Monthly Archives: February 2010

Turning the tide

SeaGen is the first tidal current or wave system in the world that has exceeded a 1.000 hours of operation.  This 1-2 MW tidal current turbine is  the largest megawatt scale grid-connected marine renewable energy system that has achieved a capacity of 66%  and  so far delivered 800Mwh to the National Grid.  The prototype, designed and deployed by Marine Current Turbines Ltd (MCT), based in Bristol (England), is operating in Northern Ireland’s Strangford Lough.

MCT reports  that the tidal turbine delivers energy on average at the same rate to be expected from a wind turbine of approximately twice the rate power.   ‘Performance has exceeded expectations,  largely thanks to the intensity of the Stranford Lough tide race and the company’s own conservative design predictions.  Furthermore, output is totally predictable.

‘We are delighted with SeaGen’s performance ‘ said Martin Wright MCT’ ‘s Managing Director. ‘Passing the 1,000 hours mark is a great milestone which not only demonstrates  the potential for tidal power , but will also help to reinforce confidence in extracting energy from the seas in the future’.

MCT hopes to gain consent for continuous ’24/7′ operation before the summer. In the next few weeks the company  also plans to run SeaGen under supervison of specialists from DNV (Det Norsk Veritas) one of the  world’s leading marine classification societes, to obtain independent verification of its performance.

Algae not that green after all?

Bio fuel from algae is currently being considered as the next big thing. Research had already began at the time of the oil crisis, but ceased when oil prices appeared to drop. Now, as we are all in search of alternatives to fossil fuels, algae is once again high on the agenda. Algae seems to have lots of advantages over brother and sister bio fuel sources, but new research suggests that while algae might produce good fuel, the environmental costs involved in the production would be heavy.

Micro algae are single-celled photosynthesizes. They are extremely efficient at converting carbon dioxide into biomass. The fats they contain can be converted into bio diesel or jet fuel in relatively few steps. Agriculturally it’s very easy to grow, algae doesn’t require a lot of land like other crops. In the US you will find algae farms primarily in desert areas, where no vegetation is found. So another plus is that they don’t use up valuable farm land.

A life-cycle assessment published in the journal Environmental Science and Technology argues that algae production consumes more water and energy than other bio fuel sources like corn, canola, and switch grass, and also has higher greenhouse gas emissions. The algal life-cycle analysis, which used numbers from an online database and published research, finds that algae farms need to minimize use of fertilizer and freshwater to compete with the other bio fuel plants. So it’s not so much the algae themselves, more the condition they are grown in that seems to be the problem.

Algae farms should cut down on using chemical fertilizer, according to the researchers.. Growing algae for bio fuel requires large amounts of fertilizer, this undermines the carbon dioxide saving effect that the algae possesses. Corn and switch grass are capable of retrieving nitrogen from the soil, so they don’t need lots of extra fertilizer. The only arena where algae came off better than corn, switch grass and canola, were land use and nutrient runoff. The scientists believe that a way for the algae to get out of the red would be to put algae operations next to waste water treatment plants or facilities that emit carbon dioxide. From waste water they can capture phosphorous and nitrogen — essential nutrients for growing algae that would otherwise need to be produced from petroleum.

Scientist theorize that algae can produce 30 times more energy per acre than any other bio fuel option. The US department of Energy have estimated that if algae bio fuel replaces all conventional fuel in the country it would require 15.000 square miles of land to harvest the algae which is roughly one seventh of the area that is used to harvest corn in the US every year. Despite some hurdles to conquer, it seems the “green gold” remains to be one of the most promising bio fuel sources around and we’re not ready to give up on it yet.

Fujitsu’s zero-watt PC, a power-saving miracle?

The Esprimo Green is Fujitsu’s new solution for green machines. This zero-watt PC marks a first, able to use no power while standby mode. Even though the computer uses no power in standby mode, Fujitsu say it can still be managed with LAN, Bluetooth, and UMTS.  A demonstration will  be showed  during CeBIT on March 3rd- 8th in Hannover Germany.

Turning your PC off before going home could see a significant saving in energy use over a 12 month periode.  Doing that across an office of hundreds is surely going to cut costs noticably. But how is it possible to have a computer that is asleep and draws truly zero Watts?  Could the modification be something as simple as including low level SSD to save memory state and a BIOS level interaction to perform the equivalent of a laptop suspend to disk  ‘function’?  

There are a couple of ways to operate a soft power  that don’t  constant power supply; have a capacitor store just enough power to kick-start a physical switch in the power supply, pressing the soft on button on the front flips the switch or make the front power switch a mini-generator/linear motor. In the case of the Macbook Pro, the deeper sleep state includes saving enough state that you can survive complete powerloss and battery removal. Or has Futjitsu a battery someplace to provide the low amount of power needed to wake the system up again when needed?

The key draw of Fijitsu’s Esprimo Green is the fact it happens automatically meaning the cost saving is assured, unless you change the standby feature of course. Fujitsu is adding a premium to the sale price of these machines because of this new zero-watt feature. For one, the economic climate means business won’t pay a premium for new hardware, plus it would wipe out the short-term gains from the reduced energy costs of using them.