48 – www.energy-future.com 3.4 — Technology: clean coal a week — enough capacity to supply over 1 million people with electricity. In other words, in 2006, China built enough new coal-fired power stations to more than meet all the electricity needs of the UK population of 60 million people. Or 250 million Chinese, who will, of course, be increasing their per capita usage in the future (see chart 2). “Coal’s in demand around the world — and not just in high-growth areas such as China,” says IEA coal analyst Brian Ricketts. A variety of sources will continue to be used for power generation, including gas, nuclear, hydro and renewables, but such a big surge in demand makes it impossible to ignore coal. The IEA predicts that between now and 2030 investment of $5.2 trillion will be needed in electricity generation. Around $2 trillion of that will be spent on coal-fired generation, which will double over the next 23 years, it says. A further $0.6 trillion will be needed in the coal-mining sector. That is good news for companies that can build clean-coal power stations. A substantial reduction in world CO2 emissions will be required to limit the rise in global temperature to what is thought to be an acceptable level — a maximum of 2°C above the preindustrial level. And enabling increased coal use without accelerating global warming depends on technological innovation. Progress has been made in cleaning up coal’s act. Technology is now routinely installed in new power stations that can treat pollutants, such as sulphur dioxide, nitrogen oxides and dust — virtually removing them. But the next task is to deal with emissions of CO2 — the main cause of global warming. Improvements in the efficiency with which coal is burned are an important first step, says Alstom. In the pulverised- coal combustion process, for example, coal is ground to a fine powder, which can be burned more quickly, reducing environmental damage. The average efficiency level of today’s power stations is 32% — meaning about a third of the energy in coal is harnessed as electricity. Boosting this to 48% would slash CO2 emissions by almost a third, says Alstom. State of the art Efficiency improvements in the power sector in general are partly being achieved by fitting existing plants with modern technology. This, says Alstom, accomplishes the essential goal of cutting CO2 emissions, while having the additional benefits of reducing operating costs and extending the lifetime of plants. However, cleaner-burning techniques and efficiency improvements are just part of the story. To develop genuinely green power plants, the CO2 must be captured and buried. There are two leading technologies in development: integrated-gasification combined- cycle (IGCC) technology removes the CO2 before combustion, making synthetic Chart 2: Per capita electricity usage Megawatt hours a year Source — Governments; IEA 0 3 6 9 12 15 US UK China Million 0 400 800 1,200 1,600 2,000 Population (right scale) Energy consumption (left scale)