Carnegie Wave Energy’s offshore energy-generating infrastructure is purposefully inconspicuous. Its patented CETO buoys, which resemble large circular tanks, are tethered to an anchor in the seafloor and remain fully submerged, out of sight.
It’s a design feature that prioritises long-term survival in the ocean over efficiency in converting energy, says Michael Ottaviano, Carnegie’s managing director.
“You could have the most efficient technology, but if it dies after the first big storm then it’s worth nothing,” he says. “We never breach the surface. We can simply ride under a large wave as it comes through, and we follow the peak and the trough up and down.”
This rise and fall movement is the basis of Carnegie’s world-leading wave energy technology. The movement, in harmony with ocean swells, drives a pump attached to the tether. In its next-generation CETO 6 buoys, a system contained inside the tank will convert that pressurised fluid into clean electricity, which is carried onshore by a cable.
Formed in 2006, the Australian-listed company has just launched its $90m (£60m) commercial wave energy project in Cornwall in the United Kingdom, after receiving $15.5m (£9.5m) from the European Regional Development Fund for the first phase.
Cornwall’s wave hub is billed as “the world’s largest and most technologically advanced site for the testing and development of offshore renewable energy technology”, and the funding is a significant boost for Carnegie’s global expansion plans. The project is to begin immediately, with commissioning set for 2018, followed by 12 months of operations.
It all began off the West Australian coast. After developing the technology, Carnegie deployed the world’s first grid-connected wave energy array on Garden Island in 2015, with $13m in support from the Australian Renewable Energy Agency (Arena).
Three CETO 5 buoys, each seven metres in diameter, generated clean power and desalinated drinking water for the country’s largest naval base. The array, which has since been decommissioned, operated over 12 months for a cumulative 14,000 hours. It set a world record for a grid-connected wave energy system.
Carnegie’s next objective is to build the world’s first wave-solar-battery microgrid on Garden Island. Stage one will feature a 2 MW solar PV array and a 2 MW/0.5 MWh battery storage system. The $7.5m microgrid is expected to be operational by mid 2017, and recently received $2.5m in support from Arena.
Carnegie hopes to plug into the system between one and three of its new CETO 6 buoys by the end of 2017. Larger than their predecessors, each CETO 6 unit has diameter of 20 metres, a generating capacity of 1MW, and has been designed to last for 12 months. The cost of the whole demonstration will be between A$35 and $40m, says Ottaviano.
The microgrid is designed to operate “on-grid” and in “island mode”. Ottaviano says it will be “critical” for showcasing Carnegie’s technology and capability to potential buyers, including foreign governments and utility operators, and fringe-of-grid communities in Australia.
The company sees islands as a major prospective market, as they tend to have good wave resources but expensive power, due to heavy reliance on imported fossil fuels. They have high CO2 emissions and can be exposed to energy security and price volatility risks.
Ottaviano says wave energy can complement solar and wind on islands as it’s predictable, fairly consistent around the clock and doesn’t require precious land.
But after detailed investigation of some island markets, Carnegie decided it wasn’t enough to simply sell clients a wave energy system without a game plan for integrating it and scaling up renewable energy penetration more broadly. So the company made a strategic decision to expand into microgrids – a market estimated to be worth up to $40bn by 2020.
Earlier this year, Carnegie paid $17.5m for Energy Made Clean, an Australian microgrid company with a track record of delivering clean energy projects.
Along with the Cornwall project, Carnegie has been working with the government in Mauritius – an island nation of about 1.3 million people in the Indian Ocean – using funding from Australia’s Department of Foreign Affairs and Trade. Ottaviano says this work has involved assessing the country’s wave resources, designing a roadmap for transitioning to greater than 60% clean energy, and designing a microgrid.
In September, Carnegie signalled its intention to expand its wave and microgrid operations into Sri Lanka, signing a memorandum of understanding with Lanka Energy Conservation based in Colombo.
Ottaviano says the objective is to build microgrids initially focused on solar, wind and battery technologies, but in locations with good wave resources, which will allow CETO systems to be integrated once they become more cost competitive in a “three-to-five-year horizon”.
He says Carnegie would design and finance these microgrid systems and sell power over the system’s 20-year lifespan: “It’s a true win-win. They get something that’s cleaner, cheaper, more secure and costs them less than what they’re currently getting [in diesel] and costs them nothing up front.”
Stephen Doig is a managing director at the US-based Rocky Mountain Institute, where he is helping island economies transition to renewable energy. He says renewables offer a number of advantages over diesel for islands, including “lower costs, lower volatility of costs, reduced CO2 emissions, greater energy security and equal or improved reliability”.
Wind and solar are the “frontrunners in many regions” and further cost reductions will keep them competitive into the future, Doig says.
He says wave energy can be “a fairly low energy density resource in many places so can require a fair amount of infrastructure”.
“The question is whether there is a realistic roadmap to get to low costs.”
Ivor Frischknecht, CEO of Arena, says if wave, solar and wind can all be generated in one place, there’s a good chance the network would have a higher level of reliability and a “much lower level of required storage”.
Prospective customers “might actually think about having a network with three or four or even more forms of renewable generation, even if one or two of them are much more expensive than the others”.
“Really, all it needs to be is cheaper than diesel,” he says. “I think [Carnegie] have a pretty good chance of getting to that point.”
