Scare-mongering is ON: just eight years no freaking way

[THX_1138]

Re: Scare-mongering is ON: just eight years no freaking way

wind generators installed offshore

First time i am hearing about this. Could you please show me some more info about this ? I don't get it how off-shore wind generators are gonna work...is it like a huge oil-rig pontoon except with a windmill at the top ? And the electricity generator is a small scale generator on each pontoon ? Somehow this sounds like an engineering blunder to me...but i will hold off judgement for now.

actually quite the reverse... see the problem with wind generation is that on land, the closer you are to the surface, the slower the air currents and thus lesser yield. hence for a wind farm on land, you need to construct massive windmills which are very high above the ground to catch the air currents and convert it into kinetic energy and eventually electricity. in fact, there is some talk of an air borne wind mill that will use part of the currents to stay afloat and will use part of the wind currents to generate electricity which it will then transmit to a ground station using a high strength tether. sounds like science fiction? well no! its actually real. a canadian company (yes jump in joy) Skywindpower and another called Magenn makes these massive windmill which is actually an inflated helium balloon shaped and contoured like a turbine that rotates with the wind current and rises to altitudes in excess of 500 to 1000 feet. since the wind current there is much more steady, electricity generation much more steady. you can get your own personal 5kW to 500kW wind balloon. however, while this is still not that viable an option since 500kW is peanuts, another option is offshore. a few miles off the coast, the wind currents over the sea are much more steady and constant and thus the wind mill can operate at optimum capacity without any interruption and furthermore since the currents are stronger, the wind mill's mast does not have to be as high. there is an expense in the initial infrastructure of constructing the distribution system and hoisting the masts. just run a search online and you will find endless pictures of off shore wind mills. as for this being an engineering blunder, far from it. infact it might just be our saving grace. of course no one is construction these in a turbulent region but there are several regions around the world's coast lines that see steady wind current without too much turbulence that might damage the mills. i guess you have a hard time finding this plausible since you are wondering what happens at times of a gale or storm? well simple, wind mills are actually designed to operate at a uniform rate, at a wind velocity too high, instead of spinning faster, the mill employs a technique of "feathering" where it slows down and does not spin beyond a particular angular velocity lest the mill disintegrate into pieces from the centrifugal forces on the blades. moreover, at times the mill can be shut down completely and the fins are each individually rotated to such an angle that they are no longer vulnerable to air current. and finally, if you think that is brilliant, know this, there are men better than me and you working at this. trust them. i am sure the wright brothers were thought of as fools but then again thats what we thought of space travel till sputnik.

[THX_1138]

Re: Scare-mongering is ON: just eight years no freaking way

the very best polar voltaic cells are achieving at best 6-8% efficiency and the latest breakthrough (yet on the drawing table) developed in great part at my alma mater claims to have achieved 12%. moreover, these thick film pvcs do not work very efficiently in overcast skies, and there are a thin film variety that are not as efficient under the blazing sun, but over the entire day, their output is greater. for more on these thin film solar cells, google "stan ovshinsky", a self made genius maverick industrialist.

Well when i said 15-20 %, i meant that the photovoltaic cells convert around 15-20% of incident sunlight into electricity. The net figure is going to be lower, probably closer to the 8-12% you quoted because of heat loss and resistance-related issues. Besides, i think PVCs can be chosen according to the climate in question. If its a solar array near Jaisalmer, we can easily choose the thick film PVCs over thin film ones, given that this area sees blazing sunlight most of the year. Currently i am working a co-op term for Ballard where i have learnt a lot about renewable sources of energy and for my next job, i am going to look for an opening in the PVC market. IMO, the biggest challenge facing solar power is that it is going to be costly nomatter what. Primarily because the biggest problem in the long term is scratching of the glass reflector and cleaning off the sand/dust accumulation on the panels in a desert setting. Those two factors are always going to remain a high cost issue. PS: I agree with you completely on bio-fuel. Those who think that bio-fuel is the answer to global warming and oil dependency are truely deluded or smoking some really good herbs. If its the latter case, i request them to send me some of that they are smoking!

again, for the sheer sake of being pedantic, i have no clue where is it you are getting these numbers from. i think your sources are incorrect on this. when i mean 6-8% effeciency i mean that if on a solar panel 1m by 1m, 100Joules is incident in a second, of it, only 6 - 8 watts is recovered as usable electric charge. the rest is lost not to heat (heat losses in silicon are of the magnitude of 1, i.e. for every 1 watt generated, 1 watt is wasted to heat losses, might sound a lot, but know this, your car has heat loss of the magnitude of 3!), but is simply not harnessed. a little technical here, but most silicon molecules, tetrahedral in nature, when exposed to incident sunlight, i.e. energized photons, they disperse electrons that are collected in collection reservoirs and then channeled along the length of the wafer, and subsequently the panel to the collection electrodes. the amount thus recovered in only a small percentage of the total agitation caused in the molecules. hence we need to design better silicon wafers and semiconductors to harness more molecules. stan ovshinsky has one such wafer that is much more durable and which it too does not operate over 6-8% it does operate better during times of less sunlight like at dawn or on a cloudy day. the new age wafer i told you about, was developed along the lines of the C 60 molecule also known as a Buckyball (after Buckminster Fuller) where the structure of the silicon molecule is optimized to trap more of the electrons thus reaching efficiencies of 12 and at times 16%. now that might sound lame, but we just doubled our output and thus reduced the per kilo watt hour cost by a factor of 2! which more work is being performed with every passing day, there is no silver bullet. i.e. no single overwhelming solution. hence, the future resides in a combination of wind, solar, nuclear (still very clean and very reliable), and hydroelectric power plants. that is of course, unless we can make fusion profitable (right now we are able to recover only 85% of the energy input, and the only reason why this is low is because humanity has not constructed any substance that can withstand such high temperatures inside an ITER reaction chamber to recover the heat energy generated). the solution my friend is again in nanotechnology... and again in carbon fibers which use the same notorious buckyballs.