Tag Archives: Green Energy

Waste Heat Energy Recovery – ThermoAcoustic Refrigeration for Transportation Industry

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Revisiting the Automotive ThermoAcoustic Refrigerator – ATAR

Diagram of Simplified ThermoAcoustic Engine

I wish to further investigate the idea of thermoacoustics for waste heat recovery processes.  Also, will in future look into latest developments in thermoacoustics, including any applications, studies, reviews or products and manufacturers.

In today’s new economy of energy efficiency, there are technologies available that are worth further investigation that can be utilized for improved performance.  Automotive air conditioning is one industry which could bear further scrutiny, where running compressors consume valuable fuel, decreasing the energy efficiency and increasing operating cost of a vehicle.

For professional drivers where fuel consumption increases will come out of pocket, the utilization of air conditioning is an important consideration.  The idea of using the waste heat in the exhaust system to provide the cooling energy necessary to provide air conditioning is a novel approach to improving vehicle efficiency and comfort.  The concept of thermoacoustic refrigeration is not new, and was previously reviewed by concerns of the ozone layer depletion and refrigerants, which ultimately lead to changes in the refrigeration and HVAC industries.

See original reference paper presented at 2005 Proceedings of Acoustics:  http://bit.ly/17qwTYK

Reshaping Corporations: Can Divestment Work?

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With enough collective action, mass divestment campaigns can be effective in creating social change. 

Duane Tilden‘s insight:

>To be effective, a huge amount of money must be withdrawn from a company. Where boycotting unites individual buyers to have impact, individual stockowners aren’t likely to make a huge enough hit with divestment or negative investing for a corporation to take notice. Institutional owners, though, could impact a company or industry because collectively they control vast amounts. 

The Fossil Fuel Divestment Campaign

The current student campaign to divest from fossil fuels is interesting. For example, Harvard has $30 billion in endowment while Yale has $16.7 billion.

While it’s clearly not all in one company or industry, what kind of impact could university endowments have if they withdrew from fossil fuel companies and allied industries? By my count, there are well over a hundred campaigns at universities around the nation, and there are additional groups working to get towns and communities to join the fight. As a collective action, the potential for these divestment campaigns is fascinating to ponder.

Mass Divestment Creates Cultural Change

Perhaps the most important thing divestment shares with boycotting is publicity.  The attention that a mass divestment can bring to an issue could be profound. The student fossil fuels divestment effort is garnering national media attention, and rather than fizzling out seems to be gaining momentum. This attention could be as effective as actual divestment for dealing with climate change and fossil fuel issues. 

As Cecelie Counts wrote in January, divestment was just one tool used to combat apartheid and bring change in South Africa. I don’t know if there will be mass divestment among universities, but I suspect that this campaign will be successful in the long run because it’s educating a generation and could create the cultural change necessary to pursue long-term alternatives, change policy and pressure energy companies to adapt.<

See on csrwire.sharedby.co

Biofuel Production from Palm oil plantation waste

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NextFuels to produce biofuels from palm plantation residue – Renewable Energy Magazine, at the heart of clean energy journalism

Duane Tilden‘s insight:

>Edible palm oil has surpassed soybean to become the largest source of cooking oil in the world, accounting for over 50 million tons of oil annually.

While plantation owners have managed to increase the productivity of their land by 15X since the late 80s, the growth of the industry has created a corresponding residue problem. Approximately 4.4 to 6 metric tons of agricultural waste is generated for each metric ton of oil. There are over 1,000 crude palm oil (CPO) mills in Southeast Asia and a single (60 tons per hour) mill can generate 135,000 tons of agricultural residue a year.

NextFuels uses a system called bio-liquefaction that efficiently transforms agricultural biomass to green energy. Biomass is placed into the plant mixed with water. The mixture is then heated to 330-degree Celsius while pressure is increased to 220 bar. Increasing the pressure keeps the water from coming to a boil, which conserves energy.

When cooled, the hydrocarbons form a putty-like substance called GreenCrude. Roughly 25 percent of the GreenCrude can be burned as a solid fuel in industrial boilers. The remaining 75 percent can be converted into a liquid-fuel equivalent to petroleum that is compatible with existing pipelines and vehicles.

The equipment required to convert GreenCrude into liquid fuels, in a process called hydrodeoxygenation, is already installed at most refineries and can… <

See on www.renewableenergymagazine.com

Quantitative Analysis of Factors Contributing to Urban Heat Island Intensity

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Ryu, Young-Hee, Jong-Jin Baik, 2012: Quantitative Analysis of Factors Contributing to Urban Heat Island Intensity. J. Appl. Meteor. Climatol., 51, 842–854.

Duane Tilden‘s insight:

>This study identifies causative factors of the urban heat island (UHI) and quantifies their relative contributions to the daytime and nighttime UHI intensities using a mesoscale atmospheric model that includes a single-layer urban canopy model. A midlatitude city and summertime conditions are considered. Three main causative factors are identified: anthropogenic heat, impervious surfaces, and three-dimensional (3D) urban geometry. Furthermore, the 3D urban geometry factor is subdivided into three subfactors: additional heat stored in vertical walls, radiation trapping, and wind speed reduction. To separate the contributions of the factors and interactions between the factors, a factor separation analysis is performed. In the daytime, the impervious surfaces contribute most to the UHI intensity. The anthropogenic heat contributes positively to the UHI intensity, whereas the 3D urban geometry contributes negatively. In the nighttime, the anthropogenic heat itself contributes most to the UHI intensity, although it interacts strongly with other factors. The factor that contributes the second most is the impervious-surfaces factor. The 3D urban geometry contributes positively to the nighttime UHI intensity. Among the 3D urban geometry subfactors, the additional heat stored in vertical walls contributes most to both the daytime and nighttime UHI intensities. Extensive sensitivity experiments to anthropogenic heat intensity and urban surface parameters show that the relative importance and ranking order of the contributions are similar to those in the control experiment.

Keywords: Urban meteorology

Received: May 7, 2011;<

See on journals.ametsoc.org

NASA – Ecosystem, Vegetation Affect Intensity of Urban Heat Island Effect

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NASA researchers studying have found that the intensity of the “heat island” created by a city depends on the ecosystem it replaced and on the regional climate.

Duane Tilden‘s insight:

I have measured the heat island effect in the Greater Vancouver area, specifically Metrotown, Burnaby to be in the order of 6 deg C, during a late summer evening.

>”The placement and structure of cities — and what was there before — really does matter,” said Marc Imhoff, biologist and remote sensing specialist at NASA’s Goddard Space Flight Center in Greenbelt, Md. “The amount of the heat differential between the city and the surrounding environment depends on how much of the ground is covered by trees and vegetation. Understanding urban heating will be important for building new cities and retrofitting existing ones.”

Goddard researchers including Imhoff, Lahouari Bounoua, Ping Zhang, and Robert Wolfe presented their findings on Dec. 16 in San Francisco at the Fall Meeting of the American Geophysical Union.

Scientists first discovered the heat island effect in the 1800s when they observed cities growing warmer than surrounding rural areas, particularly in summer. Urban surfaces of asphalt, concrete, and other materials — also referred to as “impervious surfaces” — absorb more solar radiation by day. At night, much of that heat is given up to the urban air, creating a warm bubble over a city that can be as much as 1 to 3°C (2 to 5°F) higher than temperatures in surrounding rural areas.

The impervious surfaces of cities also lead to faster runoff from land, reducing the natural cooling effects of water on the landscape. More importantly, the lack of trees and other vegetation means less evapotranspiration — the process by which trees “exhale” water. Trees also provide shade, a secondary cooling effect in urban landscapes.

Using instruments from NASA’s Terra and Aqua satellites, as well as the joint U.S. Geological Survey-NASA satellite Landsat, researchers created land-use maps distinguishing urban surfaces from vegetation. The team then used computer models to assess the impact of urbanized land on energy, water, and carbon balances at Earth’s surface. <

See on www.nasa.gov

Energy Efficiency Methods in the Cement industry – Part 1: Organic Rankine Cycle

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Thomas B. Gibbons takes a look at the Conventional Rankine Cycle’s application in the cement sector

Duane Tilden‘s insight:

>The first major waste heat recovery (WHR) system in a cement plant was the 15 MW unit installed by Kawasaki Heavy Industries for Taiheiyo Cement in 1982. This was a conventional Rankine Cycle using heat from both the kiln and the clinker cooler. As the benefits became generally recognised within the industry, WHR units, the vast majority of which involved the conventional Rankine Cycle, were installed to provide up to about 30% of the power requirements of the plant. The main sources of waste heat were the exhaust from both the preheater and the clinker cooler and, in some of the developing countries where power outages are not unusual, the WHR system may be the only source of reliable power available to the plant operator.

Improvement in the overall efficiency of cement manufacture has resulted in lower exhaust gas temperatures and this development has provided opportunities for alternative technologies, notably the Organic Rankine Cycle (ORC) and the Kalina Cycle, which are more effective in recovering waste heat from lower temperature gases.<

See on www.worldcement.com

Lockheed Martin Pioneers Ocean Thermal Energy in China – Engineers

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A 10-megawatt ocean thermal energy conversion plant is under way

Duane Tilden‘s insight:

>[…] the company has been working on OTEC since the 1970s, and the technology hasn’t changed drastically since then. OTEC systems make use of the temperature differential in tropical areas between warm surface water and cold deep water. In most systems, ammonia, which has a very low boiling point, passes through a heat exchanger containing the warm water. The ammonia is vaporized and used to turn a turbine, and then it’s cycled past the cold water to recondense. This is a renewable energy technology with the rare capacity to supply base-load power, as water temperatures are fairly stable.

The ammonia passes through a closed loop, while the water comes and goes through massive pipes. The project in China may pump cold water up from a depth of about 1000 meters, using a pipe that’s 4 meters across. Varley says that some of the infrastructure can be borrowed from the offshore drilling industry: “We showed them our requirements for the platform, and they yawned and said, ‘Is that all you got?’ ” he says. “But then we showed them the pipe.” Attaching the massive pipe to a relatively small floating platform creates unusual stresses, Varley says. Lockheed also had to find materials for the pipes and the heat exchangers that could withstand the harsh marine environment.<

See on spectrum.ieee.org

Debunking the Renewables “Disinformation Campaign”

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Misleading coverage fuels policy uncertainty and doubt, reducing investment security and industry development. Disinformation hurts the industry and retards its—and our nation’s—progress

Duane Tilden‘s insight:

The Fox Business example is not a singular incident. Some mainstream media around the world have a tendency to publish misinformed or, worse, systematically and falsely negative stories about renewable energy. Some of those stories’ misinformation looks innocent, due to careless reporting, sloppy fact checking, and perpetuation of old myths. But other coverage walks, or crosses, the dangerous line of a disinformation campaign—a persistent pattern of coverage meant to undermine renewables’ strong market reality. This has become common enough in mainstream media that some researchers have focused their attention on this balance of accurate and positive coverage vs. inaccurate and negative coverage.

Tim Holmes, researcher for the U.K.’s Public Interest Research Centre (PIRC), points out press coverage is important because it can influence not only “what people perceive and believe” but also “what politicians think they believe.” […]

The disinformation campaign about job creation is not limited to Europe. A Cato Institute article claimed that if people believe a commitment to renewables will fuel job growth “we’re in a lot of trouble.” Yet in 2012 alone, more than 110,000 new U.S. clean-energy direct jobs were created, and in 2010, the U.S. had more jobs in the “clean economy” than in the fossil-fuel industries. The Bureau of Labor Statistics reportsthat direct employment in May 2012 totaled 181,580 for oil and gas extraction, 87,520 for coal mining, and 93,200 for iron and steel production. BLS doesn’t similarly classify solar or wind jobs, but reputable analysts have determined from bottom-up industry surveys that in September 2012, for example, the U.S. had 119,016 direct solar jobs (89 percent full-time, the rest at least half-time), up 27 percent in two years—more than in steel-making or coal-mining. Had you heard that before? Why not?

THE COST OF DISINFORMATION

The sad truth is that the debate on clean and renewable energy is unbalanced, and seldom by accident. The CCGroup’s study showed that only 10 percent of articles focusing on renewables even contained comment from a spokesperson from the renewable energy industry. This violates basic journalistic standards. Renewables must be a part of their own conversation. Much of the conversation on renewables is misinformed and misrepresented. And when bad news does happen, says ACORE president and retired U.S. Navy Vice Admiral Dennis McGinn, opponents of renewables are pushing it “as if it’s the only news. They are dominating the conversation through misrepresentation, exaggeration, distraction, and millions of dollars in lobbying and advertising.”<

See on blog.rmi.org

Jobs for the Future: Energy Efficiency creates Employment — ECEEE

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Energy efficiency initiatives create jobs, and normally very good jobs.  Recent analysis shows that between 17 and 19 net jobs can be created for every million euros spent.

Duane Tilden‘s insight:

>Jobs to improve energy efficiency in all end-use sectors are of high value.  Many require technical qualifications, such as engineering or architectural degrees.  Many require re-training from existing jobs. There will be a demand for financial specialists, construction engineers, behaviour specialists, project managers, auditors, data base managers, policy analysts and the like.  And these jobs are available to all, regardless of age or gender.

The hard work of creating these jobs begins once the Directive is finally approved.  The long-term policy framework needs to be in place and the funding and implementation strategy need to be well developed. But in the longer term, opportunity is knocking at the door, and it deserves a welcome mat.<

See on www.eceee.org

A Republican Case for Climate Action

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By WILLIAM D. RUCKELSHAUS, LEE M. THOMAS, WILLIAM K. REILLY and CHRISTINE TODD WHITMAN Published: August 1, 2013The United States must move now on substantive steps to curb climate change, at home and internationally.

Duane Tilden‘s insight:

>Mr. Obama’s plan is just a start. More will be required. But we must continue efforts to reduce the climate-altering pollutants that threaten our planet. The only uncertainty about our warming world is how bad the changes will get, and how soon. What is most clear is that there is no time to waste.<

See on www.nytimes.com