The BMW Group's energy strategy
Mobility needs energy. To ensure a sufficient supply of energy to meet future needs, the BMW Group's chosen priorities are to promote efficient use of today's available energy sources and develop innovative solutions for tomorrow's mobile society ? thus preserving "sheer driving pleasure" for future generations.
 

" Water is the coal of t h e future. T he energy o f to morrow is water broken down into hydrogen and oxygen us ing electricity. These elements willse re the earth`s power supply for an indefinite period."
Jules Verne "The Mysterious Island", 1874

Sustainable mobility To ensure the long-term availability of adequate energy supplies, the BMW Group is committed to the principle of sustainable mobility, a concept that places emphasis on efficient use of today's available energy sources and the development of innovative

solutions to meet future n e e d s . This reduces dependency o n fossil fuels and c u t s down environmental pollution. Another o f t h e BMW Group's top priorities, alongside this sustainable approach to energy consumption, is customer-friendliness ? in keeping with its famous slogan "sheer driving pleasure". Customer friendliness thus also forms part of o u r c o n c e p t o f s u sta i n a b l e mobility. Both today a n d in the future, cars must be built to limit their environmental i m p a c t a n d yet a l s o provide highest sta n d a rd s of c o m fo r t , performance, equipment, utility va l u e and safety, while at the same time fully satisfying the individual needs of each customer.

Economical use of energy
The question of fuel efficiency i s equally important . Bearing this in mind, the BMW Group pursues the twin o b j e c t i ve s of l o w e r i n g the fuel consumption of i t s m o d e l s and developing competitive products. A n u m b e r o f te c h n i c a l advances bear w i t n e s s to the s u c c e s s f u l integration of t h e s e two objectives. As for f u t u re developments, here too the BMW G ro u p has ve r y c l e a r i d e a s concerning energy u s e and future engine design concepts.

Fo r manydecades , efforts to improve vehicles from anecological standpoint h ave focused on reducing fuel c o n s u m p t i o n and limiting emissions. The BMW G ro u p

 

The 7 Series hydrogen car:
driven by a hydrogen-fuelled
internal combustion engine,
with electrical power supplied
by a fuel cell
has achieved some remarkably s u c c e s s f u l results in b o t h of t h e s e areas. The average fuel consumption of B M W G ro u p cars has been reduced by ro u g h l y 3 5 per cent between 1978 and 2000. And the progress doesn't sto p there: the German car m a n u fa c t u re r s ' federation VDA has agreed to reduce average fuel consumption by 2 5 per c e n t by 2 0 0 5 , compared to the level existing in 1 9 9 0 . The BMW G ro u p already re a c h e d this target i n 2 0 0 2 , and continues to push forward with the developm e n t o f h i g h l y a d va n c e d technologies that w i l l enable the company to meet the related targets concerning the re d u c t i o n of c a r b o n dioxide (CO 2) emissions,on the

b a s i s of a n average European benchmark (ACEA). S i m i l a r l y s u c c e s s f u l results have been achieved in e f fo r t s to cut d o w n or e l i m i n a te noxious emissions. Tra f f i c pollution in Germany h a s fallen significantly b e t w e e n 1990 and 2000, with reductions of a p p rox i mately 70 per cent in emissions of carbon monoxide and n i t ro g e n oxides, and a drop of a l m o st 9 0 per c e n t i n hydrocarbon emissions.

Better engines and lighter cars

This gratifying progress has been helped along by many technical innovations, including BMW's new Valvetronic syste m , which variably c o n t ro l s valve lift t h ro u g h o u t i t s e n t i re range and has replaced the conventional throttle va l ve in normal driving mode. The system allows fuel c o n s u m p t i o n to be improved by a ro u n d 10 per c e n t according to the standard EU combined-cycle ratings. The energy needed to propel the vehicle can be further reduced by reducing its weight. Consequently,

the BMW Group is a firm believer in the advantages of lightweight construction. Fibre-reinforced composite materials and light metals can help to reduce weight, but they have to b e used in an intelligent m a n n e r. When considering w h e re and to what ex te n t t h e s e innovative materials might be used, it is always a question of weighing up the ove ra l l benefits, in terms of b o t h ecological factors and d r i v i n g performance. For t h e total energy b a l a n c e not o n l y i n cl u de s

the energy co st s of p ro d u c i ng the vehicle a n d fuel consumption during its useful life, but a l s o the c o st o f e n d - o f- l i fe recycling. The rational approach to optimisation involves taking a holistic view of all of these factors. N ex t t a rg e t : Reducing carbon dioxide (CO 2) emissions T h e significant i m p rove m e n t s achieved so far h ave m a d e today's cars much more environmentally a c c e p t a b l e than their p re d e c e s s o r s . But f u t u re requirements w i l l be even more exacting. At p re s e n t , the most p re s s i n g demand is to reduce carbon dioxide emissions. C a r b o n dioxide is one of t h e chief g re e n h o u s e gases, s u s p e c te d of b e i n g responsible for t h e gradual rise in t h e temperature of t h e Earth's atmosphere. The agreem e n t s signed at t h e close of t h e Kyoto conference on climate change in 1997 aim to cut the volume of carbon d i ox i d e generated by ve h i c l e s on a global scale. Reductions in the fuel consumption of private vehicles in Germany since 1995 have succeeded in bringing down the level of carbon dioxide emissions due to road traffic, d e s p i te a constant i n c re a s e in the total mileage driven o n German roads. In order to take this progress even f u r t h e r, the search is now on for a l te r n a t i ve fuels that re l e a s e the least p o s s i b l e carbon dioxide. Possible c a n d i d a te s include fossil fuels such as natural gas as w e l l as biofuels like methanol or e t h a n o l . Each of t h e s e f u e l s has its own specific advantages and drawbacks. But they still share the disadvantage of releasing carbon dioxide as a combustion product. The forward-looking solution: Hydrogen T h e only c o m p l e te l y c a r b o n - f re e fuel is hydrogen (H 2) . Fired in an internal combustion engine or converted in a f u e l cell, the end product o f t h e reaction is water ( H 2O ) . I n view of t h i s fact, the BMW G ro u p has been engaged i n a continuous series of d eve l o p m e n t p ro j e c t s on

 
 

hydrogen-fuelled vehicles over m a ny ye a r s now. The c o m p a ny h a s deliberately c h o s e n to keep the internal combustion engine as the propulsion system, regarding i t a s a mature technology, successively o p t i m i s e d over many decades of experience. The BMW G ro u p has been conducting research on hyd ro g e n - p o w e re d engines and vehicles since 1978. It embarked on the first practical tests with prototype cars o n e year l a te r. By 1 9 8 4 , the second generation was b e i n g driven in road tests, to be succeeded by a third g e n e ra t i o n in 1988. In 1996, the fourth generation e m e rg e d and was test-driven under v i r t u a l l y

n o r m a l operating conditions. Finally, in 2000, BMW became the world's first car manufacturer to produce an experimenta l fleet o f 1 5 hydrogen cars, the model 750 hL. These ve h i c l e s have meanwhile proved their m e t t l e on real roads, and have clocked up a total of more than 170,000 k i l o m e t re s . The BMW 7 5 0 hL has a bivalent e n g i n e , c a p a b l e of r u n n i n g on either hyd ro g e n or p e t ro l , as required. In addition to its 140-litre hydrogen ta n k , storing liquid hydrogen at a n extremely l o w temperature, it a l s o has a petrol tank, which extends the vehicle's range from around 300 to 900 kilometres. This allows the car to be used on today's road network, where hydrogen filling stations are still few and far between.

Using renewable energy sources H yd ro g e n has long been in use as an important ra w material in the chemical industry, and can be produced i n several ways ? and relatively c h e a p l y to o . Typical p ro c e s s e s include steam reforming of n a t u ra l gas, or e l e c t r i c a l separation of wa te r ( e l e c t ro l y s i s ) . But t h e c a r b o n dioxide emissions associated with the product i o n of hyd ro g e n will only b e lower t h a n the emissions a s s o c i a te d with the use of to d ay ' s automotive fuels if the electricity required by the production process itself i s not d e r i ve d from fossil fuels, i.e. petroleum, natural gas or coal. The ultimate goal must therefore be to use re n e wa b l e resources such as water, solar o r w i n d e n e rg y to generate this electricity. The choice of a s u i ta b l e alternative energy s o u rc e will depend on the available natural resources in each region. I n order to ensure a smooth transition from fossil fuels to a sustainable hydrogen economy, the most sensible ro u te would appear to be an intelligent m i x between o n e of t h e relatively l o w- c o st fo r m s of hyd ro g e n p ro d u c t i o n , using natural gas for i n sta n c e , and hydrogen production by means of electrolysis using electrici t y f ro m a renewable source. For t h e BMW G ro u p , the long-term perspective for hydrogen as a future fuel lies in the use of renewable energy sources.

 
Start of series production
Preparations for the series production of hydrogen cars started at the BMW Group in 2001. The first customers will take delivery of series-produced hydrogen cars during the lifetime of the present 7 Series. Like its predecessors, the series-production model will be equipped with a bivalent engine, capable of running on hydrogen and petrol, and carrying two types of fuel. The hydrogen tank has a

capacity of 170 litres of liquid hydrogen, sufficient to travel a distance of around 300 kilometres, and the supplementary petrol tank will extend this range by a further 500 kilometres. The BMW Group presented one of its concept hydrogen engines in 2003: a twelve-cylinder V-engine with a capacity of 6.0 litres, capable of developing an output of over 170 kilowatts at 5,500 revolutions per minute. It reaches its maximum torque of 337 Nm already at 2,000 rpm.

During the development of the hydrogen production model, the BMW engineers had to make allowance for the fact that hydrogen and petrol have very different physical properties, requiring a considerable number of new parts to be designed for the engine. One such part is a new feed valve for hydrogen gas, developed in collaboration with several partner companies, which sets the optimum inward feed pressure depending on the engine running speed. Because a controlled level of high pressure is maintained in the tank, there is no longer any need for a fuel pump to transport the hydrogen gas to the engine. Electronic feedback control systems ensure that the temperature in the combustion chamber does not exceed defined limits. Through such measures, the BMW hydrogen engines already comply with all statutory requirements, including the EU4 directive and the severe Californian emissions standard, SULEV.

 
 
The potential of the
hydrogen internal combustion engine


BMW engineers have been demonstrating the potential
of the hydrogen internal combustion engine on the test
rig. While the present series-production hydrogen
engine is capable of operating with external gas mixing
and a fuel-to-air ratio (lambda) of 1, investigations and
experiments on the engine test rig are taking this performance a good step further. Tests on monovalent research engines have successfully demonstrated the charging, external gas mixing and direct injection of hydrogen into the cylinder. On the
basis of this research, the BMW Group has submitted a p a te n t a p p l i c a t i o n for a hydrogen direct f u e l - i n j e c t i o n m e t h o d which combines the best p e r fo r m a n c e characte r i st i c s of p e t ro l and diesel engine combustion processes. Its performance is superior to that of presentday petrol engines. The next stage is to further optimise various parameters specific to the hydrogen combustion p ro c e s s , by m o d i f y i n g the engine, optimising the auxili a r y p o w e r s u p p l y a n d incorporating all of t h e s e elements in an integrated energy management system. T h ro u g h these measures, the BMW G ro u p aims to
Supercooled hydrogen in the tank

In its liquid, supercooled form, hydrogen takes up 4.5
times less space than compressed hydrogen gas at 250 bar and 0°C. Liquid storage of hydrogen allows thevehicle to travel for an acceptable distance on one tank, despite the fact that, litre for litre, diesel or petrolcontains almost four times as much energy. The BMW hydrogen cars are equipped with a heavily insulated tank to store liquid hydrogen at a temperature
of minus 253 degrees Celsius. But even the best insulation cannot prevent hydrogen from gradually evaporating and escapingin g from the tank if t h e vehicle is not u s e d for a n ex te n d e d period of t i m e . Efforts are therefore being m a d e to prolong the period for w h i c h the vehicle can re m a i n immobile before this phenomenon, known as " b o i l - o f f " , starts to take effect. One possibility, which is b e i n g investigated by o n e of t h e project p a r t n e r s , is to u s e a counterflow system to liquefy i n c o m i n g air w h e n hyd ro g e n is extracted from the tank. This liquid air i s then used to cool the insulating layer when the engine is r u n n i n g , thus reducing the temperature difference b e t w e e n the stored fuel and the inner wa l l of t h e tank a n d slowing the rise in temperature of t h e hydrogen inside the tank. This effect can be maintained when the vehicle is stationary until such time as all the air stored in the insulation layer has evaporated. Using this process, it is expected that a "resting time" of around 12 days could be achieved. The filling process, too, has been designed for maximum simplicity and ease of use. It takes just three minutes to fill the tank, either using a fully automated filling robot or a simple manual procedure. The resistance of t h e d o u b l e -wa l l e d tank to the extremes of h e a t , cold and p re s s u re generated by va r i o u s filling operations and accident scenarios has been demonstrated in numerous tests and simulations. This data has led safety experts to t h e conclusion that t h e use of hyd ro g e n as an automotive fuel presents no more danger than the more familiar petroleum products.  
 
Autonomous power supply N a t u ra l l y, the BMW G ro u p has by n o means turned its back on the innovative technology of fuel cells. But the focus of research has been placed on the area in which it offers the highest potential benefits, namely as an onboard electrical power supply. The BMW Group is using a fuel cell as an extremely efficient power supply for the ve h i c l e ' s electrical network. This so-called auxiliary power unit (APU) delivers an output of five kilowatts at a vo l ta g e of 4 2 volts. The researchers are looking into P E M (proton exchange membrane) fuel cells with a p o l y m e r e l e c t ro l y te and solid oxide fuel cells (SOFC). T h e SOFC operates at a higher te m p e ra t u re range, d o e s not re q u i re the use of p re c i o u s metals, and is c a p a b l e of o p e ra t i n g with lower-purity hyd ro g e n . This m a ke s the SOFC suitable for u s e in petrol-engine ve h i c l e s , because it i s possible to generate hydrogen from petrol onboard the vehicle using a reformer.
The infrastructure question H yd ro g e n can only c o m e into widespread use as an a u to m o t i ve fuel if c u sto m e r s are offered an attractive range of vehicles and if they have access to a sufficiently close-knit network of filling stations, served by a reliable supply infrastructure under the appropriate political and e c o n o m i c conditions. As described above, the first s e r i e s - p ro d u c e d hydrogen cars are already a t a n advanced stage of development, but work still needs to b e done to create a widely ava i l a b l e network of f i l l
i n g stations. As of 2003, Germany possesses about 16,000 conventional filling stations for petrol and diesel fuel, but a t p re s e n t o n l y o n e public filling station for hyd ro g e n . It o f fe r s a manual filling service for b u s e s and a fully automatic filling-robot service for cars. C o nve r s i o n of t h e existing energy-supply i n f ra st r u c t u re to meet t h e needs of t h e hydrogen economy c a n only progress satisfactorily if the influential parties, including p o w e r g e n e ra t i n g companies, the petroleum industry, t h e automotive industry, plus the political parties and the relevant g ove r n m e n t m i n i ste r s , work hand in hand towards the same goal. Consensus has been achieved regarding the choice of future energy sources. E ve n something as apparently s i m p l e as building up an adequate network of f i l l i n g stations calls for p u b l i c approval and takes a correspondingly l o n g time. To accelerate progress in this area, the BMW G ro u p has joined forces with a number o f o t h e r l e a d i n g ind u st r i a l companies in the German Transport E n e rg y S t ra te g y ( T E S ) . Their c o m m o n objective is to propose p l a n s for a nationwide supply i n f ra st r u c t u re for n e w, environmentally f r i e n d l y fo r m s of e n e rg y. The G e r m a n government s u p p o r t s and mediates the work of this group. A n o t h e r c o l l a b o ra t i ve venture is pursuing the objective o f te st i n g the everyday p ra c t i c a l aspects of hyd ro g e n fuel: the Clean Energy Partnership (CEP), a joint project involving Aral, BMW Group, DaimlerChrysler, Ford, GHW, Linde and Opel, was launched in June 2002. One of the activities of this project, initially planned to last five years, is to set up a hydrogen filling station in Berlin: the site is d u e to be inaugurated in autumn 2003. It w i l l include a fa c i l i t y fo r p ro d u c i n g hydrogen from water o n - s i te , as well as providing storage facilities for supercooled, liquid hyd ro g e n produced elsewhere. The new filling station w i l l offer a manual filling service using a pressure- and temperature-sealed pipe connection that latches to the hyd ro g e n fuel-tank filling valve, rather t h a n the convent i o n a l type of n o z z l e . One of t h e basic aims of t h i s project is to test the viability of hydrogen fuel in an everyd ay m o b i l i t y c o n tex t . It w i l l cover s u c h aspects as the l o c a l generation and supply o f hyd ro g e n , methods of f i l l i n g vehicle fuel tanks and the operation of f i l l i n g stations and hydrogen cars. Taking hydrogen round the world Industry and society have the capacity to actively shape t h e i r o w n future. That i s why i t i s important n o t to leave the choice of future fuel supply options to pure chance.
 
I n ste a d of a s k i n g "Which energy s o u rc e s are likely to d o m i n a te our f u t u re ? " , we should be saying "Which fo r m s of e n e rg y d o we want to use with a view to the s u sta i n a b l e management o f o u r n a t u ra l resources?" To e n a b l e this vital process of re f l e c t i o n to be directed a l o n g the right l i n e s , given that i t w i l l probably ta ke several decades to find answers to all of our questions, it i s most i m p o r ta n t t h a t w e start to d ay w i t h the task of i n fo r m i n g the general public about t h e s e issues in g e n e ra l , and particularly a b o u t t
h e advantages of t h e hydrogen
economy. To promote sustainable mobility, the BMW Group organi s e d the CleanEnergy Wo r l d Tour to present i t s "zerog a l l o n " vehicles to a worldwide public audience. Each sta g e of t h e tour re p re s e n te d a specific aspect o f t h e hyd ro g e n cycle. One of t h e more important sto p ove r s wa s Brussels. The BMW G ro u p took advantage of i t s visit to the administrative capital of the European Union, w h e re high-level decisions are made concerning statutory requirements and political frameworks, to make the p o i n t t h a t i n d u st r y n e e d s a stable set o f p l a n n i n g p a ra m e te r s in order to invest i n activities related to the i n t ro d u c t i o n of t h e hydrogen economy. Other h a l t s on t h e route of t h e CleanEnergy Wo r l d Tour w e re devoted to the generation of hyd ro g e n from renewable energy s o u rc e s , especially i n countries blessed with an a b u n d a n t s u p p l y o f s o l a r e n e rg y, and to the distribution a n d end use of hyd ro g e n . In this context, the BMW G ro u p emphasised the significance of hyd ro g e n as a means of reducing environmental pollution in the heavily populated regions of the industrial countries. The need for public acceptance By initiating and organising the HYFORUM international conference in 2000, the BMW Group created a platform that allows private companies, financial analysts, investm e n t b a n ke r s , insurance companies and political decision-makers to participate in the creation of the new hyd ro g e n age. BMW i s an active sponsor o f t h i s forum. S o m e 500 international representatives of i n d u st r y,
 
business, research and government administration took part in discussions that not only covered the technologic a l aspects of hyd ro g e n but a l s o took in its economic, political and ecological implications and the question of safety. The BMW Group intends to play a similar participatory role in the next HYFORUM conference in 2004. A n o t h e r m a j o r ro u te to promoting public awareness of future energy strategies lies in the presentation of intera c t i ve exhibitions, such as the CleanEnergy ex h i b i t i o n organised in
collaboration with the Deutsches Museum i n Munich, and educational work in schools. The future g e n e ra t i o n of d e c i s i o n - m a ke r s and consumers needs c o m p re h e n s i ve information on hydrogen and its possib l e uses, to fill in any g a p s in the standard education t h ey re c e i ve . To provide school students with a basic k n o w l e d g e of t h e technical background to hydrogen te c h n o l o g y, the BMW G ro u p has compiled a set o f c l a s s ro o m material in German and English, which has b e e n officially re c o m m e n d e d for u s e by te a c h e r s of students in the 12-19 age group at secondary schools in
 
Bava r i a . This course material includes handouts coveri n g such subjects as energy, hydrogen chemistry a n d hyd ro g e n technology, and includes a teaching package a n d an interactive CD-ROM. The BMW G ro u p also o f fe r s a set o f c l a s s ro o m material for p r i m a r y- s c h o o l children, which deals in a less academic fashion with the s u b j e c t o f e n e rg y s o u rc e s and their u s e . And finally, for C h i n a ? the market o f t h e future ? the BMW G ro u p is p re p a r i n g information material on hydrogen in Chinese (Mandarin). All of these materials can be supplied by the BMW Group on request.
 
For more information, please visit:
http://www.bmwgroup.com/cleanenergy
http://www.bmwgroup.com/scienceclub