The new IDTechEx report, Airborne Wind Energy (AWE) 2017-2027 finds that making electricity by flying kites and the like can potentially address two very different opportunities: kill diesel or kill wind turbines. The twenty leading AWE developers are mostly choosing one or other as their target. A few say they are chasing both opportunities but since most of these small companies are underfunded it is only a matter of time before they have to choose. These two objectives require very different products. This is despite the fact that the different variants from tethered kites, semi rigid wings, fixed wings, rotor craft to turbines in balloons all make cheaper electricity when bigger than they are now. Another common factor across all these variants is higher power density than solar but also potential for partnership with solar to reduce intermittency: enemy and friend. However, choices of targeted application and therefore very different specification are essential. AWE is put in context in the IDTechEx report, High Power Energy Harvesting: Off-Grid 10W-1MW 2017-2027.
Firstly, the kill diesel option is more precisely defined as competing with diesel engines, kerosene heaters and fuel oil powered devices. This means being a replacement, or more often part of a replacement for the hassle, fire risk, pollution and legislative threat of diesel gensets used by remote communities and as stand-by power for hospitals and so on.
For example, Windlift in the USA was founded in 2006 to develop portable AWE technology for postconflict reconstruction, disaster relief and third-world development. It says its technology has the potential to also benefit military operations by displacing diesel generators as the primary source of electricity for forward operating units. Currently, most electricity for forward outposts is provided by supply lines transporting fuel to the front lines. Supply lines are costly to operate in terms of dollars and lives lost. Supply lines are the limiting factor in speed of advance and the most vulnerable part of military operations. A prototype of the Windlift AWE system was therefore delivered to the US Marine 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. It has been developed for applications such as lighting, cooking, pumping water, compressing air, and charging batteries. It is testing two 12 kW prototypes and it has developed a conceptual design for a 23 kW Humvee-towable system.
Contrast eWind also in the USA which seeks to serve farmers using an interesting lease and sell back scheme when its product is ready. e-Wind focuses on off-grid applications competing with diesel and starting with 12 kW output. This is seen as attractive to farmers renting out space. 50K kWh/year is seen as 50% of a farmer's needs in the USA and there are over 200,000 of these farmers in the USA. Some farmers want it to cast the shadow of a large bird of prey to protect crops from birds. They tried advertising on their kites but has been a failure as they are too small and distant.
The company says, "eWind's revolutionary airborne wind energy design delivers four times more electricity per dollar than conventional wind energy systems. We use new materials and drone technologies to harness strong, consistent winds at higher altitudes than conventional wind turbine systems can access. Our affordable flying devices allow us to bypass building and maintaining costly towers. Once commercialized, the eWind system is expected to deliver clean, renewable electrical power with a levelized cost of $0.05 to $0.07kWh (comparable to hydroelectric). IDTechEx considers price promises to be very speculative given that no one has yet flown their device for much 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 $0.18 per kilowatt-hour, about half the price of off-grid electricity in Alaska where it is currently operating. Its sweet spot 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' Buoyant Airborne Turbine (BAT) is an inflatable, helium-filled ring with a wind turbine suspended inside. It floats at a height of 300 meters, where winds tend to be far stronger than they are on the ground. Like alternatives, the altitude of the BAT is about double the hub height of the world's largest wind turbine with higher in prospect.
The BAT has a power capacity of 30 kilowatts and will create enough energy to power about 12 homes, the company says. It can also lift communications equipment such as cellular transceivers or meteorological devices and other sensing equipment. Altaeros said 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 the electricity to be sent back to the ground. A power station on the ground controls the winches that hold the tethers and pulls in the power from the turbine before sending it on to a microgrid connection.
IDTechEx finds that the low power off-grid applications will often involve private individuals strongly influenced by up-front price and transportability. A substantial battery is usually involved, so battery costs matter. Indeed, combination with solar to minimise intermittency and thus battery cost and weight is often important. Grid parity is not an issue. An estimated 1.16 billion people (17% of the world's population) currently live without access to electricity. 10 000 inhabited islands around the world and an estimated 750 million islanders. Canada, USA and Chile are the countries with the largest number of islands, while Indonesia, the Philippines and China are the countries with the largest population of islanders. Many rely on diesel generators for their electricity production and spend a considerable percentage of their gross domestic product (GDP) on import of fuels.
Kill wind turbines
Not so with on-grid high power application - the other basic choice for AWE developers - where off-shore wind farms with much lower levelised cost of electricity over conventional GW level wind farms is the typical objective. Think AWE in huge wind farms off-shore not for the wind - AWE taps the stronger and more consistent winds higher up - but AWE off-shore for safety and availability of real estate with no-fly zones for aircraft. Off-shore AWE could fly from unstabilised buoys containing the new 6D motion harvesters as a supplement and the huge cost of decommissioning enormous wind towers in the sea at end of life is not incurred. Nor is the hazard to shipping.
Investors in AWE such as Conoco Phillips, Shell, E-On and Alphabet (owner of Google) push their companies to concentrate on power station replacement because they think that is the big opportunity and it is a world with which they are familiar either as users or suppliers of huge amounts of electricity. However, Dr Peter Harrop, leader of the team of IDTechEx analysts that research AWE and alternatives says,
"As Altaeros reports, there is also a $17-billion remote power and microgrid market that could benefit from the technology. Many off-grid sites, including small islands, mining sites or military bases rely on expensive diesel generators to provide some or all of their power needs. There are many projects that are trying to develop integrated solutions to tackle this market, particularly microgrids that integrate some type renewable energy. The International Renewable Energy Association (IRENA) finds that 400 GW of gensets of 0.5MW and above is candidate for replacement as new emissions laws kick in but 150GW of that is where there are long intervals of no sun or low level wind: AWE uses stronger wind higher up. IDTechEx believes that smaller gensets could be a similar opportunity in value. IRENA finds that photovoltaics and conventional wind power are already cheaper than the diesel generators traditionally used to supply remote communities and islands. This is even relevant to cities where Las Vegas businesses now make most of their own electricity from solar panels in the desert to save money. In duller climes, the wind power alternative reinvented as AWE could appeal in microgrids for individual buildings for example. It would be ironic if AWE becomes a big business at the small end and not as a major on-grid power source. At present the jury is out: no one knows."
Energy independent shipping
Meanwhile, in September 27-28 IDTechEx is staging the world's first conference on energy independent vehicles at the Technical University of Delft in the Netherlands and AWE speakers are in the line up. Why? Large ships each pollute as much as 30,000 cars and large AWE with solar roads on board could make them energy independent and totally clean. Maybe the smaller AWE systems could power small electric ships too. Who knows? Development has begun.
Find out more about the Energy Independent Electric Vehicles event at www.IDTechEx.com/Delft17.