Tag: photo
LISTEN: Great Lakes Today on toxic fish in the immigrant community
Photo by Georgie Pauwels (Creative Common License) We love this short radio piece from our friends at Great Lakes Today that follows the efforts of organizations on the ground in Buffalo, New York as they reach out to the diverse population who fish there to educate them on the dangers of contamination consumption. Contaminated fish aren’t just an issue in […]
Vertical-Axis Wind Turbines: The Future of Micro Wind? [w/video]
Walking the floor of WINDPOWER 2008, the annual conference and trade show for the wind energy industry, one couldn’t help but be transfixed by all of the different types of turbines – at least I couldn’t. The wind turbine has become the iconic symbol of clean, renewable energy. But the classic three-bladed turbine horizontal axis wind turbine, with its gracefully swooping blades, has become the symbol of not only renewable energy, but also of environmental consciousness and ecological possibility.
Despite the ubiquity of the three-bladed turbine, the oft-overlooked vertical-axes turbines are making quite a splash in the world of wind energy, especially in small and micro-applications. So what’s all the fuss about? Vertical-axis turbines apparently do not suffer from some of the same problems that plague small wind applications in urban settings including, aesthetic concerns, space requirements and sound levels.
Other advantages of vertical-axis turbines:
- Can produce up to 50% more electricity per year than conventional turbines with the same swept area
- Generate electricity at much lower wind speeds, as low as 4 mph (1.5 m/s)
- Will continue to generate power in high wind speeds, up to 130 mph (60m/s) depending on the mode
- Direct-drive units have no gearbox. No gearbox means a more efficient transfer of energy and no leaking oil
- Will not harm wildlife, in terms of bird and bat strikes
Below, I’ll cover some more basic differences and show you a few photos and short videos of some of these turbines I saw down in Houston at WINDPOWER 2008.
The designers from Taiwanese start-up A.N.I.T.A. Energy (pictured above and in video below) showed me why their models have a low start-up wind speed, and that is because of the light metal bands you can see surrounding the turbine itself. Apparently this design allows users with a less substantial wind resource (particularly those in urban applications), squeeze some electricity from the local winds. The larger model pictured above is scalable and can be stacked as many as three-high and integrated with the rooftops of large buildings.
Another design I saw scattered throughout the show floor were those that integrated small solar and wind together on the same unit (top photo and photo below). The unit below integrates both solar and wind onto a single 400W streetlight platform.
The turbine itself is a “GUS” from a company called Tangarie which features a reflective coating that reduces glare and can even be slathered with an advertisement or a state flag of Texas, as is the one below. The complete solar/wind/streetlight/pole package (made by another company altogether) costs about $7,000, not including installation.
There will undoubtedly be substantial growth in the vertical-axis turbines, especially in urban settings. Personally, I think this technology could best be applied in poorer countries to help address the most basic of energy needs, like lighting and light-duty water pumping.
Other Posts on Small and Micro Wind Energy:
“Top Five Micro Wind Turbines”
“Liveblogging from WINDPOWER 2008: Photos of Small Wind Turbines”
“Small Wind Remains in Farm Bill”
*Thanks again to the American Wind Energy Association for providing travel and conference support to WINDPOWER 2008.
Evaluating the Cleanliness of Solar Photovoltaics Can Be Complicated
I am a frustrating individual who likes to delve deeply into decision making computations and hates easy answers that sound like sales pitches. One of the best compliments I ever received came from one of my division officers when I was serving as the Engineer Officer on a submarine – he told me “Eng, you ask hard questions.”
As vocal advocate for nuclear fission power I recognize that it has many associated questions, but I after 30 years of study, I have determined to my own satisfaction that most of the important questions have reasonably good answers. In contrast, I have not yet found reasonable answers for many of my questions related to other renewable energy sources. (Yes, I – perhaps controversially – classify fission as renewable, but that is a discussion for a different post.)
Solar photovoltaic (PV) cells are a popular and often discussed (see, for example Atlantic City Convention Center Plans Largest Solar Roof in U.S., 10% of U.S. Electricity From Solar by 2025, SF Passes Largest City Solar Program in U.S. (Finally), all of which were published within the past week) form of “renewable” or “green” energy, but a casual scratching of the surface knowledge that many people have about the technology reveals some troubling details.
Not only are the panels expensive sources of electricity, but they do not last as long as advertised, they do not provide as much energy as the nameplate capacity implies, they consume significant quantities of energy in their production, installation and transportation, and they often use some very nasty materials in their manufacturing process.
The longevity of a solar panel will vary greatly depending on where it is installed, but any customer should remember that they are buying a product that will inherently need to spend as much time as possible fully exposed to the sun and weather. Though there are no visibly moving parts in a solar PV panel, there are many parts of the system where continuous chemical and physical reactions take place that can eventually lead to system degradation and failure.
Take a good look at panels that have been installed for several years and you will notice discontinuities and shiny areas where the components have been damaged and where the power production is reduced. If you have any panels, might want keep a record of the current production so that you can see this effect – or perhaps you will not want to find out just how fast that long term investment is decaying.
The literature accompanying most solar panels provide customers with numbers related to their peak capacity – what I call “noon on a clear day at the Equator”. That quantity of power is only available when the sun is directly overhead, when the panel is perfectly clean and when there are no clouds shading the cells. The cleaning part is important, any panel owner that wants maximum performance needs to set up a routine for cleaning and clearing the panels of any debris.
Leaves and snow are particular nuisances for rooftop solar panels, but sand and bird droppings can be important in some areas as well. Not that the article was specifically discussing PV panels, but I recently read about the 4,000 gallon water tanker trucks that are part of the maintenance equipment at some desert solar power plants.
Some of the most energy efficient solar panels, in terms of both the energy required to produce the panel and the panel operating efficiency are made of a semiconductor material called CdTe (Cadmium Telluride). Companies that make CdTe cells like to brag about the quality of their products, but they have also recently had to warn their investors that they may not be able to sell their panels in the EU for much longer because of rules about using toxic heavy metals in electronics. What they have not made clear yet is what their long term liability is for the panels that they have already sold. What will happen in 5, 10 or 20 years when the panel output is no longer useful and the materials need disposal? Can they be recycled without releasing the heavy metals? Will their customers be able to return the panels to the original producer? Will they make the effort or simply take the systems to the dump like many consumers do with batteries made of similar materials? (Those are the kinds of questions that my former division officer was talking about.)
There are definitely answers to some of the questions that I have about solar PV, but that does not mean that the issues are fully solved. If you are in the market for solar PV systems, please ask the hard questions and realize that anyone who wants you to buy the systems without good answers is just a salesman who is not much different from any other salesman.
Photo credit – The Sun Works (photos to be shared)
10% of U.S. Electricity From Solar by 2025
Solar energy currently generates .1% of the electricity used in the U.S. According to a study released today, this will change rapidly as the cost of electricity increases and the cost of solar energy drops.
The Utility Solar Assessment Study produced by Clean Edge and Co-op America finds that solar energy is already reaching cost parity with conventional sources in some areas of the U.S. where electric rates are highest. By 2015, this will be achieved in many more areas, including Boston, San Diego, and New York. By 2025, cost parity will be achieved throughout the U.S.
The implications of this are huge. The U.S. solar photovoltaic market now relies heavily on state incentives to lower the cost of solar energy. Many people utilize solar energy because it is “the right thing to do” or businesses like the positive publicity solar brings.
Unique Advantages of Solar Electricity
Solar energy does not have fuel costs, like power generated from coal, natural gas, oil, or nuclear energy. The maintenance costs of solar are relatively low , it can generate electricity at the point of use, and emits no carbon. Solar is ideally suited to produce peak electricity, when demand is highest on the power grid and utility companies pay the highest rates. This is also where there is the greatest growth in electricity demand.
“The daily and seasonal variation in grid load in the United States matches solar availability,” said John O’Donnell, executive vice president of Ausra. Solar effectively generates electricity when the rates and demand are the highest.
Action is Needed to Advance Widespread Use of Solar Energy
Solar Companies
Large-scale use of solar energy depends on prices dropping to $3 per peak watt of electricity by 2018, according to the study. This involves quickly implementing advanced technologies in a cost-effective manner. Solar technology needs to be easier to install, thus reducing installation costs and other installations barriers.
Utility Companies
Utilities have become more and more interested in solar energy. California is a great example, where many utilities have signed purchase agreements for solar plant output. The U.S. will also need trained workers, which is another opportunity for utilities to take the lead.
A large investment in solar energy is needed for 10% of U.S. electricity to be generated by solar energy by 2025. Utilities will need to invest between $26 and $33 billion per year, a pretty hefty sum. To put this number in perspective, utilities invested $70 billion in 2007 on new power plants and transmission and distribution centers.
Solar Regulation and Policy
There is currently a 30% commercial tax credit for solar energy, but it is set to expire at the end of the year. There are purchase agreements for 3.2 gigawatts of concentrated solar power during 2007, but these solar power plants cannot be constructed before the tax credit expires. A long-term extension of the renewable energy tax credit is needed for large-scale use of solar energy. Many states also have renewable portfolio standards, but a national renewable portfolio standard would also help strengthen the industry.
Related Posts on Solar Energy
Solar Thermal Electricity: Can it Replace Coal, Gas, and Oil?
Senate Coalition Introduces Clean Energy Tax Package
Solar Panels and the Quest for $1/Watt
Clean Energy Intro: Solar Businesses
4 Things to Consider Before Going Solar
Photo Credit: Solar Service Inc of Illinois
Should Ships Slow Down, Go Back to Sails, or Use Nuclear Fission?
There was a time when commercial shipping was an emissions free transportation mode that required little or no fuel. Inventors, craftsmen, and engineers all worked to refine the hulls, sails and control systems and skilled people spent their entire careers figuring out weather patterns, determining efficient loading schemes, and recognizing opportunities for transporting goods with a long shelf life. When things went well, owning sailing ships was a lucrative investment.

Of course, there were some limitations of that technology that encouraged a number of very smart, number crunching businessmen and engineers to look for a better way. Sailing ship limitations included time consuming voyages, space and weight constraints, inability to maintain a schedule, dependence on poorly paid or forced labor, vulnerability to numerous natural hazards, and a high mortality rate caused by lack of good nutrition and clean water.
In May, 1918, Captain Moses Roberts, Steven Vail and some unnamed investors formed a company called the Savannah Steam Ship Company and began the work necessary to build a ship that could cross the oceans using coal and wood heat to create steam power to assist the sails. S. S. Savannah made a successful two way crossing but was a financial failure. Sailing ships continued to dominate the seas, but engineers kept improving coal and wood heated steam engines for railroads and inland river travel.
Within twenty-five years after Savannah’s initial voyage steam ships began crossing the Atlantic regularly and within seventy years steam essentially replaced sails in commerce. I can testify that sails have never disappeared – I live in one of the world’s most sail addicted towns – but anyone who has ever operated both sail and power vessels understands that as a business vessel, a sailboat is a great hobby.
Not surprisingly, when fuel prices increase rapidly, people focus their attention on ways to save money on fuel purchases. They seek to reduce their specific fuel consumption and to find cheaper sources of fuel. Both can require trade offs.
One of the easiest ways to reduce consumption is to slow down, but slowing down reduces productivity. I know that some environmentally minded people might scoff and say, “so what”, but if all of the ships on the ocean slowed down by 10%, we would need 10% more ships to carry the same quantity of goods. Each of those ships would require materials and energy to build, they would be a bit less profitable and some of the owners might be tempted to find other ways to save money, like buying cheaper fuel.
With the large engines used on ships, there are often a variety of available fuel options at different price points, but the lower priced fuel often comes with some real environmental baggage. There has been a lot of attention paid – finally – to the fact that ocean going ships are prodigious sources of sulfur emissions and other noxious pollutants since they often burn the dregs left over from refining – a fuel known as residual fuel. Based on studies that made a big splash at the end of 2007, ship emissions are now considered to the source of about 60,000 early deaths every year.
A friend of mine pointed me to a post on Treehugger.com titled Slower Shipping Could Reduce GHG Impact that discussed additional options for reducing fuel cost and environmental impact. In addition to slower speeds, the post and associated comments mention schemes that add sails to assist in propulsion. When fuel prices are high enough, such schemes can provide a positive return on investment by cutting several percentage points of off some large fuel bills. (An ocean going ship with a 70 MW power plant would burn about 90,000 gallons of fuel every day. When marine diesel fuel costs $5 per gallon, a 5% fuel savings is worth $22,500 per day.)
My recommendation is different. Let’s get rid of all of the emissions, switch to a fuel that costs about 2% of the cost per unit heat (50 cents per million BTU versus $25 per million BTU) as marine diesel fuel, and increase shipping speed so that ocean going ships can more readily compete with aircraft for time sensitive shipments. It is possible to achieve that amazing feat using technology that has been in use for more than 50 years, all we have to do is to follow the example of another pioneering financial failure named Savannah.
Nuclear powered ships are well proven, there are tens of thousands of people around the world who know how to operate, build and maintain them, and they offer capabilities that the world needs today. Because nuclear ship propulsion plants would be much smaller than the commercial nuclear power plants that are currently either under construction or being planned, they would not necessarily have to wait in the same supply chain lines for large components.
There was a time (1962-1972) when the United States produced about 100 ocean going nuclear plants in just a decade; such an industrial effort today would yield great benefits. Just think about all of the emissions that would not be released and all of the oil that would no longer be burned at sea. The effect on the market price for the rest of us would be the same as finding a new deposit capable of expanding production to about 5-8 million barrels of oil per day. That is at least 2-3 times as large as ANWAR.
Update posted June 20, 2008: A couple of days after posting this, Joe Stroud contacted me to share an updated photo of the N.S. Savannah that was taken in Baltimore, Maryland on May 23, 2008. The date was 50 years to the day after her keel was laid in 1958.
Until last year, Savannah had been slowly deteriorating in the James River Fleet, but the Maritime Administration has invested some money to stabilize and repaint her. Though her reactor has not operated for more than 30 years, she is still a pretty ship.
Photo credits: Schooner under full sail and Annapolis Sailboat Show from Rod Adams under Creative Commons.
N. S. Savannah under power from US Government archives.
Savannah moored in Baltimore, MD on May 23, 2008 with permission from Joe Stroud.

