Rail travel is considerably better for the environment than other forms of transport. This is particularly true when you consider how much CO2 we emit per person that travels by car compared to a train. Despite this, trains still release CO2 emissions, and so, what is the opportunity for rail to improve by drawing on renewable energy? Can we really have renewable energy trains?
Why Should We Consider Renewable Energy Trains and Railways
Research from the European Environment Agency looked at the CO2 emitted per passenger-kilometer. Air travel was the worst at 285 grams per passenger-kilometer. Road transport fared better at 158 and rail at a significantly better 14 grams of C02 per passenger-kilometer.
From passenger to freight trains, many are still driven by diesel engines. Diesel trains emit nitrogen oxides as well as CO2 and particulate matter6. All of these can have a negative effect on the environment and our health.
Trains are easier on the environment, a term that we use rather loosely. There's little doubt that a full train powered by one engine is vastly better than the equivalent amounts of non-electric cars on the road to transport the same number of people.
However, we cannot hide from the fact that trains still contribute to greenhouse gas emissions.
This fact is further compounded if we consider that trains do not exist as the sole means of transport. Often, especially in commuter contexts, feeder roads and other more polluting forms of transport link to rail hubs5.
Railways, Renewable Energy & Climate Change
Globally, we are taking climate action. And as we do so, we're looking to new means to fuel our transport requirements. As technology improves options for more cost-effective and cleaner fuel choices in the transport sector are increasing1. We are seeking renewable energy alternatives in many industries and the rail industry cannot and should not be overlooked.
In fact, researchers argue that coupled with its already cleaner footprint encouraging wider rail use can play a key role in reducing greenhouse gas emissions7.
Many countries are investing huge amounts of money into rail infrastructure. The UK alone is likely to spend £80bn on its HS2 network. This will utilize electricity to power faster trains between key cities.
While this is a move away from the dirty diesel fuel, it still requires electricity. As does roughly 40% of the UK network also powered electrically. Needless to say, the environmental footprint of our train travel is significantly improved if renewable electricity sources can power these trains.
If we are to make a significant positive impact on CO2 levels then we must focus on all areas. Ultimately looking for transport solutions that avoid polluting CO2 entirely.
When you consider that a plane from London to Madrid will emit 118kg of Co2 per passenger compared to just 43kg by train, it is clear to see the difference. Despite this, reducing rail CO2 emissions by considering options and making changes can only aid the case for a cleaner, greener rail.
Are Renewable Energy Trains a Possibility?
Absolutely. the idea of operating transport using renewable energy sources of energy is not a new concept. In the same way, as we can now power cars with solar energy, we can use solar to power trains. We can also look at how we can generate electricity during braking and store it to power the electric motors modern trains need to accelerate2.
In India, Indian railways have already run a pilot project using the power of the sun. It is utilising solar panels in order to power trains and rail lines.
Connecting solar panels deployed along the track can replace 4 GW of electricity that coal-fired power plants previously generated. This will enable trains to operate more efficiently and at a lower cost. Moreover, this project will also help reduce carbon dioxide emissions by 270,000 tonnes each year.
This is far from insignificant, albeit just a start. Researchers have forecast that overall in India, despite growth in passenger numbers, favoring rail and public road transport could present up to a 46% reduction in energy requirements and subsequent CO2 emissions.
Solar-powered trains are also a real thing in Australia. Using nothing other than clean energy, trains can now harness the power of the sun. Their renewable energy trains contain batteries and an electric motor, both of which can make use of renewable solar energy.
It is not just solar power that we can use to power trains. In Holland, all trains are now powered by electricity that is generated by the wind. Around 600,000 passengers each day are travelling on these trains.
In a similar way to solar power, it is possible to use wind power to deliver electricity to the tracks and overhead lines. Again, this is clean and renewable power that we can use to reduce emissions and create a cleaner rail industry.
Renewables driving the railways forward
When we consider that rail accounts for just 3% of the overall CO2 emissions from transport3, we can see that overall it is not a large contributor. Despite this, there is no denying that renewables will fuel more and more of the rail industry's future and aid carbon dioxide reduction. Especially as older diesel-powered trains are phased out and more electric railway systems and trains come into service.
However, the switch to electric trains also results in demand for increasing electricity generation. The climate friendly gains of electrification are only wholly realized when energy sourcing is also renewable. That is, if coal powered plants fire up to power overhead lines, the problem of emissions still remains, just further afield and out of sight.
Among the moves to net-zero the installation of wind turbines, solar farms, geothermal power and the prospective support of carbon emission-free nuclear plants all play a role in the overall greenification of the railways.
Scientists and researchers are also looking at hydrogen-powered trains which we can also consider powered by renewable energy. Although nascent, hydrogen power shows promise for rural routes where mass electrification may prove too costly in the effort to cut carbon emissions.
Rail Projects and Renewable Energy
The rail industry is not shying away from the importance of renewable energy. Countries all around the world are playing their part. From India to Australia and even the UK the railways are promoting renewable energy.
Solar Powered UK Railway
In August 2019, the first railway line opened in the UK that is powered by solar. It's not just the trains that are benefitting from renewable energy4. This exciting project in Hampshire, UK uses a small solar farm to supply power to signaling and lights. Additionally, the track also receives a small amount of electricity.
Climate change charity 10:10, Community Energy South, and Network Rail launched the project. Known as Riding Sunbeams, the project is proof that renewable energy has the potential to change the rail industry.
The hope is that eventually, they can bypass the national grid. These examples are the beginning of the future for the railway industry powered by renewable sources of energy.
Solar Panelled Tracks
Bankset Energy Corporation also has big plans for the rail industry. Using solar panels that can be attached to railway sleepers, it plans to eventually undertake the largest solar panel installation in the world.
Once the solar panels are attached to the sleepers, they can generate electricity. We can then use this to power trains, lights, signals, and even homes. The trial is taking place in 12 countries, to begin with, including the UK, US, China, and Australia. However, following the trial, they plan to roll it out to 165 countries.
For every 1,000km of track, the panels will generate 200mw of energy. When we consider that there are over one million kilometers of track in the world, the potential is clearly huge.
Japan's renewable energy trains
Meanwhile the operator of trains through Tokyo, Tokyu now runs all its trains using renewable energy sources. One of Japan's electricity utilities, Tokyo Electric Power Co, has certified all energy from renewable energy sources across the network of Tokyu railways trains running across the capital. This is particularly noteworthy given that Japan still relies heavily on fossil fuels which make up as much as 88& of its primary energy supply.
Can Clean Energy Trains Make a Difference?
The rail industry is actually making great strides to become greener. Despite it being the better form of transport, it still can play a significant role in mitigating climate change and improve on the status quo
When we consider that many trains are using electricity from the grid or diesel, it is clear improvements can be had. Diesel is harmful to the environment and most electricity from the grid does not come from green sources in the majority of countries. Although this is improving. For example, the UK now has a number of days a year where it no longer needs to fire up its coal generators, especially in the summer when the need for heating is less.
Many now believe we need a complete overhaul of where and how we source our energy. We are now living in an era where we are attempting to turn things around. An increase in greenhouse gases could have irreversible, damaging effects such as increased temperatures and rising water levels.
Adopting Cleaner Transport
Meanwhile, governments are encouraging people to use trains instead of taking to the roads in cars. If this is the case then it could increase the amount of CO2 that the rail industry emits each year. As a result of an increase in trains and services.
Therefore, if we rely on trains to help improve CO2 emissions, looking for green sources of energy to power trains and railways is crucial. It is clear to see that we are making progress. There are projects currently underway that use wind and solar power to conserve energy from our finite resources.
What's more, there are innovative products becoming available that could change things. From solar-paneled sleepers to solar panel-clad trains and solar farms that power railways, all of these changes are for the better as train technology evolves. If we continue to develop and utilize renewable energy, the railway industry could lead by example.
|Christian Azar, Kristian Lindgren, Björn A Andersson, Global energy scenarios meeting stringent CO2 constraints—cost-effective fuel choices in the transportation sector, Energy Policy, Volume 31, Issue 10, 2003, Pages 961-976, ISSN 0301-4215, https://doi.org/10.1016/S0301-4215(02)00139-8
|J. A. Aguado, A. J. Sánchez Racero and S. de la Torre, "Optimal Operation of Electric Railways With Renewable Energy and Electric Storage Systems," in IEEE Transactions on Smart Grid, vol. 9, no. 2, pp. 993-1001, March 2018. doi: 10.1109/TSG.2016.2574200
|Robinson, Mark and Schut, Dennis, Rail as the Sustainable Backbone of the Energy Efficient Transport Chain – A World View (August 31, 2014). OIDA International Journal of Sustainable Development, Vol. 07, No. 04, pp. 19-30, 2014. Available at SSRN: https://ssrn.com/abstract=2489755
|Vorobiev, P. and Vorobiev, Y. (2013), About the possibilities of using the renewable energy power sources on railway transport. J. Adv. Transp., 47: 681-691. doi:10.1002/atr.189
|O'Toole, Randal, Does Rail Transit Save Energy or Reduce Greenhouse Gas Emissions?. Cato Policy Analysis No. 615. Available at SSRN: https://ssrn.com/abstract=1263426
|Alan C. Lloyd & Thomas A. Cackette (2001) Diesel Engines: Environmental Impact and Control, Journal of the Air & Waste Management Association, 51:6, 809-847, DOI: 10.1080/10473289.2001.10464315
|Baker, C. J., Chapman, L., Quinn, A., & Dobney, K. (2010). Climate change and the railway industry: A review. Proceedings of the Institution of Mechanical Engineers, Part C: Journal of Mechanical Engineering Science, 224(3), 519–528. https://doi.org/10.1243/09544062JMES1558