Kadri Penjam

In recent years, more and more attention has been paid to alternative fuels in the public transport sector as well: gas, hybrid and electric buses are becoming increasingly common among both city and long-distance buses and will continue to do so in the future.

Whereas elsewhere in the world the transition to alternative fuels has already lasted for a long time, Estonia has started turning its attention to climate-neutral behaviour, and therefore is considering the alternative options on the fuel market, especially in recent years. The European Union plans to achieve climate neutrality by 2050 and public transport is one area where it is possible to make a contribution.

Estonian capital as an alternative fuel Mecca

When speaking about public transport, there is no way of ignoring our capital – Tallinn. “Tallinn has good news for those who prefer environmentally friendly public transportation,” explains Deniss Boroditš, chairman of the management board at TLT (the public transport company in Tallinn). “TLT will continue testing electric buses to discover the best choices in view of our goal for 2035 of using electric public transportation in Tallinn that is based on renewable energy. If everything goes as planned, we will see 10 electric buses working every day in September 2021.
We will also move towards a greener capital, contributing to the reduction in exhaust gases by means of new, environmentally friendly biomethane buses as well as trams and trolleybuses that only consume green energy. All 100 renewable fuel buses have now arrived in Tallinn and replaced the oldest diesel buses. In 2021, we will have another 100 buses.”

According to the estimates of environmentalists and city planners, the use of public transport will reduce traffic jams and the general pollution level in the city. The acquisition of new gas buses and the construction of biomethane terminals is a strategic objective to replace all current diesel buses with an environmentally friendly and modern alternative by 2025. In total, TLT will replace the 200 oldest buses with new compressed gas buses in 2020-2021. “Thanks to this, we can make the company’s fleet much more modern and passenger-friendly,” says Boroditš. “The new buses have low floors, being mindful of residents with special needs, and take into account the comfort and safety of passengers.” He adds that a total of 350 gas buses are planned to be acquired in the coming years. For this purpose, in December 2020 TLT announced a public procurement for the acquisition of another 100 city buses of category M3, class I with an internal combustion engine operating with compressed gas, with the option of purchasing up to 50 such vehicles in the future, if necessary. “This is the biggest environmentally friendly innovation in Tallinn public transport in recent years,” adds Boroditš. “With the introduction of new buses, the ecological footprint of Tallinn’s public transport on the urban environment will decrease by approximately 25,000 tons per year. By introducing gas buses, TLT is leading the way for the entire transport sector, encouraging other companies to take bolder steps to purchase environmentally friendly vehicles. Higher demand for biomethane generates renewable energy production and makes it more accessible on the market.”

However, when thinking of the future, we cannot ignore electric buses either. Planning far ahead, the company has launched the first pilot projects to improve the competence of using electric buses in order to keep up with the development of technology and be ready to use electric buses for servicing bus lines. The objective is that by 2035 all public transport vehicles in Tallinn will be powered electrically.

TLT has already tested MAN, Solaris Urbino, Yutongi and Mercedes-Benz eCitaro electric buses in Tallinn. As the electric buses of different manufacturers have been tested in different seasons, and all of them have their added value, the multi-annual pilot project to be launched this year will help establish the criteria on which future bus procurements will be based.

“All of the buses that have briefly been tested so far have shown their suitability for Tallinn’s conditions and confirmed that electric buses are efficient and reliable and that their price per kilometre is 3-4 times lower than buses driving on diesel fuel,” adds Boroditš. “As part of the 2021 pilot project, we can conduct a more detailed analysis of how seasons, temperature changes and long-term regular services in the city affect electric buses, as well as the most important criteria for electric buses in the case of regular services.”

Tartu and Pärnu also using gas buses

While buses running on various fuels can be seen being driven and tested in the capital, Pärnu and Tartu have now transferred to gas buses and are contributing towards more eco-friendly public transport as well.

Public transport has taken a big step forward, especially in the field of gas buses, all over Estonia. For example, Tartu city buses and those used for city and near-city lines in Pärnu as well as public transport vehicles on Saaremaa and in Võru have for some time mostly used fuel with biomethane certification. When consuming CNG fuel, the footprint of public transport decreases considerably.

Jaanus Tamm, a project manager with Tartu City Government, explains that the introduction of biomethane buses is a result of 10 years of hard work and a big step towards carbon neutrality. Tartu is one of the few European cities among those of its size where public transport is completely carbon-free.

Biomethane buses have been used in Pärnu for a couple of years. Andrus Kärpuk, the head of the NPO Pärnumaa Ühistranspordikeskus, confirms that biomethane was introduced in Pärnu city buses on 1 May 2018 and in buses working on near-city lines on 1 November 2019. “Being first is both a great responsibility and an honour,” he explains. “The decision was easy thanks to the financial support of the European Union Cohesion Fund.”

Kärpuk adds that for Pärnu, the introduction of biomethane has been a question of reputation as at the core of the resort city is nature conservation and a green world view. Secondly, it is an exciting innovation that local people can take pride in and that sparks curiosity among tourists. “Thirdly, who should strive to achieve the European Union’s renewable energy transport objective, and when, if we don’t do so ourselves?” he asks. “Fourthly, green and innovative solutions increase the popularity of public transport, which is a necessary step in making transport solutions more economical. Our experience so far has shown that we are on the right track.”

Alternative fuel buses in the SCANIA range

Although Estonia is small, there are a number of alternative fuel bus solutions available in the range of resellers who have reached the domestic market. And Europe is right around the corner with new winds constantly blowing in this industry.

For example, Ragnar Jürgens, the Product and Sales Manager for Scania Baltics buses, confirms that in order to provide sustainable and innovative mobility solutions, the Irizari Group has also included in its technology solutions the compressed natural gas (CNG) and liquefied natural gas (LNG) offered by Scania.

Due to this, the group is expanding its range of efficient and sustainable products and technological solutions and is becoming a trademark that covers all technologies currently on the market. “That starts with integrated and conventional buses with internal combustion engines running on Euro 6D diesel fuel, HVO and B100 and goes through to natural gas or biogas buses and 100% electric vehicles, including class I and II models with hybrid technology for city and long-distance lines,” lists Jürgens.

He states that the environmental advantages of buses with new technology reduce CO2 emissions by 20-25%, NOx emissions by up to 60% and solid particulate emissions by more than 98%. Furthermore, such engines are more efficient and experience less vibration and noise. “In terms of operation, it can be estimated that total fuel and maintenance costs can be reduced by up to 20%,” Jürgens adds. “Above all, significant savings arise from the difference in gas and diesel costs. Maintenance costs remain in a price range similar to that of conventional diesel vehicles.”

However, according to Jürgens, sparing the environment and saving on operating costs do not result in any compromises in steerability, durability or performance. “Scania built their gas engines on an established diesel engine block,” he adds. “Most of the engine components are the same as the diesel analogue. However, parts such as the ignition system, gas distribution valve and oxygen sensors make it an Otto engine. Scania’s 9-litre gas engines have a capacity of 280 and 340 horsepower and develop a torque of 1350 Nm (1000-1400 rpm) and 1600 Nm (1100-1400 rpm) respectively. Performance and control remain similar to Scania’s diesel engines.” The distance travelled by the vehicles is up to 500 km with CNG fuel and twice as far with LNG fuel.

The choice of gas vehicles includes Irizar i4 and Irizar i3 12-15 metre models in the CNG version and Irizar i4, Irizar i6 and Irizar i6S 12-15 metre models in the LNG version – all of them with a Scania chassis. The first vehicle equipped with gas technology is an Irizar i4 class II model, a versatile and ideal bus for large cities, near-city lines, school and commercial transport.

The versatile properties of the 12.920 m long Irizar i4 version H are supplemented by the selection of current engine technology. “With a total weight of approximately 750 kg it contains four longitudinal type IV CNG cylinder-shaped tanks with a total volume of 1260 dm3 and an approximate gas volume of 240 kg,” Jürgens explains. “Depending on the operator’s needs, an additional tank can be installed to increase the driving range. The bus is also equipped with a filling panel with two gas outputs and a manometer. Tank integration preserves the vehicle aesthetics and aerodynamics and means that it can operate in the same way as a vehicle with a diesel engine with optimum road-holding capabilities and the maximum safety level.” He adds that the vehicles are equipped with the same air-conditioning system used in diesel engine vehicles. The height of the passenger lounge, the overhead shelf and the volume of the luggage compartment are also the same as in the diesel version.

Driver convenience has also been kept in mind. “The driver has a gas control screen to ensure all safety protocols,” Jürgens says, describing the innovative models. “This is used to detect leaks and initiate the automatic fire extinguishing system. These vehicles comply with the R66.02 regulation even with the extra weight of 700 kg on the roof in the form of the gas cylinders. Fire safety and mechanical safety comply with regulation R110. Although the new-generation i4 model was only presented in October 2019 at the international Busworld exhibition, the first orders are already in production.”

Innovative electric and gas buses from MAN

Andres Mängel, a member of the management board of Keil M.A., the official distributor of MAN buses in Estonia, points out that MAN is already focusing on a more ecologically clean future in the choice of its models.

For example, the MAN range includes the MAN Lion’s City E electric bus, whose main characteristics are as follows: quick depot charging, a large range per charge of 200-270 km, an optimised interior, the option to add batteries and a reliable and maintenance-friendly central engine. CCS standard charging with a fast charging capacity of up to 150 kW. The model is available as a 12 m long solo bus with up to 88 passenger spots (25 seats and 63 standing spots) and the power of the electric motor is from continuous 160 to max. 240 kW, the battery capacity is 480 kWh. The 18 m articulated bus accommodates 120 passengers (43 seats and 77 standing spots) and the power of its electric motors is from continuous 267 to max. 400 kWh, the battery capacity is 640 kWh.

“The new MAN Lion’s City exhibits a good deal of technical innovation both inside and out,” Mängel explains. “The new bus range has also been awarded the 2020 IF Gold Award and was also the winner of the Automotive Brand Contest 2020.” According to Mängel, the model is a perfect companion in urban traffic – the model stands out for its innovative technology, modern design and driving comfort. Economic efficiency must also be highlighted. In 2021, serial production will include MAN Lion’s City E (12C) and MAN Lion’s City E (18C) models. The new generation diesel buses are seeing a 17% lower rate compared to the old Lion’s City, but this is also a direct and significant reduction in CO2 pollution.

MAN has news in the field of gas buses as well. The new MAN Lion’s City CNG bus is now even cleaner and more eco-friendly. The 12 m solo bus has up to 90 and the 18 m articulated bus up to 150 passenger spots and the 18.75 m articulated bus can carry as many as 165 passengers. “The new E18 CNG engine proves itself with increased torque and smaller capacity and it can be combined with the MAN Efficient Hybrid generator drive,” Mängel says. “Fuel consumption is also up to 28% lower thanks to the new E18 engine (9500 cm3).”

The electric van MAN eTGE, with a gross mass of 3.5 tons, and the M1 category 8-seat minibus are also already available as new models. They can drive approx. 150 km with a single charge, which is significant mileage for city traffic distribution transport, couriers and bus companies today. Battery packs with a capacity of 111 Ah have an eight-year manufacturer’s warranty up to a distance of 160,000 km, which in turn gives eTGE clients a sense of security. A fast charge of 45 minutes (with a charging power of 40 kW and using a CCS-compliant plug) can increase battery capacity to 80% and add another 80 km to the range. The power source is a 100 kW synchronous electric motor with a torque of 290 Nm. The efficiency of the electric motor is 90%. The load-bearing capacity of the vans remains at 1000 kg, offering 11 m3 of cargo space.