E-Mobility: Lightweight Design Can Stimulate Electric Car Development
Twice a year at the end of the first and third quarters, Roland Berger Strategy Consultants and Forschungsgesellschaft Kraftfahrwesen mbH Aachen creates its E-mobility Index, a statistical snapshot of how the world’s 7 major car manufacturing nations compare when it comes to the market for electric and plug-in hybrid automobiles. The index looks at three principal areas: industry, technology and market.
In terms of technology, Germany falls from first to fourth position due to the ending of government subsidies and further shifts in the fleet mix. The broad rollout of xEVs in the high-volume mid-range segment announced by German manufacturers and the related increase in the share of BEVs and PHEVs with lower equipment levels is just as significant as the termination of a large proportion of the state funding programs. At the same time, technological maturity continues to grow. Korea loses out for the same reason, now lying in third place behind Japan and France. The continuation of funding programs and a further shift in the French fleet mix in favor of technically high-value vehicles favor this development. Japan has increased state subsidies while maintaining the same value for money for its domestic vehicles, pushing it into pole position. China shows a slight improvement in technology due to continuing high levels of state subsidies. The introduction of domestically produced full xEVs in China leads to a long-term improvement in this parameter.
Many funding programs for e-mobility in the US, Germany, Italy and Korea terminated at the end of 2014. Japan was the exception here, introducing a number of new funding programs, albeit on a smaller scale than in the past. In China and France, the total level of subsidies available remained constant.
In industry, the US continues to close the gap to Japan, as does China. As the only nations with a high domestic share of value added in both vehicle and cell production, these three countries are well ahead of other automotive nations. The high concentration of demand on the US and Japanese markets continues to have a negative impact on European volume OEMs, as newly introduced vehicles in Europe play a relatively small role in the US model mix.
In terms of cell production, the global distribution of national value added remains largely the same as in the previously examined period. Korea is up slightly, with domestic manufacturers increasing supplier volumes for European OEMs in particular. The trend already noticeable in the last E-mobility Index (Q3/2014) toward strong growth in China's share of value added continues, supported by further increases in domestic demand for cells primarily manufactured locally. As long as Japanese and Korean cell manufacturers do not plan to localize cell production in Europe in the medium term, it remains unlikely that Europe will gain a significant share of global value added for cells. The stronger decline in the price of Lithium-Ion cells has led to a stable overall market volume compared to the previous period, despite the growing demand.
In terms of market, sales of EVs and PHEVs display strong growth in all markets. Chinese sales of xEVs more than doubled compared to last year, while both Germany and France experienced double-digit growth – 27% in the case of Germany and 13% in France. The only exception here is Korea, where sales were down around 22%. France is in pole position again in terms of the share of electric vehicles in total vehicle sales, increasing its lead over its closest rivals US and Japan, both of which saw growth of under 10%. Germany is catching up with the leading nations, but is still a considerable distance behind. Italy remains at the same level as in the last period, with no significant growth impetus visible.
In the framework of developing, testing and launching new xEV models, most OEMs intentionally left sufficient construction space in their modular vehicle platforms to create the necessary technical and organizational conditions for e-mobility to move out of niche segments and become more mainstream. While OEMs desisted to introduce BEVs and PHEVs in the early phase of development for their biggest-earning and most important vehicle lines – mainly due to fear of damage to their image and concerns about technical costs – partially or fully electric drives are now gaining ground in their volume models. In many cases, OEMs have recently presented plans to offer at least one partially or fully electric variant in all their vehicle lines in the coming years. The challenge of e-mobility for OEMs therefore is shifting from the industrialization of partially and fully electric drive systems to their marketing and full integration into the overall portfolio – in other words, model policy.
With the increasing integration of PHEVs and BEVs into manufacturers' model portfolios, attention is now focused on the structural design of vehicles. The first BEVs introduced were based on the principle of converting combustion-engine vehicles – an approach known as "conversion design". The increasing number of electrified models and the small production volumes initially planned call for a more mature vehicle design, however. To reduce volume risks and minimize development activities, OEMs currently base their electric vehicle designs strongly on their conventional series, or integrate electric drive options when defining the vehicle platform and structural concepts – a "modular design" approach. They leave enough space for construction and alterations in the early development phases to be able to produce electrified vehicle variants, and they set up offline assembly areas to allow their production on the same assembly lines as the combustion-engine models. This also makes the material flows in procurement and production simpler. Such a modular approach has obvious advantages in terms of volume planning and allocating development costs. But it prevents OEMs from exploiting the full design, package and lightweight construction potential that electric vehicles would have in a BEV-specific design approach – or "purpose design".
As a result, the PHEVs and BEVs currently available based on modular design weigh 10-30% more than comparable combustion-engine models and do not compensate for the weight of the battery. Current xEV models are mainly built using conventional self-supporting unibody structures and make limited use of alternative materials such as aluminum and fiber-reinforced plastics. Moreover, the protection of the battery cells needed for good levels of crash safety is often achieved by putting the batteries in massive casings (see E-mobility Index Q1 2013). The BMW i Series is a notable exception in terms of its structural concept: It makes great use of fiber-reinforced plastics in the Life module (i.e. the passenger cell) and of aluminum in the Drive module (i.e. the independent drive platform), which more than compensates for the weight of the battery. Small-series and up-and-coming producers such as Bolloré and Tesla also make use of alternative structure and materials concepts, especially in their use of aluminum.
The modular design approach – and with it a strong reliance on the structural and material concepts of conventional vehicles – continuing to expand over the coming years. At the same time, increasing discussion about the range and efficiency of electric vehicles and the lack of major breakthroughs in battery technology in lightweight construction are putting more and more pressure on OEMs. However, the introduction of more radical lightweight construction approaches and hence the achievement of higher lightweight indexes will continue to result mainly from the inclusion of lightweight construction components in modular approaches and the gradually integration of multi-material concepts, rather than from the introduction of purpose-designed vehicles with radical design concepts.