# GreenCity Simulation Library Reliable, easy-to-use dynamic simulation for connected energy systems — proven in commercial and industrial engineering projects for more than 15 years. Simulation Library ## GreenCity Library Simulates All the Energy Systems You Can Imagine GreenCity is your simulation library for energy systems interaction in Modelica-SimulationX. It is the tool for energy engineers to understand, analyze and test their designs. With power plants, storage and distribution systems and consumers, it contains all the models you need. Use this power to dynamically simulate the system concept and energy management algorithms. Ready-to-use, flexible and extensible. [Request a demo](/contact/) ![GreenCity Energy Simulation – schematic overview](/_astro/green-city-simulation-overview.D0WbJZwp_1oGcJb.webp) Benefits ## Your Benefits of Using GreenCity Significantly speed up your planning process with GreenCity. Develop efficient and reliable system designs. Control your investment and operational costs. Optimization of Efficiency and Operating Costs Quantitative Evaluation of Multivalent Influencing Factors Variant Studies and What-If Analysis Risk-Free System Evaluation for Control Strategies Typical Tasks ## From System Design to Control Optimization Design connected energy systems, evaluate control strategies and explore sector coupling with GreenCity — combining dynamic simulation with technical expertise built over more than 15 years. [Discuss your simulation project](/contact/) - **Energy System Design** Design and evaluate interconnected generators, storage and consumers. - **Control Optimization** Develop and test control strategies for energy systems. - **Sector Coupling** Analyze interactions between heating, cooling, electricity and mobility. - **Energy & Mobility** Evaluate how mobility requirements affect energy supply. - **Model Predictive Control** Explore predictive control using dynamic system models. - **Virtual Testing & Failure Analysis** Test system behavior under normal operation and fault conditions using a virtual test bench. [Discuss your simulation project](/contact/) Simulation Models ## An Overview of Available Components The GreenCity Library contains our technical know-how and more than 15 years of experience in energy systems simulation. We continuously improve it to provide the best results for state-of-the-art consulting to our customers. - **Renewable Energy** - **Energy Storage** - **Heat Pumps** - **Controllers** - **HVAC** - **E-Mobility** - **Hydrogen** - **Grids** - **Global Weather Data** - **Heat Exchangers** - **Cost Calculation** ![Example model of a single family home with heat pump, photovoltaics, storage, wind generator, electric vehicle and stationary battery](/images/sites/green-city-library/pages/index/simulation-model-single-family-home.svg) **Example Model: Single-Family Home**Heat pump, photovoltaics, storage, wind generation and electric mobility in one integrated system. GreenCity ## GreenCity Extensions GreenCity extensions provide a more detailed evaluation of specific energy systems for your use cases. Many customers also use private extensions that cover their specialized tasks and intellectual property. ### [Hydrogen Systems](/extensions/#design-and-evaluate-hydrogen-energy-systems) Model hydrogen production, storage, conversion and consumption to evaluate integrated energy concepts and control strategies. ### [District Heating Grids](/extensions/#design-and-optimize-district-heating-networks) Simulate thermal and hydraulic network behavior to identify bottlenecks and evaluate extensions, supply concepts and control strategies. ### [Indoor Air Control](/extensions/#design-and-optimize-indoor-air-quality) Analyze indoor temperature, humidity and CO₂ levels to design ventilation systems and effective control strategies. ### [Steam Systems](/extensions/#analyze-and-optimize-industrial-steam-systems) Simulate steam generation, distribution and condensate recovery to analyze energy losses and assess operational changes. ### [Thermodynamic Machines](/extensions/#design-and-optimize-refrigeration-and-heat-pump-systems) Dynamically simulate refrigeration and heat pump circuits to evaluate component interactions, controls and integration with air handling systems. ### [Your Individual Industrial Process Library](/extensions/#custom-library) Extend your models with tailored components, system models and interfaces for your specific application requirements. [Explore Library](/extensions/) Practical and Extensible ## What Makes GreenCity Outstanding? The practical application of the GreenCity Library means that it is constantly reviewed and tested by trained engineers. Practical Orientation Interdisciplinarity Ready-to-Use and Pre-Parameterized Flexible and Extensible By Engineers, for Engineers 15 Years of Industrial Experience Use Cases ## Examples of Energy System Models ![Aerial view of the industrial hall planned for conversion into a flexible marketplace](/images/sites/green-city-library/pages/index/use-case-industrial-hall-marketplace.webp) ### Industrial Hall Conversion into a Flexible Marketplace With future energy demand uncertain, GreenCity compared 22 supply concepts for converting a vacant industrial hall into a flexible marketplace. Two promising concepts emerged, with operating-cost savings of up to €790,000 over 10 years for the most efficient configuration. The simulations assessed demand, supply security, CO₂ emissions and investment costs at each expansion stage, providing an energy roadmap for future tenants and uses. ![YADOS domestic hot water unit with insulated piping and a control cabinet](/images/sites/green-city-library/pages/index/use-case-yados-district-heating-substation.webp) ### Reducing District Heating Return Temperatures with Optimized Domestic Hot Water Systems For YADOS, dynamic simulations compared conventional domestic hot water systems with optimized configurations, capturing intermittent demand that static calculations cannot reliably represent. Across load and circulation scenarios, optimized systems achieved lower district heating return temperatures, reaching around 40 °C under favorable conditions. The study quantified part-load effects and circulation losses, helping operators assess efficiency benefits and select configurations for their operating conditions. ![Berlin district energy system model with heat pumps, cooling machines, ice storage and heating and cooling consumers](/images/sites/green-city-library/pages/index/use-case-berlin-district-ice-storage.webp) ### Optimizing District Energy Systems with Ice Storage and Peak Load Shifting Simulations of a Berlin district evaluated heat pumps, chillers, passive cooling, recoolers and ice storage under current and future extreme weather conditions. The analysis identified oversized ice storage whose costs for storage and housing could have been significantly reduced through earlier optimization. Using the storage for peak load shifting reduced required recooler peak capacity by 25%, saving space and investment costs while improving resilience. ![Combined heat and power plant for a building district](/images/sites/green-city-library/pages/index/use-case-combined-heat-power.webp) ### Combined Heat and Power Plant for a Building District The model shows a simplified heat, warm water and electrical energy consumer which is supplied by a combined heat and power plant. The consumption is defined via timetables. A heat storage serves to buffer load peaks. It can be observed in the simulation that the power plant cannot continuously meet the electrical load without electrical energy storage. ![Multi-zone building with electrical vehicles](/images/sites/green-city-library/pages/index/use-case-multi-zone-electric-vehicles.webp) ### Multi-Zone Building with Electrical Vehicles Model of a building with two thermal zones and an electric vehicle including its own charging station and battery. The model calculates the thermal behavior of the building through the balance of all heat quantities (transmission, internal loads, solar radiation). Electrical power is provided by a photovoltaic system and a small wind power plant. An air/water heat pump provides the building with heat. ![District heating grid model](/images/sites/green-city-library/pages/index/use-case-district-heating-grid.webp) ### District Heating Grid The model represents a district heating grid with all pipes, house connection stations and heat generators. The thermal and hydraulic properties of each component can be simulated in the grid, enabling analysis and optimization of critical grid nodes over the course of a year. This detailed grid model serves as the foundation for all further transformations towards a sustainable district heating grid. [Explore GreenCity for your project](/contact/)