Fuels from the Sea: Micro-Algae and Macro-Algae

Marine ecosystems are an untapped resource that account for over 50% of global biomass and seaweeds themselves are capable of producing more biomass per square metre than fast growing terrestrial plants such as sugar cane. _Daisy Brickhill

On the micro-algae front, scientists from the U. of Western Ontario have discovered a way to increase the growth of algae by almost a factor of 4. They did this using magnetic fields!

Wankei Wan, a professor of biochemical engineering at the University of Western Ontario, thinks he's found a potentially significant way to stimulate algae growth.

Wan and a team of research students built a small raceway pond - a tabletop pond shaped like a racetrack, that is - and began growing a common type of single-celled algae called Chlorella kessleri.

They measured the pace of algae growth and oil production. They then changed the set-up such that the algae in the pond were circulated through an area exposed to static magnetic fields.

What they observed, which is described in an upcoming research paper, surprised them.

The magnetic field exposure “almost quadrupled the biomass and lipid (oil) production rate in raceway ponds,” according to the paper.

Wan's team also noticed the magnetically stimulated algae produced dramatically more antioxidants, such as Astaxanthin - often used as a food supplement.

In an interview, Wan said the algae behaved differently depending on the strength of the magnetic fields and length of exposure to them. The researchers noticed that growth would increased steadily as field strength grew. Then, once peak growth was reached, there would be a steep decline.

This suggested to Wan that there is a “sweet spot,” that might vary depending on the type of algae being grown. _CheckBiotech

On the macro-algae front, scientists at Aberystwyth University have found that kelp contains higher levels of carbohydrate at the peak of summer. They suggest that this may be the best time to harvest kelp for biofuels production.

Collecting monthly samples of kelp from the Welsh coast researchers used chemical analysis to assess the seasonal variability. Their results, which will be presented at the Society for Experimental Biology Annual Conference in Glasgow on the 4th of July, showed that the best month for biofuel harvest was in July when the kelp contained the highest proportions of carbohydrate and the lowest metal content.

Kelp can be converted to biofuels in different ways including fermentation or anaerobic digestion producing ethanol and methane or pyrolysis, (a method of heating the fuel without oxygen) which produces bio-oil. The chemical composition of the seaweed is important to both of these processes.

Research into biofuels has focused on terrestrial plants; however these have the serious drawback of the conflict between using land to grow food or fuel. Marine ecosystems are an untapped resource that account for over 50% of global biomass and seaweeds themselves are capable of producing more biomass per square metre than fast growing terrestrial plants such as sugar cane. _DaisyBrickhill

The assumption of the researchers is that the kelp will be used in the fermentation of ethanol or anaerobic fermentation of methane -- which may not be a wise assumption in the long run. Gasification or pyrolysis of macro-algae depend far less upon the chemical constituents and far more upon absolute biomass. It is those thermochemical approaches which are better positioned to take advantage of the prolific nature of marine aquaculture. Macro-algae can produce up to 6 harvests per year, depending upon local conditions.

Cornwall Wave Energy Hub

A £21m wave energy farm in Cornwall has been agreed to.

More than £21m of funding has just been agreed for Wave Hub, a giant electrical terminal on the seabed 10 miles off the coast of Hayle, near St Ives, through which wave energy devices can transmit the energy they generate along a high-voltage undersea cable back to the National Grid on shore.

When it is operating next year it is likely to support the largest array of wave energy machines in the world, and mark an enormous step forward in the development of wave power, which has long been the Cinderella in the family of renewable energy technologies - far less advanced than wind and solar power.

....Wave Hub will allow developers of wave energy devices to test new wave energy technology. Groups of devices will be connected to the terminal and float on or just below the surface of the sea to assess how well they work and how much power they generate before going into full commercial production.

The terminal will be connected to the National Grid by a 15.5 mile cable linked to a new electricity substation at Hayle. It could generate 20 megawatts of electricity, enough power for 7,500 homes or three per cent of Cornwall's domestic electricity needs.

Source

Although surfers fear the Wave Hub will detract from their surfing excitement, only time will tell whether the surfers' waves lose energy and height as a result of this experimental project.

Energy from the Sea

The sea stores massive amounts of energy from both the sun and the wind. The Energy Blog points to a recent news story on marine energy.

After sputtering along for nearly a decade, marine power appears poised to join the alternative energy juggernaut, though the technologies are still in the early stages and have no guarantee of success. Developers are using an array of contraptions — from spinning turbines to bobbing buoys and undulating, snakelike cylinders — to convert ocean or river movements into electricity.

The world's first commercial wave farm is scheduled to launch this summer off Portugal's coast. The first pilot tidal generator in the USA revved up in New York City's East River last December. And the USA's first utility-scale wave project, off Oregon beaches, won preliminary federal approval this year. All told, the Federal Energy Regulatory Commission has cleared 21 preliminary permits, and about 35 are pending for wave and tidal projects, largely off the West Coast and shores of Florida and New England.

Widespread use of marine energy is about a decade away, says Roger Bedard, ocean energy leader for the Electric Power Research Institute. In 50 years or so, he says, 20% of offshore wave energy could be tapped practically. That, combined with tidal energy, could constitute 10% of all U.S. power sources.

I am particularly interested in any energy technologies that would facilitate the success of seascapes or undersea habitats.

Ocean Thermal Energy Conversion--OTEC

A very nice video illustrating Earth's thermohaline circulation, and the OTEC method of extracting electrical energy from the temperature differential of the tropical ocean. Definitely worth four minutes of your time.

Improved Oil Discovery Under the Sea--Expect More

The recent discovery of a huge new undersea oil reservoir in the Gulf of Mexico is causing more intelligent people to rethink the issue of "peak oil."

The well sustained a flow rate of about 6,000 barrels a day, strong enough to encourage analysts to predict that the field may contain anywhere from three billion to fifteen billion barrels of oil, although the results of a second well test scheduled for 2007 will sharpen the accuracy of those figures considerably. If the higher-end estimate is correct, though, the discovery would approach Prudhoe Bay in size, and possibly increase total U.S. reserves by some 50 percent.

Technology Review.

This huge undersea oil field was found by improved seismic techniques. But oil discovery science is not limited to seismic methods. A new generation of petroleum prospectors are learning to use these new techniques, which promise a new wave of oil discovery that could last for decades.

Other parts of the world that once appeared beyond the pale may also come into play. Areas believed to have oil deposits extremely deep beneath the ocean floor, which could now become commercially recoverable, include the North Sea off the coast of Britain, the Nile River Delta off the coast of Egypt, and possibly coastal Brazil, says Andrew Latham, a vice-president at energy consultancy Wood Mackenzie in Edinburgh, Scotland. Other analysts say West Africa could harbor lots of ultra-deep deposits. The areas have produced oil before but never from these depths.

Source.

Of course, these huge new oil fields will take time to develop. Much of the new oil reserves will probably lie undisturbed, like the ANWR oil fields in Alaska, due to lack of desperate need for it. Oil prices of $70 US per barrel are not economy busters by any means. Yet those prices are high enough to encourage development of renewable sources of energy, as well as novel uses for coal, and increased use of nuclear energy. The current price level also encourages oil companies to stretch their nets of oil discovery wider and deeper.

So, although the move away from petroleum and toward alternative fuels is real and probably irreversible, it is still in the early phase, and is not due to any hardship associated with the old "catastrophic peak oil" quasi-religious belief. It is basic economics combined with a desire by developed societies to move toward cleaner and ultimately more sustainable forms of energy.

OTEC---Energy From the Deep and Shallow

Solar energy is the most abundant form of energy available on Earth. But since sun energy is only available for part of the day, it is difficult to store that energy for use when it is needed. One way around that is to use solar energy that has already been stored. The oceans soak up the sun's energy and store it as heat in the surface layers. Deeper layers of ocean are much cooler. By using the heat differential between deep and surface layers, huge quantities of usable power could be extracted from tropical parts of the Atlantic, Pacific, and Indian Oceans.

This story from Technology Review replays some of the history of the thinking about OTEC:

In the October 1978 issue of TR, William F. Whitmore invoked an idea from the 19th century: ocean thermal energy conversion, or OTEC. Exploiting the temperature difference between the sun-heated surface of tropical waters and the chilled depths thousands of feet below, Whitmore argued, could provide clean, renewable energy in the lower latitudes.

In the tropics, the oceans store an immense amount of energy from the sun. The band of surface water within 10º of the equator basks around at 80º F., while cold regions 3,000 ft. below are around 40º F. [OTEC] uses this thermal gradient, like the hot and cold terminals of a gas turbine, to generate electricity. The essence of the system is the circulation of a fluid such as ammonia or propane. Where it comes near the warm water it is brought to a boil and so expands; where it comes near the cold, it liquefies once again. In the course of its circulation from one place to another, it drives a power-generating turbine. A typical closed-loop system would include two exchangers (evaporator and condenser), a turbine, and a generator.

... The engineering challenges to be bridged demand solutions of scale rather than of technical innovation. Ship designs and structures used for offshore oil platforms have blazed the trail for the physical platform on which OTEC will be mounted. A general design goal is to isolate the platform as much as possible from the influence of the ocean surface, where the interaction of wind and wave can induce violent platform motions. A leading candidate is a large spar buoy configuration, with most of the platform mass several hundred feet underwater and a relatively small surfacepiercing mast for access; this would also give warning to marine traffic. The OTEC system, with power cabled to shore, is necessarily fixed in place. Both steel and concrete are considered as possible platform construction materials.

In the 1990s, 250-kilowatt test facilities in Hawaii's tropical waters demonstrated OTEC's feasibility. For a plant to be commercially viable in the United States, however, it would have to produce between 50 and 100 megawatts. Developing such plants would require "patient financing," according to Luis Vega, test director of the largest test plant operated by the Pacific International Center for High Technology Research, which ran the Hawaiian facilities. The first step would be a prototype plant of a few megawatts. Ultimately, Vega believes, not only would a commercial-scale OTEC plant be viable, but it could operate at six to eight cents per kilowatt-hour, making it competitive with other renewable energy sources and even with fossil-fuel plants.

More at Technology Review.

In international waters, an enterprising group able to install a permanent infrastructure incorporating a seastead community and resort, OTEC, international financial services, aquafarming, and perhaps ocean based space launch and recovery services, could go from a billion dollar conglomerate to a trillion dollar superpower in a very short time.

The oceans are a giant solar pond, storing the sun's energy for anyone willing and able to tap it. The OTEC news blog is one website that tries to keep up with developments in this area.