2G Blog

February 09, 2022

What are CHP systems, aka Cogeneration?

It is a fact of modern life that everyone needs electricity and thermal energy. It’s crucial to run manufacturing plants, hospitals, and airports and to heat our homes. Without it, society can’t function. Yet it’s also a fact that traditional ways of generating energy are harmful to the Earth, the environment, and health. To add insult to injury, prices can be cost-prohibitive, and weather, occasional power outages, and natural disasters can have severe disruptions to everyday life. 

For these reasons, it’s becoming increasingly popular to look for alternative energy sources, in steps combined heat and power systems (aka cogeneration). But what, exactly, is it? How does it work? What are the benefits? And how can you generate such a type of energy? 

What Is Combined Heat and Power? 

Combined heat and power (CHP) is an energy-generating technology that works twofold: It creates electricity and captures the heat it generates to use it as thermal energy. This allows for the captured calefaction to heat the water and create steam. In a nutshell, it’s an energy-efficient way of powering large-scale operations, such as manufacturing plants, airports, college campuses, apartment buildings, and hotels. 

Depending on the need, a CHP power system installed on a site can be within a building or pre-packaged in its own housing. They can be installed singularly, or several can work together to produce energy for an entire geographical location. 


How Does CHP (aka Cogeneration) Work? 

Traditionally, electricity is produced from the combustion of fossil fuels (such as crude oil, natural gas, shales, bitumens, and coal). All of these fuels are extracted from layers of rock under the Earth’s surface through mining and drilling. They are then burned in a furnace to release heat energy. This heat boils water, which in turn, creates steam. This steam powers steam turbines, which drive generators, and these generators create electricity. 

The problem with this method is that it wastes energy throughout every single step. And since this is the main source of energy for most of the planet, it’s done extensively and has caused significant environmental pollution

CHP reduces this impact by capturing what would normally be wasted heat and using it to either heat other things or use the heat in a chiller to create cooling. 

CHP reducing Emissions Impact Image

To better help you understand its inner workings, it’s important to go over the main components: 

  • The prime mover is the engine that powers the technology. CHP can work with different ones, such as gas or steam turbines, combustion engines, fuel cells, or combined cycle gas turbines, to name a few. (2G Energy offers 100% hydrogen reciprocating engines — the only company to do so). 
  • The generator converts energy into electricity. It can be grid controlled or self-controlled. 
  • The heat recovery unit captures heat that escapes from the power generation process.

CHP technology works by going through the following steps: 

CHP technology process

  1. Fuel is added to the technology (the combustion turbine or reciprocating engine, which both have a heat recovery unit). 
  2. The CHP engine burns fuel through the combustion process. 
  3. A power generator is connected to the engine. 
  4. The electricity produced can be put on the electrical grid or used by the CHP operator.
  5. As the engine releases exhaust, a converter extracts pollution. Heat is also collected from the exhaust and the engine itself as it creates heat while running.
  6. The exhaust gas heat exchanger absorbs the hot exhaust air created in the engine and passes it on to a liquid consisting of glycol.
  7. The heat is then extracted from the hot glycol and passed to the customer's heating circuit.
  8. The heat can also be sent to an absorption chiller to produce cooling.

While these processes also use fossil fuels, they reduce the amount needed to generate energy. Therefore, they contribute to less land degradation and reduce air pollution. Alternatively, CHP technology can work with biogas (fuel produced from decomposed organic matter, such as animal manure and/or food scraps) and hydrogen. 

Benefits of CHP 

There are several benefits to using cogeneration over traditional sources of energy. These include: 

1. Versatility

CHP technology can be used with renewable energy, such as RNG, biogas, hydrogen, and fossil fuels. And in addition to powering industrial and manufacturing facilities, it can efficiently generate power for commercial buildings, municipal landfills and water treatment plants, residential developments, and institutions (such as hospitals, college campuses, and prisons). 

2. Energy Efficiency

Cogeneration creates thermal energy out of the heat that would normally be wasted during the power generation process. And because it does so concurrently as it creates electricity, it works more efficiently than producing each energy source independently. 

3. Cost-Effective

Since combined heat and power technologies produce two types of energy at once — and reuse escaped heat to create even more energy that can be used to heat water, cool spaces, or create steam — it significantly drives down operating costs. 

4. Resiliency

Cogeneration makes operations less dependent on traditional power grids. This means that there's no downtime in the event of a power outage, as it continues to generate a high energy supply. 

5. Emissions Reduction 

Cogeneration reduces pollution because it burns methane instead of letting it go into the environment (which would cause heat to become trapped in the atmosphere and contribute to global warming). This makes it a much more efficient way of generating energy. Also, a component called the carbon dioxide scrubber absorbs most CO2, decreasing carbon emissions. And if the technology runs on hydrogen, it has zero emissions. 

CHP Fuel Types

Different types of operations have specific energy requirements. Regardless of what these may be for you, CHP provides a reduction in energy costs and more environmentally friendly technology.

Options range from small power plants with an electrical output of up to 60kW to larger ones for high power consumption above 500kW. You can also interconnect multiple units for even greater power output. 

They can also be installed within existing buildings or heating systems or set up separately in a container or engine room. In addition, they can be set up with different types of insulation and low noise emission, depending on local conditions and types of operations. 

In addition, CHP technology is compatible with different sources of fuel, including: 

Are you looking towards the future of 100% but not sure when you can make the switch? Our systems are able to fuel blend from 0-100% as needed, so you can focus on the now and worry about the future later.