The Future of Manufacturing: Overcoming Challenges in Energy Recovery on Existing Factory Sites

Overcoming Challenges in Energy Recovery on Existing Factory Sites

Factory energy recovery is the process of capturing and reusing the waste heat generated by industrial processes. It can help factories reduce their energy costs, carbon emissions, and environmental impact. Sounds great, right? But how easy is it to implement energy recovery projects on existing factory sites?

In this article, you’ll discover the main challenges and opportunities of factory energy recovery, and how to overcome them with practical tips and examples. You’ll also learn how to assess, design, install, and optimize energy recovery systems for your factory site. Whether you’re a factory owner, manager, engineer, or consultant, this article will help you take your factory to the next level of energy efficiency and sustainability.

Challenge #1: Assessing the Potential and Feasibility of Energy Recovery

Before you can implement an energy recovery project on your factory site, you need to know if it is worth it. How much energy can you save? How much money can you generate or conserve? How much carbon can you reduce? These are the questions that an energy audit and a feasibility study can help you answer.

An energy audit is a systematic analysis of the energy consumption and waste streams of your factory processes. It can help you identify where and how much energy is being used, lost, or wasted, and what types of energy sources can be recovered. An energy audit can also help you benchmark your energy performance against industry standards and best practices.

A feasibility study is an evaluation of the technical and economic viability of an energy recovery project on your factory site. It can help you determine the optimal type, size, location, and design of the energy recovery system, as well as the expected costs, benefits, risks, and returns of the project. A feasibility study can also help you assess the environmental and social impacts of the project, such as emissions reduction, carbon footprint, regulatory compliance, and stakeholder engagement.

How Energy Recovery Systems Work and What Types of Energy Sources Can Be Recovered

Energy recovery systems are devices or processes that capture and reuse the waste heat or other forms of energy that are normally discarded or released to the environment by factory processes. By recovering and reusing this energy, you can reduce your energy consumption, costs, and emissions, and improve your energy efficiency and sustainability.

There are many types of energy sources that can be recovered from factory processes, depending on the nature, temperature, quality, and mass flow rate of the waste streams. Some of the most common energy sources are:

  • Waste heat: This is the thermal energy that is released or transferred by factory processes, such as combustion, chemical reactions, evaporation, drying, cooling, or refrigeration. Waste heat can be recovered by various technologies, such as heat exchangers, heat pumps, thermoelectric generators, or organic Rankine cycles, and used for heating, cooling, power generation, or other purposes.
  • Waste pressure: This is the mechanical energy that is released or dissipated by factory processes, such as pumping, compression, expansion, or venting. Waste pressure can be recovered by technologies such as turbines, expanders, or compressors, and used for power generation or other purposes.
  • Waste gas: This is the gaseous energy that is released or emitted by factory processes, such as flaring, incineration, anaerobic digestion, oven, dryer, or heater. Waste gas can be recovered by technologies such as gas engines, gas turbines, fuel cells, boilers, or heat exchangers, and used for power generation, heating, or other purposes.
  • Waste water: This is the liquid energy that is discharged or drained by factory processes, such as washing, rinsing, or cooling. Waste water can be recovered by technologies such as heat exchangers, heat pumps, or membrane distillation, and used for heating, cooling, or other purposes.

The Benefits and Difficulties of Evaluating the Potential and Feasibility of Energy Recovery Projects

Energy recovery projects can offer many benefits for your factory site, such as:

  • Energy savings and efficiency: By recovering and reusing the waste energy from your factory processes, you can reduce your energy consumption and improve your energy efficiency. This can lower your energy bills and increase your profitability.
  • Cost savings and revenue generation: By recovering and reusing the waste energy from your factory processes, you can reduce your operating costs and generate additional revenue streams. For example, you can sell the excess power or heat to the grid or to other customers, or you can use the recovered energy to produce new products or services.
  • Emissions reduction and carbon footprint: By recovering and reusing the waste energy from your factory processes, you can reduce your greenhouse gas emissions and your carbon footprint. This can help you comply with environmental regulations and standards, and enhance your reputation and competitiveness.

However, evaluating the potential and feasibility of energy recovery projects on existing factory sites can also pose some difficulties, such as:

  • Lack of data and information: To conduct an accurate and reliable energy audit and feasibility study, you need to have sufficient and relevant data and information on your energy consumption and waste streams, as well as on the available energy recovery technologies and their performance and costs. However, collecting and analyzing this data and information can be challenging, especially if your factory site has complex and diverse processes and equipment, or if you lack the necessary tools and expertise.
  • Complexity and diversity of factory processes and equipment: To conduct an effective and efficient energy audit and feasibility study, you need to understand and account for the complexity and diversity of your factory processes and equipment, as well as their interactions and interdependencies. However, this can be difficult, especially if your factory site has multiple and varied processes and equipment, or if they are old, outdated, or poorly maintained.
  • Technical and financial constraints and risks: To implement a successful and sustainable energy recovery project, you need to overcome the technical and financial constraints and risks that may arise. For example, you may face space and layout limitations, integration and compatibility issues, safety and regulatory requirements, maintenance and operation costs, or performance and reliability uncertainties.

Tips and Best Practices for Conducting an Energy Audit and a Feasibility Study for Energy Recovery Projects

To conduct a successful energy audit and feasibility study for energy recovery projects on your factory site, here are some tips and best practices:

  • Hire a qualified and experienced energy consultant or engineer: A professional energy consultant or engineering agency that can help you conduct a comprehensive and reliable energy audit and feasibility study, and provide you with technical and economic advice and recommendations.
  • Use appropriate tools and methods: To collect and analyze the data and information for your energy audit and feasibility study, you need to use appropriate tools and methods, such as energy meters, sensors, software, models, or standards. You can find some useful tools and methods at the International Energy Agency or the Global CCS Institute.
  • Consider the whole system and the whole life cycle: To evaluate the potential and feasibility of your energy recovery project, you need to consider the whole system and the whole life cycle of your factory processes and equipment, as well as the energy recovery system. This means taking into account the energy inputs and outputs, the energy flows and losses, the energy quality and quantity, the energy interactions and interdependencies, the energy performance and efficiency, the energy costs and benefits, the energy risks and uncertainties, and the energy impacts and implications. You can find some guidance on how to do this at the UK IETFUS Department of Energy or the European Commission.
  • Compare and prioritize the options: To select the best energy recovery option for your factory site, you need to compare and prioritize the options based on your objectives and criteria, such as energy savings, cost savings, revenue generation, emissions reduction, carbon footprint, payback period, return on investment, environmental and social impacts, or stakeholder preferences. You can find some examples of how to do this at the World Bank or the UK Government.
  • Industrial Energy Transformation Fund (IETF): To fund your energy recovery project, you may be eligible for the IETF, which is a UK government scheme that provides grant funding for industrial energy efficiency and deep decarbonisation projects.

Challenge #2: Designing and Installing Energy Recovery Systems

Once you have assessed the potential and feasibility of your energy recovery project, you need to design and install the best energy recovery system for your factory site. But how do you choose the right system from the many options available? And how do you overcome the technical and practical challenges of designing and installing the system on your existing factory site?

The Different Types of Energy Recovery Systems Available

There are many types of energy recovery systems that you can use to recover and reuse the waste energy from your factory processes, depending on the nature, temperature, and quality of the waste streams. Here are some of the most common types of energy recovery systems and how they work:

  • Air-to-air energy recovery systems: These systems use air as the working fluid and transfer heat or moisture or both between the exhaust and supply airstreams. They employ air-to-air heat exchangers, such as fixed-plate, rotary enthalpy wheel, heat pipe, or run-around coil. These systems are suitable for applications where the exhaust and supply airstreams are close to each other and have similar flow rates and pressures. They can recover both sensible and latent energy and improve the indoor air quality and comfort.
  • Air-to-liquid energy recovery systems: These systems use liquid as the working fluid and transfer heat between the exhaust airstream and a liquid circuit. They employ air-to-liquid heat exchangers, such as coils, tubes, or plates. These systems are suitable for applications where the exhaust and supply airstreams are far apart or have different flow rates or pressures, or where the liquid circuit can be used for other purposes, such as heating, cooling, or domestic hot water. They can recover only sensible energy and require a pump to circulate the liquid.
  • Liquid-to-liquid energy recovery systems: These systems use liquid as the working fluid and transfer heat between two liquid circuits. They employ liquid-to-liquid heat exchangers, such as coils, tubes, or plates. These systems are suitable for applications where the waste heat source and the heat sink are both liquid, such as wastewater, cooling water, or process water. They can recover only sensible energy and require a pump to circulate the liquid.
  • Heat pumps: These systems use a refrigerant as the working fluid and transfer heat between a low-temperature source and a high-temperature sink. They employ a vapor-compression cycle, which consists of a compressor, a condenser, an expansion valve, and an evaporator. These systems are suitable for applications where the waste heat source is low-grade, such as ambient air, ground, or water, and the heat sink is high-grade, such as space heating, domestic hot water, or process heating. They can recover both sensible and latent energy and require electricity to operate the compressor.
  • Thermoelectric modules: These systems use a solid-state device that converts heat into electricity or vice versa. They employ the Seebeck effect, which generates a voltage difference between two dissimilar materials when subjected to a temperature difference, or the Peltier effect, which creates a temperature difference between two dissimilar materials when an electric current is applied. These systems are suitable for applications where the waste heat source is high-grade, such as flue gas, exhaust gas, or process heat, and the heat sink is low-grade, such as ambient air, ground, or water. They can recover only sensible energy and require no moving parts or fluids.
  • Waste heat recovery units: These systems use a working fluid that undergoes a thermodynamic cycle to convert heat into mechanical work or electricity. They employ various technologies, such as organic Rankine cycle, steam Rankine cycle, Kalina cycle, or Brayton cycle. These systems are suitable for applications where the waste heat source is high-grade, such as flue gas, exhaust gas, or process heat, and the heat sink is low-grade, such as ambient air, ground, or water. They can recover only sensible energy and require a turbine, a generator, a pump, and a condenser.

The Advantages and Disadvantages of Each Type of System and How to Choose the Best One for a Specific Factory Site and Process

Each type of energy recovery system has its own advantages and disadvantages, depending on the characteristics of the waste heat source and the heat sink, as well as the technical and economic feasibility of the project. Here are some of the factors that you need to consider when choosing the best type of system for your specific factory site and process:

  • The nature of the waste heat source and the heat sink: You need to know the type, temperature, quality, and availability of the waste heat source and the heat sink. For example, if the waste heat source is gaseous and high-temperature, such as flue gas or exhaust gas, you may consider using a thermoelectric module or a waste heat recovery unit to generate electricity. If the waste heat source is liquid and low-temperature, such as wastewater or cooling water, you may consider using a heat pump or a liquid-to-liquid heat exchanger to provide heating or cooling. If the waste heat source and the heat sink are both air, you may consider using an air-to-air energy recovery system to improve the indoor air quality and comfort.
  • The technical feasibility of the system: You need to evaluate the technical feasibility of the system, such as the performance, reliability, durability, and compatibility of the system. For example, if the system requires a high level of maintenance, such as a rotary enthalpy wheel or a run-around coil, you may need to consider the availability and cost of spare parts and service. If the system requires a high level of integration, such as a heat pump or a waste heat recovery unit, you may need to consider the compatibility and complexity of the system with the existing equipment and infrastructure.
  • The economic feasibility of the system: You need to evaluate the economic feasibility of the system, such as the capital cost, operating cost, payback period, and return on investment of the system. For example, if the system has a high capital cost, such as a thermoelectric module or a waste heat recovery unit, you may need to consider the availability and cost of financing and incentives. If the system has a high operating cost, such as a heat pump or a compressor, you may need to consider the electricity tariff and demand charges. If the system has a long payback period or a low return on investment, you may need to consider the expected lifetime and resale value of the system.

The Challenges of Designing and Installing Energy Recovery Systems on Existing Factory Sites

Designing and installing energy recovery systems on existing factory sites can pose some challenges, such as:

  • Space and layout limitations: You need to find enough space and suitable layout for the system, such as the heat exchanger, the ductwork, the piping, the wiring, and the controls. You may need to modify or relocate some of the existing equipment or infrastructure to accommodate the system. You may also need to consider the aesthetic and acoustic impact of the system on the factory site.
  • Integration and compatibility issues: You need to integrate and coordinate the system with the existing equipment and infrastructure, such as the pumps, the fans, the valves, the sensors, the meters, and the controllers. You may need to upgrade or replace some of the existing equipment or infrastructure to match the system. You may also need to consider the safety and operational impact of the system on the factory site.
  • Safety and regulatory requirements: You need to comply with the safety and regulatory requirements and standards for the system, such as the electrical, mechanical, thermal, and environmental codes and regulations. You may need to obtain the necessary permits, approvals, and certifications for the system. You may also need to conduct the appropriate testing, commissioning, and training for the system.
  • Maintenance and operation costs and responsibilities: You need to maintain and operate the system properly and efficiently, such as the cleaning, lubricating, inspecting, repairing, and replacing of the system components. You may need to hire or train the qualified personnel and contractors for the system. You may also need to monitor and optimize the system performance and impact on the factory site.

Tips and Best Practices for Designing and Installing Energy Recovery Systems

To design and install a successful and sustainable energy recovery system on your factory site, here are some tips and best practices:

  • Hire a qualified and experienced energy contractor or installer: A professional energy contractor or installer can help you design and install the best energy recovery system for your factory site, and provide you with technical and practical support and guidance. You can find a list of certified energy contractors and installers at the “Energy Saving Trust” or the “American Council for an Energy-Efficient Economy”.
  • Use appropriate equipment and materials: To design and install a high-quality and durable energy recovery system, you need to use appropriate equipment and materials, such as heat exchangers, ductwork, piping, wiring, and controls. You can find some useful equipment and materials at the “Heat Recovery Solutions” or the “Energy Recovery Products” websites.
  • Consider the whole system and the whole life cycle: To design and install an effective and efficient energy recovery system, you need to consider the whole system and the whole life cycle of your factory processes and equipment, as well as the energy recovery system. This means taking into account the energy inputs and outputs, the energy flows and losses, the energy quality and quantity, the energy interactions and interdependencies, the energy performance and efficiency, the energy costs and benefits, the energy risks and uncertainties, and the energy impacts and implications. You can find some guidance on how to do this at the “US Department of Energy” or the “European Commission” websites.
  • Test and commission the system: To ensure the proper and safe operation of the system, you need to test and commission the system before and after the installation, such as the pressure, temperature, flow, voltage, current, and power of the system components.

Challenge #3: Monitoring and Optimizing Energy Recovery Performance

Designing and installing an energy recovery system on your factory site is not enough to ensure its success and sustainability. You also need to monitor and optimize the performance of the system and how it affects your factory operations. But why is this important? And how can you do it effectively and efficiently?

Why Monitoring and Optimizing Energy Recovery Performance is Important

Monitoring and optimizing the performance of your energy recovery system is important for several reasons, such as:

  • Improving the return on investment and the environmental impact of your energy recovery project: By monitoring and optimizing the performance of your energy recovery system, you can ensure that the system is delivering the expected benefits and outcomes, such as energy savings, cost savings, revenue generation, emissions reduction, and carbon footprint. You can also identify and address any issues or gaps that may affect the performance and impact of the system, such as inefficiencies, malfunctions, or deviations. By doing so, you can improve the return on investment and the environmental impact of your energy recovery project, and justify its value and viability.
  • Enhancing the energy efficiency and sustainability of your factory site: By monitoring and optimizing the performance of your energy recovery system, you can improve the energy efficiency and sustainability of your factory site. You can reduce your energy consumption and waste, and increase your energy productivity and quality. You can also optimize your energy demand and supply, and align them with the availability and price of energy sources. By doing so, you can enhance the energy efficiency and sustainability of your factory site, and increase your competitiveness and reputation.
  • Supporting the decision making and planning of your factory operations: By monitoring and optimizing the performance of your energy recovery system, you can support the decision making and planning of your factory operations. You can use the data and information from the system to make informed and timely decisions and actions, such as adjusting the settings, parameters, or schedules of the system or the factory processes, or implementing corrective or preventive measures. You can also use the data and information from the system to plan and forecast your future energy needs and opportunities, such as expanding, upgrading, or replacing the system or the factory processes, or pursuing new energy projects or initiatives. By doing so, you can support the decision making and planning of your factory operations, and enhance your performance and profitability.

Tips and Best Practices for Monitoring and Optimizing Energy Recovery Performance

To monitor and optimize the performance of your energy recovery system effectively and efficiently, here are some tips and best practices:

  • Use appropriate tools and methods: To collect and analyze the data and information for your energy performance indicators and metrics, you need to use appropriate tools and methods, such as energy meters, sensors, software, models, or standards. You can find some useful tools and methods at the International Energy Agency or the Global CCS Institute websites.
  • Compare and benchmark the results: To evaluate and improve the performance of your energy recovery system, you need to compare and benchmark the results against your targets, baselines, or best practices.
  • Ensure reliable results: By comparing data from three months before and three months after the implementation of the system. This way, you can account for any changes in production that may affect the results.
  • Be careful about seasonal changes: These may not be captured by a small amount of data. You may need to adjust your comparison or use longer periods of data to account for these variations.
  • Identify and implement improvement actions: To enhance the performance and impact of your energy recovery system, you need to identify and implement improvement actions, such as adjusting the settings, parameters, or schedules of the system or the factory processes, or implementing corrective or preventive measures.
  • Continuously monitor and optimize the performance: To sustain and increase the performance and impact of your energy recovery system, you need to continuously monitor and optimize the performance, such as by using real-time data, feedback, and control, or by pursuing new energy projects or initiatives.

Conclusion

You have reached the end of this article on factory energy recovery. Congratulations! You have learned a lot about this topic and how it can help you improve your factory site and the world.

Let’s recap what you have learned:

  • Understanding the Process: We’ve explored how capturing and reusing waste heat and other energy forms, typically lost in factory processes, can revolutionize our approach to industrial energy use.
  • Benefits Unveiled: The significant advantages include slashing energy consumption, reducing operational costs, cutting emissions, and enhancing overall energy efficiency and sustainability.
  • Revenue and Compliance: Beyond cost savings, this initiative opens up new revenue streams, aids in meeting environmental regulations, and bolsters your market reputation and competitive edge.
  • Navigating Challenges: We delved into the three primary hurdles—conducting thorough assessments for potential projects, the intricacies of system design and installation, and the critical role of ongoing performance monitoring and optimization.
  • Strategic Implementation: Achieving the best outcomes necessitates a methodical and strategic approach, leveraging the right tools and methodologies to tackle these challenges effectively.

By now, you should have a clear understanding of what factory energy recovery is, why it is important, and how to do it. You should also have a sense of the benefits and opportunities that factory energy recovery can offer for your factory site and the environment.

But don’t stop here. There is still more to learn and do. Factory energy recovery is not a one-time project, but a continuous process of improvement and innovation. You need to keep up with the latest trends and technologies, and explore new ways to optimize your energy recovery potential and impact.

That’s why we invite you to take the next step and contact us today. We are a team of energy experts and consultants who can help you with your factory energy recovery project. We can provide you with a free energy audit and a quote for an energy recovery system that suits your needs and goals. We can also help you design, install, and optimize your energy recovery system, and monitor and evaluate its performance and impact.

Don’t miss this opportunity to take your factory to the next level of energy efficiency and sustainability. Contact us today and let us help you make the most of your factory energy recovery project. We look forward to hearing from you soon.

Francois Pierrel
Francois Pierrel
Hi, my name is François and I am passionate about solving process engineering problems. Over the years, I have developed a number of process equipment and control systems which have had a significant impact on reducing energy usage, waste and impact on the environment. My business ethos is to always get to the root cause of problems and data analysis and modelling are always at the forefront of any project we undertake.

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