Many governments and institutions are advocating for higher renewable energy deployment to lower their carbon footprint and mitigate the effects of climate change. Cornell University instituted the “climate action plan” to achieve carbon neutrality, of which geothermal heat extracted from deep rocks (Earth source heat) is a critical component. This paper proposes coupling baseload geothermal heating with energy from waste biomass from Cornell's dairy farms to meet the campus' peak heating demand. The envisioned biomass peaking system, consisting of a hybrid anaerobic digestion/hydrothermal liquefaction/biomethanation process, produces renewable natural gas (RNG) for injection and storage into the natural gas (NG) distribution grid and uses NG withdrawals at times of peak heating demand. We show that 97% of the total annual peak heating demand (9661 MW h) can be met using continuous RNG production using manure from Cornell's 600 dairy cows, which provides 910 × 10⁶ l of RNG/year. The overall RNG system requires $8.9 million of capital investment and, assuming favorable policies, could achieve an effective levelized cost of heat (LCOH) of $32/GJ (minimum RNG selling price) and a net present value of $7.5 million after a 30-year project lifetime. Favorable policies were quantified by examining a range of incentivized prices for RNG injection ($47/MJ) and assuming wholesale utilities costs (NG withdrawals and electric imports). Selling RNG at the New York commercial NG price ($7/GJ) with utilities imports at commercial rates produces an LCOH ($70/GJ) in excess of the RNG selling price, highlighting the importance of carbon credits for financial profitability.

中文翻译：

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将生物量峰值与地热基本负荷加热相结合的可持续区域能源：以康奈尔能源系统脱碳为例

许多政府和机构倡导更多地部署可再生能源，以减少碳足迹并减轻气候变化的影响。康奈尔大学制定了“气候行动计划”以实现碳中和，其中从深部岩石中提取的地热（地球源热）是关键组成部分。本文提出将基础负荷地热供暖与康奈尔奶牛场的废弃生物质能相结合，以满足园区的峰值供热需求。设想的生物质峰化系统由厌氧消化/水热液化/生物甲烷化混合过程组成，可产生可再生天然气（RNG），用于注入和存储到天然气（NG）配电网中，并在高峰供热需求时使用NG。每年⁶升RNG。整个RNG系统需要890万美元的资本投资，并且如果采取有利的政策，则可以实现32美元/ GJ（最低RNG最低售价）的有效平均热成本（LCOH），以及30年后的净现值750万美元。项目生命周期。通过检查RNG注入的一系列激励价格（$ 47 / MJ）并假设批发公用事业成本（NG抽取和电力进口）来量化优惠政策。以纽约商业天然气价格（$ 7 / GJ）出售RNG并以商业价格进口公用事业产生的LCOH（$ 70 / GJ）超过了RNG出售价格，这突出了碳信用对于财务盈利能力的重要性。