[{"data":1,"prerenderedAt":-1},["ShallowReactive",2],{"detail-sidebar-cat-0-en-105":3,"doc-seo-657156-105":59,"doc-detail-657156-en":130},{"code":4,"msg":5,"data":6},0,"success",[7,13,18,23,28,33,38,43,48,51,55],{"id":8,"doc_module":4,"doc_module_name":9,"category_name":10,"show_sort_weight":11,"slug":12},1,"Document","Story & Novel",90,"story-novel",{"id":14,"doc_module":4,"doc_module_name":9,"category_name":15,"show_sort_weight":16,"slug":17},2,"Literature",80,"literature",{"id":19,"doc_module":4,"doc_module_name":9,"category_name":20,"show_sort_weight":21,"slug":22},4,"Exam",70,"exam",{"id":24,"doc_module":4,"doc_module_name":9,"category_name":25,"show_sort_weight":26,"slug":27},5,"Comic",60,"comic",{"id":29,"doc_module":4,"doc_module_name":9,"category_name":30,"show_sort_weight":31,"slug":32},6,"Technology",50,"technology",{"id":34,"doc_module":4,"doc_module_name":9,"category_name":35,"show_sort_weight":36,"slug":37},7,"Healthcare",40,"healthcare",{"id":39,"doc_module":4,"doc_module_name":9,"category_name":40,"show_sort_weight":41,"slug":42},8,"Research & Report",30,"research-report",{"id":44,"doc_module":4,"doc_module_name":9,"category_name":45,"show_sort_weight":46,"slug":47},9,"Religion & Spirituality",20,"religion-spirituality",{"id":46,"doc_module":4,"doc_module_name":9,"category_name":49,"show_sort_weight":46,"slug":50},"World Cup","world-cup",{"id":52,"doc_module":4,"doc_module_name":9,"category_name":53,"show_sort_weight":52,"slug":54},10,"Lifestyle","lifestyle",{"id":56,"doc_module":4,"doc_module_name":9,"category_name":57,"show_sort_weight":24,"slug":58},19,"General","general",{"code":4,"msg":60,"data":61},"ok",{"site_id":62,"language":63,"slug":64,"title":65,"keywords":66,"description":67,"schema_data":68,"social_meta":123,"head_meta":125,"extra_data":127,"updated_unix":129},105,"en","hybrid-systems-part-2-design-methodology-sankey-diagrams-in-ghetool-cloud","Hybrid systems (part 2) - Design methodology - Sankey diagrams in GHEtool Cloud","","Sankey diagrams are used to visualise how quantities flow through a system, tracking connections from inputs to outputs without creating or losing totals. The article explains how these diagrams should be read, discusses cycles and why GHEtool Cloud restricts diagrams to directed acyclic graphs, and highlights the four colour roles for hot side, cold side, environmental interactions, and seasonal thermal energy storage (STES). It then links STES, ground imbalance (negative or positive), and efficiency in borefields, extending the approach to complex cases such as passive/active cooling and hybrid systems.",{"@graph":69,"@context":122},[70,84,105],{"@type":71,"itemListElement":72},"BreadcrumbList",[73,77,79,82],{"item":74,"name":75,"@type":76,"position":8},"https://docshare.wps.com","Home","ListItem",{"item":78,"name":9,"@type":76,"position":14},"https://docshare.wps.com/document/",{"item":80,"name":40,"@type":76,"position":81},"https://docshare.wps.com/document/research-report/",3,{"item":83,"name":65,"@type":76,"position":19},"https://docshare.wps.com/document/hybrid-systems-part-2-design-methodology-sankey-diagrams-in-ghetool-cloud/657156/",{"url":83,"name":65,"@type":85,"image":86,"author":91,"headline":65,"publisher":94,"fileFormat":97,"inLanguage":63,"description":67,"dateModified":98,"datePublished":99,"encodingFormat":97,"isAccessibleForFree":100,"interactionStatistic":101},"DigitalDocument",{"url":87,"@type":88,"width":89,"height":90},"https://docshare.wps.com/thumbnails/hybrid-systems-part-2-design-methodology-sankey-diagrams-in-ghetool-cloud/657156.png","ImageObject",300,407,{"name":92,"@type":93},"Lucas Martin","Person",{"url":74,"name":95,"@type":96},"DocShare","Organization","application/pdf","2026-10-30","2026-10-26",true,{"@type":102,"interactionType":103,"userInteractionCount":24},"InteractionCounter",{"@type":104},"ViewAction",{"@type":106,"mainEntity":107},"FAQPage",[108,114,118],{"name":109,"@type":110,"acceptedAnswer":111},"How should a Sankey diagram be read in these system simulations?","Question",{"text":112,"@type":113},"Read it from left to right, moving from inputs to outputs so the flow through the system becomes clear.","Answer",{"name":115,"@type":110,"acceptedAnswer":116},"Why do GHEtool Cloud Sankey diagrams avoid cycles?",{"text":117,"@type":113},"They are implemented as Directed Acyclic Graphs (DAGs), so flows strictly follow one direction even when a return flow could otherwise create a cycle.",{"name":119,"@type":110,"acceptedAnswer":120},"What do the four main colours represent in GHEtool Cloud Sankey diagrams?",{"text":121,"@type":113},"Red/orange represents the hot side (heating and DHW), blue represents the cold side (cooling), purple shows environment interactions as input streams, and green represents STES as an input for the GSHP.","https://schema.org",{"og:url":83,"og:type":124,"og:title":65,"og:site_name":95,"og:description":67},"article",{"robots":126,"canonical":83},"index,follow",{"doc_id":128,"site_id":62},657156,1792974947,{"code":4,"msg":5,"data":131},{"doc_id":128,"user_id":132,"nickname":92,"user_avatar":133,"doc_module":4,"category_id":39,"category_name":40,"doc_title":65,"doc_description":67,"doc_content":134,"file_id":135,"file_url":136,"file_type":137,"file_size":138,"view_count":24,"is_deleted":4,"is_public":8,"is_downloadable":8,"audit_status":8,"page_count":24,"language":139,"language_code":63,"site_id":62,"html_lang":63,"table_of_contents":140,"faqs":141,"seo_title":142,"seo_description":67,"update_tm":129,"read_time":143},8796095360427,"https://ap-avatar.wpscdn.com/davatar_994ba38a5ba835b3df7d355c54d3ed8d","Hybrid systems (part 2): Design methodology  \nAuthor: Wouter Peere – Date: 6/05/2025  \nSankey diagrams are ideal for visualising how things flow through a system—whether it’s money, materials, or energy. That’s why we’ve added them by default as a result in every GHEtool Cloud simulation. Read the article to learn more about the insights you can gain from these diagrams.  \nWhat is a Sankey diagram?  \nSankey diagrams were originally developed to explain the efficiency of steam engines. They illustrate how the inputs of a system are connected to its outputs and can therefore be used to visualise interesting dynamics within the system. Although they were developed in the context of thermodynamics—where they are still frequently used—they have since found their way into economics, international collaboration and trade, and now, as of today, into geothermal engineering as well! Below is a sketch of a Sankey diagram for material use.  \nSketch of a Sankey diagram (source: [https://sketchplanations.com/sankey-diagram](https://sketchplanations.com/sankey-diagram))  \nEvery Sankey diagram should be read from left to right, moving from input to output. In the example above, all the packaging materials are inputs to the diagram and can be separated into multiple streams: cardboard, plastic, compost, and landfill.  \n!Note  \nThe example above also includes a return flow of ‘milk bottles’. This creates a cycle in the graph, which is typically avoided (although not strictly forbidden). In GHEtool Cloud, all Sankey diagrams are Directed Acyclic Graphs (DAGs), meaning they strictly flow in one direction.  \nAn important aspect of any Sankey diagram is that the total input must always equal the total output. This ensures that no material, energy, or other quantity is lost or created within the diagram itself.  \nBefore we take a closer look at how these diagrams are represented in GHEtool Cloud, we first need to introduce the concept of Seasonal Thermal Energy Storage (STES) .  \nSeasonal thermal energy storage (STES)  \nWhen we talk about shallow geothermal borefields, we refer to using the ground as a heat battery rather than as a source. Unlike deep geothermal applications—where heat is harvested for industrial processes, electricity generation or district heating—borefields are typically used in scenarios where there is both a heating and cooling demand.  \nIn summer, heat is stored in the ground, to be used later by the ground source heat pump (GSHP) during winter to heat the building. This extraction cools down the ground, making it suitable for (passive) cooling.  \nIdeally, the energy the GSHP extracts from the ground comes entirely from the stored energy from summer. However, in many cases there is an imbalance, meaning the stored energy is not sufficient to cover the full heating (or cooling) demand. In such cases, the ground is partly used as a source as well.  \nBoth of these heat sources—the Seasonal Thermal Energy Storage (STES) and the imbalance—are shown separately in the Sankey diagrams.  \n!Note  \nIf you are not familiar with the concept of imbalance, you can read about it in our article here.  \nSankey diagrams in GHEtool Cloud  \nEvery calculation in GHEtool Cloud will from now on also be visualised using a Sankey diagram. Although the appearance of these plots may vary depending on the specific design, the main colour scheme will always remain the same. A first example, showing a borefield with a negative imbalance, is provided below.  \nSankey diagram fora borefield with negative imbalance.  \nEvery such diagram in GHEtool Cloud consists of four different colours:  \n• Red/orange – represents everything related to the ‘hot side’ of the system, including heating and domestic hot water (DHW) .  \n• Blue – represents everything related to the ‘cold side’ of the system, such as cooling.  \n• Purple – indicates all interactions with the environment, which can be considered input streams. This includes the electricity required to run the heat pu","cbCaibePtyoSTwb9","https://ap.wps.com/l/cbCaibePtyoSTwb9","pdf",514149,"English","# Sankey diagrams in system design\n## What is a Sankey diagram?\n## Key reading rules and constraints\n# Seasonal Thermal Energy Storage (STES)\n## Shallow geothermal borefields and seasonal demand\n## Imbalance and heat source/sink behavior\n# Sankey diagrams in GHEtool Cloud\n## Colour meaning in GHEtool Cloud plots\n## Negative, positive, and near-balanced imbalance\n# Extended examples\n## Passive vs active cooling\n## Hybrid systems and combined technologies","[{\"question\":\"How should a Sankey diagram be read in these system simulations?\",\"answer\":\"Read it from left to right, moving from inputs to outputs so the flow through the system becomes clear.\"},{\"question\":\"Why do GHEtool Cloud Sankey diagrams avoid cycles?\",\"answer\":\"They are implemented as Directed Acyclic Graphs (DAGs), so flows strictly follow one direction even when a return flow could otherwise create a cycle.\"},{\"question\":\"What do the four main colours represent in GHEtool Cloud Sankey diagrams?\",\"answer\":\"Red/orange represents the hot side (heating and DHW), blue represents the cold side (cooling), purple shows environment interactions as input streams, and green represents STES as an input for the GSHP.\"}]","Hybrid systems (part 2) - Design methodology - Sankey diagrams in GHEtool Cloud | PDF",13]