Rising Tides Provide Energy Solutions

Renewable energy solutions from waves and tidal activity are still in their infancy, but are improving and reaching the stage where some are near ready for broad commercialisation. 

While we have no doubt that some in the ocean energy sector will suggest we have over simplified their work in this article, we think it is important to provide information in the simplest possible manner. For many CarbonEdge subscribers, this will be the first time they have given more than cursory consideration to wave or tidal power.

As a start to our simplifications, we decided to divide the available technologies into just two categories, conventional and modern.

Conventional Options Ready for Commercialisation

The more conventional wave technologies appear generally to be anchored to the sea floor, with the main moving part - the turbine, sitting above the water. Proponents suggest that performance will be better than both wind and solar because the resource - ocean activity - is more consistent and predictable.

Oceanlinx, an Australian based company that is in the process of bringing a surface operating wave technology to the market suggest they can predict energy output up to five days in advance. 

Technologies like these surface wave energy harvesters are fast reaching maturity from an investment point of view, having cleared proof of concept some years ago and now completing their advanced trial and engineering phases. To CarbonEdge they appear to be ready for investment by those seeking to take renewable energy to the supply market or who have a specific coastal need for renewable energy, like the energy hungry desalination plants. 

However, companies like Oceanlinx can only operate their technology on ocean surfaces and the greatest ocean energy is at the lower levels of the seas and oceans. If for no other reason, this lower efficiency makes it likely that one of the newer ocean energy technologies will overtake the conventional harvesters, but the question is when.

Oceanlinx is backed by renewable energy venture capital specialists, Cleantech Ventures. In July 2009 it announced additional funding from a European consortium of venture capital funds.

Modern Technologies Set to Deliver

Among the more modern ocean power technologies, the work of Biopower Systems has caught the attention of CarbonEdge.

The BioStream technology is a tidal energy system shaped a little like a fish tail. It is intended to operate in arrays, on the sea floor. The units are around 15 metres in length and can pivot around 360 degrees depending on the tidal direction. Essentially, these computer controlled devices move as the sea moves (biomimicry) and store the energy created from the movements. Given this is a tidal technology, it is clear the BioStream units have to be located in the right places to be effective.

CarbonEdge understands that a 15 metre unit is capable of generating 250 kilowatts of energy, but interestingly, the suggestions from BioStream are that a 30 metre unit could deliver as much as 1000 kilowatta. That requires confirmation because normally, scale is not usually that big an advantage. If the 30 metre unit is that good, investors will not be keen to purchase the 15 metre unit and it begs the question, just how good would the 60 metre unit be?

Although it is still early for this technology, it has obviously achieved proof of concept and is due to go to full field trials in 2010, off Flinders Island in Bass Strait.

The BioWave technology that Biopower Systems is developing is also a sea floor unit, but in this case, it is a 25 metre high unit of 'balloons' with a solid exterior that can move as ocean waves move. Again, this use of biomimicry is intended to harness all of the ocean's movements in what is again a computer controlled unit. This is a newer technology from Biopower Systems, so more time has to pass before a more definitive judgement can be made about it.

Biopower Systems is already funded by a venture capital fund and is due to conduct its BioStream trials with some support from the Tasmanian Government and from Aurora energy. 

CarbonEdge Analysis

Whether each of the latest technologies will advance beyond proof of concept and trials into commercialisation will depend on installed cost, energy output, costs over time, and regulatory and community issues in some markets is a question that only time will answer.

CarbonEdge estimates that the newest technologies are four to five years away from reaching equality with wind and solar. If, as an example, Biopower Systems is successful with its tidal and wave technologies, we think it is likely that they will prove more successful than the earlier technologies that in many ways are harnessing water in pretty much the same way they would harness wind.

For investors, there are decisions to be made about which stage to invest in these technologies and what returns to expect for the risks that exist. But CarbonEdge thinks that for the sophisticated energy user, especially those with coastal operations, the commercialised wave and tidal power technologies will provide an option for meeting their renewable energy needs in their own right.

We still want to see the energy production to whole of lifecycle costs (including the costs of the emissions from manufacture and maintenance). That is a must for any investor or even energy purchaser. In that respect, these new ocean energy technologies are a distance from achieving equality with other renewable energy technologies, because this important information remains relatively hard to access.

The comparative constraint of the Biopower Systems technologies to the more conventional technologies is maintenance. With equipment 15 to 25 metres below surface, the sea floor technologies will need to be very reliable. The surface technologies might deliver less energy, but they will be far easier to maintain.

Keep on eye on the ocean energy technologies and if the location is right, don't exclude it from your renewable energy mix.

The BioPower Systems website can be found at www.biopowersystems.com and the OceanLinx website is at www.oceanlinx.com.

CarbonEdge conducted interviews and analysis for this article at the All Energy Conference conducted in Melbourne on 7th and 8th October, 2009.

19th October 2009

 

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