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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! 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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. 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