 Concept: Extracting electricity out of humidity  Not just a pie in the sky  Atmosphere : A...

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Transcript of  Concept: Extracting electricity out of humidity  Not just a pie in the sky  Atmosphere : A...


HYGROELECTRICITYConcept: Extracting electricity out of humidity Not just a pie in the sky Atmosphere : A great source of electricityCould be of great utility in region of high humidity

What is the need ?

Humans : A creative creature but still acts as virus when it comes to energy consumption The end of fossil fuel Global population Demand for Energy Global Warming Conclusion: A need to look for alternative and renewable source of energy

HYGROELECTRICITY : The basic principle

A metal placed in humid environment develops charge on its surface.The charge increases with the increase in relative humidityThe amount of charge depends onNature of metal Exposure time Relative humidity Surface area

Contrast with electroneutrality principle

Electroneutrality principle statement water droplets in the atmosphere were electrically neutral, and remained so even after coming into contact with the electrical charges on dust particles and droplets of other liquids Recent researches shows ion imbalancesNot actually contradiction water has ion imbalances that could allow it to produce a charge. The principle of electroneutrality states that if you consider the liquid as a whole that the net charge within the liquid will be neutral . The principle does not state that if you subdivide a liquid and only consider a portion of its volume that the charge in that portion has to be neutral

Unexpected pattern of R H v/s Static electricity

Decreases with increase in RH .

Due to increase in conductance,the charge dissipation increases.

Actually this idea was for dielectrics.

Charge deposition on metals due to humidity remain undiscovered.

Recent researches shows opposite behaviour in case of metals

Gameblacks report

Presented on Aug 25 at 240th meeting of ACSRevealed his research showing unexpected electric charge distribution on metals and insulator surfaces.Questioning the well proved concept of electrostatics.Our lack of knowledge about the identity of charge forming species.Builds and tests models explaining adsorption of H+ and OH- on metal in humid environment.Aims at capturing this electricity calling it hygroelectricity.Experimental Observations

According to the previous theory of charge dissipation, static electricity decreases with increase in RH

Behaviour of humidity

Dual behaviour of humidity Encourages reproducibility of electrostatic experiments .Electric shocks experienced from boiler surfacesAge old mystery unfoldThe idea was actually given by Faraday long ago but was buried in grave of time due to technological limitations

Isolated metals within faraday cages acquire charge spontaneously Aluminium and CPB becomes negative SS rendered positiveFirst observed during faraday cup experiment Electric charge on isolated metal should remain zero if it is groundedSample made of brass or electrolytic copper mounted within but electrically isolated from an outer hollow CPB. Charge drifts slowly to negative values Independent of RH

Different behaviour when outer hollow cylinder is made of aluminium Similar behaviour at low Humidity But at 50% or more RH , sharp steep on the curve.Aluminium acquiresnegative charge, SS acquires positive charge.

Possible explanation

Acidic behaviour of Aluminium oxides attracts OH-Basic behaviour of SS oxide attracts H+Charge flows through conducive wiresH+ and OH- left out in atmosphere recombines

Verification of adsorption thery

Coating the aluminium and SS cylinder with silicone oilSilicone oil reduces water vapour contactCharge accumulation negligible upto relative humidity =95%HYGROPANELSAll the results encourages development of device to capture the charge to produce electricityCharge on metal easily transferable to circuitry


Stacked sheets of filter paper, Al, filter, SS, filter paper and so on in this order.Acts as capacitorThe electrodes to be chosen so as to form oxide layer on its surface One should be acidic in nature, the other basicFilter paper used because it is an excellent dielectric and great adsorbent of moistureA large number of capacitor bank should be connected in parallel by means of conducive wires

Allowing it to charge and short circuiting after certain intervals shows the following pattern

Quite reproducible at high humidity Thus electricity can be generated continuously

Possible application and quantitative analysis

The hygropanels can be mounted on the roof tops and electricity generated can be utilized like solar panelsAs a supplement to solar panelsA 5cm2 area sheet can develop 10-4 C charge at RH> 60%we use 10 cm thick stacks or piles made of Aluminium or SS sheet (thickness-0.3-0.4 mm)A stack of 10 cm thickness approx. equals to 200 sheets Let n be the number of sheets in 1 m2 area, 10 cm thick paneln=(100*100/5)*200*10 =4*105Energy generated by one capacitor bank =0.8(v)*10-5(C/s) WThis multiplied by n gives 3.2W of energy

Cost analysis of the proposed hygropanels We have calculated the approximate cost as given below:The hygro panel taken is of 1m2 area 10 cm thickMaterials used where aluminium, stainless steel, filter paper, conducive wires, etc.Supposing 33% of the panel is made with aluminium and another 33% by stainless steel, and the rest with filter paper, conducive wiring, etc.Density of aluminium = 2700kg/m3 Hence amount of aluminium used = 2700/1*1*0.1*3 = 85 kg approxSimilarly density of stainless steel = 8000 kg/m3Hence amount of SS used = 240 kg

Rates Aluminium = Rs 70 per kgSS = Rs 100 per kgTotal cost on metal = 70*85+240*100= Rs 29950Extra cost on wiring panel and filter paper = Rs 10000Total cost of hygropanel = Rs 39500 approx Although in this amount of money we can have a 224 W solar panel, but further researches and developments would for sure bring down the cost per unit of electricity produced . Efficiency Talking of the efficiency , we dont have any idea about the exact value because it has never been practically implemented but it could be well around 90% due to the static nature of the device.

Why to invest money on development of this technology ?

Other possible future energy sources are using waste heats , body electricity etc.But in this technology small electricity needs not to be stored because of the static nature of the systemUnlike solar technology, doesnt work only in day time Need not to be mounted on roof tops only Doesnt involve manual interference Can be employed as supplement to solar technology Can prove to be of great utility in coastal areasThe metals used are not so costly Can act as absorber of atmospheric electricity formed during lightningThus useful in country like Brazil

CHALLENGESSince theoretically fascinating but practical application still a dreamLow level of current produced Can only work in high humidity areasDevelopment of reverse potential between the electrodes due to desorbed or left out charges

CONCLUSIONThis technology will be challenged on many practical grounds but that doesnt concern me a lot because That's how science works