Nonaxial Wind Turbines A New Class of Wind Turbines By Mike Fallwell

Wind Turbines vs. Aircraft Aircraft typically couple 1000 times as much mass and energy to air as wind turbines do for their weight. Reciprocity laws point to the fact that wind turbines should be much more economical if they were more like aircraft. A typical sailplane in 200 ft/min (2mph) up draft is producing over 10kW. A tethered sail plane could develop 360kw in a12 mph wind. Global development of alternative energy systems is currently blocked by the low cost of coal. This system may be competitive to coal even on its capital costs.

Nonaxial Wind Turbine generator pulley Flight path The glider crosses the wind and drags the loop of cable through pulleys and generators on the ground. Wind is blowing toward the viewer The low mass structure couples to a large air mass economically.

Low Speed Wind Energy Systems Low wind speed turbines that can operate economically have been identified as a key element of the national renewable energy plan for future growth of wind energy. The goal of our project is to demonstrate the utility of a wind system based on tensile structures and begin to determine its scale limits and costs per kWh. Tensile based wind systems can be optimized for lower wind speeds and higher utilization.

HAWT vs. NAWT Horizontal Axis Wind Turbines (HAWT) can generate 1 watt/ lb. and cost $50/lb. Because Nonaxial wind turbines are largely tensile structures they can generate about 100 watts/lb. at lower wind speeds Span can be adjusted to match lower local wind speeds to increase capacity factor Types o

Turbine weights and loads For a wind speed of 12 mph the glider speed is 100 mph with a L/D of 8. For a 20 ft span, the lift is 4000 lbs and thrust is about 400 lbs, giving an output of about 50 KW. The combined length of the Kevlar cable is 1/2 mile and for a strength of 10,000 lbs, the weight of the cable would be approximately 300 lbs. The turbine develops 100 watts/ lb. excluding the generator

Advantages of the nonaxial wind turbine Operate at higher altitude Not exposed to storms Ground maintenance and safety Less vibration (100x) Low tech (metal or fabric) Much less expensive gear box (100x) A vast increase in the number of productive wind sites will reduce the need for new power lines Low visual impact, low noise Short lead time installation Have the highest power to weight ratio of any wind energy system

Advantages of the nonaxial wind turbine Environmental Impact Durability Maintenance Safety Cost Market Size

Environmental Impact Low Noise (lower speeds) Operate at higher altitude (less contact with birds) Low visual impact (smaller)

Durability Less vibration (100x) High max wind (150+) Smaller loads overall

Maintenance Ground maintenance and safety Easy wear inspection

Safety Ground maintenance and safety Low mass Simple aircraft avoidance system

Cost Low tech (metal or fabric) highest power to weight ratio A vast increase in the number of productive wind sites will reduce the need for new power lines

Market Size Can displace coal in areas with hydro or hydro storage

Development Many mechanical problems still need to be resolved If capital cost of the system proves out to $200,000/MW at the high capacity factors predicted, it will be cheaper than a coal plant on capital costs alone.

History A very similar device was patented in the 60s that has the key features needed for low cost. It was not developed and problems still exist. I will apply for patents on those issues when they are clearly resolved. A brief history of the company and development plans. Two years ago I was building the prototype. Last year I was still working on the math to compare it to all the other patented tethered wind systems. This year was spent mostly trying to raise funds. I have also been looking for a retired aerospace person to assist. I think a 200 kW system is about the minimum economic size since the electric power system will cost about twice what the turbine does below this size. I"m not really qualified to design this power system as there are several possible routes you could take and it needs to be functional on the first cut. It will probably need to be a high frequency alternator with a commutating converter and flywheel. An existing SCADA system can probably be adapted.