Ready for geothermal energy storage?

Hysopt is proud to announce a new release of the Hysopt software, as we included several new features to support the design, simulation and optimisation of geothermal energy storage systems.

These systems are amongst the most promising technologies for long-term energy storage, from both technical and economical points of view. Seasonal energy storage is a natural way to shift peak demands but also to provide thermal energy at much higher efficiencies. On the other hand, these applications are very complex and sensitive to design flaws. Besides the thermal behavior of the ground and the need for hybrid production, the complexity originates from the inseparability of the heating and cooling system to store excess heat in summer and excess coolth in winter. Because of the complexity, the system is sensitive to design errors, often resulting in an inadequate system and a yearly deterioration of the geothermal energy storage.

Hysopt provides user friendly guidance for the flawless design, simulation and optimisation of geothermal systems. The Hysopt calculations and component optimisations are automated by the software, based on the concepts and designprocedures as defined in the Dutch ISSO 39 publication and the Cibse CP3 Code of Practice from the UK.

ATES & BTES

ATES (Aquifer Thermal Energy Storage)

An ATES system typically consists of extraction and injection wells. The groundwater in underground aquifers is used for thermal storage and medium.During summer, cold groundwater is extracted from the cold well and by means of a heat exchanger, the thermal energy is transferred to cool the building.Through this process, the water is heated after which it is injected in the hot well. During winter, this system reverses and the stored warm water is extracted. Several hydraulic ISSO concepts have been added to the Hysopt software.

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BTES (Borehole Thermal Energy Storage)

Borehole thermal energy storage (BTES) systems uses the underground itself as the storage material. Large pipes in the underground are used as a large, underground heat exchanger. A BTES system consists of an array of boreholes resembling standard drilled wells. Several hydraulic concepts of typical BTES systems have been added to the software.

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Operation mode in different seasons

An ATES or BTES system has different operation modes in different seasons. Hysopt provides full insight in these operation modes. The conditions and the behavior for storing excess coolth in winter (“cold deposit”) and heat in summer (“cold withdraw”) can be visualized both in design mode as in simulation mode.

All ATES & BTES subcomponents (heat exchangers, pumps, valves, pipes) must be able to operate correctly in all operation modes. The dimensioning and configuration of these components is very complex, and therefore fully automated in the Hysopt software.

Hysopt inspiration library

Hysopt provides templates, containing examples and best practices to design and control your ATES or BTES system. It includes templates of multiple system concepts, predefined control logic, regeneration strategies and hybrid production configurations.

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One of the BTES templates in the Hysopt software, providing control logic and optional regeneration strategies

Thermal balance

In some countries like in the Netherlands, regulations prescribe an energy balance in the geothermal system. Apart from regulations, thermal imbalance can cause several problems and can ultimately result in a thermal breakdown.

Hysopt provides full insight in the thermal balance and the behavior of the soil. For in-depth analysis, Hysopt supports long term simulations up to 20 years.

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One of the techniques commonly used to establish thermal balance, is regeneration using ambient exchange units like dry coolers and cooling towers. In geothermal systems, ambient exchange units are often used for multiple purposes (e.g. both hot release as cold supply), resulting in multiple design conditions in which every component has to be correctly operating in. This is automated in the Hysopt software.

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Economic and ecologic optimum

Using these new features, Hysopt users have all the tools to design multiple geothermal system variants, optimise concepts, analyze simulation results, provide insight in energy cost savings, and find the economic or ecologic optimum, as illustrated below.

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Other improvements

Hysopt is continuously expanding its functionality and improving its usability. A noteworthy change introduced in this release is the “single click”functionality throughout the user interface. All actions to load or save a model or to start a calculation, now only require one click, increasing your efficiency even more.

Special thanks

Last but not least, we would like to thank Hans Buitenhuis (managing Partner at DWA consultancy), and Nic Wincott (NeoEnergy UK, former CEO GSHPA UK, and lead author of the CIBSE guides CP2 & CP3), for the close cooperation and feedback during our ATES and BTES development. Thank you Hans and Nic!