What is the role of Combined Heat & Power (CHP) within the energy transition? It’s served the heat and power needs of organisations for decades, yet net zero goals are leading some organisations to deactivate their existing CHP systems in favour of something new. The commonly accepted narrative is that electrification is “good”, natural gas is “bad”.
But is it really that simple? ENTRNCE’s Carbon Monitor tool is analysing CHP’s emissions and reveals a more nuanced picture – where CHP is sometimes the lower-carbon option.
In this blog post, Jaron Reddy examines some of the misconceptions surrounding CHP, and why it pays to take a closer look before ruling out CHP as the lowest carbon option.
"Installing a CHP would be a backwards step because they run on gas."
It’s true that over 80% of total CHP fuel input comes from natural gas, which is a fossil fuel. But most organisations without a CHP system are already heavily reliant on gas. The chances are that you have a gas boiler for your heating and hot water, plus grid electricity for your power needs. In the UK, the largest single source for electricity generation is…natural gas. (the UK is one of the heaviest gas consumers in Europe.) So the traditional combination of gas boiler and grid electricity means you’re already using natural gas from two sources. Moving to a CHP means you’re still using gas, but a lot less of it because these systems are highly efficient.
"To cut carbon, we need to rip out our CHP unit and electrify our heating."
The Climate Change Committee does indeed recommend heating electrification to reduce carbon emissions from buildings. But this is in the context of decarbonising grid electricity – and the UK isn’t there yet. Electrification alone could actually increase your emissions; converting gas into electricity in a power station then transmitting it to your site involves a lot of energy waste along the way. Burning gas on site and using it directly for your building’s heating and hot water is much more efficient and means lower emissions for the same results. (Of course, grid electricity isn’t the only option – on-site renewables and/or a green corporate power purchase agreement can help to reduce your emissions from electricity if you do it right.)
"Installing a CHP unit would make our organisation dependent on fossil fuels."
You want to futureproof your organisation’s heating system, so you don’t want to get locked into reliance on an unsustainable fuel source. But CHP systems don’t have to run on natural gas. They can also run on biogas, renewable biomass or waste oils, such as used cooking oil.
CHP systems that currently run on natural gas have the potential to convert to biogas from sources such as wastewater treatment plants or landfill sites.
The key is to ensure that the fuel for your CHP has International Sustainability and Carbon Certification (ISCC).
“We have to choose between CHP and renewables.”
Installing an on-site renewable generation source is a great move, but it won’t meet all your energy and heating needs. The natural intermittency of renewables means you will need backup for the times when your green asset isn’t producing anything. Many large organisations find that CHP is the perfect complement to renewable energy, filling in the gaps when there is low output from your solar panels or wind turbine.
“It’s impossible to know if a CHP unit is a green option or not.”
Renewables are a growing proportion of the UK’s fuel sourcing for grid power and there will be times when electricity from the grid has lower carbon than your CHP output. You just didn’t know what those times were…until now.
The ENTRNCE Carbon Monitor measures the greenhouse gas emissions produced by a CHP in operation at half-hourly intervals. Crucially, it also takes the same half-hourly snapshot of the grid’s carbon intensity. So you can compare the two and see when the CHP was cleaner – or dirtier – than conventional sources of heating and power.
The best way to see through the myths about CHP is to arm yourself with the data – not just general information, but data specific to how CHP works for your organisation. Using the Carbon Monitor will help you make an informed decision about your CHP asset and make the case for that decision to other stakeholders in the organisation. For a free demonstration of the Carbon Monitor, get in touch.
