Archive for the ‘informative’ Category

The future of sharing, sharing for the future

Tuesday, September 7th, 2010

Earth2Tech’s Katie Fehrenbacher offers her take on Rachel Botsman’s forthcoming book What’s Mine Is Yours: The Rise of Collaborative Consumption. Fehrenbacher highlights the positive environmental impacts of peer-to-peer sharing and how the Internet is enabling the practice.

The article gets to the heart of the matter:

In the U.S., Botsman says “80 percent of the items people own are used less than once a month,” and collaborative consumption is “the reckoning of how we can take this idling capacity and redistribute it elsewhere.”

The ultimate idea is to have our economy value units of usage over units sold, and then the notions of “eco-efficiency and business efficiency align,” explains Botsman. In that world, sustainable design and longevity of goods become much more important in the production process. Car sharing might represent one of the largest available efficiency gains and Botsman says that “one car share gets approx 7-8 vehicles off the road.”

US energy use down, efficiency too? UPDATE

Friday, August 27th, 2010

The numbers are out on how much energy the country used in 2009: less than we did in 2008. This isn’t surprising given the economic situation.

We’re also using more renewable energy, particularly wind power. This isn’t surprising either, given the growth in the wind energy sector in recent years and the stimulus funding.

The numbers, from Lawrence Livermore National Laboratory, show the same trends as last year.

Energy efficiency has also stayed consistent. The US lost 58% of the energy it generated in 2009 and 57.5% in 2008. Transportation energy losses were 75% and electricity sector losses were 68% in both years.

However, look a few years further back and you’ll see that our national energy efficiency is declining. The US lost 56% of the energy it generated in 2006. Transportation losses were 71% and electricity sector losses were 65%.

I combined the 2006 categories cars, freight and aviation into the equivalent of the 2008 and 2009 transportation category, so there could be a discrepancy there. But as far as I can tell there haven’t been any methodology changes.

So what’s the story? A couple of percentage points might not seem like a lot, but it represents a huge amount of energy. That’s about 2 quadrillion BTUs, which is nearly double the combined amount of wind, solar and geothermal energy the US generated last year. More importantly, it shows we’re moving in the wrong direction.

If anyone has an explanation or more details, let me know.

UPDATE 8-31-2010

Turns out there are some changes in how the numbers were derived from 2006 to 2008 and 2009, particularly the electricity generation numbers, according to A.J. Simon, an Energy Systems Analyst at Lawrence Livermore National Laboratory.

But the main reason for the apparent drop in efficiency is a shift in where we spend our energy.

“The slight decline in efficiency that you calculated is due to the slowly changing distribution away from the industrial sector and towards transportation,” said Simon.

This helps put in perspective the importance of efficient transportation.

Peak coal looming?

Thursday, August 5th, 2010

Unlike the high concern over peak oil, discussions about peak coal have tend to produce less energy, so to speak. This might change with a new study that adds weight to the idea that global peak coal will happen sooner rather than later, and this should make coal reserves a bigger consideration in today’s decisions about climate change and energy security.

The study says peak coal will happen next year or near to it, and studies and policies based on assumptions about centuries worth of coal remaining available are flawed. For instance, the Intergovernmental Panel on Climate Change (IPCC) has incorrectly assumed 100 years of increasing carbon dioxide emissions under business-as-usual scenarios, according to the study’s authors.

At the same time, the study’s lead author, Tad Patzek, said in a press release that carbon sequestration efforts are misguided:

“The current global hysteria around carbon capture and sequestration is leading to desperately poor government policies,” says Patzek. “For instance, large-scale subsurface sequestration of CO2 will decrease power plant efficiency by up to 50 percent. The same resources could be spent more wisely on increasing U.S. coal-fired power plant efficiency by 50 percent from the current 32 percent.”

Making coal-fired power plants emit less carbon may be a better route than trying to capture some of the carbon they produce, but this is arguing at the margins of the larger problem. We’ve already emitted enough carbon dioxide to assure nasty climate change effects. We need to drastically reduce emissions rather than simply slow their growth.

The notion that peak coal is just around the corner complicates efforts to model climate change. But it doesn’t change the problem we face or the stark choices we’re left to consider.

Peak coal will increase the cost of coal over time, but it’s not likely to do so sharply enough for soon enough to substitute for a price on carbon emissions. And growing energy demand could easily lead governments to find ways to increase coal subsidies.

From an energy security perspective — if nothing else — peak coal should spur us on to kick the carbon habit (no, it won’t be easy; yes, there will be pain). I worry when, instead, people talk about devoting resources to getting the most out of the fossil fuels we have left.

Statistical illiteracy

Sunday, April 25th, 2010

Clive Thompson has a nice piece in Wired on statistical illiteracy. He points out that without a good understanding of statistics it’s hard to understand climate change, among other issues. As he puts it:

“There are oodles of… examples of how our inability to grasp statistics — and the mother of it all, probability — makes us believe stupid things.”

Ultracapacitors in the news

Monday, February 22nd, 2010

An Intel lab is developing nanomaterials for ultracapacitors, according to EE Times Asia (via Technology Review). The lab’s goal is to make devices that store more energy than today’s lithium-ion batteries.

And Mitsubishi Electric has a prototype hybrid ultracapacitor, according to a Nikkei Electronics story. The device has high power and high capacity but a relatively low number of cycles.

Intel and Mitsubishi Electric have a lot of company, as detailed in the new ERN report on ultracapacitors.

Report on ultracapacitors: major advances on tap (updated)

Tuesday, February 2nd, 2010

You’ll be hearing a lot more about ultracapacitors in the next few years. The devices are poised to transform energy storage by taking over high-power functions from batteries in three key areas:

* Tying wind and solar farms to the power grid
* Stabilizing the grid
* Powering hybrid and electric vehicles

The ERN Research report, Ultracapacitors: Emerging technologies for high-power energy storage, analyzes ultracapacitor technologies for these large-scale applications.

The report details ultracapacitor types, emerging ultracapacitor applications, the components that make up ultracapacitors, the factors that contribute to ultracapacitor cost, performance variables, and future directions.

The report includes detailed profiles of

* 15 startups that are readying potential ultracapacitor breakthroughs
* 27 manufacturers and 29 other companies that have recently developed ultracapacitor technologies
* 52 researchers around the world who are pushing the boundaries of ultracapacitor science and engineering

Some highlights:

One of the hottest ultracapacitor technologies is electrodes made from closely-packed, vertical carbon nanotubes. These prototype electrodes store an order of magnitude more energy than today’s best commercial devices. Players to watch include MIT spinoff FastCAP Systems, research firm ADA Technologies and major ultracapacitor manufacturer Nippon Chemi-con.

Much ultracapacitor development is aimed at driving down costs. This usually means making cheaper carbon electrodes. Players to watch include startup SolRayo, activated carbon maker Reticle, research company TDA Research and University of Kentucky researcher Stephen Lipka.

Electrolytes are another key area, and ionic liquids and lithium are the hot topics. Players to watch include ADA Technologies, Kansai University’s Masashi Ishikawa, Bologna University’s Marina Mastragostino and research company LithChem.

Meanwhile, cutting-edge materials and nanotechnology research promise to push the boundaries of ultracapacitor technology. Researchers to watch include Yonsei University’s Kwang-Bum Kim, University of Texas’ (and Graphene Energy, Inc.’s) Rod Ruoff, MIT’s Yang Shao-Horn and Florida State University’s Jim Zheng.

Given the expected boom in ultracapacitors over the next five years and the differences among application requirements, it’s likely that there will be room for several emerging technologies to reach the market.

Ultracapacitor energy storage capacities are likely to increase by five to 10 times in the next five years, but ultracapacitors aren’t likely to make batteries obsolete. They will, however, replace batteries for many power-intensive applications, including hybrid vehicle acceleration and regenerative braking.

Several laboratory ultracapacitor prototypes are already providing 10 times the power and capacity of today’s commercial ultracapacitors. The key question is how readily these materials can be mass-produced and whether they can be made cheaply enough.

Biofuel chemistry — taking the sugar out

Thursday, January 7th, 2010

Turning biomass into liquid fuel isn’t all that difficult, but doing so cleanly and efficiently involves some tricky chemistry. Researchers are working on catalysts that completely convert precursor liquids into final products and that can be readily recovered and reused.

A paper in the current issue of Science details double-sided nanoparticles that accomplish both goals by collecting at the water-oil interface. Accompanying the paper is a perspectives article by University of St. Andrews’ David J. Cole-Hamilton.

The chemistry professor does a nice job of putting things in perspective with a nifty image. He asks us to imagine stirring milk and sugar into a hot cup of tea and then extracting the sugar. He points out that in biofuels processing, the “sugar” is catalysts that are often highly toxic.

So green biofuels processing requires more than just mixing oil and water. It also means finding ways to get the sugar out.

A thought for food

Monday, November 2nd, 2009

For every one degree Celsius increase in global temperature, there’s a 10 percent decrease in crop yield.

Crop yields could be down by 1/3 to 1/2 by 2100, when the global population is likely to be considerably larger than it is now, said David Battisti, a professor of atmospheric sciences at the University of Washington. Battisti was a speaker at a geoengineering workshop at MIT Friday.

A recent study shows that U.S. crop yields are likely to decrease somewhere between 30 and 82 percent by the end of the century, depending on the pace of global warming.

Battisti said that rising sea levels and increasingly destructive droughts and flooding caused by global warming aren’t severe enough problems to convince him to consider drastic measures like geoengineering — deliberately altering the climate to counteract our unintended alterations. The impact of global warming on global food production, however, is another matter. “It’s the one thing that scares me,” he said.

There’s not a lot of unexploited viable cropland left, and we already have a billion people malnourished today, he said.

While today’s food security issues probably have more to do with political and economic factors affecting food distribution networks than they do with crop yields, the larger picture Battisti paints is scary. I hope a lot more research focuses on the problem. This also raises the stakes in the biofuel-versus-food debate.

The MIT workshop addressed the questions of whether geoengineering is possible and whether we should attempt it. The consensus was that precious little science has been done on geoengineering, what science is emerging is revealing that geoengineering is highly risky and uncertain, global warming is so bad that we need to consider geoengineering anyway, and we need to get busy with research on the problem. Several scientists expressed concern that we won’t be able to reduce the uncertainty in the time we have left.

The issue of the geoengineering moral hazard — whether taking geoengineering seriously leads people to weaken their resolve on emissions reductions — was also discussed at the workshop (see previous post).

Geoengineering at MIT: The spike on the steering wheel

Sunday, November 1st, 2009

There’s serious concern in the scientific and environmental communities about the geoengineering moral hazard — the fear that studying or even just talking about geoengineering will cause people to give up on or at least lose focus on our primary mission: reducing greenhouse gas emissions. The issue came up several times at the MIT geoengineering workshop Friday.

It’s an important concern, especially given the entrenched interests who are opposed to reducing emissions and the difficulty of convincing the public to make sacrifices when faced with a long-term, difficult-to-perceive threats.

I don’t think researchers should avoid studying geoengineering. We might want to be careful about the name, however. It implies a greater degree of control and precision than we have or are likely to gain in the next generation or so. A misperception about precision could make it easier to persuade the public to accept geoengineering uncritically.

You can’t restrict a term to its teleological argument, said Jim Fleming, a science historian from Colby College. In other words, no matter how imprecise or unsuccessful the practice may be, it is still engineering.

It’s important to capture intentionality, said David Keith, an environmental sciences and chemical engineering professor at the University of Calgary. In other words, it’s engineering because engineers are attempting to achieve the degree of control and precision we associate with the term engineering.

Looking through the pessimism-brings-optimism lens, I see an inverse of the moral hazard. If these really smart people who understand climate as well as anyone say that geoengineering is fraught with peril and may not work but we should still consider it, then the threat from global warming must be truly scary and we should curb emissions now. I’m not counting on this idea to get much traction in Washington or with the public, however.

Better still, why not go on the offensive? MIT’s Kerry Emanuel, who moderated the panel discussion at the workshop, proposed threatening people with geoengineering: he cited British academic, environmentalist and risks expert John Adams’ rhetorical suggestion that if we want lower automobile accident rates, we should put spikes sticking out of every car’s steering wheel. “The [spike] is geoengineering, and it’s what we’re going to do if you don’t take your foot off the gas,” said Emanuel.

There are two unrelated categories of climate management, or geoengineering: solar radiation management and carbon dioxide removal. Much of the MIT workshop focused on solar radiation management, which could be implemented cheaply and would take effect quickly.

Solar radiation management calls for blocking sunlight with mirrors in space, aerosols in the stratosphere or artificially produced clouds. It would lower the planet’s temperature relatively quickly. However, it wouldn’t directly reduce CO2 levels. It would also alter precipitation patterns. And it could cause a rapid rebound in temperatures if it failed or was otherwise stopped.

There are two types of carbon dioxide removal: ocean and terrestrial. They’re more expensive and longer-term.

Ocean carbon dioxide removal involves fertilizing the oceans to amplify the natural carbon cycle, which sequesters carbon in the deep ocean. A consensus is emerging that this is a bad idea. It’s not clear that any of the proposals would work, and it appears that many if not all of them would be carbon positive, meaning they would produce more carbon in emissions than the carbon they would remove from the atmosphere.

Terrestrial carbon dioxide removal schemes could reduce carbon dioxide levels. The schemes range from forest management to industrial-scale chemical processes. Many of the scientists at the workshop said that terrestrial carbon dioxide removal could be an important or even necessary complement to emissions reductions. The principal downside is local and regional impacts: social, economic and environmental impacts of industrial facilities, and resource and land-use trade-offs involved in biomass management.

I’m still extremely wary of geoengineering. I think the proper context is climate scientist Ken Caldiera’s analogy to a parachute. You only use it in the face of certain disaster. We also don’t know yet whether what we have in geoengineering is a functional parachute.

Personalized energy

Thursday, May 21st, 2009

Call it the Jeffersonian energy model. MIT chemistry professor Daniel Nocera’s “personalized energy” plan has every home generating its own electricity and fuel from sunlight, and has power plants, transmission lines and gas stations fading into history.

Nocera has outlined the technology needed to realize this vision. And he says we’re in sight of making the technology economically viable.

The scheme, detailed in an essay in the journal ChemSusChem, boils down to using photovoltaics to generate electricity and solar water splitting to generate hydrogen. The hydrogen would fuel vehicles and power fuel cells for nighttime electricity.

Nocera’s lab developed a key enabling technology last year: a stable, inexpensive water-splitting catalyst made from cobalt and phosphate. Other research teams are working to integrate the catalyst with semiconductor materials in order to power the water-splitting reaction entirely by sunlight.

Nocera assumes that the average American home uses 20 kilowatt hours of electricity a day (the US Energy Information Administration puts the figure at about 30). A 3- by 2.5-meter solar water splitting panel can generate the hydrogen equivalent of 20 kilowatt hours from 5.5 liters of water in three hours, he said.

The challenge to making personalized energy affordable is lowering the cost of the scheme’s four components: water-splitting electrolyzer, photovoltaics, hydrogen storage and fuel cell. The electrolyzer is the most expensive component but the cobalt phosphate catalyst “puts a dent in that,” Nocera said.

In general, three things must happen to make personalized energy affordable, said Nocera.

First, researchers need to make fuel cells more efficient and less expensive. The key is finding alternative cathode materials. Today’s fuel-cell cathodes use platinum, which accounts for 38 percent of a fuel-cell’s cost. Researchers are looking for materials that are abundant, inexpensive and minimally damaging to extract and refine.

Second, researchers need to develop good hydrogen storage systems. Many research teams are working on materials that can store hydrogen at reasonable temperatures and pressures, but this is long-term research. We might see something practical in a decade or two. Another option is storing compressed hydrogen gas in tanks, said Nocera.

Third, researchers need to find ways to use sunlight to power water splitting. Many researchers are working on the problem, and many of them are looking at titanium dioxide nanostructures. The cobalt phosphate catalyst developed by Nocera’s group has opened new possibilities here.

University of Washington researchers are working to combine the catalyst with iron oxide, commonly known as rust. The work so far allows sunlight to generate some of electricity needed to drive the water splitting reaction, said Daniel Gamelin, an associate professor of chemistry at the University of Washington.

In the long run, all of the power should come from sunlight, said Gamelin. “As a community, we’re not so incredibly far away from this objective.”

The electricity generating aspect of personalized energy has been around for years in the form of residential photovoltaic systems, said Martin Green, a photovoltaics pioneer at the University of New South Wales. “The challenge is clearly the cheap storage systems,” he said.

Personalized energy is the most direct path to solving the energy challenge and should be a major goal of national and global energy policies, said Nocera.

I like his vision of everyone on the planet owning the means of their own energy production. I’d also like to see an economic and environmental analysis comparing regional, local and personal energy generation and storage.

When do economies of scale make energy produced in large centralized plants less expensive than personalized energy after factoring in transmission/transportation and environmental impact? Is it better economically for a small village to have a shared energy system than personalized energy? How about city centers, where sunlit surface area and storage space are smaller on a per person basis than in neighborhoods, suburbs and rural areas?