The Ultimate Guide to Combined Heat and Power (CHP) System Design

CogenS™

Your Free Combined Heat and Power Design & Analysis Tool

Combined Heat and Power (CHP), also known as cogeneration, is a cornerstone of modern, efficient energy strategy. By producing both electricity and useful thermal energy from a single fuel source, CHP systems can achieve efficiencies exceeding 80%, drastically cutting energy costs and carbon emissions. However, the success of any CHP project hinges on a rigorous and accurate initial design phase.

Historically, this required complex, time-consuming spreadsheet models prone to error. Today, there’s a better way.

Watch CogenS™ Tutorial

Effortless Software for a Complex Problem

Evaluate, Model and Design
CHP Microgrid projects

CogenS™ Design Tool is a free, powerful software platform that gives engineers, consultants, and facility managers the ability to conduct a comprehensive Combined Heat and Power feasibility analysis. Move beyond basic calculations and model the real-world performance, financial returns, and environmental benefits of your CHP project with engineering-grade precision.

What is CogenS™ - CHP MFG Selector?

CogenS™ is a free, downloadable software platform that empowers you to perform a complete technoeconomic analysis of a Combined Heat and Power system. It allows you to:

Model Different Prime Movers: Analyze systems based on reciprocating engines, microturbines, or fuel cells.
Use Real-World Data: Input your facility’s unique electrical and thermal loads, weather data, and utility tariffs.
Simulate Performance: Accurately forecast annual energy production, fuel consumption, and operational hours.
Calculate Financial Viability: Generate key financial metrics, including Total Cost of Ownership (TCO), Net Present Value (NPV), Internal Rate of Return (IRR), and simple payback period.
Quantify Environmental Benefits: Calculate the annual reduction in CO2e emissions compared to conventional energy sources.

CogenS™ replaces guesswork with data, providing the clarity you need to design and propose a successful Combined Heat and Power project.

CogenS™ Resources

CogenS™ System Diagram

This diagram represents the working concept of CogenS™; a Comparison based Combined Heat and Power Modeling Design Solution; Conventional VS Cogeneration Energy systems. CogenS™ allows you to design, model, optimize and evaluate each system without loss of generality, in a unique design process.

CogenS™ Project Design Process

Project Info

Location.
Building Type (Industrial, Commercial or Residential).
Microgrid components (Combined Heat and Power, Combined Cooling Heat and Power, Energy Storage and PV).
Modeling interval (15, 20, 30 and 60 minutes).
Metric VS Imperial Units.
Weather Data.

Energy Profiles

Building energy profiles Estimation and Analysis (Electric, Gas, Oil, Cooling, Heating, Domestic Hot Water).
Fuel specifications (Heating Value and Density).
Scenario Analysis Option (Maximum, Average and Minimum Load Profiles)
Peak, Minimum, Average Demand and Load Factor.
Grid Emissions Factor.

Cooling

Chillers

Equipment modeling features:

Screw, Centrifugal, Scroll and Reciprocating compressors.
Water- or air-cooled condenser.
Electric or Gas-Fired absorption.
Indirect Hot Water or Steam absorption.

System modelling features:

Identical multi-unit system.
Variable or Constant Flow.
Supply Temperature Reset.
Part-Load Efficiency Performance.
Optimized number of operating units.
CO2e emissions.

Cooling Towers

Equipment modeling features:

Open or closed loop.
Cross or Counter flow.
Single, 2-speed or variable speed fan.

System modelling features:

Identical multi-unit system.
Free Cooling Heat Exchanger option.
Wet-Bulb Reset Control Scheme.
Variable or Constant Flow.
Supply Temperature Reset.
CoolTools or YorkCalc Heat Rejection Performance.
Optimized number of operating units.

Heating

Boilers

Equipment modeling features:

Condensing or Non-Condensing.
Hot Water or Steam.
Electric, Gas or Oil.
Mechanical or Natural draft.

System modelling features:

Identical multi-unit.
Variable or Constant Flow.
Supply Temperature Reset.
Part-Load Efficiency Performance.
Optimized number of operating units.
CO2e emissions.

Hot Water Heaters

Equipment modeling features:

Storage or Tankless.
Cycle or modulating control.
Heat Exchanger, Electric, Gas or Oil.

System modelling features:

Identical multi-unit.
Variable or Constant Flow.
Part-Load Efficiency Performance.
Optimized number of operating units.
CO2e emissions.

Energy Cost

Electric and Gas Utility Tariff

Fixed and minimum charges.
Rates Escalation.
Unlimited Energy and Demand charges by Period and Tier.
5 Different Metering and Billing Types:

Net Energy Metering
Net Energy Metering with $ Credits
Net Billing
Net Billing with Carry Over to next Month
Buy All/Sell All

Oil Cost

Fixed and minimum charges.
Rates Escalation.

Microgrid sizing

Optimum CHP Electric and Thermal Outputs.
Battery and Thermal Energy Storage Sizes.
Auxiliary boiler system size.
CHP Microgrid System Load Duration Curve Representation.

Energy Resources

Combined Heat and Power

Equipment modeling features:

Fuel Cell, Reciprocating Internal Combustion Engine and Microturbine.
Hot Water or Steam.
Natural Gas, Renewable Natural Gas, Hydrogen or Liquified Petroleum Gas.

System modeling feattures:

Identical multi-unit system.
Variable or Constant Flow.
Supply Temperature Reset.
Shut down and replacement simulation.
Output Control.
Cost-based Dispatch Optimization with Energy Storage and Grid.
Unit Sequencing simulation based on runtime.
Dynamic Response.
Annual, Temperature and Restart Degradation.
Part-Load Efficiency Performance.
Optimized number of operating units.
Capital and O&M costs.
CO2e emissions.

Solar Photo-Voltaic system PVWatts Version 6 API

System locatiion.
System DC nameplate capacity.
Array and Module Types.
Azimuth and Tilt angles.
Annual Degredation.
Capital and O&M costs.

Energy Storage

Thermal Energy Storage

Single Hot Water Energy Storage Tank.
CHP Priority.
Supply Temperature Reset.
Stratified tank approximated model.
Capital and O&M costs.

Battery Energy Storage System

Single System.
Idealized flat charge and discharge curve.
Dynamic Response.
Annual, Temperature and Cycle Degradation.
Replacement simulation.
Capital and O&M costs.

Hydrogen Energy Storage System

Multi-unit System.
Electrolyzer model.
Pressurized vessel + Compressor model.
Metal Hydride model.
Dynamic Response.
Annual, Temperature and Cycle Degradation.
Replacement simulation.
Capital and O&M costs.

Finance

Power Purchase Agreement Provider or Building Owner investment financial models.
Inflation, Discounting and effective tax rates.
Capacity and Production based incentives.
Assets Depreciation, Loans and Reserves.
Project Financial Metrics (PV, IRR, SPB, DPB, BCR, EAS, BTCF, CFAT).

Results

Summary

Energy, Financial and Emissions savings.
Financial KPIs
Project Capital and Operating Activities pie charts.
Conventional VS Cogeneration Pie charts:

Energy Bill and Consumption by fuel.
Gas Consumption by fuel.
Electricity production and emissions by equipment.

Tables

Lifetime profiles for key project variables in tabular format:

Sub hourly
Hourly
Daily
Weekly
Monthly
Yearly

Plots

Lifetime profiles for key project variables in plot format:

Sub hourly
Hourly
Daily
Weekly
Monthly
Yearly

Core Benefits at a Glance

Why use CogenS™ for your next CHP procurement decision?

Technoeconomic Engine

Perform a complete analysis combining technical performance with detailed financial modeling.
Real-World Inputs

Use your own load profiles and utility rates for a custom analysis tailored to your specific project.
Multiple Technologies

Model various CHP prime movers to find the best fit for your application.

Financial KPI Reporting

Automatically generate the key financial metrics (NPV, IRR, TCO) needed to justify your project.
Emissions Analysis

Quantify the carbon reduction benefits, supporting sustainability goals and regulatory reporting.
100% Free to Download

Access a powerful engineering-grade tool at no cost to support your initial design and feasibility work.

Who Should Use It?

This tool is designed for any professional involved in the early stages of energy project development.

Mechanical & HVAC Engineers
Facility Engineers & Energy Managers
Energy Consultants and ESCOs
EaaS Providers and Project Developers

Quickly conduct a preliminary feasibility study to determine if Combined Heat and Power is a good fit for your client’s project.

Build a powerful business case for a CHP investment by accurately projecting long-term energy cost savings and sustainability benefits.

Provide clients with a robust, data-backed analysis of the potential savings and ROI from a CHP installation.

De-risk your projects by validating their financial viability and technical performance before committing significant capital.

Food for thought Why a Data-Driven Approach to CHP Design is Essential

A successful Combined Heat and Power installation is more than just selecting equipment; it’s about designing an integrated system that is perfectly matched to a facility’s unique energy demands.

The Challenge of Load Profile Matching

A CHP system is only cost-effective when its electrical and thermal output is consistently used. According to the U.S. Department of Energy, proper sizing and design based on a facility’s detailed energy load profiles is the most critical factor for project success. A system that is too large will be inefficient and financially unviable, while one that is too small will fail to deliver the expected savings. CogenS™ allows you to input your actual load data to ensure your design is optimized for maximum utilization and ROI.

Navigating Complex Utility Tariffs and Incentives

The financial viability of a CHP project is deeply intertwined with local utility rate structures, including demand charges, time-of-use rates, and standby fees. Furthermore, government bodies and utilities often offer incentives for high-efficiency generation. The CogenS™ tool allows you to model these complex financial variables to get a true picture of your project’s economic performance.

Meeting Environmental and Resiliency Goals

CHP is a key technology for reducing greenhouse gas emissions. The U.S. Environmental Protection Agency (EPA) actively promotes CHP as a strategy for decarbonization and improving energy resiliency. By providing reliable on-site power, a well-designed CHP system can keep critical facilities operational during grid outages. Our tool helps you quantify these emissions savings and resiliency benefits, making the case for your project to all stakeholders.

Vision

A vision for a Net-Zero CARBON Future

At JIS energy, this is how we envision the role of Combined Heat and Power in a Net-Zero future. Read our report on the subject here.

CogenS™ is an attestation to our passion on the subject matter. Combined Heat and Power Design requires vigorous studying of the different project possibilities. CogenS™ allows the user to exercise with different system sizes, technologies and configurations to achieve optimum results.

Combined Heat and Power Projects are Complex

Combined Heat and Power Design requires an eclectic knowledge base across Mechanical, Electrical and Control Systems engineering disciplines. CogenS™ gives you the ability to gain insight into these areas very early in the process.

If you’re working on a Residential, Commercial or an Industrial building and thinking about Combined Heat and Power for your energy project, you need to try CogenS™.

Or reach out to us and we will do the work for you. We provide CHP Feasibility study engineering services, ask for our engineering services agreement.