Optimizing Cornell’s future geothermal district heating performance through systems engineering and simulation

• Published in: Energy and buildings Vol. 230; p. 110529
• Main Authors: Galantino, Christopher R., Beyers, Steve, Lindsay Anderson, C., Tester, Jefferson W.
• Format: Journal Article
• Language: English
• Published: Lausanne Elsevier B.V 01.01.2021; Elsevier BV
• Subjects: Augmentation; Carbon; Carbon footprint; Centralized heat pumps; Coefficient of performance; Deep direct-use; District heating; Economic analysis; Energy; Energy systems; Environmental impact; Geothermal district heating; Geothermal energy; Heat exchangers; Heat generation; Heat pumps; Low temperature; Optimization; Systems engineering; Troubleshooting; WWHP; Coefficient of performance; CentHP; GHG; HP; CHP; GDH; HX; Energy systems; DDU; ESH; MEnU; OR; COP; TBR; USDOE; CAPEX; SOI; EGS; LCOH; O&M; BCZ; Deep direct-use; Centralized heat pumps; Geothermal district heating
• ISSN: 0378-7788; 1872-6178
• DOI: 10.1016/j.enbuild.2020.110529

•Geothermal district heating can financially compete with conventional sources.•Centralized heat pumps significantly improve performance of direct use well-sets.•Geothermal baseload district heating with biomass peak heating has advantages. Cornell University’s intention to lower its carbon footprint has motivated this engineering evaluation of using low-temperature geothermal energy to supply heat to the campus district energy system. Optimal selection and operation of heat pumps can significantly improve system performance. To support this analysis, we model the quantitative relationships between heat pump configurations and source flow, supply and distribution temperatures, facility heating design options, output heat generation, and carbon abatement outcomes. A systems approach is used for analysis, troubleshooting, and improvement of the model. The result of this effort is a dynamic tool that appropriately responds to hourly thermal demand and communicates energy response for techno-economic analysis. Simulations indicate that a single well-pair in the local Basement Contact Zone reservoir can satisfy almost 68% of annual thermal demand at nearly 20 MWth average capacity while remaining financially competitive compared to conventional heating with levelized cost of heating (LCOH) as low as $4.55/MMBTU ($15.53/MWhth). A direct-use scheme with heat pump augmentation provided more carbon abatement and 50 to 150% more annual heat supply than one without augmentation. Exploration of three and four well-pair scenarios prove the capability to achieve 50 MWth baseload heating capacity with competitive LCOH and significant carbon reductions.