Smart Gas

No two cities are alike. But, they often share similar challenges. It is therefore becoming increasingly important to propose common concepts in a “city context”. Traditionally, we have focused on the bus and its impact. Going forward, the imperative would be to look holistically, into areas such as synergies between clean energy and waste management. The idea is to deliver energy sustainability without taking more out of depleting fossil fuels and food production.

Volvo and Siemens Industrial Turbomachinery AB have jointly researched a novel concept for smart cities over the last 6 months. On May 2, for the first time, Bengt Gudmundsson (Siemens) and I presented the concept of “Smart Gas” at the ‘India Unlimited’ Seminar organized by the Indian Embassy in Sweden along with some partners.

We feel that we have found a beautiful concept to improve quality of living in cities:

  • Wastes and sewage is an increasingly sanitary issue. Cities need to find methods to reuse wastes in efficient ways. By fermentation, wastes are converted to biogas and the remains become nitrogen rich fertilizer meant for agriculture.
  • Congestion is and increasingly an issue that amplifies the negative impacts of cars. Cities need to provide public transport alternatives that can compete with private cars when it comes to comfort and convenience for citizens. The new generation of fast charged electric buses have what it takes to attract car users. The eco-friendliness and ability to climb in steep inclinations (in contrary to rail bound alternatives) allows buses to use compact cost efficient tunnels to pass under congested crossings. Or why not run in metro-style tunnels in parts of the cities?
  • Air quality is improved radically by extremely low emissions at the power plant. The contribution to city smog becomes 100 times less than today and no emissions are let out in the air close to the travelers.
  • Noise is reduced by a great extent. This allows public transport to more effectively access residential districts.
  • Modern living in cities includes climate controlled apartments. Unfortunately, most commonly, apartments are equipped with small inefficient Air Conditioning units, frequently placed on the façade of the building facing sunlight. District cooling can increase efficiencies and bring forward astonishing energy synergies with gas turbine power generation.
  • Electric Power supply is a growing concern in most cities. Electrified transport solutions mostly become a strain for the electric grid. The smart gas concept is different. Firstly, it provides energy to the grid with very high energy efficiency. Secondly, the energy storage of the buses allows for smart grid controls. The smart charging station can allow the grid to ramp-up or down charging second-by-second to compensate for other loads in the grid.

What is Smart Gas?

  • As a first step biogas is produced from wastes.
  • Delhi, India for example produces, 11,558 tons of wastes that generates about 500 tons of biogas.
  • Wastes from agriculture can just as well be fed to the biogas production plant.
  • As a byproduct from the bio gas production there is an equivalent amount, 500 tons, of bio fertilizer.
  • If it were to be required, natural gas can back up biogas production.
  • The enriched biogas can be used as fuel for a combined cycle power plant to generate both electricity and district cooling with a total efficiency of 87 percent. The electric power generated from 500 tons of biogas at an ambient temperature of 30C is 130 MW and the district cooling power is 120 MW. The ratio between generation of electric power and cooling can be optimized depending on the specific requirements.
  • District cooling can be used for any housing cooling purpose. If applied to apartments it is sufficient to cool 3,50 000 apartments of 100 m2.
  • The 130 MW electricity generated by the biogas can be used to drive 20 000 Volvo electric buses.

Smart Gas Concept

  • That means the Smart Gas electricity can drive four times as many buses or correspondingly longer distances for the same number of buses as compared to a situation where bio gas is directly used to drive buses.
  • An air conditioned electric bus in Delhi will use 1.8 kWh electricity per km while the corresponding gas bus uses 7 kWh CNG per kilometer.
  • Each bus has an energy storage battery of at least 75 kWh.
  • This opens up endless opportunities for smart grids
  • The bus can be connected to the grid over night or be charged at terminals while waiting for passengers
  • The on-board energy buffer and a variable charge power of 0 to 300 kW allows us to charge the bus with suitable power that the grid can provide.

We have demonstrated the undoubted gains of the novel concept of Smart Gas from wastes to smart grids, electric buses and district cooling.

But, how about city smog?

Smart Gas Emissions

Today exhaust gases from buses are let out on in the street level. In the graph to the left we compare emissions of the most modern Euro VI buses with the Smart Gas bus.

If that is not striking enough, we should see the comparison with the existing gas bus fleet in Delhi. The gains are at least fivefold higher!

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Volvo Technology Award 2016

In June 2015 Volvo and the ElectriCity partners introduced electric buses on a new bus route, route 55, in Göteborg (see the blog from the 26th of June). It has become an unusual success with a ridership that beats the plan. In addition more than 4000 international visitors from all over the world have visited route 55 and the ElectriCity partners. Behind the success lies a great deal of innovation and new development.

Today, the 6th of April 2016, at the yearly general assembly of the Volvo Group, the team and coworkers behind the electric bus are awarded for the development efforts and innovation. The developmentwork has been characterized by a close cooperation of widely different parts of the Volvo organization, from traveler and bus operators via research and science, design, mechanics, controls and telematics. And, those are just examples.

Electric Bus TeamThe team was represented by: top row Martin Sanne, Erik Lauri,  Ove Hjortsberg, Andreas Gillström, mid row myself (Edward Jobson), Mats Andersson, Fredrika Berndtsson, Roger Andersson,  sitting Patrik Pettersson, and John Lord. Not in picture Mattias Åsbogård.

Library bus stop at Bananpiren

The clean and silent buses are quilifiers for getting close to the travellers. In the picture is the temporary library at Bananpiren. And, many visitors have appreciated the indoor bus stop at Lindholmen.

The electric buses in Göteborg are charged rapidly by up to 300 kW. It takes roughly 3-4 minutes to charge 10 km drive.

The main building blocks of the innovative development are:

  • An efficient lightweight high-speed electric motor and an in-house developed 2-speed gearbox that realize high power in combination with high efficiency. It is unique to maintain high efficiency of the electric drive in such a broad speed range. This in turn enables a positive helix of efficiency improvements by lower thermal losses, less energy use, and higher passenger capacity.
  • A new control system platform for electric buses including a multi-battery energy management system that allows us to utilize the energy in the most efficient way to the electric drive as well as to auxiliaries, such as steering servo, air compressor and climate system.
  • A new charging system that enable fast opportunity charging of 300 kW. Rapid charging enables buses to use the lay-over time at the terminal end stops for charging. The new charging technology is now introduced as an open platform for the bus industry in Europe.
  • An off-board back-office telematics environment that enables precise control of the properties of the buses meter-by-meter in the city, Zone Management. E.g. by setting different speed limitation outside a school during school hours.

The new electric bus concept enables very high transport efficiency in combination with resource efficiency (optimized amount of batteries) and high passenger capacity (minimized component weight).

The passengers benefit from silent and emission free buses that can take us close to our destinations. The ElectriCity partner, Västtrafik, demonstrates the benefits of an in-door bus stop at one of the terminals stations of route 55. The

 

7900 Electric in Edinburgh

ElectriCity electric buses (to the right) get around in the world, here at a visit in Scotland, during 2015.The local Volvo 7900 Hybrid bus to the left has contributed to increased ridership at Lothian Buses in Edinburgh.

We are very proud that Volvo has recognized the contributions of our teams and that we already have contributed to a new way of thinking in public transports, where zero emissions and silent buses makes a true difference in everyday life of the travelers in cities.

 

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ElekBu 2016

 

I’m sitting at the airport on my way from this year’s electric bus conference, ElekBu 2016, in Berlin. Professor Müller-Hellman was moderating the seminars and the debates and he has been the pro-motor since the start 7 years ago .

This year two secretaries of the state, Rainer Bomba and Jochen Flasbarth honored us with their visits. There is a strong interest for electrical buses in Germany and the federal government is clear on their intention to support the introduction of electric buses in Germany.

For me it was the 5th time, after two years interruption.

We displayed the charging rails in the Volvo stand. They are mounted on the roof top. A screen displayed the facts and function of the opportunity charging concept.

Charging_rails

Picture: Opportunity charging rails and display at the Volvo stand in Berlin.

Volvo_Electric_Bus

Picture: Volvo Electric Bus, from the Gothenburg ElectriCity project, on display in Berlin.

On my way to the conference I reinvented a diagram I have been using for a while, to explain how opportunity charging supports long operational hours and high daily mileage. The new feature shows how increased average speed has a direct impact on the life time fuel saving.

Cities that are determined to implement electric buses and that have recognized the advantage of opportunity charging refers to the following advantages: high passenger capacity,  long workdays and short nigh stops and distributed power outtake from the grid (geographically and over time).

Divedrse_blog2

Picture: Opportunity charging supports long daily mileage and long workdays. The life time fuel saving is enhanced by electrification of the buses with the highest utilization.

Initially, many cities think of electrical buses in the slowest and most congested routes of the city. Those routes are important for their high visibility and for the high impact on local emissions and noise in the city center.

However, as evident from the diagram above there are strong benefits of increasing the speed of the route, when it comes to fuel savings. The electrification is a qualifier for increasing the priority of the buses in the city, to the benefit of the travelers. By introducing separate lanes, signal priority or dedicated tunnels or bridges the speed can be increased and the economy is improved, a lot.

An opportunity charged bus can increases the average speed and grow with the traffic planning ambitions of the public transport authorities.

 

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Opportunity Charged Electric Buses

opportunity charged electric bus

In today’s blog I have borrowed a lot of the material from my group mates Johan Larsson, Magnus Broback and from our manager, Jessica Sandström.

Volvo Buses has gained experience of charged electric buses, since the introduction of the Sunwin (Joint venture in China with 50% Volvo ownership) Super Cap bus in 2006.

super capacitor

Super capacitor since 2006.
Fast charging at every bus stop for 40 seconds. The system has challenges with high infrastructure cost and low energy storage capacity.

battery electric buses
Battery electric buses since 2010.
Battery swap system:  The system has challenges with: Low battery utilization and  time loss when swapping.
Battery overnight charging: The system has challenges with: Limited range and heavy and expensive batteries.

volvo 7900 hybrid

Volvo 7900 Hybrid was an in-house development and the first automotive application using lithium-ion battery technology. Volvo has more experience in automotive battery and control technology than any other HD automotive manufacturer.
When comparing opportunity charging to overnight charging, then the high utilization of charging infrastructure and the limited battery weight in the opportunity charging concept makes it superior in cost efficiency compared to  overnight charging.

increased speed improves efficiency

Opportunity charging has “unlimited” daily mileage giving high fuel saving.
The opportunity charged buses can be used in slow and rapid bus routes. By increasing the speed of the buses it:
- saves times for travellers
- gives higher passenger transport capacity.
Overnight charging limits the daily range and the passenger capacity.
In dialogue with cities I have found that some bus routes are today limited to less than 200 km and thus potential routes for overnight charging. Still, the ambition of the city is mostly to raise the attractiveness by higher speed and higher capacity. To go for opportunity charging is thus a future safe choice.

energy use

Each bus route has characteristic power consumption and it varies with the climate.
The system design needs to handle different routes and climate. I have been in dialogue with many cities to analyzing each route in the city to determine their specific needs. Again, mostly we find that opportunity charging and the battery buffer used, account for all eventualities.

opportunity charging ideal for solar and wind

Opportunity charging is ideal for electric supply by solar and wind
Many cities have decided to decrease imports of fossil energy and to increase local and sustainable electricity. Opportunity charging makes sense, to utilize the energy when it is most available.

To conclude, all types of electric buses utilize much less energy than diesel or gas alternatives. The longer the daily distance, the stronger the benefit.

Compromises are needed:

Passenger capacity                                 <->                   Battery weight

Driver/bus utilization                            <->                   Charging time

Cost for fast charging stations           <->                   Battery cost
We find that:
– High utilization of charging infrastructure and the limited battery weight in the opportunity charging concept makes it superior in cost efficiency towards overnight charging.
– The opportunity charging concept allows 17% more passengers.
– Overnight charged battery buses are convenient for testing the new technology in small scale, but have strong limitations in the daily range. This restricts it to slow routes, therefore with limited benefits.
-The opportunity charged buses can adapt to long workdays, high passenger capacity and high mileage. Thereby they deliver strong benefits for the city.

In the choice between different types of electric buses this is why so many cities now inves in opportunity charging infrastructure:
– The city wants to incest in a system that is future proof for increased mileage and speed.
– The city wants to secure transport/passenger capacity.
– The city wants to secure a reliable battery system that minimizes the risk of the investment (Volvo Turn Key solution allows cities to pay by the kilometer).
– They want to reach out to all routes, longer and faster transits as well as the down town business district.
– The city wants a local energy source and buses energy use that match the supply by renewable energy.
– The cities have analyzed the bus traffic pattern and found that the bus stops at the same spot every now and then for several minutes and wants to take the opportunity to charge the batteries to prolong the life and extend the distance.

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How much electricity do you need for an electric bus?

Or, did you ever ask you self: what is the fuel consumption of a hybrid bus?
The ElecTrip App has the answer.

The general answer to the initial questions is not satisfactory: “it depends on which route you think of”. The speed and topography are important. So are the stops. A stop directly after a downhill drive is really bad for the fuel consumption while an up-hill stop hardly has any negative impact. We clearly need to measure each route to give the answer.

So my colleague Ulf Gustafsson and I discussed if we could use a smart phone with GPS to analyze any bus route in the world with the objective to calculate the expected CO2 emissions and energy use for different bus technologies. After logging some routes it was not too hard to say yes, it is possible but the GPS signal is very noisy, in particular in altitude, causing random errors and too high energy use for all technologies.

With the help of e.g. colleague Jonas Hellgren at Volvo research division we made the ElecTrip APP for iPhones ®.   The result was so unique that we filed a patent application that is pending. Still we have been able to make it available for the public and it is free.
The APP is pretty self-explanatory but the results may deserve some comments.

The first result display an overview of the logging:
Date: of the logging.
Distance: is the total distance from the start to the end of the route. My recommendation is to logg routes in two directions. Mostly routes are asymmetric and the result will depend on the direction.  Logging in two directions allows a more precise forecast.
Duration: is the time measured from the start to the end of the logging.
Departure address: indicate the postal address closest to the start point of the route.
Arrival address: indicate the postal address closest to the start point of the route.

Electrip app1

Next the calculated results of the logging are presented in a bar graph.
My screen dumps are unfortunately not very easy to read. To clarify the order in which the technologies are presented it’s always the same:

Diesel Bus Euro VI: Standard diesel fuel is assumed.
Gas Bus Euro VI: Compressed fossil CNG is assumed.
Volvo 7900 Hybrid Bus: The energy efficiency is calculated based on the real engine calibration of the Volvo Hybrid bus. For the CO2 emission data standard diesel fuel is assumed although Volvo Engines can use Hydrogenated Vegetable Oils.
Volvo 7900 Electric Hybrid Bus: The energy efficiency is calculated based on the real engine calibration of the Volvo Electric Hybrid bus. We have assumed a distance of 10 km between the charging stations, since many trips are not from terminus to terminus. For the CO2 emission data again standard diesel fuel is assumed although Volvo Engines can use Hydrogenated Vegetable Oils.
Volvo 7900 Electric Bus: The electric bus is assumed to use sustainable and renewable electricity.

Electrip app2

Electrip app3
The bars display the total fuel consumption in diesel liter equivalents, meaning that the data for the gas bus has been converted to the corresponding heat value of diesel to enable comparison. And the Electric Hybrid and the Electric Bus displays the corresponding electricity use.

We have confirmed the results for route speeds from 10 km/h to 30 km/h. Results from faster and slower routes are not reliable.
The blue bars below display the carbon dioxide emissions for the route:

Electrip app4

Electrip app5

Electrip app6

Disclaimer
In the first version we:
– don’t compensate for local hot or cold climate. The figures represent yearly average central European climate.
– the speed calculation is not sufficiently precise to differentiate harsh breaking and similar driver behavior induced effects on the emissions
– road quality and friction due to sharp curves is not included
– when logging short routes the error can be rather large
– routes with average speed less than 10 km/h or more than 30 km/h have not been validated experimentally and should be regarded as uncertain data.

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Vacation

After four weeks vacation without interrupt I now returned to the office.

Apart from my constantly failing ambition to exercise extensive laziness in the peaceful summer of Sweden a few other achievements can be reported in the blog today.

The Pater Noster Lighthouse viewed from Carlsten castle on the Marstrand island.

The Pater Noster Lighthouse viewed from Carlsten castle on the Marstrand island.

Gull nesting on a pole in Edshultshall harbor

Gull nesting on a pole in Edshultshall harbor

The first two weeks were spent sailing in the archipelago of Bohuslän. We have this year installed 80 W Solar panels on the yacht. We have also installed a small 35 W (running about 20% of the time) refrigerator to keep some grocery cold. A logger soon revealed that balance between solar power and energy used by the fridge was kept with a healthy margin both hot sunny days and darker cloudy days. No specific action has been needed to keep the solar panel in the sun. I just glued them on a free horizontal space on the deck.

Althought, the Swedish summer is usually not challengingly hot it is useful to keep some of the food at lower temperatures than provided by the air and the sea.

Previously, I filled half the box with ice to keep it cool for some 4-5 days. Others connect to the electric grid in each harbor.

Seals resting on a rock outside Grundsund.

Seals resting on a rock outside Grundsund.

Sailing takes us close to nature. The seals are not much disturbed as we pass them serenely in the light breeze.

Hasselösund viewed from the bridge by mid-night.

Hasselösund viewed from the bridge by mid-night.

Even sailboats now days have an engine for the last mile docking or for getting to the targeted harbor. We filled up the tank with 13 liters diesel fuel after two weeks. Since we were 3 persons on board (in average that is, since we constantly had kids, friends and crew signing on and off the boat) we have used 2.2 litre diesel fuel per person and week.

For coking on the stove we use LPG on board. We consumed almost exactly one bottle of 2.3 kg Propane/Butane mix or 0.4 kg per person and week.

Once we are in official harbors we use the public bath rooms and showers there. I have estimated the energy for the hot water and the energy used for some visits to restaurants to 0.2 kWh per person. However, we mostly stay in natural harbors.

Zoie dog waiting for a guided tour to Munthes Hildasholm at Leksand, Dalarna.

Zoie dog waiting for a guided tour to Munthes Hildasholm at Leksand, Dalarna.

The third week we went by car to visit the Isabell daughter on internship at the chemical lab at ABB in Ludvika, Dalarna. The energy details are gathered below. We looked at gardens and visited the mines of Bergslagen.

On the trip back from the county of Dalarna we visited friends in Karlstad. Karlstad is a city with a lot of focus on public transports.

Like many cities around the world, Karlstad is adressing the capacity issue of the public transports. There are plans to introduce a proper BRT route. And, a lot of priority is put on promoting biking.

Karlstad makes the street space utilisation difference for bikes and cars explicit.

Karlstad makes the street space utilisation difference for bikes and cars explicit.

The fourth week was split in some days on the yacht and some days maintaining our house and garden.

Energy Summary

Week Diesel fuel Gas (for coking) Electricity solar Electricity from grid
Vacation Liter/person kg/person kWh/person kWh/person
1 2.2 0.4 0.9 0.2
2 2.2 0.4 0.9 0.2
3 22.5 19
4 10.7 19
Reference
Work week
24 38

Carbon emission summary

Week Diesel fuel Gas (for coking) Electricity solar Electricity from grid
Vacation kg CO2 kg CO2 kg CO2 kg CO2
1 6 1.2 0.0 0
2 6 1.2 0.0 0
3 59 0
4 28 0
Reference
Work week
63 0

Judging from this years’ vacation, a conclusion is that much less energy is required for the vacation than for ordinary life.

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ElectriCity rapid implementation of Linje 55

In mid April this year, the Lindholmen bus stop was still a construction site. In parallel the construction of charging station at the other terminal station, at Johanneberg science park was ongoing. Linje 55 (route 55) is a good example to show that the lead-time to go from traditional buses to an electrified bus system is close to equal to the delivery time of the buses.

lindholmen indoor bus stop april 15

Lindholmen indoor bus stop and charging station was still under construction in April, 2015.

The project leader, Johan Larsson, was dedicated and worked closely with the partners in the ElectriCity project. In the background: the rapid door, the ElectriCity bus and the SVP for City Mobility in Volvo Buses, Jessica Sandström.

The project leader, Johan Larsson, was dedicated and worked closely with the partners in the ElectriCity project. In the background: the rapid door, the ElectriCity bus and the SVP for City Mobility in Volvo Buses, Jessica Sandström.

On monday the 15th of June the bus traffic started on the new bus route in Gothenburg, “Linje 55”. The press conference was hosted by the top management of the Volvo Group, Håkan Karlsson and Volvo Buses CEO Håkan Agnevall met with the international invitees.
As the Volvo Ocean Race ships finish this week the buses will give service to several hundred invitees from all over the world already the second week.

Linje 55 has already become a success. The buses are busy all day.
While Linje 55 already is ground breaking and extraordinary a lot if side projects has started and I’m sure I will have good reasons to come back to Linje 55 in the blog to report further on the progress.

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