Natural gas generators are efficient, cheap to run and cleaner burning than any other generator powered by non-renewables. And, the advantages don’t stop there. Natural gas can be made even cleaner and more efficient with Bowman’s technology.
The Advantages of Natural Gas
Natural gas is typically supplied to homes and businesses directly through underground pipes, to be burned in heating systems. This pre-existing infrastructure allows power providers to connect their gensets directly to the gas main – meaning in many cases no fuel has to be stored or transported.
Where it is required that natural gas be transported, such as when it is extracted offshore or where it needs to be moved across countries or to regional areas, it can be converted to liquified natural gas (LNG). In this form it is far easier and safer to transport.
This ease of transportation is one of the reasons Japan chose natural gas to pick up a significant amount of their shortfall following the Fukushima disaster. Use of natural gas in Japan has risen from 28% to 44% since 2011 and has stayed there since, with much of this arriving in the form of LNG imported from other countries.
The ease of transportation and centralised infrastructure goes some way to reducing the costs and pollutants of natural gas, making it cheaper and greener than most non-renewables.
Compared to coal, oil and diesel, natural gas emits far fewer dirty pollutants; sulphur, nitrogen and heavy soot compounds. In fact, a study from the US Energy Information Administration ranked it as having one of the lowest amounts of CO2 emitted per million British thermal units (Btu) out of all non-renewable fuel sources (source).
For these reasons natural gas has become the fuel of choice for companies looking to comply with emissions legislation, which has led to its use in power generation drastically increasing by more than 20% in the past decade. This trend is highly likely to continue, with the IEA predicting considerable further growth in China, The Middle East, Asia Pacific and North America (source).
Getting More from Natural Gas
As good as natural gas is, it can always be better. We’re strong believers in ensuring that the energy achieved from every fuel source is maximised and natural gas is no different.
In our work with Wärtsilä, a global provider of power systems, we created a bespoke exhaust recovery system to prove the efficiency of our Electric Turbo Compounding (ETC) technology when used on their gas engines.
Our system was installed off-engine, in a housing connected to the pre-existing turbine wastegate line through valves. The expelled exhaust gas, which had been going to waste previously, was routed through the valves into our turbo generator, where additional electricity was generated.
1.5% of additional free power was generated over 12,500 operating hours. As the Wärtsilä 34SG engine has an output of 9MW, this 1.5% increase led to a considerable amount over time, with over 650MWh of free energy generated in total. This was achieved with zero impact on engine reliability and gave Wärtsilä accelerated payback on their power plant project.
The Downsides of Natural Gas
Natural gas isn’t perfect. It is primarily comprised of methane (CH4) a potent greenhouse gas – up to 100 times as harmful as CO2. The amount of methane in natural gas can vary from country to country, from 84% in the US to 98% in Russia (source). Whilst much of this methane is removed as part of the internal engine combustion process, unburnt methane and other hydrocarbons (UHC) still pass to the exhaust and are released in to the atmosphere.
This is equally true for other gas fuel sources, including renewable sources like landfill gas and biogas, where the amount of UHC released from the internal combustion engine burning these fuels can be even higher.
You can read more on the science of how the UHC gets trapped and then released here.
For this reason, we strongly believe that legislation is on the horizon to regulate the use of gas fuel sources in power generation to cut down on the amount of UHC created.
Thankfully, early results from trials by the engineering team at Bowman indicate that UHC emissions could be reduced by 25-50%, simply by installing our Electric Turbo Compounding (ETC) technology system – all while saving fuel, increasing power and cutting costs.
Working to Improve Natural Gas
Both of these developments prove that there are always ways fuel sources can be cleaner. Whether it be the use of fossil fuels, or more renewable sources like biogas, there are considerable improvements to be made in energy efficiency and emission reductions.
To learn more about our technologies, get in touch.