Ampyx Power systems start where conventional wind turbines end. The PowerPlane moves at an altitude of up to 450 metres where the wind is strong and constant.
From wind to energy
There is enough wind, but what is the most efficient way of using it? Ampyx Power is developing an Airborne Wind Energy system with a PowerPlane, a tethered aircraft that converts wind into electricity.
How this technology works:
1. A tethered aircraft
PowerPlanes are autonomous aircraft tethered to a generator on the ground. They move in a regular figure-8 pattern at an altitude from 200m up to 450m. When the aircraft moves, it pulls the tether which drives the generator. Once the tether is reeled out to a predefined tether length of ~750m, the aircraft automatically descends towards a lower altitude causing the tether to reel in. Then it ascends and repeats the process.
PowerPlanes take off, fly and land autonomously from an innovative platform, by utilizing a vast array of sensor suites which provide the autopilot with critical information to perform the task safely.
Ampyx Power has specific in-house aircraft knowledge and expertise in constructing autonomous aircraft. For instance, in terms of the algorithms the automatic pilot is equipped with. Many code lines in the software ensure that the aircraft can fly completely autonomously while responding to changes indicated by numerous sensors. Adjustments can be made within milliseconds, allowing the aircraft to continuously fly in a figure-eight pattern.
2. The generator
When the PowerPlane ascends, tensile force causes the tether to be reeled out from the winch. The winch is connected to a generator, that also serves as a motor to reel in the tether during the PowerPlane’s descends towards lower altitudes. The energy used when reeling in the tether (5 sec.) is only a fraction of the energy produced when the tether is reeled out (25 sec.).
3. Launch- and land platform
We are developing an innovative launch- and land platform in which the generator is mounted. The platform rotates automatically in the wind, allowing the autopilot-controlled aircraft to launch and land safely. The platform can be used for both onshore and offshore.
"We are set to disrupt the energy market. In the future our Ampyx Power parks will provide abundant renewable energy at market utility scale, at cost levels below ANY other methods of electricity generation."
Wolbert AllaartDirector Ampyx Power
Costs and benefits
The PowerPlanes move in a cross wind pattern at an altitude of up to 450m where the wind is stronger and more constant with a large swept area. This is why the energy yield is so high, while the material and installation costs are relatively low. Our system comprises less than a tenth of the material than a wind turbine with the same capacity.
The prototype with a wingspan of 5,5 metres produces, when optimized, approximately 50 kW and can supply about thirty houses with energy. The commercial type has a much larger wingspan of up to 30 to 40 metres. With these autonomous aircraft, 2 MW power can be generated, supplying 2,000 homes with sustainable energy.
Flying across the wind accelerates our system and enables it to extract more power. A simple illustration of this phenomenon is to consider the movement of a water skier which enables them to overtake their tow boat. When the skier is behind the boat, the two travel at the same speed. However, if the water skier moves in a ‘slalom’, they travel faster than the boat. Similarly, flying a cross wind pattern means our system can go faster than the wind speed, which results in a significantly higher energy yield.