Renewable "Energy Islands" at Sea To Power Cities, Produce Fresh Water and More
by Alex Pasternack, Beijing, China on 11.14.08
Courtesy Energy Island
Some artificial islands seem necessary. Some just are and some are excessive. And some may sustain human life in the future. Yesterday LiveScience reminded us of a promising idea that we covered earlier: creating rig-like islands that drill the oceans not for oil but for renewable energy.
At the core of each man-made island -- the brainchild of inventor Dominic Michaelis and his son and architect Alex -- are power plants that rely on ocean thermal energy conversion (OTEC). That is, they use the differences in temperatures at the depths and surface of the ocean to evaporate and condense another fluid substance, like seawater, which in turn pushes a turbine. The resulting power, they say, would be 250 megawatts (MW) -- enough to drive a small city.
But the OTEC process itself -- one that's been around for over a century -- requires pumping up large amounts of cold water from the depths of the ocean -- more than 100,000 gallons (400 cubic meters) of cold water per second to be exact. To do it, the 2,000-foot-wide (600-meter-wide) energy island would draw energy from additional windmills, solar collectors, wave energy converters and sea current turbines. As if that weren't enough, if seawater is used to push the turbine, it would be desalinated in the process, yielding 300,000 gallons of fresh water per megawatt of electricity produced every day.
The How -- and How Much
To bring the energy to shore, the Energy Island would require underwater cables, or it could produce hydrogen that could be shipped to the mainland to be used in fuel cells.
According to the Michaelises, the exported electricity might cost 9 to 13 cents per kilowatt-hour, depending on financing. Today, energy produced by a modern wind turbine (at about 50 percent efficiency) costs about 8 cents per kilowatt-hour, while coal costs about 4. A single one of these energy islands has an estimated price tag of $600 million, say the Energy Island team. Though seeking $25 million from Richard Branson's Virgin Earth Challenge, the group was in Shanghai this week looking for investors.
The Times of London also reports this week that another energy island -- although one utilizing a hydroelectric system and costing €3-3.5 billion -- is being planned by Dutch company Kema for the North Sea. The 1,500MW project would provide supplemental power to the Netherlands wind portfolio starting in 2020.
Vacation Hot Spot?
Already, the father-son designers envision a colony of workers, complete with vegetable farms and homes.
But string a few of these islands together and you have an archipelago of energy platforms that could also serve as larger greenhouses for food, a harbor for ships, and a singular eco-resort for tourists. Just imagine: vacationing on a power plant, one that features not only swimming and water sports but -- thanks to all that deep ocean water -- some pretty lively fish and awesome aquaculture.
There's Always a But
Compelling as a sustainable, OTEC-solar-wind-energy-and-drinking-water-producing-island may be, especially given the resistance renewable projects suffer on land, it's important to ask what sort of impact these islands would have on oceans that are already being altered by human-induced climate change.
And it's still unclear if investing in this technology now -- and the infrastructure needed to connect it to the countries that need it -- trumps the solutions for renewable energy that are still being developed (or blocked) on land.
But there's nothing wrong with experimenting -- and the greater our energy and climate challenge becomes, the more we're going to be looking for ideas like this one.
And a not insignificant benefit: the energy island floats, meaning it can survive rising sea levels.
Via LiveScience, The Times and EcoGeek
See OTEC News for more on the process. Hawaii has been working on its own OTEC project.
Also on TreeHugger
Energy at Sea
Drinking with the Wind: Wind-Powered Seawater Desalination
Sea-Water Air Conditioning Plan for Honolulu, Hawaii Finishes Funding
68 Gigawatts of Offshore Wind Power in North Sea = No More Nuclear or Coal: Greenpeace
Tired of Living on Earth? Build Your Own Island!
Ocean Thermal Energy Conversion
Ocean Thermal Energy Conversion: Renewable Ocean Power & Air Conditioning Research Receives Federal Funding
Sea Solar Power, or Ocean Thermal Energy if you prefer
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From the Forums: Have You Turned on The Heat Yet?
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My feelings are mixed on this. One the one hand, desalination is going to be an important source of water as we move forward, for many reasons, and desalinating at sea is probably better than desalinating on-shore, since at sea it would be easier to get rid of the excess salt without damaging the local environment.
On the other hand, I really think we should avoid mixing up the ocean's temperature gradients- they are what drive ocean currents, after all, and we depend on those a lot more than most of us realize.
After raping the oceans of their piscine inhabitants, let's put things on top of the water that prevent natural regeneration through solar energy. While we're at it, let's get on the task of heating up the remaining deep ocean water!
Looks quite promising. Interesting how much power will it produce daily? Solar and wind energy combined, that would be A LOT.
These would cover what, a millionth of a percent of the oceans total square mileage? I think they're a great idea!
Um... for the same reason you don't build a solar farm in the forrest, you don't build a solar farm in the middle of a wind farm. Whoever came up with this plan is clueless.
the tourist idea is just for argumentative purposes. no one in their right mind would vacation on one of these islands. they're just coming up with more economical reasons to sell this idea.
and i think we should think carefully on how we would affect ocean life. "but there's nothing wrong with experimenting" is great until you screw up...and we've screwed up in the past. it's time to learn from our mistakes and analyze everything closely. that includes disregarding the monetary incentive entirely and considering the environmental incentives.
This island is a unique concept in the progression of renewable energy. It is promising to see a proposed idea being calculated down to monetary and feasibility levels. The way you have presented the content in your entry is very helpful, as you provide facts, opinions, the pros, and the cons. For someone like myself who was previously unaware of this idea, it is quite helpful that you detail exactly how the islands will generate energy. Most importantly, you address a few of my major concerns with this design. First, the cost of building the project is rather discouraging. You mention that these "energy islands have an estimated price tag of $600 million" Additionally, you state that the exported electricity cost will be slightly higher than that of wind turbines and almost double that of coal. I agree that it is not necessary to build these just yet considering the vast amounts of energy that can be harvested at a much cheaper price on land. Another concern that you somewhat mention is the safety of these islands. Although the islands do float, rising sea level will not be the only pertinent meteorological worry. Do you believe that such projects will only be successful in certain parts of the oceans where they are not prone to hurricanes or tsunamis? It would be a shame to invest 600 million dollars into each island only to have them destroyed. Despite my worries, such products will no doubt serve multiple purposes. But their credibility as tourism hot-spots is rather implausible. Even though inventors suggest that a cluster of these solar isles can create new destinations for tourists, I question whether or not people will choose them over natural islands. You mention the "awesome aqualife" and water sports, but what about the atmosphere that island visitors expect? The fact that they float terminates the possibility for beaches and greenery, while water sports and sea life can be found at any tropical vacation spot. Personally, I think that the concept is groundbreaking, but for the time being we should focus on the single purpose of providing power. I am glad that you have continued to report this story as it develops and I will be keeping my eye out for the final product.