How do we make wave competitive with wind?

At low technology readiness level, before tank tests and numerical models have been done, it is very difficult to estimate the levelised cost of energy. Indeed, this is not so much an estimate as complete guess work– we don’t know the optimum system size, nor relative subsystem size.

I’d like to propose a different early stage metric: the revenue to cost ratio. Both revenues and costs can be expressed as engineering parameters (such as loads, power, stroke or time). The ratios of these parameters can be informative and insightful. The most well-known example of the gain to pain ratio had been around for decades: the ratio of mean to extreme. Revenue is a function of the mean; costs are a function of the extremes. This ratio can give insights into a whole bunch of design choices. For example, it indicates that low variability can be a more important consideration than average power when choosing a site for installation. As the gain to pain ratio can be applied to many types of renewable energy, we can also use this perspective to ask: what are the design requirements for wave energy to be competitive with wind?

Consultation Deadline 29 February

The Ocean Energy Forum has a public consultation that is closing on 29 February 2016.

Doctor doctor, is negative spring like a flux capacitor?

Many thanks to the reader who asked me the following question about the post on negative spring:

' I am a bit puzzled as to how two springs in series can exert a force at right angles to their longitudinal axis. Didn't the pair of springs (providing the negative spring) in the CorPower device sit at an angle in a Back to the Future "flux capacitor" type arrangement?'

Negative spring is a mysterious thing

Negative spring may well be the answer to making wave energy economic, so it would be good if it were less obscure and mysterious. This post describes what negative spring is, and how it can be used to control wave energy converters.

Tidal is the new wave

The 2015 SuperGen annual assembly was forward-looking and upbeat. The recent closure of Abengoa and Aquamarine did not send out the same shockwaves as the demise of Pelamis and MCT a year earlier. Prof Robin Wallace warned that the biggest threat to marine energy was pessimism. So it was good to detect what can be best described as a determination to weather the present storm. There was a particularly high level of enthusiasm and ‘sexy science’ coming from tidal energy research, the highlights of which are worthy of sharing.

I listen to the ocean

Tracey Emin is one of those artists for whom the term 'art wank'* seems entirely appropriate. For many years I did not get, or want to get, her work. She seemed to me a self-obsessed celebrity artist who was only interested in shock-value.

EWTEC 2015 - a leisurely sail through the papers

There were so many talks in this year’s EWTEC that I found interesting, it was impossible to pick just a few. Here are highlights that I think will be of general interest.

WES winners

Wave energy Scotland recently announced the eight projects that won funding for the novel device call. So, just who are the people behind the winning teams, and how does their tech wiggle? Have any of the device developers that suffered from the recent crisis of investor confidence secured funding?

Brought to you by the wonders of Google, here is a quick summary (or speculation) of each of the winning projects. The first point of note is that over half the grants went to devices that could be described as attenuators.