SOLAR ON TRAIN TRACKS
Solar panels will be rolled out “like carpet” on railway tracks in Bangladesh. The sun seems to be sweeping the globe when it comes to harnessing power for cars and homes. The sun is the most efficient form of energy, making it a great alternative fuel for cars. If cars can be powered by the sun, why not trains?
On the one hand, solar energy seems to be a great alternative for traditional fuels to power cars. On the other hand, it is extremely difficult to power cars through the sun as they drive in and out of shadows. They don’t receive enough juice from the sun for a long period.
However, trains have enough space for solar panels, and they travel on the same route. Photovoltaic Cells are either located on the roof of the train or beside the railway lines. The solar trains get the power for their movement from there. For many years now, solar trains have been the target of many renewable energy projects as they can be easily and quickly recharged on every stop by static solar panels. Even on busy rail networks, the gap between lines can spend much of its time doing little but face skyward, so why not put that space to good use?
This system uses the vast network of underutilised railway tracks for solar energy generation, creating a highly scalable, efficient, and environmentally friendly way to produce clean power. A key advantage of this innovation is that it capitalises on existing infrastructure, eliminating the need for acquiring additional land for solar farms. Europe alone has over 200,000 km of railway tracks, representing a significant opportunity for energy production. If just 10% of these tracks were equipped with solar panels, it could generate enough electricity to power approximately 300,000 homes annually.
Using existing railway tracks minimises the environmental impact compared to building new solar farms on undeveloped land. This aligns with growing global priorities for reducing the environmental footprint of energy projects and meeting carbon reduction targets.
Rail companies can install PV modules on the roof of trains to generate power for onboard
services, such as air conditioning, lighting, and security. They can also install PV panels nearby or on train tracks to generate electricity to run trains and distribute power to the grid.
This could provide a solution for rail networks that rely heavily on distribution grids, as some grids are approaching full capacity and lack the financing that they need to expand their capacity. While it is difficult to secure the grid capacity to supply renewable electricity to power rail networks, by installing PV generation for their own use operators can reduce their reliance on overloaded grid networks.
The International Energy Agency (IEA) predicted in 2019 that the global rail network could expand from 1.6 million kilometres in 2016 to 2.1 million kilometres in 2050, an increase of 34%. That would increase electricity demand from the sector to nearly 700 TWh, requiring additional power generation capacity to be installed. Renewable energy provides a solution to increasing energy supply while reducing the transport sector’s CO2 emissions.
PhotoVoltaic Train (Pvtrain), a project run by Italy’s primary train operator Trenitalia, was thefirst attempt in Europe to test the viability of using PV cells to charge onboard accumulators. The project ran from November 2003 to October 2005, with an observation period starting in July 2003. During the observation period, the prototype trains used 1,378.42 kWh of electricity, reducing CO2 emission by 1,033.82 kg.
Between August 2004 and October 2005, the prototypes used 159.3 kWh, which was enough to power the onboard accumulators while reducing CO2 emissions by 119.95 kg. The prototype freight wagons used 540 kWh, enough to power the electrical locks while reducing CO2 emissions by 405.51 kg. It is estimated that for every kWh of electricity generated, using PV modules emits 750g less CO2 into the atmosphere. In addition, the constant flow of electrical current extends the lifespan of the onboard accumulators.
Photovoltaic rail transport: The benefits
In December 2022, French railway operators SNCF Reseau and INESannounced a collaboration to develop PV systems to enable rail networks to use renewable electricity. The collaboration aims to:
- reduce energy losses
- optimize costs
- increase PV generation efficiency
- increase digitalization
- improve reliability
Innovative converters will connect medium-voltage direct current (MVDC) modules to the microgrid. The microgrid will demonstrate how to increase PV production efficiently while interconnecting assets within the MVDC network. The MVDC microgrid will connect to the main grid through a solid-state transformer (SST), with the aim of operating a smart system. The system will include an energy management system designed for alternating current (AC) / direct current (DC) hybrid networks and a decision support system to increase network efficiency and reliability.
In China, which is installing massive amounts of solar generation,research shows that the landscapes around rail infrastructure have the potential to produce abundant solar power. Companies can make use of the large trackside land spaces, slopes, medians, station rooftops, and train roofs to increase PV capacity installation and play a role in sustainable development. By 2030, PV installations in rail transportation could produce around 12 TWh of electricity, accounting for around 6% of the sector’s total energy consumption.
Railways typically own their rights-of-way and control access to their land, making it relatively straightforward to install solar equipment. They also typically own their overhead electrical infrastructure, so they can directly use the electricity they generate. The Indian government has announced plans to install 20 GW of solar farms to make its railway network carbon-neutral by 2030. It has identified land close to the railway infrastructure and would feed the solar power directly into the railway substations and the electricity grid.
Solar panels installed alongside railway tracks do not need to support heavy loads, although in areas where tracks are in poor condition, heavy vibration could result in panels becoming cracked and broken.In Germany, developers have focused on developing hydrogen-powered trains as an alternative to the high cost of electrifying lines, but installing PV panels on rail beds could make the economics more favourable.
In addition, one common complaint often seen when talking about the expansion of renewable infrastructure is the destruction of farmland in order to accommodate energy generation plants. By installing PV panels into rail beds, it is estimated that 100 KW of electricity could be generated per kilometre of rail line. This will lessen the need for agricultural land to be taken over for renewable projects and mitigate the environmental impact of such initiatives.
The railway industry boasts a relatively advantageous starting point in this context, contributing to only a small percentage of emissions globally and representing one of the most sustainable transport methods on the market.
Across Europe it is becoming almost standard for railways to have some sort of PPA system in place to source renewable energy. French-Belgian high-speed train operator Thalys has been using 100 per cent green energy for all trains running through France, Belgium and Germany since 2020.
Belgium’s national rail company SNCBis raising the bar with rooftop solar, fixing 20,000 panels to its stations and buildings. And France’s SNCF has taken things a step further by launching a dedicated subsidiary to develop solar projects.
Solar energy seems to have no boundaries. Solar panels can be found on many previously unused surfaces, from the roofs of houses and noise barriers along highways to the walls of
dams and even bodies of water.
A specially designed train will unfurl the panels as it travels along the track.
How are solar panels added to tracks?
The Company will use a mechanical system to install its removable solar panels. A train developed by Swiss track maintenance company Scheuchzer will travel along the rails, laying photovoltaic panels as it goes. It’s just “like an unrolling carpet”. The specially designed train uses a piston mechanism to unfurl the one-metre-wide panels, pre-assembled at a factory. It claims to be able to install up to 1,000 m2 of solar panels per day. During an three-year test phase, 48 panels was added to a 100-metre section of track operated by transN, the canton’s public transport company, at a cost of roughly CHF585,000 (€623,000).
A specially designed train will unfurl the panels as it travels along the track.
How much energy could solar panels on railway lines produce?
This is an eco-innovation project. In theory, panels could be rolled out across the entirety of Switzerland’s 5,317 kilometre-long railway networks. The photovoltaic cells would cover an area around the size of 760 football fields. Beyond Switzerland, there is involvement in similar projects being planned in Spain, Romania and South Korea.
“There are over a million kilometres of railway lines in the world,” Sun-Ways co-founder Baptiste Danichert told SWI Swissinfo last year. “We believe that 50 per cent of the world’s railways could be equipped with our system.”
The International Union of Railways previously expressed concern that the panels could suffer micro-cracks, lead to a higher risk of fires in green areas beside the railway tracks, and additional noise due to reflection of the hard surface on the ballast (which also has the function of absorbing noise), and even distract train drivers with reflections. Sun-Ways said its panels are more resistant than conventional ones and could have an anti-reflection filter to keep out of train drivers’ eyes. Built-in sensors also ensure they work properly while brushes attached to the end of trains could remove dirt from the surface of the panels. Some have pointed out that ice and snowfall could stop the horizontal panels from being useful, but Sun-Ways had an answer for this too. It is working on a system to melt frozen precipitation.
Bankset's pioneering solar rails road design.
It’s all very welcome, and maybe unsurprising, Rail Networks generally have a large land portfolio to work with, manage big rooftops, and must meet high energy demand. With the appeal of rail travel growing thanks to the green footprint of the train vs plane, renewable energy sourcing really supports the planet-friendly selling points. As well as grasping the ‘low hanging fruits’ of rail-side land, some forward-thinkers are experimenting with
incorporating solar into the lines themselves.
Boosting solar power is one of the main planks of Switzerland’s 2050 net-zero strategy. The authorities want 45 terawatt hours of solar and wind-generated electricity a year by 2050 (a seven-fold increase on 2023). Recently, Switzerland passed legislation to accelerate the uptake of solar power nationwide. The Swiss government supports the installation of panels on a range of surfaces, from roofs to motorways—and even Alpine pastures.
The train is powered from the solar PV panels on the shed roof
Solar panels have been fitted to the roof of each carriage to collect and generate solar power to charge the train’s batteries. When it is sunny, the train can run 4-5 times a day only on solar power received by the panels. In bad weather, renewable energy is charged with the help of local retail companies in order to operate the train.
Bangladesh is having a golden opportunity to have the “Tainovoltaics” in the entire network of rail system. This will improve the quality of environment around the train tracks.
Now cleared for a 2025 pilot project, turns the space between railroad tracks into removable solar power plants
Each “full black” panel measures 1 x 1.7 m (3.3 x 5.5 ft) and features an anti-reflective filter to prevent glare. This is mounted as a multi-array format in a frame where all components and wiring are housed within. The current setup is designed to fit track gauges of 1.43 m (4.6 ft), though this can be adapted for non-standard installations. The multi-panel modules can be installed and connected manually by engineers, but railway maintenance company Scheuchzer SA has developed a machine capable of installing up to 1,000 m2 of Sun-Ways panel arrays per day.
The solar power plant has been designed so that the panel modules can be temporarily removed while railway engineers perform track maintenance, and then put back down when work has been completed. And the setup has been tested for stability for trains passing overhead at up to 150 km/h (93 mph), and can withstand 240-km/h (150 mph) winds.
Since the panels are laid flat, snowfall during winter months will naturally adversely affect performance. But the company told us that cylindrical brushes could be attached to the ends of trains to deal with the inevitable accumulation of dirt—so it’s not a huge leap to come up with something similar to clear snow. Electricity produced by the system could be used to power nearby infrastructure such as switches or points—or even stations. Of course it could be fed into the grid, or routed to the traction energy network that powers locomotives—which negates the need for ground-based inverters.
Can Trains be Powered Solely with Solar Energy?
How do solar trains work? Although a train doesn’t entirely touch the rails, it is a massive structure! This implies that it takes a great deal of energy to get it moving. Even while the amount of energy it requires to keep it moving is far less, unless on steep slopes, it is still a lot. A high-speed passenger train can utilize roughly 0.03 kWh per passenger per kilometre, which equals 18 kWh/km for a 600-person train. At a speed of 250 km/h, one kilometre is covered every 14.4 seconds, consuming around 3.6 MW.
To supply enough momentum for all of the energy needed by the train to be electric, 18,000 m2 of solar panels would need to be erected next to the railway line with a generation of 200 W per square metres. From a technical standpoint, it is a real challenge. But the deployment of this infrastructure and its use on a circuit with many trains running makes operating only solar trains only a theory today. As nations, companies, and even individuals strive to cut down on their carbon footprints worldwide, solar energy is the next big thing!
The idea of installing solar panels along railway tracks is not new. Two other companies, Italy’s Greenrail and England’s Bankset Energy, are testing photovoltaic elements installed on railway sleepers. However, Sun-Ways is the first to have patented a removable system, in collaboration with EPFL, the Swiss federal technology institute in Lausanne.
“That is the innovation,” says Danichert. Indeed, the possibility of removing the panels is essential for maintenance work, such as rail grinding, to be carried out. Rail grinding ensures that trains continue to run smoothly along the tracks.
An Indian railway network is installing over 1,000 hectares worth of solar energy. The Central Railway, one of 18 rail ‘zones’ in the country, has committed to developing 1 megawatt (MW) of solar units at 81 spots throughout its network. It’s part of a growing trend of railways using their large land portfolios to go greener and help meet national renewable energy goals.
“To facilitate the installation of the solar plants, we have identified around 2,700 acres [1,093 hectares]of vacant or unused railway land,” explains Shivraj Manaspure, chief public relations officer for the railway.
Central Railway has a pioneering track record; it operated the first passenger railway line in India 170 years ago. Now it has secured a tender for a 1MW capacity solar plant at a new electric locomotive shed at Ajni in Nagpur, the Times of India reported. This takes the form of a power purchase agreement (PPA)—a contract drawn up between an electricity producer and a user. According to SolarPower Europe, more and more railway companies are signing PPAs across Europe too.
If India can do it, why not Bangladesh? Bangladesh has huge potentiality on Railway Solar and it will even improve the environment, socio-economic conditions, and the social fabric of the surrounding areas of the rail lines with solar panels on the train-track will alter forever. And ExpoTech will be proud to be a part in that change of constant flux.
Design and Drawing of Solar Panels on Railway Tracks
Bangladeshi Railway Solar Panels are different and they are not on the track, they are off-track, alongside the rail station juxtaposed on parallel.[1]
[1]www.researchgate.net: Schematic diagram of photovoltaic power plant alongside the railway track in Bangladesh.
This way of lying simply solar panels along the train track side is not the right solution for Railway Solar. Bangladesh needs to put solar panels on the track itself and ride alongside the world advancement. In my view, lying panels along the track is old-fashioned and primitive. Our company ExpoTech Renewable Energy Limited is for Innovation and bringing new ideas to improve Bangladesh.
A Pilot Study
A pilot study to test the concept was carried out upon a 100-metre section of rail line in active use. The panels are laid by a specialised train which is also used for carrying out track maintenance. The train can install up to five hundred panels a day. However, unlike rooftops or fields where solar is typically located, railway lines need to be maintained with regular upkeep. As such, the same train which installs the panels, can remove them, carry out the needed maintenance, and then reinstall the panels so they can continue soaking up the sunlight.
The pilot was approved by the Swiss government and preceded. The panels withstood both high train speeds, and high wind speeds, demonstrating their durability and successful coexistence with rail infrastructure.
Will it Work in Practice?
Practical concerns have been raised with the viability of the project. Including the following:
- Theft of panels: Theft of electrical infrastructure from public transport ways is a continuing issue, such as cooper cable theft. However Sun-Ways cites the panels require specialist tools to be required to remove them, and their markings make them easy to track.
- Visual impact upon train drivers: Developers of solar installations in the vicinity of rail lines will know that careful assessment of potential reflections towards train drivers must be undertaken to ensure safety. Sun-Ways reassures that glare analysis is carried out for all projects as standard.
- Cleaning: Panels are most efficient when they are clean. A specially designed brush is installed to the front of a train which cleans the panels as they are driven over, ensuring they remain clean and efficient.
While there are obstacles to overcome, such as cost effectiveness and government approval, the potential gains of track mounted solar are significant.
Solar-powered trains growing in popularity
Yet, while solar PV could soon land in underground networks around the world, it might still be a while before it is applied to large-scale railways.
That is not to say, however, that efforts have not been made in this direction. Years of collaboration between 10:10, the UK’s Community Energy South and Network Rail have recently brought to life the world’s first solar-powered railway line, which opened in Hampshire, UK in August 2019. “Projects of this kind also recently kicked off in Australia and Argentina.”
The brainchild of the Riding Sunbeams project, the line can now completely bypass the national grid by drawing power from around 100 solar panels. In the coming years, it is hoped it will be included in the world’s first full-scale community and commuter-owned ‘solar-traction farm’.
But this is not the only existing model. In India, for example, trains have solar power on their roofs and in 2017, the city of Guwahati became host to the first station in the country to be 100% solar-powered. The local government is further working to adopt solar PV at 8,500 stations in the coming years. Projects of this kind also recently kicked off in Australia and Argentina, though so far in relatively small locations.
The importance of railway sleepers
The idea of attaching solar panels to railway sleepers is also gaining considerable traction across the industry, as it potentially allows for solar PV to work on long routes at relatively low costs. Initiatives within this framework have started popping up over the past few years, with companies like Bankset Group and Greenrail leading the way.
The former, Bankset Group, is a British renewables financial investor whose prestige in the industry is growing at impressive speeds. The company is currently working on a project that, if effective, will see it deliver the largest solar installation in the world.
“The idea of attaching solar panels to railway sleepers is also gaining considerable traction.”
Having kicked off in 2013 with financial support from European, Chinese and US partners, Bankset is conducting trials to attach solar panels made of silicon and aluminium to railway sleepers on a number of European and international networks. While still carrying tests in 12 countries including Italy, France and the UK, as well as overseas, the company has already installed the first-ever solar panel on a rail track in Switzerland and is now pursuing a similar project in Germany.
If the trials prove to be successful, the technology could be a game changer in the sector, as it could be extended to some 165 countries around the world and become the largest installation on the market.
On the other hand, Italian company Greenrail is currently gaining momentum thanks to its range of solar-powered sleepers, which incorporate photovoltaic panels and also contribute to a circular economy – being made up of some recycled materials.
Transport plays a vital role in the world’s economic growth and societies’ development, which facilitates passenger mobility and freight transport across the globe. However, the transport sector is a major source of carbon emissions due to its high reliance on fossil fuels. On a global basis, the share of fossil fuels in the transport sector is very large at around 96%. Meanwhile, this sector accounts for 29% of global final energy use and nearly one-quarter of carbon dioxide emissions. With the global demand for transport services increasing in the future, the transport sector need to undergo an energy transformation from fossil fuels to renewable sources to reduce emissions and evolution towards a completely decarbonised system.
From the energy perspective, rail is among the most-efficient transport modes, which carries 8% of passenger movements and 7% of freight transport with only close to 2% of transport final energy use. In rail energy use, electricity constitutes 47%, amounting to 290 TWh. the global rail network is expected to expand to 2.1 million kilometres by 2050. Among these, China will account for a larger share of electrified rail developments with nearly half of the railway constructions between 2019 and 2050. The strong activity growth brings up the dramatically increasing rail traction power demand, which reaches as high as around 700 TWh by 2050. This also exacerbates the contradiction between rail power supply and demand. Following the Paris Agreements to restrict global temperature rise to 2 °C, scaling up the electricity from renewable sources is crucial. Among various renewable sources, solar energy is the most widespread and accessible type due to flexible installations of photovoltaic (PV) panels in power stations, in buildings [6], on rooftops, in park lots, etc. Meanwhile, the rail sector provides enough available spaces for PV panel installations on the covered and trackside land, and the station rooftops in its infrastructures and ancillary facilities without increasing land use. Therefore, this results in a greater future for solar energy integration in the rail sector.
Recently, many rail managers are increasingly using the land that they own to reduce their dependence on the utility grid by operating the solar energy generation. In Japan, 453 kW solar panels, serving Tokaido Line Trains, were installed at Tokyo Station. In Santiago, Chile, the city metro operator built two solar power plants, which suppled 60% of the metro’s energy use, bringing the share of renewable energy to 76%. Similar examples have also been found in China. In 2008, a 220 kW rooftop solar power generation in Beijing South Station was operated. It is estimated to generate 223 MWh per year for the use of the rail station itself. Then, a larger 10 MW solar power generation was installed on the canopy and rooftop of Hangzhou East Station and began operation in 2013. These initial field trials demonstrate that the usage of the solar energy generation in the rail sector has a strong potential with the technological progress and cost reduction in the future.
As seen, it is forecasted that the solar energy would play a vital role in the rail sector for renewable power supply and carbon emission reduction. Focused on the usage of solar power generation in the rail sector, the available solar energy on the covered land and trackside land in the rail itself is assessed for the rail integration. Then, several configurations for the integration of solar power generation in the rail traction power supply systems (TPSSs) are investigated. For the flexible current provision between powering single-phase locomotives and feeding back to the three-phase grid, an individual phase current control (IPCC) of PV converters is fully designed. It is implemented in the stationary reference frame without any extractions between sequences.
Despite barely touching the rails, a train is an extremely large vehicle. This means that it takes a great deal of energy to make it move and although the amount required to keep it moving is lower (except on steep gradients), it is still a significant amount.
A high-speed passenger train can consume around 0.03 kWh per passenger and kilometre, which, for a 600-passenger train, is a total of 18 kWh/km. At a speed of 250 km/h, one kilometre is covered every 14.4 seconds and therefore around 3.6 MW are consumed.
With a generation of 200 W per square meter, 18,000 m2 of photovoltaic panels would need to be installed next to the railway line in order to provide sufficient momentum for all the energy used by the train to be electric. From a technical point of view, it is a feasible challenge, but the implementation of this infrastructure and its use on a circuit that could have various trains running, make operating strictly solar trains today just a theory. But ExpoTech teams believe that solar panels on Train Track is the FUTURE………………….
