Thermal energy for space heating and for domestic hot water use represents about a third of the overall energy demand in Germany. An alternative to non-renewable energy-based heat supply is the implementation of closed and open shallow geothermal systems, such as horizontal ground source heat pump systems, vertical ground source heat pump (vGSHP) systems and groundwater heat pump systems. Based on existing regulations and local hydrogeological conditions, the optimal site-specific system for heat supply has to be identified. In the presented technical feasibility study, various analytical solutions are tested for an urban quarter before and after building refurbishment. Geothermal heat supply rates are evaluated by providing information on the optimal system and the specific shortcomings. Our results show that standard vGSHP systems are even applicable in older and non-refurbished residential areas with a high heat demand using a borehole heat exchanger with a length of 100 m or in conjunction with multiple boreholes. After refurbishment, all studied shallow geothermal systems are able to cover the lowered heat demand. The presented analysis also demonstrates that ideally, various technological variants of geothermal systems should be evaluated for finding the optimal solution for existing, refurbished and newly developed residential areas.

中文翻译：

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满足需求：德国城市地区的地热供热率

用于空间供暖和用于家庭热水的热能约占德国总能源需求的三分之一。不可再生能源供热的替代方法是实施封闭和开放式浅层地热系统，例如水平地面源热泵系统，垂直地面源热泵（vGSHP）系统和地下水热泵系统。根据现有法规和当地水文地质条件，必须确定最佳的现场供热系统。在提出的技术可行性研究中，对建筑物翻新前后的市区进行了各种分析解决方案的测试。通过提供有关最佳系统和特定缺点的信息来评估地热供热率。我们的结果表明，标准的vGSHP系统甚至可以通过使用长度为100 m的钻孔热交换器或与多个钻孔结合使用，从而在热量需求较高的较旧和未翻新的居民区中使用。翻新后，所有已研究的浅层地热系统均能够满足较低的热量需求。提出的分析还表明，理想情况下，应该对地热系统的各种技术变型进行评估，以找到现有，翻新和新建住宅区的最佳解决方案。