I attended the above-named conference in Munich last week (24th and 25th March) and I have outlined below a few top-level things I took away.

On the conference itself, this was a relatively small event with around 60 delegates and very much focused on the practical end of energy harvesting. This meant a predominantly industrial audience and a focus on the here and now of application. The small size also ensured a good networking opportunity. I found it very useful for gauging the state of development since a study we published in mid 2008.

The development of energy harvesting technology in Europe still appears to be being driven by small companies - the usual suspects e.g. EnOcean, Perpetuum, Micropelt etc. There does however appear to have been a growing interest and involvement by some larger players e.g. Texas Instruments.

It is still only building automation and condition monitoring that have established themselves as viable applications so far. EnOcean have built an impressive market in the former and Perpetuum are establishing sales in the latter. The rest of the industry is still at the stage of R&D or exploring applications and trying to find that combination of volume and value to enable a viable business model.

The aerospace industry has a very real need for energy harvesting but there are some significant technical challenges of operating in such a harsh environment including extremes of temperature, weight, size and concerns about reliability to be overcome as well as finding the right type of energy harvesting for the specific applications. Nevertheless, this sector is relatively price insensitive so does offer hope for a reasonably significant and high value market if the technical issues can be overcome. Work so far has established that there is no one best energy harvesting technology and certainly no multi purpose solution possible.

The impending legislation on tire pressure monitoring in the EU could offer a huge market but indications so far are that the motor industry and legislators do not put a particularly high value on safety, seeking energy harvesting solutions costing cents rather than Euros. This is going to severely restrict the possible solutions.

Efforts to establish standards have certainly moved along in the last year and a half since I paid it much attention. At the level of being able to compare devices and ensure standard interconnection for power sources to wireless sensing devices there appears to have been progress through ISA100. This is about to become more formalised but is certainly heading in the right direction and addresses a significant concern we have heard time and again from end users of the technology. At the level of communications protocols there are two current approaches. The EnOcean Alliance has set a very low power wireless standard designed specifically for the needs of the building automation market. The ZigBee standard has now, with energy harvesting in mind, also been working on a lower power standard. This appears to be much more of a time consuming compromise effort and as such is not as low power as the EnOcean alliance standard but does promise a wider compatibility with other wireless devices in the overall ZigBee family of standards. There were arguments for both approaches and some concern that the EnOcean Alliance standard might not be as open as the ZigBee one. Nevertheless it is hard to argue with well the rapid progess and over 100,000 buildings having EnOcean technology installed and a full supply chain already in existence. I expect it will continue to be a case of horses for courses with each finding its champions for some time to come.

There have certainly been a number of advances in power management over the last 18 months with a number of speakers touching on this topic. It appears to be one of the main factors in driving up the amounts of useful energy made available from energy harvesting devices.

A concern expressed at the conference was that with improvements in battery lifetime outpacing improvements in energy harvesting and its cost reduction the situation where the battery lasts longer than the product it is powering is not far off. In this scenario the case for energy harvesting needs to be more clearly made. This means that consumer goods may not necessarily be the ideal market. We need to be finding those application where the lifetime of the battery is still not enough e.g aerospace and building management where lifetimes of 25 years + are wanted or those applications where environmental conditions are such that batteries can just not be relied upon.

There was an impressive demonstration of the Infinite Power Solutions 'Thinergy' a thin film flexible micro-energy cell rechargeable battery. The size of a large postage stamp and apparently able to handle 20 years plus of use with more than 45,000 charge and full discharge cycles. As the energy storage part of an energy harvesting solution this looks to have enormous potential and some very interesting applications have been demonstrated over the last year or so. It will be interesting to see whether in time this becomes the complementary component that allows energy harvesting to overcome its limitations of intermittency. Definitely one to watch.

Anyway, there was plenty more at this conference so if you need pointing in the direction of particular expertise please get in touch.

If you are interested in energy harvesting generally and particularly in the development of new research challenges in this field I encourage you to join the Energy Harvesting Network at www.eh-network.org.

Next we look forward to 'Energy Harvesting & Storage Europe and Wireless Sensor Networks & RTLS 2010' on 26th & 27th May, again in Munich. We have negotiated a 60 percent discount on this for members of the Sensors & Instrumentation KTN and the Energy Harvesting Network so if you are interested please do get in touch.