Researchers at Sandia National Laboratory are developing a new gas turbine to increase the efficiency of conventional electrical power plants with a generation system that could increase the thermal-to-electric conversion efficiency by 40 to 50 percent.

Electrical generation is an especially dirty process when coal is being used as the fuel source. It's not too efficient, either, with only about 1/3 of the energy from the burned coal being turned into useful electricity. Research is currently being done on two test assemblies which use supercritical carbon dioxide (S-CO2), rather than water and steam as the working medium, and a system using the Brayton cycle with equipment more akin to a jet engine than a conventional steam turbine.

While most coal-fired electrical plants could see benefits from this new method, other kinds of power generation would also be able to apply these developments. Nuclear power, biomass, and solar thermal power plants also could be improved through adoption of S-CO2 Brayton generation.

The S-CO2 Brayton equipment is also much more compact than equivalent power generating conventional turbines, which helps to reduce installation costs. This should also serve to make retrofitting of existing power plants easier, since available space for the conversion would be easier to allocate. A small, 4 cubic meter (about 141 cubic feet) system could replace more than 120 cubic meters (about 4,238 cubic feet) of equipment and produce the same amount of power.

Furthermore, while special materials are needed for conventional Rankine cycle turbines, because steam is corrosive at the temperatures and pressures involved, this is not an issue with S-CO2 Brayton equipment, which can be fabricated from simple stainless steel.

With efficiency increases like that, old, outmoded coal plants could be retired, and swapping in new, more efficient equipment could replace the need for building new coal plants altogether.

image via Wikimedia

via: Solar Thermal Magazine

We've written a few times about the fuel-reducing power of the ship-propelling SkySail kites.  In trial runs, the large sails, which are mounted to the front of container ships, have been able to cut fuel use by 20 percent and the company says that the sails could cut fuel use by up to 35 percent in real-world applications.

Now SkySails has a major customer in Cargill, a shipping company that transports more than 185 million tons of goods each year.  Cargill doesn't own any ships themselves, but the companyhas signed a contract with SkySails to test a kite on one of the handysize vessels that it operates through an agreement with the ship's owner.  The handysize vessel weighs in at 25,000 to 30,000 tons, which means it will be the largest ship so far to be propelled by a kite.

The SkySail system should be outfitted on the ship by early 2012 and if all goes well, Cargill will make a larger order.  A study by the United Nations International Maritime Organization found that use of SkySails on ships worldwide could reduce shipping CO2 emissions by 100 million tons a year.  Let's hope more large ships will be outfitted with this technology soon.

via Environmental Leader