Combined Heat and Power: Pros and Cons

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Combined heat & power (CHP) or cogeneration, is really not an energy source itself, but rather more of an energy multiplier, squeezing more usable energy out of each unit of fuel most everywhere it is applied.

According to the EPA, CHP is not a single technology, but rather, an integrated energy system that provides electricity and heat, usually in the form of hot water or steam. Heat is an inevitable byproduct of any power produced by gas or steam turbines, which would include all gas, coal, oil or nuclear power plants in use today. In these turbines, pressurized hot gas or steam is expanded across a turbine, which spins the blades that ultimately drive the generator. The hot gas needs to be cooled immediately after leaving the turbine for the system to work. This was traditionally done with a condenser or cooling tower, but using the heat to keep a building comfortable or drive a production process, with steam or hot water, will also do the job with little loss in efficiency. However, in order for the heating application to replace conventional cooling systems, the demand for heat must be continuous. Typical CHP system will reclaim upwards of 80 percent of the heat that would otherwise be wasted.

A conventional fossil fuel plant achieves a thermal efficiency of approximately 33 percent.

When integrated into a CHP system, the same power plant can achieve efficiencies between 60 and 80 percent. It is estimated that CHP systems can reduce carbon emissions by up to 30 percent.

Without CHP, fuel is used to provide electricity and then additional fuel is used for heat, which in many cases is a missed opportunity.

Cogeneration systems are generally installed on-site for large facilities, such as factories, institutions, commercial buildings, multi-unit residential buildings and district energy systems. It is particularly attractive for facilities with a high heating demand. These facilities then have their own source of electricity as well as a source of heated water or steam. The CHP needs to be located close to where the heat will be used so it won’t cool down. It is therefore an inherently distributed energy source. CHP is seen to be cost-effective in areas where the cost of electricity is seven cents per kWh or higher.

CHP is generally based on fossil fuel  technology, though some companies are now marketing solar cogeneration products: Naked Energy in the UK, and Cogenra in the US.

The number of building with CHP potential in this country has been estimated at well over a million, with energy usage close to 80,000MW. Cutting that by 30 percent would be equivalent to shutting down twelve 1000MW coal plants.

The systems can be installed by any of a number of contractors, many of whom are members of the EPA’s CHP Partnership.

Pros


  • Increased efficiency. CHP systems act as energy multiplier which:

    • saves energy

    • saves money

    • reduces carbon emissions by up to 30 percent

  • Increased reliability. System is independent of the grid and therefore immune to grid-level blackouts.

  • The technology is available and in use today.
Cons

  • Not an actual energy source, only a means of extending energy

  • Could end up preempting more sustainable options

  • Only suitable where there is a need for both electricity and hot water on site

  • Heating and electricity demand must remain fairly consistent

  • Capital intensive

  • Not long term sustainable when based on fossil fuel technology

  • Heating demand must be continuous

  • Efficiency claims are sometimes overstated since heat energy and electricity are not equivalent

When used with a fossil fuel input source, CHP cannot be considered an ultimately sustainable solution for the long term. However, it can help slow the rate of carbon emissions with substantial energy savings in situations where more sustainable options are not available or affordable. On the other hand, when used with renewable energy sources, such as the recently announced solar cogeneration, or certain biomass applications, CHP can act to enhance the efficiency of sustainable energy systems.

***

What about other energy sources?


Image credit: Courtesy of US EPA (with permission)]

RP Siegel, PE, is the President of Rain Mountain LLC. He is also the co-author of the eco-thriller Vapor Trails, the first in a series covering the human side of various sustainability issues including energy, food, and water in an exciting and entertaining format. Now available on Kindle.

Follow RP Siegel on Twitter.

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Unilever Improves Supply Chain, Faces Challenges with Customer Behavior

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Image: Unilever CEO Paul Polman. 

On Tuesday, Unilever released its first year’s progress report on the progress it made to meet its Sustainable Living Plan targets. The results so far are mixed. The report shows significant progress in many of the targets as well as real difficulties in others. For example, Unilever reports that sustainably sourced agricultural materials grew last year from 14 to 24 percent on the way to reach 100 percent in 2020. On the other hand, there was no progress in Unilever’s ambitious plan to halve its carbon footprint by 2020.

It’s not really surprising to see these mixed results given the fact that Unilever deliberately gave itself very challenging targets in the first place. “Many of our goals look as daunting now as they did when we announced them, but you have to set uncomfortable targets if you are to really change things,” explains its CEO, Paul Polman in the report. So taking into account the high bar Unilever set up in this plan, with goals like doubling its sales while halving its carbon footprint by 2020, my impression is that the Sustainable Living Plan is so far a success story.

The plan, published in November 2010, broke new ground by committing to take responsibility for the company’s impacts throughout the value chain, from the sourcing of raw materials all the way through to the consumer’s use of its products to cook, clean and wash. Looking at the progress report you can see a clear division in the value chain - while Unilever has made good progress in its supply chain and within the company’s operations, it had difficulties moving forward on changing consumer behavior.

The areas where Unilever made genuinely good progress included:


  • Sustainable sourcing – 24 percent of total agricultural raw materials now being sourced sustainably, versus 14 percent in 2010. Unilever made a significant progress with its two main raw materials - 64 percent of palm oil and 60 percent of paper and board are coming now from sustainable resources.

  • Nutrition – over 90 percent of Unilever’s leading spreads now contain less than one-third saturated fat.

  • Renewable energy now contributes 20 percent of Unilever’s total energy use and 100 percent of electricity purchased in Europe is now from renewable sources.

  • Safe drinking water – 35 million people have gained access to safe drinking water from Pureit water purifier since 2005.


Unilever reported a little less success in the areas of health and hygiene: The goal was to help more than a billion people to improve their hygiene habits and bring safe drinking water to 500 million people by 2020. By end 2011, Unilever had reached over 135 million people – 48 million with Lifebuoy, 44 million with its toothpaste brands, 8.5 million through the Dove Self-Esteem Fund and 35 million people with safe drinking water. There were also few areas where Unilever reported on real difficulties to make progress, especially regarding targets that require consumer behavior change, such as reducing the use of heated water in showering and washing clothes, or encouraging people to eat foods with lower salt levels.

It’s interesting to see that Unilever is aiming to reach this broad set of goals with collaborative efforts. In its global supply chain it collaborates on climate change, water and agricultural issues to create new standards, new frameworks and new forms of governance. When it comes to consumers, Unilever cooperates to change consumer behavior in issues such as health and hygiene, nutrition and recycling. The idea is not just to create better solutions, but as Paul Polman explains, to drive concerted, cross-sector change because he believes that even if Unilever meets its goals, it will still consider it a failure if no one else follows.

This approach is reflected not only in the vast number of collaborations in which Unilever is participating, but also in the openness of its innovative process. Unilever adopted a crowdsourcing approach, inviting all stakeholders, not just NGOs and governments, to take part in the effort to find the ways to meet its goals. A few weeks ago, for example, Unilever unveiled a new Open Innovation platform to gather and assess ideas from external resources, inviting “anyone who has a fresh, serious approach to new thinking” to pitch in. Another example took place on Wednesday, when Unilever initiated the Sustainable Living Lab, a 24-hour online dialogue aimed to create and inspire a discussion about the challenges Unilever is facing, co-create new ideas and share good practices.

The online discussion focused on several specific issues, including consumer behavior change, which is one of the most important keys to success. After all, consumers’ use of Unilever products represents 68 percent of the company’s carbon footprint – there is no way for Unilever to halve its footprint without getting consumers to reduce their own. But how do you do it? How do you convince people to wash their clothes in lower temperatures or use less water when they shower? And in addition, how do you integrate Unilever products into the process of shifting consumers to a more sustainable behavior? These are very difficult questions and from what I saw on the online discussions no one in or outside Unilever has yet to come up with a good answer.

Still, even with this sort of challenges, Unilever is proving in this report it knows not only to draw an impressive road map, but also to follow it.

Image credit: Transparency International/Flickr

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Liquid Fluoride Thorium Power: Pros and Cons

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Last August, I posted an article on Thorium reactors, a form of nuclear power that supposedly overcomes many of the concerns associated with traditional nukes. Despite my admittedly anti-nuclear bias, I had heard enough good things about this technology to want to learn more and share what I learned. The technology has attracted an enthusiastic following, many of who feel that this is the best of all currently available alternatives. Supporters claim that it sufficiently addresses the numerous issues that have made nuclear a less attractive, if not outright frightening option.

Among the concerns about traditional nuclear are the following:


  1.  Proven risks of dangerous meltdowns (e.g. Fukushima. Japan is now shutting down all reactors).

  2.  Very long time required for approval and construction.

  3.  Potential terrorist target.

  4.  Too big to be liable, taxpayers will likely pick up the cost of an accident.

  5.  Highly centralized and capital intensive.

  6.  Non-renewable and rare fuel source: Uranium (much of it controlled by indigenous tribes).

  7.  High level of embedded CO2 in concrete and steel.

  8.  Dangerous radioactive waste lasts 200 – 500 thousand years.

  9.  No operating long-term waste storage sites in the U.S.

  10.  Shipping nuclear waste poses an increased potential risk of spills or interception by terrorist groups.

  11.  Fissile material can be converted into nuclear weapons.

  12.  High construction costs generally requiring subsidies and loan guarantees.

  13.  Competes with renewables for investment dollars.

Unlike conventional light water reactor designs, the liquid fluoride thorium reactor (LFTR) is a type of molten salt reactor (MSR), that was first demonstrated in the 1960s. It is generally considered inherently safer, cleaner and more economically viable than conventional reactors, but was not chosen by DOE as the technology of choice  because it did not produce weapons grade material as a byproduct, something DOE was looking for at the time. That would be considered an advantage today. (11)

This design is less radioactive and more proliferation resistant. Its reaction in a molten-salt reactor (MSR) does produce U233 but that is apparently not a weapons-grade material. Thorium is about four times more abundant in nature than uranium (6). The largest reserves are in Australia, India, and the U.S.

LFTR reactor cores are not pressurized. Any increase in temperature results in a reduction in power, thus eliminating the problematic runaway meltdown scenario. If the fluid should get too hot, a salt plug at the bottom of the tank simply melts dumping the entire mess in to a storage vessel directly below the reactor. (1,4)

The question of waste (8,9,10) is also far better. Thorium produces about a thousand times less waste throughout the supply chain than uranium. It is mostly consumed in the reaction. Of the remaining quantity, which is quite small (I’ve been told it’s  about the size of a coke can for every billion kilowatt hours), 83 percent is safe within ten years and the remaining 17 percent requires 300 years of storage before it becomes safe. While that is still a long time, it is far more manageable than the 10,000 years required for today’s spent fuel.

It is expected to cost far less than conventional reactors and because of its simplicity, it can be assembled in a factory (2) scaled down to the point where one can be carried on the back of a tractor-trailer and used in a distributed manner. (5,12)

The technology already has a large following at sites like Nuclear Green and Energy From Thorium.

 

Pros:


  • Carbon-free operation

  • Inherently far safer than conventional light water reactors

  • Abundant fuel (thorium)

  • Chemically stable

  • Currently being developed in China and by US  companies like Flibe

  • Very small amount of  low-level radioactive waste. Should be much easier to manage.

  • Concentrated energy source, requiring far less land than solar

  • Runs round the clock, good base-load and load-following source

  • Less suitable for weapons proliferation that conventional nuclear

  • Relatively low cost and scalable

  • Could potentially be used in a distributed manner

  • Technology is currently at the demonstration phase

  • Requires less cooling water than conventional reactors

Cons

  • Non-renewable fuel

  • Still produces hazardous waste (though far less)

  • Can still facilitate proliferation of nuclear weapons

  • Quite different than current technology

  • Primarily conceived as a centralized plant

  • Like all big plants, could be a terrorist target

  • Technology not ready for prime time yet

  • Competes with renewables for investment dollars

Because of the first two items on the cons list, I consider thorium to be ultimately unsustainable in the very long term, though I do believe it can play a significant role for several generations, if needed. For me, the perfect energy source requires no fuel and, like nature, produces no waste. But those that meet that criteria today (e.g. wind, solar) are intermittent and have a low energy density which means they require quite a bit of land, which is also a problem. I suggest you become familiar with thorium energy, as I expect you will be hearing more about it in the future.

***

What about other energy sources?


[Image credit: US National Archives: Flickr Creative Commons]

RP Siegel, PE, is the President of Rain Mountain LLC. He is also the co-author of the eco-thriller Vapor Trails, the first in a series covering the human side of various sustainability issues including energy, food, and water. Now available on Kindle.

Follow RP Siegel on Twitter.

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Tar Sands Oil: Pros and Cons

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You might not know this, but Canada has oil reserves of 170 billion barrels, more than Iran and Nigeria combined. This fact is not widely known since much of that oil has been considered “not economically recoverable,” lying deep underground in a mixture of bitumen, a thick, tarry substance, sand and water known as oil sands or tar sands. Development of these tar sands, located near the Athabasca River, by Suncor Energy, began in the 1960s but has been conducted at a relatively small scale because of the costs involved. Only recently, with declining supplies and increasing prices have attempts begun to try and ramp up production, especially after PetroChina acquired a 60 percent interest in two major wells in Alberta in 2009. This was followed in 2010 by Sinopec paying $4.65 billion for a 9 percent stake in Syncrude Canada Ltd.

Chinese investors find this resource to be attractive, since Canada is considered to be a low political risk when compared with, say, the Middle East. As of 2010, the three biggest of many players were Syncrude Canada, Suncor, and Albian Sands, a joint venture of Chevron, Shell Canada and Marathon Oil. BP also has a substantial stake, with a 75 percent interest in Terre de Grace, which it also operates.

Projections made after slowdowns in offshore production show that as much as 36 percent of American oil could be coming from Canadian oil sands by 2030. According to oil expert Daniel Yergin, “Canadian oil sands…have gone from being a fringe energy source to being one of strategic importance.’’

Sounds good so far, but not so fast; there are numerous major environmental problems and risks associated with this technology.

For starters, extracting this oil requires a good deal more energy than conventional drilling, which means more greenhouse gases before the oil even reaches the pump. The net energy return on energy invested ratio of tar sands oil by the time it is converted to gasoline is roughly half that of the equivalent process for conventional crude oil. It is the largest source of carbon emissions in Canada, making Alberta, with only 10 percent of the population, the highest emitting province.

The Canadian government has invested heavily in the use of Carbon Capture and Storage (CCS) for the tar sands recovery process, but this technology is yet unproven. The process requires also vast amounts of water and chemicals to wash the sands. Anywhere from 2 to 4.5 times the amount of water is required for each barrel of oil produced. The discharge that accumulates in highly toxic waste ponds pose a huge threat to wildlife. In one incident, a flock of 1,600 ducks mistakenly landed in one of these ponds and they all died. Now, propane cannons, using even more energy, are used to frighten away wildlife. Tailing pools now cover 50 square miles adjoining the Athabasca River, in the middle of the world’s largest intact forest, a key absorber of CO2 and wildlife habitat. The projects have also been a mixed blessing for the numerous First Nations people living in the area. While it has brought a significant number of jobs and economic activity, the developers not only pollute the area, but they don’t take First Nations’ interests into account, destroying hunting and fishing, habitat and bringing a number of health risks to the region.

Recently, a number of environmental groups and 23 First Nations groups have asked for a moratorium on new tar sands development. They are also asking to halt the Keystone XL pipeline which would strongly encourage further development of the Tar Sands, by allowing the oil to be shipped from Texas to China, where most of it will be used.

Pros


  • Very large supply. Second largest oil field in the world.

  • Economically recoverable at today’s oil prices

  • Will help keep oil prices relatively low

  • Enormous growth potential. Less than 5 percent has been produced.

  • Big economic driver in Alberta. Jobs for Native Americans.

  • Stable source country (a rarity for oil)

  • GHG emissions could potentially be minimized through CCS

Cons

  • Enormous GHG emissions. Oil sands are already Canada’s largest source of CO2 emissions.

  • Relatively low net energy return compared to other sources

  • Alberta, with only 10 percent of the population, emits the most GHG emissions of any province. Provincial government has been slow to respond.

  • Large amounts of water required: roughly 3:1

  • Water pollution. Roughly 3 million gallons of toxic runoff per day. Fifty square miles now covered in toxic pools

  • Destructive to major boreal forest, an important carbon sink

  • Widespread habitat destruction, both on land and water

  • Destructive to ancestral lands

  • Requires expensive and risky pipeline to reach faraway markets

In summary, tar sands oil has a cost/benefit profile that is similar in many ways to coal, except that coal is used for electricity while oil is used for transportation. At the present, there are probably more alternatives for electricity than there are for transportation. This could begin to shift if we see tractor-trailers trucks being converted to natural gas, as T. Boone Pickens predicts. Of course, the current historically low natural gas prices, combined with high oil prices has, at least for the moment, rearranged the whole energy picture.

The similarities between tar sands oil and coal are the large supply on the one hand and the massive environmental problems on the other. I would have to say that, as bad as the environmental impacts of coal are, these tar sands might even be worse, despite what the developers might say. There is no question that the approval of the Keystone XL pipeline will encourage expansion of this resource, while bringing questionable benefits to the US, since most of the oil will be shipped to China. Mostly though, I think the whole conversation is really about price and Americans’ desire to live in a world where gas is cheap and no one bothers them to worry about global warming. That world may have existed in the 1950s and 60s, but it certainly doesn’t exist anymore.

***

What about other energy sources?


[Image credit: 4Blue Eyes Pete Williamson: Flickr Creative Commons]

RP Siegel, PE, is the President of Rain Mountain LLC. He is also the co-author of the eco-thriller Vapor Trails, the first in a series covering the human side of various sustainability issues including energy, food, and water. Now available on Kindle.

Follow RP Siegel on Twitter.

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The Problem with the TOMS Shoes Charity Model

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Remember the old proverb about how it's better to teach a man to fish then catch a fish for him to eat? I am reminded of that saying when I think about TOMS Shoes buy-one pair, give-one pair model. A Fast Company article points out that the model “does not actually solve a social problem.” Instead, it functions more like colonialism, diving in to local economies to solve problems rather than listening and figuring out how best to help.

There are several big problems with TOMS' model: by giving away shoes, it creates a dependency, and it disrupts local economies. Values and Capitalism points out that the TOMS model “needs improvement” because “giving away free stuff… almost always has a negative long-term impact on local economies.”

While it may be harsh to call the TOMS model another form of colonialism, it is fair to say that it is essentially based on paternalism. While doing research for this article, I stumbled across an insightful blog titled, A Personal Diaspora. The author of the blog, in a post about TOMS, warns that paternalism “creates dependency, removing the responsibility to provide from the poor themselves to some unknown (to them) outside source.” In other words, paternalism gives a fish and never teaches how to fish.

Fast Company suggests three things TOMS can do to improve its model:


  1. Better understand the problem of poverty in developing countries. The problem of poverty is deeper than just children lacking shoes. It is important to know the systemic reasons for poverty in a given society.

  2. Create a solution, not a band-aid. Developing countries do not need paternalism.

  3. Innovate business models, not marketing campaigns. The TOMS model is a great marketing campaign in that it appeals to a person’s sense of compassion.

Are there alternatives to the TOMS model?

There are two companies that operate from the “teach a man to fish” paradigm: Oliberté Footwear and SoleRebels. Both are based in Africa. Canadian Tal Dehtiar started Oliberté in 2009. The name itself comes from the French word for freedom and the “O” in the Canadian’s national anthem. Oliberté makes shoes in Africa using local materials and sells them in Western countries. The company went from 200 pairs sold in the beginning, to 10,000 in 2011.

Oliberté’s shoes are made in Ethiopia with leather “sourced from local free-range cows, sheep and goats,” according to an article by Good. The natural rubber in the soles of the shoes is processed in Liberia. Last year, the company expanded its line to include leather bags and accessories that are made in Zambia, with some of the leather coming from Kenya. The woven labels on the products are produced in Mauritius.

Oliberté’s website states that the company “partners with factories, suppliers, farmers and workers to produce premium footwear in Africa” and creates “fair jobs, with the goal of contributing to the development of a thriving middle class.” The company calls itself the first to “make premium leather shoes and goods exclusively in Africa.”

SoleRebels is a shoe company founded by Bethlehem Tilahun, an Ethiopian. It employs about 100 workers, and pays four times the legal minimum wage and three times the industry average wage for similar work in Ethiopia, plus covers workers’ healthcare costs.

Tilahun said something about TOMS that sums it up: “If you give a kid shoes, they wear out or they grow out of them, and then what do they have? If you give the kid’s parents a job, the whole family will always have shoes.”

Photo credits: Ariel Waldman/Flickr

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Algae-based Biofuel: Pros And Cons

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Algae–based biofuel is a new energy source that has been getting a lot of attention lately. Certain types of algae contain natural oils that can be readily distilled into a vegetable oil or a number of petroleum-like products that could serve as drop-in replacements for gasoline, diesel, and jet fuel.

But because it’s a bio-fuel, it is essentially carbon-neutral because the carbon emitted when it is burned had just recently been absorbed as food, which means that the net CO2 emission is essentially the same as if the algae had never been grown. That does not include CO2 utilized in production. Industry claims assert that algae-based bio-diesel has a GHG footprint that is 93 percent less than conventional diesel. Some algae production is sited near sources of CO2 such as power plants, in a kind of symbiotic relationship. Algae-based fuel yields considerably more energy per unit area than other bio-fuels. It can also be grown on land otherwise unsuitable for agriculture. The technology is quickly moving out of the lab and into commercial scale production. A number of companies developing refineries include Solazyme, Sapphire Energy (which just last week announced another $144 million in funding) and OPXBIO. Aviation trials with several airlines including United and Qantas have been successfully completed using fuel blends of up to 40 percent algae-derived fuel.

Algae was initially raised in large shallow ponds which produced about 5,000 gallons per acre-year and required a fair amount of water to compensate for evaporation. More recently, companies have migrated to vertical photo bio-reactors (PBRs) that are gravity fed, with no evaporation, and in which 85 percent of the water is recycled along with excess nutrients and CO2.

Here is a list of pros and cons for algae-based biofuels.

Pros


  • Bio-based fuel with essentially carbon neutral combustion

  • Drop in replacement for petroleum-based liquid fuels

  • Inherently renewable

  • Absorbs carbon dioxide as it grows

  • Both waste CO2 and wastewater can be used as nutrients

  • Higher energy per-acre than other bio-fuels

  • Can be grown on land unsuitable for other types of agriculture

  • Scalable: Study found that 17 percent of U.S. oil imports could be met with algae

  • Investments are being made

  • Production is presently scaling up (Navy buying 100,000 gallons this year)

  • Research has been underway for 50 years
Cons

  • Need to be grown under controlled temperature conditions

  • Requires a considerable amount of land and water

  • Cold flow issues with algal biofuel

  • Some researchers using genetic engineering to develop optimal algae strains

  • Requires phosphorus as a fertilizer which is becoming scarce

  • Fertilizer production is carbon dependent

  • Relatively high upfront capital costs

  • Not clear yet what the ultimate cost per gallon will be. Presently too high.

In summary, algae-based bio-fuel is a promising energy source that is in the latter stages of development. A number of issues related to the ultimate cost of the product need to be resolved, but there is a good deal of research money going into this as production is beginning to scale up. Land issues can be addressed using marginal land. Water can be recycled in reactors. Cold flow issues might result in the fuels being blended with other fuels or possibly additives. Fertilizer issues could be addressed using waste streams, thereby recycling the critical nutrients. Time will tell, though I believe this is an important technology to watch.

***

Learn about the future of biofuels here.

What about other energy sources?


[Image credit: Oliver Dodd: Flickr Creative Commons]

 

RP Siegel, PE, is the President of Rain Mountain LLC. He is also the co-author of the eco-thriller Vapor Trails, the first in a series covering the human side of various sustainability issues including energy, food, and water. Now available on Kindle.

Follow RP Siegel on Twitter.

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Clean Coal: Pros and Cons

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Let’s face it, coal is nasty stuff. It contaminates everything it comes in contact with and creates problems at every step of its life cycle: from unhealthy and unsafe underground mines, to the environmental catastrophe of mountaintop removal, to the problems associated with handling the enormous piles of ash that are produced every day. But by far, the biggest problem is the enormous amount of carbon dioxide emitted. According to the EPA, coal contributes 31 percent of all CO2, the largest of any source.

The people who still support coal basically have one argument: that it’s a necessary evil, being the only source of energy within reach that is sufficiently abundant to keep up with our enormous and ever-growing appetite for energy. We have so much coal, they reason, and we need so much energy, how could we not take advantage of this resource? They could be right, as much as those of us who care about the environment hate to admit it. As much as we would like to believe that conservation, efficiency and renewables will meet our growing, but maybe-not-growing-quite-so-quickly demand, there is certainly no guarantee that they will. Considering that coal accounts for 40 percent of all electric generation (down from 45 percent) and 21 percent of all energy in the US, that’s a lot of energy to replace. Of course, with falling natural gas prices, that is clearly picking up a lot of the slack.

Meanwhile, renewables accounted for just over 10 percent of electric power in 2010, and most of that was from existing hydropower.

If that’s not bad enough, coal powers 70 percent of China’s electric grid, which is growing far faster than ours and shows no sign of slowing down. In fact, the only thing keeping them from increasing coal generation even faster is their limited ability to physically move the stuff. Together, the US and China are responsible for 33 percent of global greenhouse gas emissions.

The other thing about coal is, of course, that it’s cheap, usually cheaper by far than other energy sources, largely because so many of its true costs are still being externalized. It is worth noting that wind at 5-6 cents per kWh is closing the gap.

Given the reality of climate change, any talk of coal must be clean coal, an approach which enables the utilization of our most abundant domestic energy resource so that at least the impact on the climate is minimized. (To put this in perspective, note that the total amount of energy we received from coal in 2010 is equal to the amount of sunshine over the same period, hitting just 460 square miles. If we adjust for the low efficiency of solar PV (17 percent at the low end), then that number goes up to 2706 square miles, well below 0.1 percent of the land area of the US, though we are nowhere close to capturing all of that any time soon.)

Clean coal has a number of variations, but all of them involve stripping the CO2 out of the coal, either before or after it is burned and then capturing it. It is then either utilized for industrial purposes or for enhanced oil recovery, or else it is pressurized into a liquid form where it can be injected underground where it supposedly will stay indefinitely in a process called carbon sequestration. The overall process is called carbon capture and storage (CCS).

No sequestration project existing or proposed removes all the CO2 from the exhaust, because of the high energy penalty for doing so (30 percent or more). Most of them bring the CO2 level down to that of natural gas. Canada has already banned the development of any new coal generation project that does not include CCS.

No doubt the least destructive form of clean coal is underground coal gasification (UCG). This is where the coal is left in the ground and converted to gas by chemical means and then sucked up to the surface where it is burned. Most of these projects include capturing the CO2 and then sequestering it as described above. Pilot plants have been run in China, and the Swan Hills plant is supposed to come online this year in Alberta, Canada.  In the US, the Texas Clean Energy Project, outside Odessa, which received $450 million in DOE funding, will apply UCG, capturing 90 percent of the CO2 and then using that CO2 for enhanced oil recovery in nearby Permian Oil Basin. This approach eliminates most problems associated with coal mining, transportation and burning, leaving only the problems associated with sequestration and gas extraction to be grappled with.

With that background, here are the pros and cons of clean coal.

Pros


  • Abundant supply, concentrated in industrialized countries (US, Russia, China, India).

  • Relatively inexpensive.

  • Continuous power. Good utilization. High load factor.

  • Substantial existing infrastructure. Mature industry.

  • Can be made low carbon and clean with CCS and various scrubbers.

  • Can be converted to a liquid or a gas, which burn cleaner.

  • Clean coal technology is currently being used in China.

  • Relatively low capital investment (compared to gas or nuclear).
Cons

  • Coal is nonrenewable. There is a finite supply.

  • Coal contains the most CO2 per BTU, the largest contributor to global warming.

  • Severe environmental, social and health and safety impacts of coal mining.

  • Devastation of environment around coal mines.

  • High cost of transporting coal to centralized power plants.

  • Coal ash is a hazard and a disposal problem.

  • Coal mining is the second highest emitter of methane, a potent greenhouse gas.

  • High levels of radiation. Coal plants release more radiation than nuclear plants.

  • Coal burning releases SOx and NOx which both cause acid rain.

  • Burning coal emits mercury and other heavy metals that pose major health risks.

  • Coal emissions linked to increased rates of asthma and lung cancer.

  • Sequestration is new, expensive and its ability to hold CO2 for long periods of time is unproven. Risk of accidental releases of large quantities of CO2.

  • Clean coal is not carbon free.

  • Significant energy penalties are incurred for sequestration.

  • CO2 is toxic at concentrations above 5 percent. The condition is called hypercapnia.

The true costs of coal are not included in what is paid today. Coal would not be competitive if environmental costs were included. When the costs of mitigating these impacts through CCS and UCG are factored in, it will not be competitive against renewables. However we might still need to use it in some localities to meet our ever-growing demand. But with natural gas coming in just as cheap, and with the same level of GHG as Clean Coal, it's not at all clear that these investments are justified. But there's no reason I can think of that the same capture and storage technologies that were developed for coal, couldn't be used in natural gas plants to bring them down to zero carbon.

***

What about other energy sources?


[Image credit: Marc Wathieu: Flickr Creative Commons]

RP Siegel, PE, is the President of Rain Mountain LLC. He is also the co-author of the eco-thriller Vapor Trails, the first in a series covering the human side of various sustainability issues of energy (including clean coal), food, and water. Now available on Kindle.

Follow RP Siegel on Twitter.

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Solar Photovoltaics: Pros and Cons

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Solar PV is perhaps what most people think of first when they think of renewables (though we actually use more biomass). Solar PV can be used anywhere the sun shines as long as there is space available. Enough sunlight falls on the Earth in one hour, to meet the world’s energy demand for a year, if it could be collected. It is eminently scalable with installations ranging from a few kilowatts to the 48 megawatt Copper Mountain solar farm in Nevada. Utility scale solar capacity is quite small compared to the big boys, like the 8200 MW Kashiwazaki-Kariwa nuclear plant in Japan or the 5780 MW Taichung coal plant in China.

Solar presently contributes a very small share of our energy pie, around 1 percent, but it continues to grow at double-digit rates and is projected to triple from 2010-15 after growing almost ten-fold from 2003-2010.

It is also the subject of a great deal of research, so we should expect a number of breakthroughs coming down the pike, including things like nano-pillars to lower cost, concentrators to reduce the area required, and more efficient and powerful cells, to reduce both. Most solar PV systems today are either made from traditional silicon-based solar cells, or the newer thin-film technology.

Solar PV systems produce DC current, which can be used with DC appliances or converted to AC by means of an inverter. More and more of today’s electronics run on DC, which requires those little power supplies that plug into the wall which convert the AC to DC. This could be an opportunity in the future to power these devices directly from solar PV, eliminating the efficiency losses that occur when converting from DC to AC and then back again.

Let’s take a look at the solar PV pros and cons.

Pros


  • Clean energy. No combustion. No greenhouse gas emission from use.

  • Inexhaustible and abundant “fuel” supply

  • Available nearly everywhere

  • Well suited for distribution generation

  • Technology exists today and is rapidly improving

  • Generates electricity directly from sunlight

  • No moving parts required

  • Power generation is silent. No noise or pollution.

  • Little or no transmission required

  • Matches up well with air-conditioning need

  • Require minimal maintenance

  • Grants and incentives are sometimes available

  • Excess heat can be used for co-generation
Cons

  • Intermittent source. Not available at night or under clouds.

  • Relatively high cost, especially with storage

  • Requires inverter to produce AC current

  • Requires storage or grid connection for continuous round-the-clock use

  • Less available for heating demand (time of day and season)

  • Exotic materials required in many thin-film systems

  • Requires a relatively large amount of open space

  • Relatively low efficiency (around 17-40 percent)

  • Relatively low energy intensity ( ~8-12 m2/ kW)

  • Fragile materials

  • Possible aesthetic issues

  • Technology risk: a much better system might come out next year

Besides the relatively clear cut pros and cons of solar PV, there are also the transformative socio-economic impacts of moving from centralized to distributed power generation. There is clearly a technical advantage, since efficiency losses associated with long range transmission are eliminated, as are, possibly hundreds of miles of power lines that now crisscross the landscape. Lost would be certain economies of scale and centralized control. Distributed power generation is more resilient against large-scale blackouts as well as acts of terror, though it could mean a change in business models for today’s utilities. This is a trend that has been predicted by Jeremy Rifkin in his Third Industrial Revolution. After all, who wouldn’t want a house that produces its own power, rather than a house that is just a house?
***
To summarize:
***

What about other energy sources?


[Image credit: eastpole: Flickr Creative Commons]

RP Siegel, PE, is the President of Rain Mountain LLC. He is also the co-author of the eco-thriller Vapor Trails, the first in a series covering the human side of various sustainability issues including energy, food, and water. Now available on Kindle.

Follow RP Siegel on Twitter.

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Cash for Trash: Innovative Companies Profitably Upcycle, Recycle and Reduce Waste

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By Vreni Hommes

Turning worm poop into fertilizer was TerraCycle’s first big idea. Then they transformed discarded drink containers into consumer bling, which made them a world-recognized leader in this hot, new trend of “upcycling.” Upcycling is the conversion of waste destined for landfills into new products of better quality or a higher environmental value. TerraCycle upcycles unwanted trash into messenger bags, notebooks, and the list goes on.

“Buy low, sell high” is the underlying business model for upcycling companies such as TerraCycle. They buy raw source materials (waste) at low cost and charge premium prices for their fashionable, environmentally-friendly upcycled products. But that’s not all. The upcycling companies’ business partners also benefit because their scrap waste is being reused. Instead of having to pay someone to haul their waste away, someone is actually paying for it and taking it off their hands.

The good news for the environment is that as more trash is upcycled, less trash is ending up in landfills. It also lowers the consumption of raw materials, air pollution from waste incineration, and water pollution from leaking into landfills.

The upcycling trend is doing something more . . . it is raising people’s awareness about the growing trash problem and motivating them to change their behavior. For example, Recyclebank does this by educating and rewarding their customers for recycling. Terracycle does this by setting up collection centers to make it easier for communities and schools to recycle.

Upcycling is a growing industry

TerraCycle and Recyclebank aren’t the only companies coming up with innovative - and profitable - ideas for making stylish, environmentally-friendly products out of trash. Learn more about them and other cutting-edge upcycling companies below.


  • TerraCycle, Inc. is a worldwide leader in the collection and reuse of consumer packaging and products.

  • Recyclebank rewards people for taking everyday green actions with discounts and deals from local and national businesses.

  • Playback Clothing transforms trash like plastic bottles and clothing scraps into great looking eco-clothing.

  • Hipcycle offers upcycled products that are as desirable, attractive and durable as traditional equivalent products.

  • IceStone makes high design surfaces from recycled glass instead of quarried stone.

  • Preserve makes attractive toothbrushes and kitchenware from recycled plastic like yogurt containers.

Criticism of upcycling

 

Critics argue that upcycling and recycling only postpones the inevitable – the waste will still eventually end up in landfills. It is better to reduce waste to begin with to than upcycle waste after it is generated. “Zero Waste” advocates want products that are designed to be repaired, refurbished, re-manufactured and reused. They want people to change their behavior and businesses to change their practices so that less waste is created and any discarded material is used as a resource for others.

What about "Zero Waste?"

Although it remains challenging to get consumers reduce their waste and recycle, many businesses are already discovering there is money to be made with zero waste programs. According to GreenBiz, by finding ways to reduce its waste, Wal-Mart has cut the cost to haul waste to landfills in California by over 80 percent. General Motors has earned $2.5 billion from recycling over the past four years. Kraft has achieved zero waste at 36 food plants around the world and, at some locations, use manufacturing byproducts to create energy. Companies in almost any industry and of every size are seeing significant savings by reducing, reusing, or recycling materials. Besides being environmentally friendly, zero waste initiatives save money by cutting out waste and streamlining production.

Is one waste strategy better than another?

It seems that almost any waste strategy – upcycling, recycling, reusing, or reducing materials – can lead to significant savings and even boost revenues. This is clearly good for business. When it comes to the environment, however, there is a bit of a debate about which waste strategy is best. As mentioned earlier, zero waste advocates argue that any upcycled or recycled waste still eventually ends up in landfills. Thus, it is better to not create the waste to begin with.

Yet even if upcycled products do eventually end up in landfills, upcycling companies like Terracycle and Recyclebank are succeeding in raising people’s awareness of the waste problem and motivating them to change their behavior and recycle more. Plus, the new upcycling market is incenting companies to develop new environmentally-friendly products and services. While upcycling isn’t as green as zero waste, it is changing how we view and what we do with trash.

What do you think?


  • Is zero waste the only environmentally responsible waste strategy?
    Or is upcycling a good development for the environment too?

  • Is the solution to the waste problem going to come from corporate America and zero waste programs?
    Or does a lasting solution require consumers to change their behavior with regard to trash?

Image credit: Pixabay

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Natural Gas: Pros and Cons

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Natural gas has been in the news a lot lately, being hailed as the solution to our energy problems on the one hand, and a potential environmental nightmare on the other. Let's try to sort out the reality behind this old friend with a new face. Before we start, it might be useful to make a distinction between the natural gas that has historically been collected as a byproduct of oil drilling and the more recently promoted source known as shale gas. This has become newsworthy as the result of an enormous deposit of shale gas discovered in the Marcellus field extending across large sections of Pennsylvania, Maryland, and New York.  Shale gas requires a much more aggressive method of collection since it is buried deep in the earth under many layers of shale. The most popular method of collecting shale gas is hydraulic fracturing, or fracking, a relatively new technology, developed by Halliburton, which has become quite controversial. The move into fracking parallels a gradual takeover of the natural gas industry by the big oil companies.

PROS


  • Widely used, contributes 21% of the world’s energy production today

  • Delivery infrastructure already exists

  • End use appliances already widespread

  • Used extensively for power generation as well as heat

  • Cleanest of all the fossil fuels

  • Burns quite efficiently

  • Emits 45% less CO2 than coal

  • Emits 30% less CO2 than oil

  • Abundant supply in the US. DOE estimates 1.8 trillion barrels

  • Low levels of criteria pollutants, (e.g. SOx, NOx) or soot when burned

  • Can be used as an automotive fuel

  • Burns cleaner than gasoline or diesel

  • No waste (e.g. ash ) or residue to deal with

  • Lighter than air, safer than propane which is heavier than air

  • Can be used to makes plastics, chemicals, fertilizers and hydrogen

  • Natural gas industry employs 1.2 million people


CONS


  • Non-renewable fuel, supply cannot be replaced for millennia

  • Emits carbon dioxide when burned

  • Contains 80-95% methane, a potent greenhouse gas (GHG)

  • Explosive, potentially dangerous

  • Concentrated sources require long distance transmission and transportation

  • Energy penalties at every stage of production and distribution

  • Requires extensive pipelines to transport over land

  • Stored and distributed under high pressure

  • Requires turbine-generators to produce electricity

  • Liquefied form (LNG) used to transport over water, in tanker ships  is potentially very dangerous

  • Energy use competes with use for chemicals and fertilizers

  • Additionally, there are significant environmental risks associated with “fracking”

    • Water pollution due to runoff of fracking chemicals

    • Companies are not required to disclose the composition of fracking chemicals (another example of lobbying in action).

    • Water can also bring up adsorbed underground toxins including arsenic

    • GHG footprint of shale gas greater than coal over 100 year time frame

    • Fracking has been linked to earthquakes

    • Casing leaks lead to gas in the water—blazing faucets

    • Fracking requires a large amount of water


The relatively even number of pros and cons shows that this is not an easy choice. Given how widespread and available and “less bad” natural gas is from other fossil fuels, plus the number of jobs created, it is hard to ignore the argument that natural gas should serve as a bridge fuel as more sustainable alternatives are built out. We should keep in mind though, that it is a short term measure and invest accordingly. As far as fracking is concerned, considering that there is already lots of gas available right now, there is no reason (other than greed) to be in a hurry to develop shale gas. Instead, we should take whatever time is necessary to develop a safer, more responsible way to access that gas, while investing heavily in more sustainable sources that will ultimately obviate the need for it.

 

***

What about other energy sources?


[Image credit: Suncor energy: Flickr Creative Commons]

 

 

RP Siegel, PE, is the President of Rain Mountain LLC. He is also the co-author of the eco-thriller Vapor Trails, the first in a series covering the human side of various sustainability issues including energy, food, and water. Now available on Kindle.

Follow RP Siegel on Twitter.

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