EAGER: Geothermal Battery Energy Storage Technical Feasibility

这一探索性研究（EAGER）项目的早期概念资助涉及岩土工程研究，以评估利用地球（地热沉积储层）作为大规模储能“电池”的可行性，以帮助管理太阳能和风能发电的间歇性。地热电池将太阳能产生的热水储存在地下，并在需要时将其作为蒸汽提取，或者在热水二元循环发电系统中使用，特别是在太阳能和风能不可用时。太阳能和风能正被引入电网，以补充传统的电力生产，主要是由于对电力生产“脱碳”的愿望，以及最近由于太阳能和风能价格的下降。这种引进在某种程度上“过于成功”，导致了一些太阳能和风能的短期减产。此外，太阳能和风能只能在太阳照耀和风吹的时候提供电力，导致电力生产波动。与此同时，“公用事业规模的储能”（有时被称为“电网规模”）的部署并没有跟上太阳能的间歇性，风能也没有跟上。电池的概念是利用现有的地热储层，但是储层温度太低，经济上不可行。太阳能热产生的热量的增加可能能够提高低品位地热储层的温度，以有效地利用它进行蒸汽/二元循环发电。在很大程度上，这种存储概念是利用地热能和太阳能热能相结合的全部“可再生能源”。如果可行，这种储能概念的实施将提高全国各地太阳能和风能发电的可靠性和范围，从而减少对碳基燃料的依赖。为了在不造成严重干扰的情况下继续增加太阳能和风能发电，具有成本竞争力的能源储存是必不可少的。该项目的重点是确定地热电池储能系统在技术上是否可行，成本是否具有潜在的竞争力。指导委员会将在项目开始时举行会议，提供规划指导，并在项目结束时提供初步的一致结论。将举行最后一次讲习班，审查调查结果并提出协商一致的结论。该项目的结果将通过探索与地热电池储能概念相关的技术现象来增加现有的知识库，包括地热储层内的热能运动；加热储层时发生的岩石膨胀；由于储层的循环加热和冷却对岩石的化学作用；而潜在的诱发地震活动，如热膨胀和注水到储层产生一定的断层运动。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

This EArly-concept Grant for Exploratory Research (EAGER) project addresses the geotechnical engineering research needed to assess the feasibility of using the earth (a geothermal sedimentary reservoir) as a "battery" for large-scale energy storage to help manage the intermittent nature of solar and wind electricity generation. A geothermal battery would store solar generated hot water in the earth, and withdraw it as steam or use it in a hot water binary-cycle electricity generation system when needed, particularly when solar and wind are not available. Solar and wind electricity are being introduced into electric grids to supplement conventional electricity production, driven substantially by a desire to "decarbonize" electricity production, and more recently due to falling prices of solar and wind energy. Such introduction has in some ways been "too successful" leading to short-term curtailments of some solar and wind production. Also, electricity can be provided by solar and wind only when the sun shines and the wind blows, resulting in fluctuating production of electricity. Meanwhile, the deployment of "utility scale storage" (sometimes referred to as "grid scale") has not kept pace with this intermittent nature of solar, and to a lesser extent wind. The battery concept would utilize an existing geo-heated reservoir, but one where the reservoir temperature is too low to be economically viable. The addition of heat produced by solar thermal may be able to raise the low-grade geothermal reservoir temperature enough to utilize it efficiently for steam/binary cycle electricity production. To a large extent, this storage concept is all "renewable energy" drawing on geothermal energy and solar thermal energy combined. If feasible, the implementation of this storage concept would improve the reliability and extent of solar and wind electricity throughout areas of the nation, resulting in less reliance on carbon-based fuels. Energy storage that is cost competitive is essential in order to continue the addition of solar and wind electricity without great disruptions. This project focusses on the determination if a Geothermal Battery Energy Storage System is technically feasible at a potentially competitive cost. A steering committee will meet at the start of the project to provide planning guidance, and near the conclusion of the project to provide tentative consensus conclusions. A concluding workshop will be held where findings will be reviewed and consensus conclusions presented. The results of the project will add to the existing knowledge base by exploring technical phenomena related to the Geothermal Battery Energy Storage concept, including thermal energy movement within a geo-reservoir; rock expansion that occurs when heating the reservoir; the chemical effect on the rock due to the cyclic heating and cooling of the reservoir; and the potential for induced seismicity as thermal expansion and the injection of water into the reservoir produce certain fault movements.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.