IEEE Consultants' Network of Long Island

Vertical Axis Wind Turbine -- Dick LaRosa

Farmingdale State College hosted an event May 11 at which Rep. Steve Israel (D-Huntington) introduced Arun Majumdar, Director of the Defense Advanced Research Projects Agency - Energy (DARPA-E). Long Island entrepreneurs were present and some had interesting displays around the room. One was Flynn+Stott Architects, Southampton, representing Urban Green Energy of China. They make several vertical axis wind turbines which can be mounted on buildings and other structures. Richard Stott says they work well in turbulent wind that would be present around buildings. The 1 kW model has three blades, spaced 120 degrees apart around a (non-existent) cylinder. The blades have a helical pitch such that the top of each blade is directly above the bottom of an adjacent blade. The concave surface of one blade airfoil faces the wind when that blade is moving in the direction of the wind, so there is always some spot to act as a cup to catch the wind from any direction to get the rotor started. Once started, I am completely baffled by how the lift and drag forces work.

The rotor height is 2.7 m and the diameter is 1.8 m. The product of these two numbers is 4.86 m2. Their specifications say the swept area is 3.24 m2. The ratio is 2/3. I thought it should be the larger number. Can somebody explain this 2/3 factor? Anyway, at the rated wind speed of 12 m/s, the kinetic energy transport rate through the 3.24 m2 area is 3.33 kW. The rated output is 1 kW, so the power coefficient (the ratio of power out to power going through the rotor's swept area) is 0.30, if we use their specification for the swept area. Using my 4.86 m2 area, the power coefficient is 0.20. Horizontal axis wind turbine makers have claimed 0.50, and 0.45 is commonly claimed for water turbines.

The blades are carbon fiber and fiberglass. The vertical shaft can pass through the roof and extend to the alternator and lower bearing some distance below. There is electronic overspeed protection. The cut out speed is 30 m/s and the cut in speed is 3 m/s. Power output varies as the cube of the wind speed, so at cut in, the output power is 1/64 of the 1 kW output at 12 m/s (27 mph, a pretty strong wind).

GILLIG HYBRID ELECTRIC BUSES—Car Schwab

I have of recent times, had an interest to see how the hybrid electric technology was going to find a niche in what market place. Over the last few months I have noticed buses that run on the "110 corridor" from Halesite to Amityville are now showing Hybrid-Electric signs. Not all by any means but several.

I have noticed that most of the buses appear to be about the same age and made by the same manufacturer, GILLIG, but most Conventional with a mix of the Hybrid-Electric. All are 40' in length. So I set out to find out what I could.

GILLIG has made Hybrid buses for about 15 years starting with a Series mode operation but with the most recent Parallel mode hybrid. From checking on the Internet their claim is that the same bus can be converted from Conventional to Hybrid by selecting the transmission unit—the dimensions allow for this. I must say pretty clever. The hybrid transmission unit is a scaled up version of the units offered by GM for its SUVs and is made by the GM Allison Division. In this Hybrid transmission unit is two electric
mot/gen, and planetary gear set for combining the ICE power with the electric power. This is all very much like the Toyota Prius, just much bigger. Now how well does it work?