Carbon capture from coal plants

The U.S. and Canada are spending billions of dollars on Carbon Capture and Storage projects, hoping that in this way the fossil fuel industry will seem to emit less greenhouse gases into the air. I say seem to, because once the effects of the money are all counted, it is likely that it will have increased total emissions, not decreased them.

The province of Alberta has just announced the projects that will receive 2 billion dollars of funding, for which they will capture 4 million tonnes of carbon dioxide. Yes, that's a subsidy of $500 per tonne. The projects calls for the building of new coal-fired power plants, while most other developed economies are shutting them down, and of new bituminous sands upgraders. So no actual reductions in GHG emissions are planned, only the building of new plants of the type that are the greatest emitters in the world: coal-fired plants emit more than virtually all the alternatives for producing electricity, and upgrading bitumen similarly emits more than all other methods of producing fuel for transportation.

Most of the carbon dioxide that is being captured will be used for Enhanced Oil Recovery (EOR). Traditionally, EOR pumps liquefied CO₂ into the ground to be used as a solvent to wash extra oil out of the oil-bearing rock. Nearly half of the CO₂ then comes up to the surface again. Much of it is often vented, but with careful engineering and energy use, much of it can be separated once again and re-injected. The irony of using CO₂ that was separated, compressed, transported and pumped at great cost in order to produce oil that will be burned in the atmosphere is completely lost.

Removing carbon dioxide from existing coal-fired plants is the Holy Grail of CCS. These are probably the greatest fixed sources of emissions and represent a huge investment that is unlikely to be retired early. Unfortunately, removing the CO₂ from existing coal-fired plants is almost certainly a lost cause. Our hands are tied by the laws of thermodynamics. The gas coming out the chimney is hot and only has about 10% CO₂.

The physical limit to the amount of energy required to separate and compress the CO₂ is about 0.2 kWh/kg. If you look up the reference, it is for pulling CO₂ out of the air, but if you redo the calculation for the higher partial pressure and higher temperature for post-combustion gas, you get roughly the same figure. In addition to this, you must also separate out sulfur dioxide and other pollutants in order for the process to be possible at all, which requires more energy. This is the theoretical efficiency; industrial processes never get anywhere near 100% efficiency. The efficiency of coal-fired power plants is around 35% of the theoretical maximum, which is not bad for a mature industrial process. Figures of 20-30% are common in the real world.

How much extra energy is required to capture and store CO₂ from coal-fired plants? The emissions from coal-fired plants are about 1 kg/kWh, in round numbers. The theoretical lower limit to the energy required for CCS is 0.2 kWh/kg. Say that after all processes and losses are accounted for, you have an efficiency of 20%. That means that you will use 1 kWh to capture and store the CO₂ emitted by producing 1 kWh. Are you just doubling the amount of coal you need? No, because producing that extra 1kWh of electricity has just emitted 1 kg of CO₂, which has to be captured at the cost of 1 kWh, and so on.

So any amount of CCS at 20% efficiency will require all the coal in the world, and have infinite cost. You need much higher efficiency for any of this to be worthwhile. You can be confused by figures where they say that the energy used to do CCS emits less than 1 kg/kWh, since the average utility emits less. That is because the average utility does not use coal alone, but other fuels and renewables as well. But think about it for a second. How much sense does it make to use 1 kWh of renewable energy to clean the emissions from 1 kWh of coal-fired electricity? You would just use the renewable energy and not bother with the coal at all. Those types of figures are just meant to mislead.

From the point of view of energy companies, CCS subsidies are a great deal: all other planned coal power plants in North America have been cancelled, and the Alberta government is actually paying someone to build a new one. Similarly, bitumen upgraders were facing an uncertain future. And if you own an oilfield at the end of its life and the government is willing to pay you to to extract more oil through EOR, how sweet a deal is that?

Tags: Greenhouse Gas Environment Economics Carbon Tax Energy Canada Carbon Capture CCS Environment

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What is the Proper Role of Villages in Smart Growth

What is the appropriate Smart Growth response to villages outside the urban boundary that want to make large amounts of land, often agricultural land, available for development? The traditional sprawl developer response is simple: let the owners decide and before long you have a new greenfield development that either ignores the village except for its roads or that creates the fiction that your new suburban single family house inherits the image and goodwill of village living.

The Smart Growth response is more complicated. There are some who, because it is outside the urban boundary, will bang their staff on the bridge and shout "You shall not pass!" There are others who will look at older villages as the epitome of compact walkable complete communities that they would like to emulate, with farms and nature all around as a bonus, and would say we should use the village as a nucleus for a compact community, which can be infilled while maintaining its vitality. Others still look at these villages, which typically have very little zoning or planning in place, and see their lack of rules and its success as evidence that lack of rules leads to success.

I'm not certain what is the proper response. Whether these villages are treated as pristine noble savages whose purity must be preserved or as a nucleus for satellite communities like the garden city movement or the old railway suburbs tried to do, I have never seen a traditional village survive as anything other than a minor commercial hub for a low-density suburb once it gets captured by a central city, like falling into the gravity well of a black hole.

It strikes me that a town can not serve two masters. Either it has an independent economy, whether agricultural or based on a local industry, or it is subsidiary to a larger city in which case it will turn more and more into a bedroom community, with the influence it gets as both an independent political entity and from the influx of well-off city dwellers with high expectations. The road system that it got simply by virtue of being a rural town not too far from civilization becomes the start of a transportation umbilical cord that links its residents and its economy to the central city. It will stop having an independent economy and its residents will no longer care as much about local issues and more about regional ones. The local residents may never have seen the necessity of shopping at the local store as a benefit at all, given a choice between that and the greater variety and lower prices available at exurban stores. Real estate prices will rise to reflect the interest and purchasing power of big city folk. This prices the local economic activity out of the market.

At this point, should we tell local landowners, for whom increasing land values make the local economy less and less sustainable, that they should hold off on selling or developing their land, for the benefit of respecting one of several competing views of how the metropolis should grow? This is giving them a raw deal: all the disadvantages of joining the city and none of the advantages. They get priced out of their own home town and are then told that it is for the common good of a large set of people that doesn't know them.

I tend to believe that a line in the sand should be drawn. Villages should not have any part in the growth plans of the metropolis, not even as a nucleus or as an alternative. Money should be spent to protect a strong independent local economy, but preventing newcomers from settling there if they don't work there. Impractical, I know, but there are some good legal ways of preventing new residents from settling there. The growth in interest in local agricultural products is one way of doing this, because it increases the value of agricultural land while keeping agriculture as a viable industry, and ensuring that road improvements between villages and larger cities do not get funded is part of the tough love approach that will protect villages. Those that want to create new walkable communities that try to approximate idealized village life within the sphere of influence of a city should probably start from scratch or try to convert an existing suburb.

Tags: Urban Planning Density villages Smart Growth

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Green Buildings Need Design and Geographic Context

In Green Building Blues, art critic Kriston Capps wonders why "green buildings" are so ugly, and gets some surpising answers.

First, green buildings currently being built are mostly for show; looking sustainable is more important than being sustainable. That means, like the Vancouver Olympic village and the new Vancouver Convention Centre Expansion, lots of ostentatious greenery on the roof. Even when other other solutions with less steel and glass would emit even less.

The other reason is LEED standards themselves, which pay little attention to context. If you place a green building in a location that is only accessible by car, you burn more hydrocarbons than if you build or reuse something better located. That is also part of his argument - good design is more sustainable simply because people aren't so keen to demolish it and start over. But his major beef with LEED is that it is absolute. Wood gets you more points than steel even if you are in Pittsburgh, where steel is local and wood shipped in from far away. The cost of transporting just the right shade of stone from across the continent is not calculated. What would make more sense, both from an environmental and design point of view, is the use of local material and building methods, fostering an indigenous vernacular style.

He blames International Style introduced by Le Corbusier for the difficulty in getting both sustainable and well-designed buildings. The big firms and starchitects look at buildings as sculptures, singular artistic expressions, competing with each other for opulence.

It's an interesting analysis. Have we gone from conspicuous consumption to conspicuous thrift, without going through humility and frugality along the way? What architects are discovering as they progress further and further into a future having stringent new green constraints is that they do not need so much to invent new building methods, styles, and materials but rather to look around them at traditional methods, styles, and materials that have been around them for centuries.

Tags: Urban Design Architecture Sustainability LEED

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Ontario Coal Generators Are Shut Down

For the first time that I know of, the Ontario power grid was completely off coal this morning, or just about, from midnight until five in the morning. A sign of spring.

Tags: Greenhouse Gas Ontario Canada Energy Coal

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Canada and US Driving No Longer Dropping

This is an update of an earlier post

The downward trend in driving in the U.S. and Canada has stopped. These two graphs with roughly similar scales show a moving 12-month average of all driving on roads. The Canadian figures are from the quarterly Canadian Vehicle Survey and go to September 2008, U.S. figures are from the Traffic Volume Trends and go to December 2008. Both sets of figures were released in the past few days.

Starting December 2007, when gasoline went up over $3 a gallon and stayed there, US driving was dropping like a stone. Latest figures, with gas back down, shows that the drop is slowing down. It's hard to see on the graph, but it's there. Click on the pictures for a larger graph.

In Canada the trend is again very odd. The downward trend had started sooner in Canada, but driving started actually increasing even before prices had started coming down significantly. Very strange.

Tags: Transportation Vehicles USA Canada

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This Year Ontario No Longer Needs Coal

2009 is the first year in which Ontario no longer needs any coal-fired generators. For the first time, non-coal generating capacity will be greater than peak demand for electricity.

This doesn't mean that the coal-fired plants are being shut down, just that they could be shut down if we and the rest of North America were ready to accept some risk. The reason that the plants will still be operating this year is to provide a reserve and an insurance policy in case of severe weather or equipment outages. You can't just shut coal plants off, in the case of an emergency or low wind conditions it takes a while to start up these suckers. Also, the transmission network can't always reliably ship the electricity from where it is produced to where it is consumed, so even though in total capacity exceeds peak demand, you still have to burn some coal in some areas for a few more years. But for the first time, non-coal resources will be supplying not only all the forecast demand but some of the reserve as well. The NPCC (Northeast Power Coordinating Council) reserve is essentially Ontario's contribution to helping the rest of the North American power grid remain stable in times of crisis.

Ontario IS adding and in fact HAS added some natural gas plants which besides emitting a fraction of the pollution, are a lot easier to switch on and off and therefore make the use of renewables like wind and solar more cost-effective and less risky. However it is still on track for a 2/3 reduction in emissions relative to 2003 and for a complete shutdown of coal plants by 2014, where even the use of coal for a reserve, an insurance policy and a buffer will be gone.

Nearly 4,000 MW of new supply and 1,250 MW of ability to import hydro electricity from Quebec are expected to become available in the next year or so. Since the table (below) was released, a new forecast of even lower demand due to conservation and lower industrial demand has further reduced the total required. The economic recession, and the provincial Green Energy Act are two new pieces of data that may reduce demand even further and increase non-coal supply. Right now, wind capacity is being added at a rate of a few hundred MW a year, but the new legislation should accelerate this new capacity. In 2008, wind energy contributed several times more power than predicted at time of peak demand, and predictive models have been adjusted in consequence. As a result, Ontario was a net exporter of electricity almost all the time last year. Even weather-corrected, demand for electricity has been going down despite greater population and the purchase of more electric-powered stuff.

Forecast of Coal-Fired Capacity Requirements for NPCC Reserve and Insurance 2008-2014 (Effective MW)

Tags: Greenhouse Gas Ontario Canada Energy Coal

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Shaping the Public Realm

From John Massengale's Veritas and Venustas blog

In traditional architecture and urbanism, the first role of an urban building is to shape the public realm. In Modernism, the first role of a building can vary from being an interesting object, to being an expression of technology, to being a monument to the architect's genius, to being something cheap and big. Many Modern buildings do all four. All four frequently interfere with shaping the public realm and making an outdoor place where people want to be.

Which begs the question, why not build something that looks appropriate in its context, is conceived based on its impact at ground level, and that gains some maturity as it weathers? I will remain ignorant about architecture, but positive space is something that requires only a small amount of humility on the part of the architect, and costs nothing to build.

Tags: Urban Design Architecture

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