Buoyant airborne turbines generate power in stronger winds above the level of windmills, far left; airborne wind energy systems, left, supply power to ground based microgrid stations, potentially replacing wind farms, right
D
espite being a world leader in offshore wind powered energy generation, the UK renewables sector has the potential to supply an even greater share of the country's energy needs. According to Renewable UK, there are currentlymore than 7,000 wind turbines
operating within Britain, nearly 6,000 of which are onshore. But the windmill is itself under threat fromthe kite. A new
IDTechEx report, AirborneWind Energy (AWE) 2017-2027, finds thatmaking electricity by flying kites and similar equipment can potentially address two very different opportunities: to kill diesel or to kill wind turbines. The 20 leading AWE developers aremostly targeting one or the
other. A few say they are chasing both but sincemost of these small companies are underfunded, it is only amatter of time before they will have to choose. These two objectives require very different products.
KILL DIESEL An estimated 1.16bn people (17 per cent of the world’s population) live without access to electricity, including a population of around 750million people living on 10,000 habitable islands around the world. Canada, the USA and Chile have the largest number of islands, while Indonesia, the Philippines and China have the largest islander population. Many rely on diesel generators for their electricity and spend a
considerable percentage of their gross domestic product (GDP) on importing fuels. Now, AWE technologies aremoving in to compete with diesel
engines, kerosene heaters and fuel oil-powered devices. This means being a replacement – ormore often part of a replacement – for the diesel gensets – with their inherent fire-risk, pollution, hassle and legislative threat – that are used by remote communities and as stand-by power for hospitals. Windlift in the USA was founded in 2006 to develop portable
AWE technology for post-conflict reconstruction, disaster relief and ThirdWorld development. It says its technology has the potential to also benefitmilitary operations by displacing diesel generators as the primary source of electricity for forward operating forces. Currently,most electricity for forward outposts is provided by
supply lines transporting fuel to the front lines. Supply lines are costly to operate, both in terms of dollars and lives lost and are the limiting factor in speed of advance and themost vulnerable part ofmilitary operations. A prototype of theWindlift AWE systemwas therefore
delivered to the USMarine Corps last year. The company sees its system, when developed, as ideal for off-grid use in communities
in the developing world, remote agricultural areas, research facilities,mining operations and for disaster relief.Windlift is testing two 12kWprototypes and has developed a conceptual design for a 23kWHumvee-towable system. Contrast eWind, also in the USA, which is seeking to serve
farmers using an interesting lease and buy-back scheme (advertising on kites was tried as a funding option but has been unsuccessful as the kites are too small and distant). Competing with diesel and starting with 12kWoutput, e-Wind focuses on off- grid applications and is seen as attractive to farmers renting out space. Some farmers have even asked for it to cast the shadow of a large bird of prey to help protect crops fromwildlife. According to company data, eWind’s airborne wind energy design delivers four timesmore electricity per dollar than conventional wind energy systems. Newmaterials and drone technology are combined to harness strong, consistent winds at higher altitudes than conventional wind turbine systems can access. These affordable flying devices also bypass the costs of building andmaintaining costly towers. Once commercialised, the eWind systemis expected to deliver
clean, renewable electrical power at a cost of $0.05 to $0.07kWh (comparable to hydroelectricity), though price estimates are very speculative, given that no one has yet flown their device formuch more than a day or so. On the other hand, another at the low-power off-grid end, Ben
Glass, CEO of Altaeros, told The New York Times that the company expects to provide off-grid power at about $0.18kWh, about half the price of off-grid electricity in Alaska where it is currently operating. Its speciality is serving far-flung villages, military bases,mines, or disaster zones. Various researchers have been developing such balloon
supported wind turbines for years, but the 18-month project in Alaska was the first longer-term, commercial project to test the technology. Altaeros’s Buoyant Airborne Turbine (BAT) is an inflatable, helium-filled ring with a wind turbine suspended inside. It floats at a height of 300m, where winds tend to be far stronger than they are on the ground. The altitude of the BAT is about double the hub height of the world’s largest wind turbine, with the potential ability to fly even higher. The BAT has a power capacity of 30kWand will create enough energy to power about 12 homes, the company says. It can also lift communications equipment such as cellular transceivers ormeteorological devices and other sensing equipment. Altaeros says that this additional equipment does not affect the energy performance of the turbine. The technology can be deployed in under 24 hours, because it
does not require cranes or underground foundations. Instead, it uses high-strength tethers, which hold the BAT steady and allow
April 2017 /// Environmental Engineering /// 11
Page 1 |
Page 2 |
Page 3 |
Page 4 |
Page 5 |
Page 6 |
Page 7 |
Page 8 |
Page 9 |
Page 10 |
Page 11 |
Page 12 |
Page 13 |
Page 14 |
Page 15 |
Page 16 |
Page 17 |
Page 18 |
Page 19 |
Page 20 |
Page 21 |
Page 22 |
Page 23 |
Page 24 |
Page 25 |
Page 26 |
Page 27 |
Page 28 |
Page 29 |
Page 30 |
Page 31 |
Page 32 |
Page 33 |
Page 34 |
Page 35 |
Page 36 |
Page 37 |
Page 38 |
Page 39 |
Page 40 |
Page 41 |
Page 42 |
Page 43 |
Page 44 |
Page 45 |
Page 46 |
Page 47 |
Page 48 |
Page 49 |
Page 50 |
Page 51 |
Page 52 |
Page 53 |
Page 54 |
Page 55 |
Page 56 |
Page 57 |
Page 58 |
Page 59 |
Page 60