Ultracapacitors, also known as supercapacitors, have seen some setbacks lately. Market leader Maxwell Technologies has seen reduced ultracapacitor sales growth in early 2012 due to softness in Europe and Nanotecture, in Europe, developing the variant called a supercabattery went out of business. Certainly Europe, with a mere 6% of supercapacitor manufacturers, has been rather backward in adopting them beyond buses, trains and cars, something aggravated the recession. Even outside Europe, one of the top suppliers Nesscap has been struggling with heavy losses.
Why predict fast growth?
Despite all this, analyst IDTechEx persists in its forecast of 30% compound growth of this market over the coming decade and some analysts and manufacturers say more. Indeed, Maxwell Technologies is increasing production capacity by 30% and Nesscap is tripling production capacity. The number of companies making supercapacitors and supercabatteries has doubled in the last few years and most are doing business. A look at startups reveals that the number of them will triple in the next ten years or so. How can all that be justified?
The answer is closely analysed in the new IDTechEx report, Supercapacitor/Ultracapacitor Strategies and Emerging Applications 2013-2025 which involved a host of interviews with suppliers, users and experts, establishing the improvements to various device parameters expected over the next ten years and lead indicators such as where they are newly being designed into potentially volume applications and what those volumes will become. Another guide is the size of the largest orders being landed over the years. For example, there has never been anything like the Meidensha/Sojitz $318 million (¥25bn) contract to supply two 2 MW CapapostTM regenerated energy storage units for Hong Kong's South Island Line metro project. The installation of the supercapacitor technology is expected to reduce traction power consumption by 10% on the 7.1 km five-station line, which is under construction to connect Admiralty with South Horizons from 2015. IDTechEx has found many other major new commitments that will boost market size. We have also confirmed that everything points to the largest value market for supercapacitors being in electrical engineering now and in the future.
Other large orders recently
Batscap will supply large supercapacitors to go across the batteries in tens of thousands of Bluecars its parent company is making for open rental in Paris and more for open sale. In the past, these cars have not used supercapacitors but they now will, a commitment of over $10 million for the next few years, we estimate. The similar application in Mazda pure electric cars also in 2012 may also involve substantial business soon. Even more impressive is the speed with which we have gone from hybrid buses having no large power supercapacitors to having them across the battery and now MAN, the Chinese and others abandoning the traction battery completely in their hybrid buses and using supercapacitors alone, in huge banks across the roof. The only battery remaining in future production of mainstream hybrid buses is the small lead-acid starter battery. By contrast, Bombardier and others have now standardised on pure electric buses for urban use and these sometimes use large supercapacitors when made by other suppliers. It is easy to predict that, as technical advances in the laboratory reach supercapacitor production lines, there may be increased supercapacitor penetration in pure electric buses as well.
Major commitments for the next two years
Following trials, China is committed to adding supercapacitor-based hybrid capability to hundreds of electrically tethered trams and trains in 2014 so they can move in emergency and do not need ugly catenaries in attractive locations and at crossroads. The first fuel cell cars and other vehicles with the load management done entirely with supercapacitors not batteries will appear in production in 2015. You can drive one now. It is likely that tiny supercapacitors will eventually appear in up to one billion mobile phones yearly for several purposes, including longer distance flash. The list goes on and on but none of this is dreaming. It is the projection of most in the value chain and such positive predictions are mainly based on actual end use demonstrations and recent design-ins, not just dreaming.
Underwritten by rapid technical improvement
The spectacular market growth will be underpinned by the rapid improvement in energy and power density and cost of supercapacitors and supercabatteries, with many developers revealing ten year roadmaps. Only a proportion of this has to happen for the market growth to become a reality. The many start-ups are usually involved in advances involving such things as graphene active electrodes, ionic liquid electrolyte or simple aqueous electrolytes. Then there are lithium-ion capacitors (LiC), a form of Asymmetric Electrochemical Double Layer Capacitor (AEDLC) or supercabattery but not everyone thinks that the only way to highest energy density is the asymmetric route.
What advances must happen
IDTechEx has established the top ten advances needed in order of priority based on the data. More imaginative marketing is one of them. Too many suppliers wait for Maxwell Technologies to create a special device for a newly- identified market then copy them. That is changing. Watch companies such as Nippon-Chemicon.
Adoption in fast growth markets
Meanwhile, many existing markets for supercapacitors are increasing inexorably. The cold start of trucks is catching on, using a supercapacitor as a drop-in replacement for one of its three or four lead acid batteries. It is now the norm to use supercapacitors for pitch control in wind turbines and the output of these turbines is rising. If the experiments using huge banks of supercapacitors for load levelling with wind turbines, photovoltaics and other green energy are successful, there is a big multiplier to that market - increased adoption of small supercapacitors, first adoption of large supercapacitors and growth in sales of the end product. There are many examples of similar multipliers kicking in for other applications.
The initial work with supercapacitors in grid power and frequency management could open up another huge market as could the existing use in power tools and consumer electronics where a tipping point of price and performance should be reached within the decade. Think of the "fastest charging battery that you never replace", only it will not be a battery.
On the other hand, IDTechEx is not happy with the projections of 40% and more compound growth of the supercapacitor/supercabattery market that are published by some others. We feel that, in the real world, projects get delayed. We typically add three years to what people tell us. Recessions and tsunamis happen. It is also true that replacing batteries will scarcely dent the growth of the lithium-ion rechargeable battery market. Even in 2025, the lithium-ion battery market may still be four times the supercapacitor/supercabattery market compared with about 40 times today. That still leaves room for a one billion dollar supercapacitor business in a multi-billion dollar supercapacitor market even in ten years. IDTechEx details what needs to happen to create such a company.
The applications driving all this are the focus of the IDTechEx event Supercapacitors USA in Washington DC, November 7-8. There are presentations on more than the well-known automotive and utility applications and their multipliers. The presentations also cover applications in aircraft, factories, buildings, healthcare and mobile phones. Think of supercapacitors as an enabling technology like the wheel: we cannot predict gloom and doom for such things.
Figure 1. The main functions that supercapacitors will perform over the coming decade