Floating Solar Plus Wave Energy Smackdown For Fossil Fuels

Everybody is talking about a new EU clean power project that pairs floating solar with offshore wind turbines, but they’re missing half the story. Wave energy is also part of the project. The wave part is not getting much attention, probably because wave-to-electricity conversion has fallen behind wind and solar in the renewable energy race. Nevertheless, if all goes according to plan, the waters of the EU will be peppered with wave conversion devices as well as floating solar panels.

More Offshore Solar & Wind Turbines With Wave Energy, Too

The EU project is tackling the problem of how to make room for new offshore energy industries in busy coastal waters. Finding sites for new offshore wind farms can be a tough row to hoe, as offshore wind fans in the US can testify.

The new project is called EU-SCORES for “European SCalable Offshore Renewable Energy Sources.” The idea is to pair wind turbines with other clean power systems, with the aim of reducing the overall footprint of marine energy development.

EU-SCORES comes under the umbrella of the Dutch Marine Energy Centre, which will assess two sites for hybrid marine energy systems. One is a solar-plus-wind site in Belgium, which has been getting a lot of attention, and rightfully so. Floating solar is a relatively new idea that has been catching on fast for application to inland water bodies including reservoirs as well as natural lakes and ponds. The idea of setting solar panels afloat in the open sea poses new technology challenges.

In that regard, EU-SCORES shares some similarities with the CrossWind offshore wind project under way in the Netherlands, which is also on track to receive floating solar panels.

However, EU-SCORES seems to be taking a much more aggressive approach to hybridizing offshore wind farms. As DMEC describes it, the “full-scale demonstrations are intended to prove how the increased power output and capacity installed per km2 will reduce the amount of marine space needed, thereby leaving more space for aquaculture, fisheries, shipping routes and environmentally protected zones.”

“Additional benefits achieved by co-using critical electrical infrastructures and exploring advanced operation and maintenance methodologies supported by innovative autonomous systems should lower the costs per MWh,” DMEC adds.

Wave Energy: It’s All About Co-Location, Location, Location

Where were we? Oh right, wave energy. If you caught that thing about co-using, that’s a critical issue for wave energy stakeholders. Translating the infinite, 24/7 motion of waves into electricity is a tantalizing goal, but one of the factors holding back the wave energy field is the relatively high cost of shunting clean kilowatts from seagoing wave energy generators over to coastal communities.

Back in 2014, the United Nations’ International Renewable Energy Agency took a look at the wave energy field and recorded 100 projects around the world, all of which were still in the pilot and demonstration phases. The early-stage nature of the technology made it difficult to project future costs for commercial-level projects. However, IRENA did come up with the figure of 22% for the proportion of lifetime costs that could be ascribed to power take-off systems.

IRENA also estimated that installation, operation, and maintenance, and mooring would account for another 41% of lifetime costs for wave energy projects. Co-location with offshore wind turbines would presumably shave away some of those costs as well.

About Those Locations…

Another kind of challenge for the wave energy industry is that the recovery potential varies considerably from one place to another. The one-size-fits-all nature of wind turbines and solar panels does not apply as much to the wave energy field, and that has slowed the development of more mature, efficient supply chains.

In 2016, the US Department of Energy’s National Renewable Energy Laboratory looked at the problem and noted that “wave energy technology is still an emerging form of renewable energy for which large-scale grid-connected project costs are currently poorly defined.”

“Ideally, device designers would like to know the resource conditions at economical project sites so they can optimize device designs. On the other hand, project developers need detailed device cost data to identify sites where projects are economical. That is, device design and siting are, to some extent, a coupled problem,” the lab continued.

A New Burst Of Energy For Wave Energy

Regardless of the challenges, wave energy fans have persisted, and it looks like all that hard work is about to pay off. The wave energy harvesting end of the EU-SCORES project is being attached to an offshore wind farm in Portugal, using buoy-type wave harvesting devices developed by the Swedish company CorPower Ocean, as the firm’s Commercial Director Kevin Rebenius is happy to explain.

“We see great value in showcasing the highly consistent and complementary power profile of wave energy, and how this can be combined with wind and solar to deliver a more stable and predictable electricity system based purely on renewables,” Rebenius said.

CorPower Ocean’s contribution to the wave energy field is a pumping system modeled on natural pumps such as those found in the human heart.

According to CorPower, its device can produce 5 times more electricity per ton than other wave energy harvesters, partly by enabling superior performance during calm periods and partly by maintaining performance during storms. Here, let’s have them explain.

“CorPower WECs can harvest the same amount of Annual Energy from a buoy with 1/10 volume compared to conventional point absorber WEC. 1. As comparison, a 300kW CorPower WEC has a diameter of 9m and weighs 60 tonnes. Getting large amounts of electricity from a small device significantly reduces CAPEX. The compact lightweight devices are also less costly to transport, install and service, bringing down OPEX.”

There Had To Be A Green Hydrogen Angle In There Somewhere…

CorPower is aiming to make the case for commercial viability by 2024. Meeting that goal will also provide a boost to other companies involved with EU-SCORES. For those of you keeping score at home, that includes the offshore floating solar company Oceans of Energy along with the familiar names of RWE, EDP, ENEL Green Power, and Simply Blue Group.

EU-SCORES could also add another notch in the belt of green hydrogen fans. CorPower, for one, is already making the pitch.

“The multi-source demonstrations in EU-SCORES will showcase the benefits of more consistent power output harnessing complementary power sources including waves, wind and sun, creating a more resilient and stable power system, higher capacity factors and a lower total cost of the power system. These aspects will also improve the business case for green hydrogen production, by allowing electrolysers to run at higher utilisation,” CorPower enthuses.

For those of you new to the topic, electrolysis refers to electrical systems that pop hydrogen gas out of water. That doesn’t make any sense at all from a climate action perspective if the electricity is sourced from fossil energy, but sub in renewables and the whole picture shifts.

The renewable energy angle is also a rather significant improvement over the current state of affairs, in which the global supply of hydrogen is sourced primarily from natural gas and coal. With the addition of seagoing solar panels and wave energy devices envisioned by EU-SCORES, it looks like end of the fossil grip on the global hydrogen economy is in sight.

Follow me on Twitter @TinaMCasey.

Photo: Array of wave energy harvesting devices, courtesy of CorPower Ocean.

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