Reduced solar production often occurs in windy conditions when a storm or front passes. It would be nice to harvest that energy. But traditional wind powered generators have esthetic and radio interference issues. A tower to put the wind mill generator into faster air faces city housing challenges along with cost, noise, and safety risks: The blades generate noise but worse, they can cause a multi path problem (variable reflection of TV and FM radio waves) that can induce unacceptable signal noise to the neighbors. But there may be a better approach, a Darrieus turbine. CONCEPT A set of cylindrical, Darrieus turbines mounted at each roof top apex: One size for the shortest apex and as many as can fit on any segment. May. include a 'hat' to improve air velocity on top Automotive alternators with custom field controller: A/C synchronous with solar roof, 240 VAC buss Tunes for maximum average power draw (i.e., optimum current) Tuned, helical blades RF resonance tuned for a "dead" band with resistor and capacitor (i.e., ~2.4 GHz microwave oven or 27 MHz CB radio.) Make it a "dead spot' in that band. helical to reduce noise 'pulses' for quieter operation BRASS BOARD My approach starts with figuring out how to make the Darrieus turbine cylinder. My first effort was to cut and tape a cardboard tube: Two flaps were cut on opposite sides Bent in so one edge forms a curve and the trailing section is taped in a taper Not meant for any practical purpose, just testing an approach. The next will print paper template that can be printed and taped into a three blade, helical, turbine, cylinder. DEVELOPMENT PLAN Once the assembly and dimensions for a sub-scale model are worked out, transfer the paper pattern to a flat aluminum sheet and fabricate a scale model. Use "car window spinner" test to make sure it self-starts and rotates in proportion to the speed. Modify the pin wheel cylinder to add a three phase, RC motor to brass board the controller and software. Again, use "car windows" testing to make sure it works as expected. The next phase entails operational dimensions, materials, and fabrication of a test article with alternator and controller. Only now, car roof testing to resolve remaining design constraints. Build one full-size test article and test on the roof. Initially on an isolated, 240 VAC circuit not connected to the solar power grid. Then carefully test with the solar power circit but disconnected from grid. Then do an integrated systems test. At this point, I should have enough metrics to determine expected power as a function of wind speed and safe operation. In effect, it becomes a wind turbine based, solar panel added to the existing system. Then begin manufacturing optimization and limited production. Bob Wilson
How much wind energy potential does your location have? Mine has very little: An additional map for wind at 100 meters AGL is available here: WINDExchange: Wind Energy Maps and Data
At low wind speeds you'll get the best energy recovery out of high sensitivity permanent magnet motors driven as dynamos. You can harvest great ones out of treadmills. Been there, done that.
The multipath problem (EMF vs. moving blades) is the National Security risk of offshore wind turbines (vs. radar) cited by Administration to cancel offshore wind farm leases.
has multipath reception distortion been a factor in anyone's enjoyment of broadcast frequencies in the 21st century?
i watched these go up, sad to see: early-morning-demolition-brings-down-hulls-last-wind-turbine-at-former-town-dump
I suspect the observations for those maps were done more inland, or the band of potentially better generation on the coast is lost in the map's scale.
My case is smaller. I have a house with solar panels and since the two, 55 year old, 180 ft pine trees are gone, have a SouthWest exposure to prevailing winds. My solar roof produces a maximum of 1-4.8 kW on a clear day. But adding an extra 2 kW of wind from the apex of the house would be nice. Especially on cold, stormy nights. Bob Wilson
Our TV reception is generally dealing with stationary multipath, not the rapidly changing version. In the digital modulation world, rake receivers (if implemented) can actually take advantage of stationary multipath's added signal power to increase their signal to noise margin. This doesn't work with fast changing multipath. I don't know what change rates they can accommodate and still keep the many filter coefficients usefully updated. The tin hat crowd was concerned about biological effects of EMF. But even that tin hat crowd never latched on to Trump's claim that the noise from wind turbines causes cancer, so he had to come with some other excuse to stop them. A quick search finds this to be an actual issue, but I haven't read enough to learn how significant.
