article: Today, fossil fuel power stations are usually built with towers that emit vapour as well as greenhouse gases into the air. Special Report: The Technology of Business Make-It-Yourself: The rise of the micro-manufacturers Could high-end camping gear save lives around the world? Could renting Fido make you rich? The maps transforming how we interact with the world Is 'mind control' now a reality? But what if a new kind of power station could create electricity without belching harmful gases into the air? Despite the development of renewable technologies, fossil fuels are still used to generate the overwhelming majority of the world's power, and it is likely they will continue to do so for many years. In the US, about 70% of the country's electricity comes from burning fossil fuels. Other major economies, such as China, are even more dependent. But now Net Power, based in the US state of North Carolina, believes it can redesign the power plant so it can still run on coal or natural gas, but without releasing harmful fumes. Rodney Allam, chief technologist at 8 Rivers Capital, which owns Net Power, says: "The perception has been that to avoid emissions of [carbon dioxide] CO2, we have to get rid of fossil fuels. "But unfortunately, fossil fuels represent over 70% of the fuel that's consumed in the world and the idea that you can get rid of that in any meaningful sense is a pipe dream." The Net Power system is different from currently operating power plants because carbon dioxide, normally produced as waste when making electricity, would become a key ingredient when burning the fuel. A brief history of climate change Carbon dioxide would be put into the Net Power combustor at a very high temperature and pressure along with the fuel, such as natural gas or coal, and oxygen. Using the carbon dioxide as a so-called working fluid - used to make the turbine function - it would pass through the system in a loop, to be recycled and used again. Mr Allam says: "I've developed a system where we can actually make use of the impurity itself to try and assist the removal of that impurity from the power system." In addition, Net Power believes its technology would be cheaper to operate than current power stations. Mr Allam says: "It was my ambition to create a cycle which would be cheaper - or at least as cheap - as existing technology without CO2 capture, and yet go for 100% CO2 capture." The system is geared to enable a process called carbon capture and storage (CCS), which would see the excess carbon dioxide from the fuel combustion funnelled into a pipeline or a tanker instead of being released into the air. Mr Allam says that because the whole cycle happens at a high pressure of about 320 atmospheres, the gas emerges with a pressure and level of purity that is "capture ready" - or ideal for storage. This is different from the carbon dioxide produced by other kinds of power plants, which is mixed with gases such
summary: Could the smoke stack of a power station soon be a thing of the past?