Electricity Producing Drones
They call it Airborne Wind Energy (AWE). It started with kites flying higher than a conventional wind turbine to create electricity from the familiar figure of eight trajectory where winds are much stronger and more consistent than those tapped by conventional wind turbines on land or even offshore.
Apr 11, 2017 Dr Peter Harrop
They call it Airborne Wind Energy (AWE). It started with kites flying higher than a conventional wind turbine to create electricity from the familiar figure of eight trajectory where winds are much stronger and more consistent than those tapped by conventional wind turbines on land or even offshore. It then progressed to many variants, the most promising in the near term being helical or circular trajectory using a drone. That gives steady electricity production before retrieval to start again and drones can even launch when there is no ground wind at all. Several companies will first sell AWE over the coming four years despite none having flown a prototype for more than 24 hours as yet: early adopters are tolerant because this may be the start of something big. Businesses want hands on experience of complete systems producing serious power.
In the research for the new IDTechEx Research report, Airborne Wind Energy AWE 2017-2027 we discovered a number of surreal aspects of this subject. Five of the developers that impressed us answered that the peer developer they most admired is Google Makani despite it having had little to tell the world over the last two years beyond key people leaving and some patents being registered for use on ships. This project reached a very impressive stage with a finely engineered 600kW prototype.
The purpose of the new report is to assist investors, developers and others in the value chain with independent technology roadmaps and appraisal of the commercial prospects for this technology and what progress most of the leading players have really made and will make in future. We focus primarily on the most promising players: those that are likely to commercialise complete systems within the next ten years at power levels of at least 10 kW. We show that the opportunity splits into two very different requirements then subsets of these. We make no attempt to assess all of the rest of the 100 or so groups and individuals experimenting, many of them being hobbyists and some in an open source community, though we have communicated with some of them.
Our contribution is unusual in being based on conference attendance, market and technical appraisal and interviews by our multi-lingual PhD level analysts across the world who are experts in next generation energy harvesting. IDTechEx has one of the largest ranges of reports on new energy harvesting technology and markets and it runs some of the largest conferences on next generation energy harvesting such as Energy Harvesting Europe where Prof Zhong Wang, inventor of triboelectric harvesting discusses its use for creating up to 1MW and Electric Vehicles: Everything is Changing which reveals many new energy independent vehicles and scope for AWE on ships. Both conferences take place at the IDTechEx Show! Berlin May 10-11 with nine parallel conferences, 3000 paying delegates and 200 exhibitors. There are masterclasses on energy harvesting and allied materials and systems topics on May 9 and 12.
The lead analyst on the new AWE report grew a large high tech. manufacturing business from near start-up to sale for $500 million: he has a measured view of time and investment needed. IDTechEx puts AWE in better context, providing many new technical and applicational ideas to increase the chances of success. The report is constantly updated with appraisal of important news and new interviews coming in.
After a slow start, AWE could be a business of tens of billions of dollars twenty years but mainly not by direct competition with conventional wind turbines. Other opportunities are much larger and do not involve the risky tactic of merely selling on price of electricity. Benchmarking and assessment reveals that software and services will be a significant percentage. There are several dilemmas being tackled on the way to this becoming a genuine business over the coming decade. Here are just a few examples.
The lightning dilemma
Anything at those heights attracts lightning. A regular aircraft is usually a Faraday cage and it and its contents will usually be unharmed by a strike. With AWE, one respondent told us the tether will be destroyed not the craft. One said that this is a reason for making the craft capable of flying free of the tether and landing safely - not flying off into the local town. One said the highly insulating tether guarantees no strike. Wet in a storm? No. Several respondents said they will rely on grounding the system based on lightning forecasts but these are unreliable so, to be on the safe side, utilisation may be more affected than is currently envisaged. The lightning dilemma may reduce the addressable market but it does not make AWE a bad idea.
The illumination dilemma
AWE will rarely be viable at the heights of conventional wind turbines and this poses the dilemma of visibility. When up at the optimal 400-1000 meters they are virtually invisible in the increasingly favorite form of aerofoils including aircraft with lifters but although that is portrayed as an advantage it is only true in no fly zones created legally or by remoteness. Otherwise they need identification lights. At night time, particularly with crosswind ones, they will draw a large lit pattern in the sky - visual pollution.
There is a dilemma as to how to do that illumination. Our interviews revealed cases of making a non-conductive tether conductive with a low power cable for lighting etc., alternatively creating the electricity in situ with a microturbine or planning tracking illumination beams from the ground. We think making electricity in the aircraft by electrodynamic, photovoltaic and/or triboelectric harvesting is particularly attractive but if the tether itself must be illuminated, that is more of a problem. Perhaps the self-powered aircraft lighting could shine down on the tether to some extent and it could be luminescent.
The idea may be wrong that AWE can go in protected areas of outstanding natural beauty because they are not ugly like conventional turbines. Zooming bright lights across the sky can also be seen as ugly in a national park. However, the illumination dilemma restricts the addressable market: it does not make AWE a bad idea.
Killing birds and bats
There is no statistically meaningful evidence and it will not be forthcoming for at least ten years but AWE probably kills fewer flying creatures than conventional wind turbines. This will be because even tethered aircraft going fastest over the largest volume of air do so primarily above where most creatures fly. AWE systems fly slower that the tip of a conventional wind turbine blade and that helps too. One interviewee even described a kite system being considered for studying flight of eagles near conventional wind turbines. Anyway, even conventional wind turbines kill less than one percent of killed flying wildlife, the big problem being such things as cats and windows. Killing birds and bats will have negligible effect on AWE addressable markets unless the media create a false outrage.
AWE technology leverages existing technology for other things, greatly reducing risk. The drone, autonomy system and ground generator with energy storage leverage electric vehicle and aerospace technology. The tether and, if used, the kite leverage existing sailing and kite flying technology. This gives hidden economy of scale and proven technology. To that extent investment in AWES is much lower risk than is commonly realised. The far bigger risk is underfunding creating a self-fulfilling prophecy of failure. The typical teams of under ten people and under $2 million funding will not create enduring business of $100 million any time soon. Fortunately the many energy giants investing at the million dollar level are well able to multiply that by one hundred. The time to do that is now but as yet, no one comes close to the Google Makani funding.
The upcoming Energy Harvesting Europe and Electric Vehicles: Everything is Changing conferences in Berlin, 10-11 May, will provide a complete overview of energy harvesting and electric vehicle technologies, revealing the latest advances. The conferences are co-located alongside a series of synergistic events on wearable, sensors, energy storage, 3D printing, graphene & 2D materials, Internet of Things and printed electronics as part of the IDTechEx Show! (www.IDTechEx.com/europe ).
On September 26-29 IDTechEx will also be hosting the world's first conference on Energy Independent Vehicles (EIV) for land, water and air at the Technical University of Delft, Netherlands. EIVs are propelled entirely by electricity produced on-board from ambient energy. Many exist today and investment is already at the billions of dollars level. Find out more at www.IDTechEx.com/delft17 .