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Inoplex Cogeneration Generator Running Costs

How much does it really cost to run a CHP generator?

One of the most common questions we get asked is, how much does it cost to run a CHP cogeneration generator? We completely understand that any business must know and control its costs, so this is a really good question that needs to be answered. Owners need to understand what costs are associated with a CHP inverter generator and what the short term and long term running financials for the equipment are. So, what are you really looking at when it comes to the $$?

Looking for Cogeneration?

If you need “Combined Heat and Power” Generation, Inoplex can help. Our Cogenerators use industry leading technology to generate heat and power when you need it.

CHP Generator Costs

There are a few different types of costs associated with generators, ranging from the direct operating costs to mechanical parts, maintenance and servicing. In saying this though, the overall picture isn’t as financially scary as it may sound.

Direct operating costs

The first cost is the direct, day to day, running cost of the inverter CHP generator. At Inoplex, we strive to reduce the costs of consumables as much as possible, as we believe that sustainability matters. We understand that minimising these reduces overall costs and minimises wastes, which are beneficial to everyone. There are still some direct operating costs in relating to consumables that must be considered though, such as:

  • Engine oil
  • Spark plugs
  • Air filters
  • Oil filters

Engine oil 

We use a basic oil that provides adequate engine lubrication and protection but nothing more.  We then run the oil at a temperature that minimises water and fuel accumulating in the oil without excess heat shortening the oils life.

Spark plugs 

We use a premium, ultra long life spark plug that reduces downtime from ignition issues and service requirements.  If the site has a suitably qualified tradesperson available, they can choose to use low-cost spark plugs that can be changed more frequently. It is worth noting however that this is not our recommended option, as the labour to change over several sets of low-cost short-life spark plugs can exceed the total cost of long-life plugs.

Air filters 

The standard air filters on Inoplex CHP generators last a full years operation at full load, and are low cost and quick to change over.  If the site is excessively dusty and the air filters are prone to block with dust, then a washable sock can be added over the air filter for protection.  

Oil filters 

Our standard oil filter will last the life of the engine and provide a very high degree of engine protection. This ensures no fuss for the owner-operator, which we understand is a big component to combined heat and power systems.  Of course, lower cost consumable oil filters can be used and are easily changed by local trades but again, the cost of the labour to install the filters adds, and we have found that using low-cost and short-life oil filters is a false economy and increase wastes of old filters and packaging.

Mechanical part costs

There are mechanical parts that wear on generators too, and must be taken into consideration when taking a look at the overall costs for CHP cogeneration generators.


Starter motors 

If engines are running on biogas and the biogas is prone to variability and low methane content, then a starter motor can wear out quite quickly. We have worked to minimise this wear and tear by starting the engine using grid connected inverters running backwards. This means only a small amount of grid power is needed to spin and start the engine, thereby reducing wear on the starter motor and providing a very fast, reliable startup. This also reduces the strain on the engine battery and prolongs their lives, as well as keeping the engine running for a larger percentage of time and increasing the uptime availability.

Engine Oil Pumps 

At Inoplex, we have found that standard OEM oil pumps can last around 10,000 hours or the equivalent of 1 million driving kilometres. This is fine for a vehicle that is undergoing regular servicing, but not for generators that we want running 24 hours a day, 365 days a year.  Our Inoplex engineers have sourced a high-quality oil pump gear set that, combined with our oil management system, has extended the oil pump life to match the end of engine life. So, provided the owner-operator follows the oil management system, they should never have to address an oil pump service problem throughout the life of the engine.


Eventually, even a well maintained engine will need to be refurbished. To keep your site producing heat and power, we can provide an engine swap over. We bring a remanufactured engine with new consumables and swap it for your tired engine in a day. If your site is on a tight financial budget, we can swap your tired old engine for a good second hand one. Your old engine is then taken to our specialist engine machine shop where it is stripped, cleaned, re-built and tested on a dynometer to ensure it meets our engine performance specifications.

Equipment Management Costs

Next, there is the cost of managing the equipment to maximise its performance and efficiency. Our team can remotely access your inverter CHP through a mobile data SIM card in the CHPs controller, so we can review its performance, your sites needs and then optimise the CHPs set points.

Total running costs

When you look at the overall picture, the cost of operating the Inoplex inverter CHP averages at around 1.2 to 1.5 cents per KW/hr of power produced, and 1.8 to 2.5 cents per KW/hr for refurbished engines, subject to confirmation for each specific site. This takes into account the cost of consumables, replacement of second hand engines, mobile data charges and ongoing support and optimisation for the whole system.  This is a relatively low $/KW service cost and it is a great reason to choose an Inoplex CHP engine. Don’t forget the fuel costs though, but they are for another day…

Service contracts

Additionally you are signed up for an Inoplex “Uptime Service Contract”, we provide all serving including the engine changeovers at this guaranteed rate for a 5 or 10 year period. So, as a business with your own Inoplex inverter CHPs embedded power generation, you can confidently understand and know your running costs for up to 10 years.

If you have any questions regarding the running costs of an Inoplex Cogeneration Generator, or how a generator can assist your business, give us a call on 1300 113 782 or complete an online enquiry form today.