Monday, 29 July 2013

USA shows some pioneering spirit

Well done to the USA (Wind and Water Power Technologies Office) for acknowledging that game-changing innovations are essential for speeding up the commercialisation of WEC technology, and that researching these innovations is most cost effective at early stages of technology development. A recent announcement proposed an innovation challenge, to be judged by numerical modelling and tank trials.

Market incentives for sea trials

For a long time, the value of a prototype marine energy technology, and hence the investment available for its development, has been measured on a 1D linear scale: technology readiness level (TRL). Consequently there has been market pressure to attain high TRLs at the lowest overall development cost.

The higher stages of technology readiness are associated with expensive sea trials of big models. The focus on TRLs alone has given a higher priority to sea trials of prototypes over tank tests of smaller models and numerical modelling.

Minimising the work conducted at low TRLs is intended to reduce the short-term development costs. This can be counterproductive though; it can pass up the opportunity to learn lessons using cheaper methods, resulting in greater lifetime development costs. This problem is recognised in a recent paper by Jochem Weber, which offers alternative development trajectories that reduce overall development cost, time and risk.

The one way street trap

The TRLs and associated model scales have been treated as milestones for specific designs. Once a technology has reached a milestone, radical design changes, and investigations using smaller models, risk being viewed as a negation of that milestone; as a step backwards. This view was expressed in a recent webinar hosted by the Wind and Water Power Technologies Office. On page 3 of the webinar minutes, a participant expressed the concern that

the challenge could be regarded as a setback. For example, in order for a developer to compete, they may go backwards in the design cycle back to a scaled prototype if they are at a more advanced technical readiness level.

Not all developers consider returning to the tank after sea trials as a setback. Pelamis for instance consider their technology development process as a series of loops through the design cycle, and conduct tank trials in parallel with sea trials. What matters however, is the view taken by those who are funding and supporting technology development: potential investors, customers and industrial partners. If these groups view TRLs as the only metric of the developer's company value, this will incentivise sea trials over tank tests or numerical optimisation. If these groups judge TRL based on the model size of the most recent work, this can trap developers in a one-way street, reducing the options for further loops around the design cycle.

Improving the performance of concepts already in development requires either comparative testing at high TRLs, which is expensive, or tests at low TRLs, which can be viewed as a backtrack, resulting in perceived loss of company value.

Performance has entered the picture

Until recently, US funding priorities have been on “getting steel in the water”, and on improving the performance of concepts that have already undergone sea trials. As recently as ICOE 2012 Mike Reed noted that the purpose of a joint project between NREL and Sandia Laboratories (Wave array simulation software) was to: “Enable developers to advance TRL 3-4 designs or increase performance of TRL 5-7 designs.

In a recent funding call (May 2013) there was an acknowledgement that readiness had been prioritised over performance:

Over the past several years the Program has advanced the technical maturity of MHK systems across the full spectrum of technology readiness levels (TRLs). The investments in this area seek to address a wide range of technical challenges associated with these emerging technologies, with the goal of developing “commercial ready” systems. Through technology demonstrations, DOE and industry have identified the performance advancements needed to better position the next generation of MHK systems to compete in the marketplace. Consequently, the Program is pursuing two complementary paths of technology advancement through its planned initiatives:
  • Advance technology readiness to reduce the technical risk of MHK technologies developed and to deliver robust products to the market.
  • Advance technology performance to drive the cost of MHK systems towards economic competitiveness.

Note that this funding call targeted existing concepts: “This FOA will focus on improving the cost competitiveness of systems already in development, with the goal of advancing the technology performance of these systems. ” which implies performance improvements were intended for concepts at higher TRLs.

Performance innovations to be carried out at low TRLs

There are signs however that the US is willing to start afresh with new ideas. A recently proposed funding scheme suggests a prize which will be awarded based on tank tests and numerical modelling. The focus is no longer on improving the performance of existing concepts. Rather, the goal of this funding scheme is to generate several new ideas quickly:

The goal of a WEC Prize is to … facilitate rapid advancements and quickly yielding a number of viable solutions to increase the performance of WEC technologies. Reaching the goal would result in game changing innovations for next generation WECs to drastically increase the WEC performance.

This competition is a very refreshing approach. Previously funding has not been available for competitive investigation of performance improvements at low TRLs. The proposed innovation challenge is an opportunity to mitigate the situation. I suspect that soon European developers will find they have tough competition as a result.

In terms of the readiness-performance matrix discussed earlier, the US funders have acknowledged the problems with readiness before performance (orange line in Fig.3 of Weber 2012). It is important to note that Weber's work does not recommend the other extreme, performance before readiness (green line in same graph). Instead, a less extreme implementation of performance before readiness is recommended, see Fig. 6 of Weber 2012. This acknowledges that there are some lessons that can only be learnt with steel in the water.

Image credit:
'Wild Bill Vegas' by Duckshow:

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