What is the Cogeneration Process?

With more and more interest being shown in environmental issues and sustainable living, the discussion regarding how electricity is produced is one that is becoming more and more prominent. The use of fossil fuels to create electricity is not the most eco-friendly option around, and the inefficiency of traditional systems to generate electricity is a recurring topic across the world. Due to this, systems such as cogeneration are becoming more common and more widely spoken about, as they offer an environmentally-friendly alternative to conventional systems at a high efficiency rate. But what exactly is the cogeneration process?

What is cogeneration?

We’ll start at the beginning by quickly defining cogeneration. Cogeneration, also known as ‘Combined Heat & Power’ or CHP, is an eco-friendly electricity generation method that aims to capture all the heat lost in the conventional electricity process and utilise it effectively. It is called ‘Combined Heat & Power’ as it generates both usable heat and electricity, meaning its efficiency rates are much higher than traditional energy production mechanisms.

How does the CHP cogeneration process work?

Although at first glance the cogeneration process may seem a little complicated, when you break it down it isn’t actually as tricky as it appears. We will first take a look at the components of a system, and then address how they all work together to generate both heat and electricity.

Components of a cogeneration system

The size of the CHP system can have a bearing on what sized components are used, as well as what types, however the general basic parts to a cogeneration system are :

  • A prime mover : this is an engine which is needed to keep the alternator running
  • A fuel system : can be run on a series of fuels including LPG, biogas, petrol, methane and natural gas
  • An alternator : otherwise known as a generator, which is used to generate electricity from rotational energy within the system
  • A heat recovery system : this is used to grab any heat that can be utilised from the engine
  • A cooling system: this is used to dissolve the heat that can not be used from the engine
  • Combustion and ventilation air systems : these are used to carry out waste gases that have been left by the engine, as well as providing clean, fresh air
  • A control system : this is used to maintain a working and efficient system. This can include Power Electronics
  • An ‘enclosure’ : this is a protection mechanism for the engine as well as machinists, and also muffles noise

All these components work together to ensure the most efficient production of electricity and heat possible.

The Inoplex difference is two-fold :
We use inverter technology to convert the electricity from our cogenerators into the type of electricity that you need; whether it’s to run computers, industrial machinery or be fed into the grid. This is combined with a variable speed engine that runs on a range of fuel types and quality (eg. low quality Biogas). This varying speed produces raw power that our electronics converts to smooth DC power and then three phase AC power, synchronised with the grid at all times.
Our use of Power Electronics allow us to decouple the power output of cogenerators from the engine speed. So, unlike a traditional generator, we don’t have to run the engine at a specific speed to generate clean, reliable electricity. We can run our engines at any speed and still generate clean electricity with a high power factor.

How does the CHP process work?

So, how do all those components work together to create both usable heat and electricity? The major steps are :

  1. A fuel is added to the prime mover - this fuel may be diesel, gas or biogas, or other renewable fuels available
  2. The fuel is burnt by the prime mover in a variety of ways, depending on the type of engine (for example, if it is a combustion engine then the fuel will be burned by ordinary combustion)
  3. The alternator/generator is connected to the prime mover and uses its driveshaft as its energy source, producing electricity from rotational energy (the amount it produces will depend on the size of the system)
  4. A heat recovery system collects all the applicable heat from the engine and generator that is usable
  5. A cooling system dissolves any of the heat that can not be used
  6. The combustion and ventilation air systems carry out any waste gases from the system that are left

Any usable heat is then released into a secondary circuit, which is what is used to heat your household items, such as taps and shower. Any electricity that is created is then utilised for powering your home or office.

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What are the benefits of the cogeneration process?

There are quite a few benefits to choosing a system that uses the cogeneration process, including :

  • Reduction in greenhouse gas emissions
  • Reduction in air pollution
  • Higher efficiency levels than traditional power production processes
  • Less wasted heat energy
  • Reduced energy wastage
  • Consistent and stable electricity
  • Lower energy bills
  • Overall reduction in carbon footprint
  • Thermal energy generation
  • The creation of not one but two forms of energy

Just like anything however, the process isn’t perfect - it does have a few flaws, including :

  • The current technology used for these systems is complex, so it can be a more expensive upfront than other options. The money saved in the long term on energy bills more than makes up for it, but the initial investment amount can be a little surprising to some
  • The costs associated with maintaining a cogeneration system can be larger than other systems
  • If a CHP system is using fossil fuels, as opposed to renewable sources such as biomass or natural gas, this offers a counter-productive approach to eco-friendly power sources

The positives clearly outweigh the negatives and, despite the higher upfront costs, the cogeneration process is a great, environmentally friendly option for energy production as long as you are using renewable sources to fuel the process.

Inoplex

If you have any questions regarding the cogeneration process or think that a CHP system would be a perfect fit for you, contact us on 1300 113 782 or complete an online enquiry form today. We can discuss all the important components when it comes to CHP cogeneration systems and the best one for your circumstances.