Geological CO2 Sequestration

This is a good update on the topic of direct underground sequestration of CO2. Enough data and thinking has now percolated through to inform us that if we chose, that we sequester as much CO2 as we like. This was likely true, for anyone with some knowledge of geology, but it still needed field practice to fully confirm. We are seeing this here.

It is not my favorite way of CO2 disposal, but it is cheap and quick. I would far sooner see the same CO2 sequestered by the expedient of subsidizing the production of biochar worldwide because that process manufactures wealth that could also be shared by the folks doing the sequestering.

In any event, we can see that point sources of massive CO2 production can presumably compress and separate the CO2 into a pumpable product that can be injected into the ground. The trouble is, is that we produce only a little CO2 so conveniently. House hold heating and automotive use will always need to dump into the atmosphere.

It also entails a parallel pipeline type gathering system mirroring the distribution system. This will occur in only special cases. In the case described in the article it is a case of reservoir CO2 been separated and been reinjected. That is good practice but is certainly a special case.

Atmospheric CO2 vastly exceeds these types of cases and will need to be offset by methods that directly gather it back from the atmosphere. Converting corn stover into biochar is one neat way to do this,


April 8, 2009

Storing the Carbon in Fossil Fuels Where It Came from: Deep Underground
Burying greenhouse gas may be the only way to avoid a climate change catastrophe

By David Biello
http://www.sciam.com/article.cfm?id=storing-fossil-fuel-carbon-deep-underground&sc=DD_20090409
Editor's Note: This is the third in a series of five features on carbon capture and storage, running daily from April 6 to April 10, 2009.

For more than a decade, Norwegian oil company Statoil Hydro has been stripping climate change–causing carbon dioxide (CO2) from natural gas in its Sleipner West field and burying it beneath the seabed rather than venting it into the atmosphere.

The company estimates that since 1996 it has stored more than 10 million-plus metric tons of CO2 some 3,300 feet (1,000 meters) down in the sandstone formation from which it came—and all of it has stayed put, which means storage may be the simplest part of the carbon capture and storage (CCS) challenge.

The basics of carbon dioxide storage are simple: the same Utsira sandstone formation that has stored the natural gas for millions of years can serve to trap the CO2, explains Olav Kaarstad, CCS adviser at Statoil. An 800-foot (250-meter) thick band of sandstone—porous, crumbly rock that traps the gas in the minute spaces between its particles—is covered by relatively impermeable 650-foot (200-meter) thick layer of shale and mudstone (think: hardened clay). "We aren't really much worried about the integrity of the seal and whether the CO2 will stay down there over many hundreds of years," Kaarstad says.

The company monitors its storage through periodic seismic testing, a process that is not unlike a sonogram through the earth, says hydrologist Sally Benson, director of the global climate and energy project at Stanford University. That monitoring indicates that between 1996 and this past March, the liquid CO2 has spread to occupy some three square kilometers, just 0.0001 percent of the area available for such storage.

"We're not going into a salt cavern, we're not going into an underground river. We're going into microscopic holes," explains geologist Susan Hovorka of the University of Texas at Austin, who has worked on pilot projects in the U.S. "Add it up and it's a large volume" of storage space.

How large? The U.S. Department of Energy (DoE) estimates that the U.S. alone has storage available for 3,911 billion metric tons of CO2 in the form of geologic reservoirs of permeable sandstones or deep saline aquifers, according to a 2008 DoE atlas. These reservoirs are more than enough for the 3.2 billion metric tons of CO2 emitted every year by the roughly 1,700 large industrial sources in the country. Most of that storage is near where the majority of coal in the U.S. is burned: the Midwest, Southeast and West. "There are at least 100 years of CO2 sequestration capacity and probably significantly more," Benson says.

The storage seems to be long-term as well; the sequestered CO2 doesn't just sit in the rock waiting for a chance to escape. Over decades it forms carbonate minerals with the surrounding rock, or it dissolves into the brine that shares the pore space, Hovorka notes. In fact, when she tried to pump CO2 out of her test site south of Dayton, Tex. using natural gas extraction techniques, the attempts failed completely.

According to the U.N. Intergovernmental Panel on Climate Change (IPCC), which issued a special report on CCS in 2005, a properly selected site should securely store at least 99 percent of the sequestered CO2 for more than 1,000 years. James Dooley, a senior research scientist at Pacific Northwest National Laboratory and an IPCC lead author, considers that to be a reachable goal. "If it took all that energy to shove [the CO2] into that sandstone, it's going to take a lot of energy to get it out," he notes. "Like an oil field, where we get out half or less of the original oil in place, a lot of the CO2 gets stuck in there. It's immobilized in the rock."

Encouraged by the success of the Sleipner project, Statoil recently began another CO2 injection program at the Snohvit natural gas field in the Barents Sea, despite the requirement that they build a 95-mile (150-kilometer) pipeline on the seabed to pump the CO2 to where it can be sequestered.

And since 2005, oil giant BP and its partners (including Statoil) in the In Salah gas field in Algeria have been stripping the nine billion cubic meters of natural gas produced there annually of the 10 percent carbon dioxide it contains and pumping a million metric tons of liquid CO2 back into the underlying saline aquifer through three additional wells at a cost of $100 million.

BP uses a variety of techniques, including satellite monitoring, to observe the impact of the CO2 storage (and natural gas removal). Whereas some areas sank by roughly 0.24 inch (six millimeters) as natural gas was extracted, near the CO2 injection wells the land rose by some 0.39 inch (10 millimeters), according to Gardiner Hill, manager of technology and engineering for CCS at BP's alternative energy arm.

"The gas has been down there about 20 million years so we know [the reservoir] has integrity," he says. The DoE's National Energy Technology Laboratory is also working on developing appropriate monitoring, verification and accounting technologies.

BP and Statoil are not doing these CCS projects for charity, of course. A Norwegian government tax on carbon of roughly $50 per metric ton inspired the CO2 sequestration at Sleipner and Snohvit. "It costs a fraction of the tax," Kaarstad says. "We are actually making money out of this."

Both Statoil and BP foresee more money-making CO2 storage opportunities. Hill notes that if CCS is deployed on a very large scale, society will need the expertise of the oil industry—its "100 years of understanding the subsurface," he says. "We would expect the experience we are building through this to position BP to take advantage of any future business."

"My one prediction is that this is going to be a very big industry, storing CO2 underground but transporting it, as well," Kaarstad adds. "It's not going to happen overnight, but it will probably be as big as natural gas after a few decades."

Floating Wind Turbines

This is a compelling bit of technology that if it can be made reliable, and I see little reason why not, will tap huge energy resources without creating inconvenient footprints. More interestingly, the economics should be superior to anything likely to ever be built on land. We may even be able to go the extra mile and tap current and tidal energy with the same hardware.

What makes it compelling is that it can be replicated a million times with no fuss whatsoever. It is very much like having dams built on demand and these will not be small machines.

The technology lends itself to continuous heavy manufacturing methods which can bring gross costs down substantially to make it very competitive with any one off engineered solution.

It will be interesting to watch this develop. It is like the early years in the wind turbine business were there were few outside believers. But once it is proven, the orders become unending.

I am sure New England and New York would love to have a few thousands of these in the Gulf Stream right now.


Floating Wind Turbines

According to a 2006 report by the U.S. Department of Energy, General Electric and the Massachusetts Technology Collaborative, offshore wind resources on the Atlantic and Pacific coasts of the United States exceed the current electricity generation of the entire U.S. power industry. NASA has also been investigating ocean wind strengths worldwide, using the QuikSCAT satellite.

http://www.sciencedaily.com/releases/2008/07/080709210529.htm

Researchers at MIT and elsewhere have been investigating the feasibility of "tension-leg" platforms for wind turbines, a technology that oil companies have been using for deep-water rigs. The structures would be assembled at a shipyard and placed on large floating cylinders that are ballasted with high-density concrete (to keep the structure from tipping over) and then tugged out to sea. Once in location, steel cables would be attached to the platform, anchoring it to the sea floor.

The MIT researchers claim that large turbines located far offshore could eventually generate cheaper power than both land based wind farms and near-offshore ones (even taking into account the increased cost of longer underground electricity transmission cables). Part of the cost advantage is the higher capacity factor achieved due to more consistent offshore winds - potentially averaging between 40 percent and 50 percent compared with 30 percent or less with land based turbines.

Some offshore wind farms could also have advantages in terms of proximity to large coastal cities compared to wind farms in remote areas, which require grid transmission upgrades to transport the power to places where it is consumed. Floating offshore wind farms also avoid bottlenecks in the supply of marine construction equipment such as pile drivers and cranes that may hamper rapid expansion of shallow offshore wind structures (however they may instead compete for some resources with offshore oil exploration and production, which could be problematical in the short to medium term).

A number of companies are active in the area of floating offshore wind technology - primarily Blue H Technologies, StatOil Hydro and SWAY.

Blue H Technologies

Blue H Technologies is a Dutch company that launched their first test platform at Tricase off Italy's southern coast late last year. The company has also announced plans to install another test turbine off Massachusetts.

The Blue H test platform in Italy is a tension-leg platform - a conventional offshore oil and gas platform design that floats below the surface, held in place by chains running to steel or concrete anchors on the seabed. The platform is located 10 km offshore and hosts an 80-kilowatt wind turbine which is mounted with sensors to record the wave and wind forces experienced by the equipment.

Blue H is now constructing a commercial wind farm for the Tricase site, which will have an installed capacity of 92 MW.

Blue H's design is unusual in that the turbine has a two-bladed rotor rather than the conventional three-blade design used elsewhere in. Technology Review has quoted Martin Jakubowski, Blue H cofounder and chief technology officer, as saying that "the noise and jarringly high rotation speeds that made two-bladers a loser on land are either irrelevant or a plus offshore" and that the fast rotation is "less susceptible to interference from the back-and-forth swing of the platform under wave action" and means less torque, resulting in a lighter structure (Blue H's 2.5-megawatt turbine will weigh 97 tons - 53 tons lighter than the lightest machine of the same power output on the market).

Tech Review also quotes Jakubowski as estimating that Blue H's wind farms will "deliver wind energy for seven to eight cents per kilowatt-hour, roughly matching the current cost of natural gas-fired generation and conventional onshore wind energy".

StatOil Hydro

Norwegian oil and gas producer StatoilHydro and Germany's Siemens (a major wind-turbine producer) are partnering in a project to build a commercial-scale floating wind farm about 10 kilometers offshore from Karmøy on Norway's southwestern tip.

StatoilHydro initially plans to operate a 2.3 MW wind turbine atop a conventional oil and gas platform, and is hoping for this to be operational in late 2009. Unlike the Blue H design, StatOilHydro is using traditional wind turbines.

The company believes floating wind farms are the way of the future, with a company spokesman saying that there are a declining number of sites available onshore and in shallow waters and citing regions without a shallow continental shelf like California, Japan and Norway where traditional offshore wind is not possible.

StatOilHydro says that deepwater wind power will be expensive in the initial stages but that the economics could eventually rival those of conventional wind power.

If deep offshore wind power in the North Sea proves to be successful it would become a major component on the planned European Supergrid, which backers hope will link up the region's power networks and allow a much higher proportion of renewable energy in future (possibly entirely fossil-free, as it will need to become eventually), including solar power from Spain and North Africa, wind from the North Sea and Ireland, biogas from central Europe and tidal power from the UK.

http://www.inhabitat.com/2007/07/02/floating-wind-turbines-in-the-north-sea/


SWAY

SWAY, based in Bergen, Norway, plans to field a prototype of its floating wind turbine in 2010. SWAY's platform is basically a spar buoy that can rise and fall gently with wave action, requiring less anchoring than the tension-leg platform. The buoy, mounted on a column nearly 200 meters tall, is held in place by a 2,400-ton gravel ballast. A three-bladed turbine is used, but, unlike conventional onshore turbines, it faces downwind rather upwind to better accommodate heeling of the tower, which may make it more effective in rougher waters than alternative designs.

The Simmons Plan

The cost estimated for Simmons' plan is $5 billion per gigawatt — more than double the amount that T. Boone Pickens’ now delayed wind farm in Texas is supposed to cost.

This seems high if the cost savings expected by the companies mentioned above eventuate, with the StatOilHydro experiment probably being the best guide, with the North Sea facing similar weather challenges to those experienced off New England.

Winter winds in the Gulf of Maine carry as much as eight times more energy as summer breezes, meaning maximum power is available during periods of greatest demand. About 80 percent of Maine residents use oil to heat their homes. The average family uses about 1,000 gallons, or 3,785 liters a year - when prices are around $4 a gallon ($1 a litre) this consumes about one-tenth of the average family's annual income, leading Simmons to declare "If we don't do this, we're [eventually] going to have to evacuate most of Maine".

Seen in that light, even an expensive offshore wind farm is better than the alternative.

As an added bonus, construction and maintenance of the structures will bring valuable job opportunities to a region hard hit by the decline of the fishing industry