Tuesday, June 24, 2008

Lake Chad now more like Pond Chad

Satellite images show Lake Chad one-tenth the size it was in 1972, not even 40 years ago. Lake Chad used to be the world’s sixth-largest lake, but its resources have been diverted for human use or affected by rainfall such that its been almost entirely depleted in a very short amount of time.

In the IPCC’s 2007 report on impacts, vulnerability and adaptation in Africa, there is no specific mention of Lake Chad. But staring at these satellite images one can’t help but wonder how global warming, which is expected to cause drastic changes to the hydrological cycle (drought, rainfall, water levels, etc.), especially in Africa, will accelerate or contribute to the already scarce resources that this map demonstrates is quite the stark reality.

Click here for article source at the Climate Progress Blog

Monday, June 16, 2008

Upward from the Climate Security Act: Stronger. Simpler. Fairer.

The following is a guest blog from KC Golden, policy director at Climate Solutions in Seattle. You can read more of KC's writings, including a more detailed version of this post, at the CS Journal blog.
-- Luis

Two weeks ago, the U.S. Senate tied itself in a procedural knot, preventing a vote on the substance of the Climate Security Act (CSA) – the first meaningful climate legislation to reach the Senate floor. Once again, the "world's greatest deliberative body" did nothing about the world's biggest problem. Twenty years after our pre-eminent climate scientist Jim Hansen warned Congress of the need for immediate action, this dilly-dallying is enough to make you scream.

But a closer look at the political tectonics at play gives cause for hope. Climate deniers and dawdlers are running out of places to hide. The election will be unkind to candidates who fail to offer real solutions to the fossil fuel dependence that is strangling the economy as aggressively as it is wrecking the climate. And months ago, we narrowed the field of presidential contenders to those who support real climate action.

Even more encouraging, a much stronger bill is already emerging. Congressman Ed Markey (D-MA) has introduced the "iCAP" (Investing in Climate Action Policy) Act. Compared to the CSA, its emission reduction provisions are stronger, it protects consumers better, and it gives more assurance against development of coal plants that lack technology to safely dispose of climate pollution.

Click here to continue reading article at the 1sky blog

Thursday, June 12, 2008

Global warming causes deluges and flooding, just like the Midwest is seeing (again)

The British and the Chinese understand global warming has driven their record flooding. The United States? Not so much.

Although you wouldn’t know it from most U.S. media coverage (here or here or here), the record “once-in-a-hundred-year flooding” the Midwest now seems to be getting every decade or so is precisely what scientists have been expecting from the warming.

A 2004 analysis by NOAA’s National Climatic Data Center found an increase during the 20th century of “precipitation, temperature, streamflow, heavy and very heavy precipitation and high streamflow in the East.” They found a 14 percent increase in “heavy rain events” of greater than 2 inches in one day, and a 20 percent increase in “very heavy rain events”-best described as deluges-greater than 4 inches in one day. These extreme downpours are precisely what is predicted by global warming scientists and models.

Click here to continue reading article at the Climate Progress Blog

Friday, June 6, 2008

A new twist for offshore wind

Jun 5th 2008
From The Economist print edition

Energy: Floating wind-turbines are being developed that can be used at sea in deep water, and do not need to be permanently fixed in place

WINDS sweeping across New England, in the north-east of the United States, blow at an average of about four metres a second (m/s). But a few hundred metres offshore they blow more than twice as fast. This increase in speed is found offshore in much of the world. But although engineers know how to build turbines to generate electricity from offshore wind—mounting them on towers pounded deep into the seabed, or anchored by massive blocks of sunken concrete—they can do so only in waters up to about 40 metres deep.

Now wind power could be taken into deeper waters. Building offshore wind farms is expensive: each turbine costs at least 50% more than one built on land. But the stronger winds out at sea can generate more electricity, and hence more revenue: wind blowing at 10m/s can produce five times as much electricity as wind blowing half as fast, and this greatly favours building more offshore wind farms, says Walter Musial, a senior engineer at the National Wind Technology Centre, a government research laboratory in Boulder, Colorado. Yet just 300-400 offshore wind turbines have been built worldwide, most of them in British or Danish waters. There are none in America. People think they ruin the view and harm the offshore environment.

Take, for instance, a project known as Cape Wind, based on plans by Energy Management, an American company, to build 130 turbines 10km (six miles) offshore in Nantucket Sound, Massachusetts. Although it is backed by a number of green groups, local opposition (not least from the allegedly verdant Kennedy family) has been fierce. Jim Gordon, Energy Management’s boss, says “visceral” local protests have delayed the project by at least three years and cost his company millions of dollars.

But what if the turbines could be put much farther out to sea? Many experts say new technology now makes floating turbines feasible. These could be sited a long way from land. Devices known as “floaters” are already used to support more than two-thirds of the 4,000 or so oil and gas rigs in the Gulf of Mexico, says Paul Sclavounos, a marine engineer at the Massachusetts Institute of Technology. With funding from ConocoPhillips, Mr Sclavounos is developing a turbine floater for the windy North Sea. He expects an industry making floating wind-turbines to flourish in about five years. Others think it may take longer, but few doubt it will happen. Building turbines on land can be just as controversial, suitable locations for fixed-base shallow-water turbines are limited and a new generation of big turbines will need lots of space: only a couple can be placed in each square kilometre.

SWAY, a company based in Bergen, Norway, is developing turbine floaters that can operate in 150 metres of water. The firm, partly funded by Statoil, Norway’s energy giant, estimates that each will cost about as much as a fixed-base turbine placed in 30 or 40 metres of water. Its design uses a hollow, buoyant cylinder that extends down from the tower to about 100 metres underwater. The cylinder is anchored to gravel ballast on the sea floor. SWAY plans to float a full-scale prototype in 2010.

In December a company called Blue H Technologies, based in Oosterhout in the Netherlands, placed a half-size prototype turbine about 20km off the coast of southern Italy in water 108 metres deep. It uses a flotation framework known as a “tension-leg platform”, similar to that used to float oil rigs. Construction of full-size floating turbines for the site has now begun. The company has had to convince Italy’s naval-certification agency that a floating turbine could withstand a “100-year wave”—which in that part of the world amounts to a 9.7-metre wall of water. When it blows at sea, it can blow very hard. That presents difficulties, but it also provides opportunities.

Mission: Transmission - Harvesting the breeze is trickier than it sounds

Apr 28th 2008
From Economist.com

“BANANA” is the wind industry’s bitter motto for its farms—meaning Build Absolutely Nothing Anywhere Near Anyone. Most people do not want to see or hear a wind farm, just as they want to stay clear of other power plants.

Although people tend not to live in windy areas, BANANA can complicate another necessity for wind farms (as it can for most sources of electricity): transmission. Given the gigantic distances in America especially, remote generators require miles of nuts-and-bolts infrastructure to get the power to population centres.

Transmission is expensive and often an afterthought, at least for consumers. Even within windy areas the generators are often scattered across wide expanses, which makes gathering it and bringing it to market difficult. Rob Gramlich of the American Wind Energy Association calls transmission the industry’s “biggest long-term barrier”.

Texas leads the nation in wind power, most of which comes from its remote western plains, and it has made transmission infrastructure a priority, according to Jess Totten of Texas’s Public Utility Commission, who spoke at an MIT energy conference earlier this month. The creation of “Competitive Renewable Energy Zones”, which identify wind-rich and encourage their development, has allowed Texas to gather wind projects together, making transmission easier.

Other parts of America are also hoping for a burst of building. In Maine, the best wind is in the northern and central parts of the state, hundreds of miles from New England’s population centres of Portland, Boston and Providence. In New York, the wind is upstate and the people down in New York City. In California, where wind development has stalled in recent years, a big project to bring power to population-rich Southern California from rural Tehachapi, one of the windiest areas of the state, is moving ahead. Its completion could restart California’s wind industry.

As America’s demand for electricity grows, transmission developers will run into BANANA issues even for wires. High-tension aerial lines are not glamorous. Nobody wants to live near them. In New York, a 190-mile proposed upstate-to-downstate transmission line has run into opposition from residents who dread the words “eminent domain”.

Stephen Conant of the New England Independent Transmission Company plans an undersea cable to shuttle energy from wind farms in Northern Maine to Boston. “We minimise BANANA by going under the ocean,” he says. “So long as the fish don’t start voting.”

Then there are costs. In a place like rural Kansas, where the right-of-way is cheap, new line can cost as little as $500,000 per mile. But putting transmission underground, through a dense suburban area like Boston’s, can cost up to $20m per mile.

In Texas, $3-6 billion more is needed for transmission, according to a recent filing by ERCOT, the Texas electrical grid operator. Overall, across America, between $12-15 billion per year is being spent on transmission infrastructure, according to Lawrence Makovich of Cambridge Energy Research Associates. Costs are worsening with the rocketing prices of steel, copper and engineering services.

All of which raises the pesky question of who pays. One way or another it is generally the users, who naturally resent the extra charges. But being fair to everyone is complicated. A transmission system is a network; when you connect a new line to an existing system, it affects power flows throughout. The actual costs can be hard to predict. The electricity industry’s answer is “socialisation”—the cost of any new capacity is spread evenly among a state’s consumers. This can be an effective quick fix, but it risks burying price signals and creating some thorny interstate issues.

Arizona, for instance, has access to much cheaper electricity than does neighbouring southern California. So naturally Arizonans chafe at the idea of building new transmission lines across their beautiful state, lines which would connect with California’s grid to reduce prices there—while raising them at home. If planners are going BANANAs, there is good reason for it.

A combination of flexible solar cells and low-energy lighting provides a way to bring electric light to isolated communities

A bag full of sunshine
Mar 6th 2008
From The Economist print edition

IF YOU live in a remote area, particularly in a poor country, obtaining electricity can be a problem. It is probably too expensive to connect you to the grid, so you are left reliant on generators and batteries—and even these have to be wired to the points, such as light bulbs, where power is wanted. But Kennedy & Violich Architecture of Boston, Massachusetts may have the answer. In collaboration with Global Solar Energy of Tucson, Arizona, it has developed a cheap, practical and portable way to capture the sun's rays by day and release them by night as useful light, wherever it is needed.

The idea, dubbed “portable light”, combines solar cells with light-emitting diodes attached to the surface of a fabric that can be made into bags, and thus carried around during daylight hours. In sunlight, the cells generate electricity that is stored in batteries stitched into the material. When it gets dark, the batteries power light-emitting diodes that are also sewn onto the cloth.

The solar cells themselves are made from a substance called copper indium gallium diselenide, Global Solar Energy's speciality. This is not quite as good at capturing sunlight as silicon, the material from which solar cells are usually made, but it is less rigid and easier to work with. Crucially, a working cell can be made by spreading a thin layer of the stuff on another material, such as a sheet of plastic. The result is flexible and fairly robust.

Storing the electricity generated by the solar cells involves small batteries that are also woven into the fabric, along with plastic-coated wire connectors. Rechargeable lithium-ion batteries—the sort used in mobile phones—can store more energy per unit weight than other types, and do not lose their charge too rapidly if they go unused for long periods.

These batteries then power hundreds of light-emitting diodes a few millimetres across that are sewn into the fabric on the opposite face from the one occupied by the solar cells. Until recently, such diodes were expensive and did not shine very brightly. But they have improved enormously over the past few years and are now used in mainstream lighting. (A town in Italy recently became the first to switch its street lighting over to such diodes.) Light-emitting diodes are well suited to providing portable illumination, because they are robust, they are not heavy and, unlike traditional bulbs, they do not become too hot to touch.

So far, so good. But there was room for further improvement. As the person carrying the bag moves around, parts of it will be in the shade while others are overwhelmed with sunlight. So the engineers devised a way to direct the energy where it is most needed. To do this, they have woven sensors and switches into the fabric. These ensure that energy from a fully illuminated photovoltaic cell is sent to batteries that are not already receiving electricity at the highest rate they can store it.

In this way, the engineers have created a device that can stash away enough electricity to power the light-emitting diodes for ten hours after three hours in full sunlight. Unlike conventional light sources, the fabric can be spread out to provide background lighting for an entire room or rolled up to generate more concentrated light for a particular task. Moreover, many pieces can be joined together to produce light for larger meetings, and also to power devices such as mobile phones.

The first beneficiaries of this technology are the Huichol, a group of Amerindian people who live in the Sierra Madre mountains of Mexico, but if all goes well, Kennedy & Violich hopes to sell its invention to rural communities in Africa and Australia as well. And at $50 per bag—less than the average Huichol spends on candles and torch batteries each year—it seems a bargain.