Turbine technology is turning the tides into power of the future

SeaGen Tidal System

Lewis Smith, Environment Reporter

The world’s first deep-water device to generate electricity from the tides on a commercial scale is due to start operating within weeks.

A seagoing crane barge has lowered the 1,000-tonne double turbine into place and an operation to fix it to the seabed with 12 metre (40 ft) pins begins today.

The SeaGen Tidal System at Strangford Lough in Co Down, Northern Ireland, is designed to produce enough electricity to supply 1,000 homes.

The system, made by Marine Current Turbines (MCT) and assembled at the Harland and Wolff dockyard in Belfast, boasts two 16m blades which will be turned by the water streaming in and out of Strangford Lough at up to 8 knots.

Martin Wright, managing director of MCT, said: “By the middle of May we will have completed the bulk of commissioning. We’ll start by turning the turbines by hand. After that we’ll try with low loads and by July we hope she’ll be fully commissioned."

“If this is successful, we are looking to build, at the end of 2010 or more likely 2011, a tidal farm. That would be off the Anglesey coast.”

Mr Wright said that the current state of tidal energy technology was equivalent in aviation terms to the first biplanes. Developments are advancing rapidly, however, and firms based in Britain are playing a central role in the emerging industry.

As work on SeaGen was being carried out, the Government also gave approval for a prototype generator, developed by Pulse Tidal, to be tested in the Humber estuary, near Grimsby.

The £900,000 Pulse Tidal trial involves 11 metre hydrofoils that rise and fall with the tide like a dolphin’s tail to generate electricity. The small prototype device is designed to have a capacity of 0.15 megawatts, but if successful an array of 1 MW devices would be produced to supply 70,000 homes.

Strangford Lough and Anglesey are among the best locations possible for tidal energy devices because of the speed and power of the tidal stream.

The holy grail for tidal energy experts, however, is the Pentland Firth, between the Scottish mainland and the Orkney Islands, where up to 3 million tonnes of water race though a narrow area of sea every second. Mr Wright described the Pentland Firth as “the big prize – the Saudi Arabia of tidal stream”, but said the technology to take full advantage of the location was “a generation beyond us”. Once attainable it could supply up to 15 per cent of Britain’s electricity.

He added: “Tidal energy has the great advantage of being predictable and no other system can harness the power of the tidal currents in the way this one can.”

Lunar Energy, another tidal energy technology firm, hopes later this year to begin installing the world’s first tidal farm in Pembrokeshire. The eight turbines are expected to be operational by 2010.

An initiative to build a huge wind farm at sea will be unveiled today as the industry demands clear guidelines on where it can develop renewable energy. The power firm E.ON is applying to build a £700 million wind farm, big enough to supply 195,000 homes with electricity, five miles from the Yorkshire coast. Wind farms on land and at sea are expected to have to provide a significant proportion of Britain’s electricity if it is to meet its renewable energy target, but wind farm developments have been put in doubt by the discovery that they can impair the efficiency of radars.

Original here

Ten Innovative Green Homes

In an attempt to create a more sustainable domicile, some homeowners use energy-efficient light bulbs, swap out normal showerheads for low-flow ones, or put on a sweater so they can turn down the thermostat. However, others are taking sustainability—and their homes—to the next level. These ten innovative designs move the owner off the grid, into the trees, and toward a more environmentally-sound future.

Earthbag House

Photo courtesy of greenhomebuilding.com

Sandbags protect houses from floods, but aren’t normally considered building material. However, Kelly Hart, a constructor who runs the Web site GreenHomebuilding.com, built this house out of misprinted rice bags filled natural material (earthbags). The outside layer is papercrete, recycled paper mixed with small amounts of cement. The earth bags provide insulation, weatherproofing, and are easy to construct. According to his Web site, the house requires minimal use of wood, concrete, and steel for construction, and many recycled materials were used. The heating is primarily solar—air tubes provide cooling and food is grown in a central greenhouse.

Build Local, Build Green

Photo courtesy of home owners

My friends Becky and Grant spent nearly two years building this house, located in Northern California. Their overall approach has been to build small, build natural, and use as much reclaimed and local materials as possible. To this end, they’ve succeeded.

Ninety percent of the exterior walls are made from straw bale; the downstairs exterior walls are covered with earth and lime plaster. The interior walls are plastered with clay gathered from their land, resulting in a beautiful, neutral-toned finish with a velvety texture. The cedar siding was milled onsite, using diseased trees from their property. The redwood deck, interior doors, and cabinetry in the kitchen use local reclaimed or restored wood. Insulation is from recycled denim and strategic placement of windows ensures natural cooling. They also have a solar hot water heater, a bountiful veggie garden, fruit trees, clucking chickens, and, as if the industriousness never ends, a baby on the way. Sustainability for generations to come!

Modular Earthship

Photo courtesy of www.earthship.net

I’m not sure if I’m ready for a hemp Earthship, but luckily I have options. They come in packaged, modular, hybrid, and custom; the above is an example of a modular Earthship. With water catchment from the roof, reuse of greywater, solar panels, and composting toilets, I could definitely tune in with nature, turn off the TV, and drop off the grid.

Project BioDome

Photo courtesy of biohome.net

Edward Dilley, creator of Project Biodome, has a vision: pull drinking water from the air, gather heat and electricity from the sun, and live completely supplied for in his geodesic sustainable dome. Somewhere in the mountain near Elko, Nevada, he seems to be doing just that. According to his Web site, you can order a kit and construct one yourself. Might want to look into local building codes first.

Tree House

Photo courtesy of www.o2sustainability.com

If you aren’t afraid of heights, the 02 Sustainability Tree House could serve as your next home away from home. It is made from small amounts of eco-friendly resources and is hung by cables rather than bolted into trees, as to not disturb your structural helpers.

PARASITE House

Photo courtesy of www.nbm.org

The P.A.R.A.S.I.T.E., which stands for Prototype for Advanced Ready-Made Amphibious Small-Scale Individual Temporary Ecological Dwelling (phew!) is a verbosely named structure that attaches to pre-existing, abandoned structures. The sustainably-built prefabricated homes would turn blighted areas into usable ones and limit urban sprawl.

Lightweight Concrete House

Photo courtesy of greenhomebuilding.com

Concrete is usually associated with boring, grey buildings, but it is actually an earth-friendly building material that can be poured to make creative structures, as this house, built by sculptor/builder Steve Kornher, shows. Lightweight concrete needs less steel structural reinforcement than traditional building materials and is a good insulator, helping to cut back on heating costs. Concrete is often made from natural, local materials.

A Yurt to Call Home

Photo courtesy of www.coloradoyurt.com

If we really wanted to minimize our home’s impact on the earth, we’d all be living out of tents. As much fun as tents are for a camping trip, tents aren’t really made to house the masses (where would you put the flat screen TV?). A happy compromise is a yurt. Yurts are like big tents, but are much more durable, insulating, and can be pimped out with hardwood floors, fireplaces, TVs—you name it. Yurts are constructed with minimal materials, create little disruption to the surrounding ecosystem, and facilitate natural lighting and heating.

Green Roof Strawbale Home

Photo courtesy of www.roofmeadow.com

Roofs aren’t traditional places to grow a garden, but growing green on top of buildings has several advantages: it can prevent storm water runoff and pollution, conserve energy, extend the life of the roof, and it looks cool. This house, located in Wrightsville, PA, has a living roof and is constructed of strawbale and cob walls—renewable, biodegradable, construction materials that help insulate. It’s green inside and out.

That Roundhouse

Photo courtesy of www.thatroundhouse.info

That roundhouse, located in Wales, doesn’t just look earth-friendly, it really is. It was constructed using a wood frame, cobwood and recycled window walls, and a straw-insulated turf roof. Solar power and wind turbine are used for electricity; there is a compost toilet, and reed beds to clean greywater.

Original here

Earth in crisis, warns NASA's top climate scientist

Global warming has plunged the planet into a crisis and the fossil fuel industries are trying to hide the extent of the problem from the public, James Hansen, seen here, NASA's top climate scientist says


"We've already reached the dangerous level of carbon dioxide in the atmosphere," James Hansen, 67, director of NASA's Goddard Institute for Space Studies in New York, told AFP here.
"But there are ways to solve the problem" of heat-trapping greenhouse gases like carbon dioxide, which Hansen said has reached the "tipping point" of 385 parts per million.

In a paper he was submitting to Science magazine on Monday, Hansen calls for phasing out all coal-fired plants by 2030, taxing their emissions until then, and banning the building of new plants unless they are designed to trap and segregate the carbon dioxide they emit.

The major obstacle to saving the planet from its inhabitants is not technology, insisted Hansen, named one of the world's 100 most influential people in 2006 by Time magazine.

"The problem is that 90 percent of energy is fossil fuels. And that is such a huge business, it has permeated our government," he maintained.

"What's become clear to me in the past several years is that both the executive branch and the legislative branch are strongly influenced by special fossil fuel interests," he said, referring to the providers of coal, oil and natural gas and the energy industry that burns them.

In a recent survey of what concerns people, global warming ranked 25th.

"The industry is misleading the public and policy makers about the cause of climate change. And that is analogous to what the cigarette manufacturers did. They knew smoking caused cancer, but they hired scientists who said that was not the case."

Hansen says that with an administration and legislature that he believes are "well oiled, our best hope is the judicial branch."

Last year Hansen testified before the US Congress that "interference with communication of science to the public has been greater during the current administration than at any time in my career."

Government public relations officials, he said, filter the facts in science reports to reduce "concern about the relation of climate change to human-made greenhouse gas emissions."

While he recognizes that he has stepped outside the traditional role of scientists as researchers rather than as public policy advocates, he says he does so because "in this particular situation we've reached a crisis."

The policy makers, "the people who need to know are ignorant of the actual status of the matter, and the gravity of the matter, and most important, the urgency of the matter," he charged.

"It's analogous to an engineer who sees that there's a flaw in the space shuttle before it is to be launched. You don't have any choice. You have to say something. That's really all that I'm doing," he explained.

Hansen was in Wilmington to receive a 50,000 dollar Common Wealth Award for outstanding achievement, along with the former prime minister of Australia John Howard, the US actress Glenn Close, and NBC news anchor Ann Curry.

The awards are provided by a trust of the late Ralph Hayes, a former director of Coca Cola and Bank of Delaware, now PNC. In 29 years, 165 former honorees in seven fields have included former US secretary of state Henry Kissinger, former US newsman Walter Cronkite, French marine biologist Jacques-Yves Cousteau and Colombian author Gabriel Garcia Marquez.

Howard, who would not sign the Kyoto protocol when he was in office, told AFP: "I thought it was the right policy at the time because the major emitters" were not on board."

He added: "You need a new Kyoto protocol with all the major emitters committed to it. Then you are cooking with gas."

Original here