Tuesday, 20 December 2016

Garage Harmony

I recently spoke to the team who won the US Wave Energy Prize– Alex and Max, to find out more about the AquaHarmonics buoy. I wanted to figure out what they did that made their concept come out on top. After careful consideration, I think what won them the prize was a combination of a smart design philosophy that had control at its core, along with being the dream-team for any kind of scrapheap-challenge-type competition. Let’s have a quick look at their concept and the control method. I’ll highlight the technical features that I think were really important for them. Then I’ll relate a little story Alex told about how he and Max met, and how they came to be tinkering with wave energy in Alex’s garage.

Monday, 21 November 2016

Wave Energy Prize results

The US wave energy prize results are through. Four teams completed the challenge of at least doubling the ratio of energy capture to design loads for a baseline design. Here are my views on how they achieved this.

Thursday, 17 November 2016

Memory and fate

Bob Dylan's nobel prize for literature and his unenthusiatic acknowledgement of the award have put him back in the news. My favourite Dylan song at the moment has been covered by many; perhaps that's why I'd previously dismissed it as 'commercial'. This summer I heard it sung around a fire, so I revisited the words. It contains gems such as "the ancient empty street's too dead for dreaming" (just as the street doesn't inspire his poetry, our old ways can't inspire the new), and "I'm ready to go anywhere, I'm ready for to fade, Into my own parade" (he will accept whatever the future brings, whether he becomes famous or a nameless vagabond).

There's also a bit about waves:

Friday, 4 November 2016

Wave Energy Club

The first meeting of the newly formed Wave Energy Club will be held at the Golf Tavern in Edinburgh on the 30th November 2016, at 8 pm. The Golf Tavern does not have the good fortune of dimensional transcendence, so places are limited.

Here is where to register: https://goo.gl/forms/8DRZumV2u4xkpjUt2.

Thursday, 6 October 2016

Old Skool Significant Wave Height Calculator

Sometimes you just want a quick and dirty calculation of significant wave height and period. Back in the day, these were calculated using the zero crossings method, and this can still be used if you want to avoid Fourier shenanigans.  Here is a spread-sheet that will calculate zero-crossings period (\(T_z\)) and significant wave height (\(H_{1/3}\)). Now it's never been easier to check what scale of model yatch you should be using on your local duck pond! 8¬)

Monday, 22 August 2016

What floats SME's boat?

Last week I visited the Isle of Wight. I took the big old car ferry. As it left Southampton port, it was dwarfed by the behemoth container ships headed for China and the berthed oil takers pumping their cargos to the nearby oil refinery. With its gas flares and funnels, the refinery loomed like an alien palace – possibly beautiful, but not by standard human aesthetics. Next, the ferry passed a sizable fossil fuel power station, with the pylons heading off towards Southampton. As the ferry approached the Isle of Wight, the ugliness spawned by our efficient economy was replaced by a thing of beauty enabled by our prosperity: hundreds of sailing boats out for Cowes week. It was sunny and breezy and a gorgeous day for sailing. Dozens of identical red-sailed dinghies hugged the coastline. The old man sitting next to me on the ferry deck explained to his grandchildren that these were the sailing school boats.

Arriving in East Cowes port, to the left is a museum, which is on the site of the boatyard where the hovercraft and flying boat were first invented and built; to the right were the offices of SME (Sustainable Marine Energy), where I could spot someone having their lunch. I couldn’t resist trying my luck for an interview. My timing couldn’t have been more fortunate. There were very few people at the office – some were in Orkney installing the SME prototype onto the moorings they’d installed in June, using their own rock anchor method (see photos below). Others were of course sailing in Cowes week. Luckily the managing director Jason Hayman was there. I asked whether he had drawn the short straw in being stuck in the office. He said he’d actually just come back from Orkney and would be sailing himself later in the week.

Thursday, 7 July 2016

Marine Renewable Energy for beginners

I’m very excited to welcome the participants of ‘One planet – one ocean’, a Massive Open Online Course. From watching earlier Q&A sessions, I can see that you come from all around the world, and from all walks of life. For those of you who would like to dig deeper into Topic 10.5, ‘Sustainable Energy from the Ocean’, I have put together this fact sheet (liberally sprinkled with opinion). I used the questions and comments you left next to this lecture to decide what to include. I will be a guest speaker on the Q&A session on Marine Renewables this Thursday. I am hoping that this blog post will spark the curiosity of those who were still deciding whether to listen in, and inspire thoughtful questions from those who already know they will be joining us.

This article covers the following topics: making the case for marine renewables, a list of the main features of the different types of marine renewables, a technology status update, a discussion of the current challenges, and some thoughts on how marine renewables could fit into a future low carbon energy mix.

Wednesday, 6 July 2016

Hangout with MOOC

MOOC stands for 'Massive Open Online Course'. There is a MOOC on the oceans running at the moment, and there are a couple of Google Hangouts this week that are relevant to ocean energy.

Thursday, 23 June 2016

Reflections on Paimpont

I just wanted to say how much I enjoyed the INORE (International Network for Offshore Renewable Energy) symposium last week.

Friday, 20 May 2016

All Energy 2016

All Energy was much diminished in size this year. However, it was not diminished in spirit - I sensed projects were progressing, and that the marine energy industry had adjusted to the slower pace. The traditional big vs small debate seems to have been side-lined by the emerging trend for a dual track development process: there are projects aimed at utility-scale markets, as well as those aimed at niche markets.

Friday, 15 April 2016

Tuesday, 22 March 2016

Six little questions

At a recent speed-networking event, I found myself at a table with the founders of a new wave technology development company. They were armed with a list of 6 substantial questions. As there was no way these topics could be covered in our 15 minute slot, I noted down the questions for further consideration. While writing the email reply, I realised that my answers might be of interest to other technology developers – no so much as advice, but as a starting-point for internal discussions about the questions posed.

Friday, 4 March 2016

Field trail adventures

In this instance, the misspelling of ‘field trials’ was intentional. This ‘alternative spelling’ amuses me, because it served as a regular reminder of my exceptional gift for switching letters. I once misspelled the name of the folder containing field trial data, and couldn’t change it because an external contractor had set up a data transfer to this folder. So I had plenty of opportunity to ponder over what a 'field trail' might possibly be. Surprisingly, I found it a very useful concept. After a discussion with a technology developer recently, I thought it was worth sharing with a wider audience.

Deciding on a development path for a new technology is a bit like hacking a trail through a jungle with a machete. Heading straight for our destination, say a mountain, may not be the best route.

Thursday, 25 February 2016

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?

Tuesday, 23 February 2016

Thursday, 28 January 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?'

Thursday, 21 January 2016

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.

Tuesday, 19 January 2016

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.