M over 30 years of operation.
This solution also minimizes the total amount of energy consumed by the school and provides
the most health and environmental benefits for our students, staff and the global community.
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
M Annual aM Geothermal Solar Storage Solution
e o e • e g • g
III IIII IIII IIIIIIIIIIIII
'►
� •
III III III VIII
� I II II 4!
IN IN •
•
I (IIII III IIIIIIIIII 111111
I II 1111
IN �I
`--E--C R -e -ye n--u--e ---------------------------------------------------------------------------------------------------------------------------------
o a Savings Geothermal
1• I• IIIIIIIIIII��
@ VIII
• IM
a IM•►��
IIII III II III I@
M I11r I11r •
, ��
IIII VIII 1
M IM
� + Hastings
SolarSavings �I► Rest
III
w •
Mur
IIIV IIIIIIIIIIIIII IIII IIIIV IIIIIIIIIIIIII
w • 111 � • 111
• I�► • • I�►
IIIIIIIIIIIIII VIII IIIIVI IIII
w • 1111
�►
Hastings Peak ■� ■► " yr SavingsHealth
II IIII VIII VIII 11111Q
• •
II III IINI III IIII
IMII� IMII�
III @IIII Iq VIII VIII
SII
Benefits
� .
' III IIIIIIII
alll UIQ IIIN��III 1111111
.IIII rlr �, •
I III�II•III 111111
iiljl 11111r Mllrll CEM
II��
soft It • �
I pill 1111111
MiM1 1111111 111 111 11� I`�
IIII • •
1. Maximize Renewable Energy Production — Sustainable Lexington recommends that the
Town commit to achieving the maximum solar energy production option for Hastings School
prepared by Solar Design Associates and presented by Town staff and DiNisco Design to
the Board of Selectmen and the School Committee. This solar design option will maximize
solar energy production, while lowering ongoing energy costs, and enabling the elimination
of on site fossil fuel emissions and greenhouse gas emissions, all while enabling Hastings
School to become the Town's first net zero energy building. We would expect to be able to
engage a third party partner to install, own and operate the solar energy system at no
upfront cost to the Town under a similar type of agreement as we have used with our
previous municipal solar energy projects.
This proposed solar energy system design takes into account several Sustainable Lexington
recommendations for maximizing solar production at Hastings, including:
a. Siting higher roof elevations (such as the gymnasium roof) on the north side of the
building to minimize solar shading.
b. Siting HVAC systems on the north side of the roof so that they do not shade areas of the
roof that could otherwise be used to produce solar energy.
c. Using higher -density, East-West rooftop installation options that allow increased
production and lower roof loading.
d. Installing solar canopy structures over the school's parking lots, generating 3 times the
solar available from the rooftop, while providing shade and snow cover for cars.
2. Achieve Net Zero Energy Design — For all new buildings, Sustainable Lexington
recommends that our design teams evaluate and present design options for achieving net
zero energy - where local renewable energy production offsets the building's annual energy
demand. The design team has prepared an energy model for Hastings School's that
estimates that Hastings School's total annual electricity energy demand will be 768,384 kWh
with the geothermal heat pump design. Solar energy production from the solar energy
system design outlined above is expected to be 901,977 kWh per year. Hastings will be
Lexington's first net zero energy school if we are able to achieve both of those estimates.
3. Solar + Storage Savings — We have analyzed the expected savings from going with the
geothermal heat pump design across three energy cost scenarios. The Low scenario
assumes that natural gas prices will remain at their 20 -year historic low price for the next 30
years. The Mid scenario assumes that natural gas prices will stay at today's current market
prices for the next 30 years. The High scenario assumes that natural gas prices will rise to
their 20 -year historic average price for the next 30 years. Under those three scenarios, the
geothermal heat pump solution will save the Town between $4K and $22K a year in
electricity costs, if we choose to buy all of our electricity from the grid.
If the Town chooses to maximize solar production as outlined above, the additional
expected savings from operating the geothermal heat pumps on solar power will range
between $35K and $44K a year. The solar energy system will also generate an additional
savings of between $76K and $95K for supplying the rest of the electricity needed to
operate the school.
By adding energy storage to the solar energy system, the expected peak demand savings
will range from 100 kW in the Low scenario to 200 kW in the High scenario.
The annual expected peak demand savings will range from $26K to $52K at today's peak
demand energy rates.
KA
4. AEC Revenue — It is also important to consider the Alternative Energy Credit (AEC)
revenue that the Town will earn by going with the geothermal heat pump design. In this case
the three scenarios consider AEC prices ranging from $20 to $30 per MWh of heat produced
by the geothermal heating system. The governor's new clean energy standard is expected
to increase the price of AECs from the current price of $20 / MWh to $30 / MWh over the
next 3 years as the demand for clean energy increases to meet the requirements of the new
clean energy standard.
5. Zero Emissions HVAC Design — The Board of Selectmen and the School Committee have
now unanimously affirmed their commitment to zero emission heat pumps instead of natural
gas boilers for Hastings School several times. They have stated on numerous occasions
during these discussions that they desire to see our schools designed for our local, regional
and global health.
a. Fossil fuel emissions adversely impact air quality and human health. MIT determined
that fossil fuel emissions resulting from heating our buildings account for about 1,775
premature deaths per year in Massachusetts alone. Fossil fuel emissions also result in
elevated CO2 levels, which have been shown by Harvard School of Public Health to
decrease cognitive performance.
b. The CDC has determined that workers at natural gas drilling sites experience a fatality
rate 7x higher than the national average.
c. The University of Pennsylvania and University of Columbia conducted a study of
200,000 Pennsylvania residents that found that people who live within 1 mile of a natural
gas fracking site are 27% more likely to develop severe heart disease, cancer and
neurological disorders. The Wall Street Journal reported four years ago that 15 million
people now live within one mile of a fracking well and that number was growing rapidly.
To put that in context, there are about 15 million people living in New England.
d. Those fracking sites generate 280 billion gallons of toxic wastewater each year
containing over 700 chemicals, many of which are considered hormone disrupters and
have been linked to birth defects and other disorders.
e. Unauthorized flaring of natural gas at those fracking sites has increased by a factor of 20
since 2010. The gas industry is currently flaring enough natural gas to power all the
homes in Chicago. You can see the waste from flaring in satellite photos.
f. Methane leaks from natural gas fracking sites are much higher than expected with leaks
measuring between 4% and 9%. Methane has a 20 -year global warming potential that is
86x stronger than CO2. That means very small leakage rates can have huge effects on
our climate. Natural gas leaks of over 3% mean that natural gas has a larger global
warming impact than using coal to produce our electricity. Harvard and Boston
University studies have measured 2.7% methane leakage rates just from the local
pipelines in the greater Boston area.
g. There is a significant health cost of transporting natural gas. Natural gas pipeline
explosions have resulted in 680 fatalities, 2,646 injuries and $1.4 billion in property
damage in the US over the last 20 years. Just two weeks ago there was a natural gas
explosion during routine maintenance at a high school in Minnesota, killing two staff
members, injuring 9 others and destroying a large portion of the building.
The good news is that the Massachusetts electric grid is rapidly switching to renewable
energy. The Omnibus Energy bill signed into law last year will dramatically increase our
renewable energy content over the next 5 to 10 years, mostly from hydro and wind power. In
addition, the Governor has enacted new clean energy standards requiring our electricity grid
to add 2% new clean energy sources each year until achieving an 80% reduction in our
greenhouse gas emissions by 2050.
3
6. Other factors — The Town can capture additional savings by going with the geothermal heat
pump design, which has an expected lifetime of 60 years versus the 20 year expected
lifetime of the natural gas boilers. The Town would bear the additional cost of replacing the
natural gas boilers twice during the expected life of the geothermal heat pump system.
Those boiler replacement costs have not been included in this analysis.
These recommendations are consistent with our values as a community and with the
overarching purpose of the Hastings School — particularly our duty to protect the children,
faculty, and staff under our care. We believe our students, faculty, and staff shouldn't breathe
fossil fuel emissions when we have an excellent alternative.
P,arkl'ing]
,Sol,ar P�V,Asse�,S,,,s,�me,nt
4