Downsizing Dilemmas

why can some things that work on the lab bench (fuel cells, for example) have difficulty scaling up in size?   Topic for a long post.  For fuel cells, it is about cost… piling stacks upon stacks does not allow for economies of scale.   What interests me today is downsizing things that work on big scales – what problems do we get when we try to make them small?    Case in point are gasifiers. Successfully built at grand scale (IGCC power plants), there are frightfully few examples that work economically on the small scale.  why???  I will throw out two – first, small scale systems will startup and shutdown frequently which is a problem with gasifiers that need perfect temperatures.  Second, and along the same lines, small gasifiers will behave more three dimensionally because of their limited size.   There will necessarily be horizontal gradients in temperature, for example, which can be ignored in monster sized vessels.   Others???

Carbon Capture, Viable or just another Parasitic Load?

Carbon Capture Plant Opens in Germany Amid Reservations

Energy giant Vattenfall has launched an emissions-free coal-fired test plant near Berlin using a technology touted as a huge potential breakthrough in the fight against global warming. But critics aren’t convinced.

Swedish energy utility Vattenfall sees carbon capture and storage (CCS) as a revolutionary answer to global warming which is largely blamed on carbon dioxide released when fossil fuels burn.

“This technology will become more important than offshore wind farms,” said Vattenfall boss Lars Josefsson.

“Our project at Schwarze Pumpe puts us at the forefront of this technology in the world,” said Tuomo Hatakka, the chief executive of Vattenfall Europe, referring to the the 70-million euro plant in eastern Germany.

Vattenfall, one of Europe’s largest energy companies, hopes the project will help provide energy security through plentiful coal supplies while avoiding the CO2 emissions that are blamed for global warming.

Vattenfall underscores “clean technology” aspect

A Finnish-born executive who heads the Swedish group’s Berlin-based subsidiary, Hatakka told German newspaper Frankfurter Allgemeine Zeitung the process was viable because companies will have to buy EU allowances for every ton of carbon dioxide they release into the air.

Chancellor Merkel visits a carbon capture and storage plant in eastern GermanyBildunterschrift: Großansicht des Bildes mit der Bildunterschrift: The CCS test plant has drawn prominent visitors including Chancellor Merkel

“In tandem with EU-wide trading in emission rights, CCS will be economic. At 30 to 35 euros per emission certificate, the technology breaks even,” he said.

The 30-megawatt pilot plant at Schwarze Pumpe in the Lausitz region of eastern Germany is very small compared to conventional power stations. But it’s the first coal-fired power plant in the world ready to capture and store its own carbon dioxide emissions — a so-called CCS plant.

Carbon dioxide emitted when lignite coal burns will not be vented up a chimney but piped away, compressed to a liquid and pumped into deep, porous rock. The concentrated carbon dioxide will then be injected “for permanent storage” in a gas field in northern Germany.

Vattenfall plans to build two “demonstration plants” 10 times that size in Germany and Denmark by 2015 at the latest. Hatakka said the company aimed to commission its first “large-scale CCS power station” in 2020.

The outcome of this new plant will be heat, water vapor, nine tons of CO2 per hour and a milestone in clean energy technology, according to  Markus Füller, a spokesman for Vattenfall.

“This process is necessary if we ever hope to continue using soft, lignite coal, he says. We need to get a handle on the CO2 problem, and we think this technology is the way to do it,” Füller said.

Critics aren’t convinced

But environmentalists say the technology uses far more energy than existing power generation and warn that there are no secure long-term storage facilities for the gas.

German conservation group BUND on Monday denounced the project as simply a cover allowing Vattenfall to expand its network of conventional coal-fired power stations in Germany.

Cooling towers of a coal power plant in GermanyBildunterschrift: Großansicht des Bildes mit der Bildunterschrift: Some critics say the focus should be on expanding cheaper renewable energy rather than on polluting coal

Thorben Becker of BUND said it was still uncertain if CCS worked on a large scale. CCS power stations would obtain 10 per cent less power from the coal than conventional plants did, and it was not clear if there were enough suitable sites to dump the CO2.

“Instead of concentrating on far cheaper renewable energy, Vattenfall is locking itself in for decades to converting climate-damaging brown coal into electricity,” he said.

The European Union wants to have 10 or 12 full-scale CCS power stations within the next few years, but it is not clear who will pay the high costs of building and running the plants.

Is burning “Biomass” carbon neutral?

This fundamental question keeps coming back to me again and again from many people. 

Is burning “Biomass” carbon neutral?

FYI: The EIA Greenhouse Gas reporting protocol treats “Biomass” particularly wood or wood-chips carbon neutral.

http://www.eia.doe.gov/oiaf/1605/coefficients.html

http://www.eia.doe.gov/oiaf/1605/coefficients.html

 

Europe Turns to Coal Again, Raising Alarms on Climate

This is an article from NYtimes.com 4/23/08

Very interesting article about how the pluses of coal outweigh the fears of climate change in Europe.  The picture is also very dramatic!!!  The entire article would have taken up 3 pages, so I just gave a teaser and the rest in online at this link

http://www.nytimes.com/2008/04/23/world/europe/23coal.html?_r=1&hp&oref=slogin

CIVITAVECCHIA, Italy — At a time when the world’s top climate experts agree that carbon emissions must be rapidly reduced to hold down global warming, Italy’s major electricity producer, Enel, is converting its massive power plant here from oil to coal, generally the dirtiest fuel on earth.

Skip to next paragraph

Marco Di Lauro for The New York Times

Italy’s Civitavecchia power plant is converting from oil to coal.

Over the next five years, Italy will increase its reliance on coal to 33 percent from 14 percent. Power generated by Enel from coal will rise to 50 percent.

And Italy is not alone in its return to coal. Driven by rising demand, record high oil and natural gas prices, concerns over energy security and an aversion to nuclear energy, European countries are expected to put into operation about 50 coal-fired plants over the next five years, plants that will be in use for the next five decades.

In the United States, fewer new coal plants are likely to begin operations, in part because it is becoming harder to get regulatory permits and in part because nuclear power remains an alternative. Of 151 proposals in early 2007, more than 60 had been dropped by the year’s end, many blocked by state governments. Dozens of other are stuck in court challenges.

Solar Thermal’s Rise to Power (get it?)

With Professor Jaluria’s upcoming lecture on solar thermal power, i figured it would be nice to have some background and context. While photovoltaic systems are what most people associate with solar-derived electrical power, thermal systems are, at this point, the most efficient method for generating electricity from solar energy.

Solar thermal power generation was first looked at in the 1970’s during the oil crisis. This research resulted in the SEGS (solar energy generating systems) commercial project, which consisted of 9 different solar plant’s in California’s Mojave Desert (constructed between 1984-1989). Total capacity of the plants, which are still in operation today, is 354 MW. By comparison, the largest PV system currently operational in the world is a 20 MW facility in Spain. This, however, was the only real solar thermal electrical generation facility in the US until 2005.

2005 saw a revival of solar thermal. A company by the name of Stirling Energy Systems emerged with economically sound proposals for new solar thermal facilities. Named Top 25 Breakout Companies of 2005 by Fortune magazine, they signed contracts with Southern California Edison to develop more solar thermal facilities (500MW) in the Mojave Desert.

Most recently, California Utility PG&E signed a contract to develop 900 MW of solar thermal power over the next couple of years from Brightsource Energy.

These are not the only companies trying to get set up in the Mojave.

It seems like solar thermal is really making a splash. Some questions to think about going into Professor Jaluria’s lecture on 4/21 (for those of you in Professor Muller’s Energy Seminar):

How far can electricity be transmitted from desert areas without significant tranmission losses? Can superconductivity be viable in such a hot environment?

Stirling Energy Systems is using Stirling Engine technology (hence the name) to generate electricity from a thermal gradient. How do these engines work? Why do they have higher efficiency than, say, a steam engine?

Thermal energy storage is a key component to any solar thermal installation. I believe they are using molten salts to store their energy. How efficient can an energy storage system like this be?

-jk

More links:

http://en.wikipedia.org/wiki/Solar_thermal_energy

http://www.sandia.gov/news/resources/releases/2004/renew-energy-batt/Stirling.html

http://en.wikipedia.org/wiki/Stirling_Energy_Systems

Alternative to load shedding?

I just came back from Bombay where they have a huge electrical congestion problem. They are trying to build new plants, but the companies that the government has commissioned for the new plants have yet to meet any of their deadlines.

The current solution is scheduled load shedding. Every morning from 9 to 10:30 and then again from 3 – 4:30 the power would go out for our neighborhood. To be blunt, it was terrible. The midday temperatures were well over 90 and without a fan, it stunk in more ways than one. Also, good luck if you were caught in an elevator at these times.

I can’t imagine this being good for anyone, particularly the local economy. I know I would not be out during these times and the shops would be very dead at these times.

One solution would be generators for the buildings. However, with all the existing vehicular pollution, adding a generator every 50 feet would considerably worsen the already poor air quality problem. Plus, generators are not cheap.
I was wondering what people thought of regulating the amount of electricity each user throughout the city gets rather than blacking out neighborhoods. At any given time, each user would not be able to draw more than a certain wattage. All that would be needed would be a fuse on the users incoming electricity that would blow if a certain draw were exceeded. This way, the store owners could at least turn on the fan, or someone could at least operate an elevator in an emergency situation, etc. I could also only turn on what is most important to me. While I understand that this would not save energy, it would make day to day living better.

While thinking about this, I really realized that energy problems and their solutions are closely tied to social habits. For example, I do not think that regulating electricity would work in America. Going from all the electricity we want to regulation would be far too difficult as it would be moving backwards. But going from 3 hours of blackouts to constant electricity would be an upgrade and welcomed (I would imagine). What works in one country will not work in another. Perhaps this point is obvious, but I really grew to understand it at around 3 pm every day for the past three weeks.

Wind power not as safe as we think?

Now before we start taking down our turbines, we have to realize that wind turbine failure is very uncommon. I’ll make the analogy to air travel. Many people are afraid to fly even though statistically its much more dangerous to travel by car. Statistics and probability do not always correlate with public fear.

The question: Are these breakdowns the product of improperly sized turbines (i.e. NYC East River tide turbines)? Or is the occasional wind turbine failure inevitable?

-jk

http://earth2tech.com/2008/02/26/vestas-wind-turbine-explodes-with-power/

High-Altitude Wind

An article I just read mentioned this concept… its the first time i’ve heard of it. Apparently Google.org (Google’s philanthropic arm) is investing $10 million into a company (Makani Power, Inc.) with a proprietary design for harnessing high altitude wind.

The idea here is that with higher altitudes come much stronger winds.

makani_high-altitude_wind-power_425_bf8.gif

Wind also becomes much more dependable:

makani_high-altitude_wind-dependability_450_bf16.gif

The upper side of these graphs, however, seems pretty ambitious. Since the tallest building in the world is about 800m, a terrestrial building wouldn’t even make it to the first tick mark. Instead, it must be some sort of massive kite or blimp.

$10 million isn’t exactly chump change… Google must really see something concrete here. Since its proprietary, no designs are disclosed on the website. Any ideas on what they could be thinking of?

http://www.reuters.com/article/ousivMolt/idUSN0630565920080206

UPDATE:

I found a few concepts for kites that people have come up with.  Pretty cool stuff.. although pretty far from safe.

laddermill_diagram.gif

skywindpower.jpg

That first one has apparently been developed and tested successfully:

http://www.rense.com/general78/kinet.htm 

List of High Altitude Wind Companies/Concepts:

http://peswiki.com/index.php/Directory:High_Altitude_Wind_Power

Article on CO2 and Temp correlations

This was on the word press homepage on sat afternoon. It has an article attached:

http://wattsupwiththat.wordpress.com/2008/01/25/warming-trend-pdo-and-solar-correlate-better-than-co2/

This guy started the weather channel and shows with data that CO2 and temp changes do not correlate well (an R squared correlation of 0.44), but rather cycles in ocean, Pacific Decadel Oscillation (PDO) and Atlantic Multidecadal Oscillation (AMO) correspond much better to the temp changes. He explains how the PDO creates El Ninos and La Ninas. He gets an R squared of 0.83. I do not fully understand PDO and AMO and its driving mechanisms, so it is tough for me to readily except the relationship. He also relates temp changes to Total Solar Irradiance (TSI) and explains how changes in the sun’s “brightness” can create atmospheric temperature changes. Finally he shows that there is a negative correlation between CO2 and temp changes since in the last decade, which is when he was seen the temperatures spike the most. I do believe that correlation is not causation, but do I think discrepancy eliminates causation.

The following link was written in response to the above by some guy at U of Alabama – Huntsville. It shows CO2 solubility in water with temperature (CO2 = 0.323e^(.0316Temp))) and suggests that perhaps rising atmospheric temperature changes are driving increased CO2 concentrations, not the other way around. He uses the data at Mauna Loa, Hawaii – which is the main source of data for atmospheric temperature that guys like Al Gore discuss.

http://wattsupwiththat.wordpress.com/2008/01/25/double-whammy-friday-roy-spencer-on-how-oceans-are-driving-co2/

He very nicely explains a dip in temperatures in 1992, writing that oceanic cooling caused by a cooling of a mountain created the drop in CO2 concentrations.

I enjoyed these articles and thought I’d send them along.

From SN:

So the questions are how much CO2 stays in the air, and how much dissolves into the ocean.

If a lot of CO2 ends up in the ocean, there will be less in the air, and the effects of global warming may be reduced. If the ocean releases CO2 back to the atmosphere, the greenhouse effect may be enhanced or prolonged.
Look at the temperature and CO2 plots with temperature and CO2 data from BATS (Bermuda Atlantic Time-Series Study)

http://www.coexploration.org/bbsr/classroombats/html/tempco2plot.html

From Jkace:

As one of the few posters here who thinks there may be something to this whole global warming thing, I will be playing the role of devil’s advocate.

It looks like someone spent a lot of time trying to compare this data. While it sure looks good as finished graphs, there are a few problems. First, the graphs scale differently on the Y-axis, showing that the data fits visually much better than it does quantitatively.

Using increased solar irradiation as an explanation for our current rise in temperatures has been disproven. If the sun were acutally getting hotter, we would see an increase in temperatures more significant on the outer layers of the atmosphere. With the “greenhouse effect”, radiation pierces these layers and heats lower levels of the atmosphere. Temperature data from the outer atmosphere has actually shown a cooling over the past 100 years.

As for PDO, I believe this is an effect more than a cause. A general warming trend would lower the solubility of CO2 in the ocean, which releases additional CO2 into the atmosphere. A lot of the effects of global warming are like this (reflection of light on ice versus absorption in liquid).  These effects help explain why CO2 is at the highest level its been in the past 400,000 years (by over 20%), even though “human produced” CO2 only accounts for 5% of the carbon cycle (a popular anti-global warming talking point).

One last point… this temperature data set, while comprehensive, only looks at the continental United States. Any true statistical analysis needs to consider the entire planet. Unless we put the US into an adiabatic box.

Cooling in a drought

A story in today’s USA Today suggests problems in the south with lack of water and cooling of nukes.

http://www.usatoday.com/weather/drought/2008-01-24-drought-power_N.htm

In NJ we have a problem with cooling at the Oyster Creek plant. Two ways to use water – one is to cool directly, taking water from a source, heating it up and returning it (hopefully not hot enough to cook fish). The second is to take water and evaporate it. The second is powerful, but actually consumes the water!!! So as water becomes scarce (and warm), which is the least harmful way to cool a power plant? mrm

From M. Khan:

… a new way to cool nuclear reactors which would supposively save upto 98% of water used by existing nuclear reactors… being built in Southern Maryland – scheduled to be up and running by 2015 (joint venture between Constellation energy and a french company) – a similar hybrid cooling tower was built in West Germany back in 1988

nuclearcooling.jpg

http://www.baltimoresun.com/news/local/bal-te.md.reactor25dec25,0,4107050.story

They call it a hybrid-cooling tower… what is it exactly a hybrid of? How does it work differently than a traditional tower? It uses fans… but wouldn’t that increase the evaporation rate, as opposed to conserving it?  -jk

I was able to find a “hybrid type” cooling tower from SPX, apparently they use a heat exchanger to pull heat from the cooling water  into an air-stream, which can help curb evaporation.  -jk

http://spxcooling.com/en/library/detail/balcke-hybrid-cooling-tower/