Wind Energy ... An independent source of Energy ?

The Sholles man can never gain Th' ennobling sense of power with men.

Those who have no(greatness of) mind, will not acquire the joy of saying in the world, "We have exercised liberality".[Thirukkural 598]

Wind Energy ... This too is a form of Solar Energy and of all the solar spectrum this one specifically uses the Infra Red Radiation part of it to enable itself. Wind is an essential part of our climate which is changing drastically today due to several factors however the fundamental driving factor for wind is the difference in air pressure between two points caused due to the direct impact of local temperature. Normally, if you have a higher temperature area wherein the air gets heated and rises up creating low pressure, the air from nearby areas having lower temperature or high pressure comparatively tries to balance that vacated space by warm air and in compensating as such gives rise to what we call as wind.

The biggest challenge with wind is the consistency ... How can one ensure that wind flows in a specific area, in a specific direction and at a speed so that the energy can be harnessed from it. Even though we have an elaborate field of engineering dedicated to it yet this wind harnessing solution is rather old. 

A Bit of History ... from the ThirdPlanetWind portal ... 

The earliest known wind powered grain mills and water pumps were used by the Persians in A.D. 500-900 and by the Chinese in A.D. 1200.

The first windmill manufactured in the United States was designed by Daniel Halladay, who began inventing windmills in 1854 in his Connecticut machine shop.  The windmill was hugely successful as a means of pumping water on farms and ranches in the expanding western frontier, so much so that Halladay moved his operation to Illinois.

The first electricity-generating wind turbine was invented in 1888 in Cleveland, Ohio by Charles F. Brush.  The turbine’s diameter was 17 meters (50 feet), it had 144 rotor blades made of cedar wood, and it generated about 12 kilowatts (kW) of power.

Coming back to the challenge that we were discussing earlier what are the possible options that we have developed to bring about a consistency in level of energy extracted from this inconsistent source of energy ? The basic necessity for installing a wind farm today starts with what we call as a wind map. Wind Map is basically used to chart out a terrain's wind behavior over a period of time which spans a year at least. This map gives us a lot of information in terms of wind speed range over a particular terrain which can be averaged out to assess the feasibility of turbine installation measured at a specific altitude, the pressure conditions, wind behavior over the days based on season, wind direction etc. The wind maps once charted and verified are used to deploy very specific type of turbines which would be ideal for those conditions. These turbines need to rotate at a specific speed in general to deliver power output. And they all come with mechanism to control both the yaw[blade adjustment] and pitch[turbine rotation].

Sample Wind map from https://eurocodeapplied.com/design/en1991/wind-peak-velocity-pressure-uk

You might be thinking what-if the wind turns in to a gale or a storm or hurricane ? The wind turbines and the blades driving these horizontal turbines are developed in such a way that they can always harness the varying speed of the wind by changing the angle of attack into the wind, something like an airplane does when it wants to reduce the resistance while climbing up and increase the air resistance when coming to halt. It must be evident to you by now that these blades are developed to perform against the wind resistance to extract energy and are aerodynamically improvised to that purpose. In addition to that, we also have brakes in the turbines which are meant to handle the over spin or excessive speed of rotation of the turbine blades in the gale or storm like situations as that might harm the overall system and even lead to crash.

There is a term I used earlier "Horizontal Turbines" ... Well yes, its true we do have "Vertical Turbines" as well and by definition the Horizontal and Vertical refers to the axis about which the blades of these turbines move with respect to Earth or let's say the wind.

VAWT vs HAWT as per https://www.energy.gov/eere/wind/articles/vertical-axis-wind-turbines-could-reduce-offshore-wind-energy-costs

Vertical Turbines have a lot of advantage over horizontal turbines where the setup is needed to be catered for large wind farms and in turn greater yield of energy is required and exactly the opposite till date in general on land it is assumed that the vertical turbines are more suitable for low to moderate wind speeds plugged to smaller sized generators.

These concepts of Wind Energy extraction have even translated to Ocean Current Energy Extraction mode as well in various places where the idea is to have turbines with blade maintained under-water in wake of the ocean current which would result into net electricity production.

Nevertheless this energy source remains erratic or rather inconsistent to take place of the technology today which drives the base load, be it solar or wind, if we intend to have a consistent power supply at the end of the day we need to maintain an elaborate measure of saving excess energy in some form so that it can be utilized or compensated when the generation is not available and again that's the reason we end up getting hooked to the grid running based load on non-renewable sources of energy mostly.

Solar Energy and its Role in the Future

Huge bulk of elephant with pointed tusk all armed, when tiger threatens shrinks away alarmed!

Although the elephant has a large body, and a sharp tusk, yet it fears the attack of the tigers. [Thirukkural 599].

Solar Energy, the average energy from the sun falling on top of our atmosphere is approximately 1360 Watts per square meter of area as per NASA. Sun is the most resplendent source of energy which would last many a human lifetimes and is solely responsible for all life form to exist on earth directly or indirectly.

 

Going by the definition of energy as we discussed earlier, how does sun helps in creating the unbalance which in turn helps us generate or convert the solar energy into electrical form ? It ain't that simple, sun emits radiation across the spectrum from infra red used for heating to ultra-violet, x-rays to gamma radiation which are some of the most potent forms of radiation in terms of energy. Here its noteworthy to mention that higher the frequency of radiation higher the energy and lower the bandwidth and its this energy which is used to convert into energy with usable form. 

So how do we capitalize on these radiations coming from sun ? We have two ways to consuming the energy from sun, one is to capitalize upon the high energy radiation of the sun to make the electrons in photovoltaic materials jump the equilibrium barrier to create a potential difference or an imbalance which when provided a path tries to achieve the equilibrium by movement of electrons[electric current] to balance out the potential difference. The other way is to capitalize on the infrared or the heat energy coming to us in form of radiation. With current set of concentrating solar panels technology it is possible to focus this solar radiation at a common point to achieve very high temperature which can then be used to convert this thermal energy into usable electric energy, this mode of energy transformation is also called solar thermal electricity. 

Efficiency in both these cases i.e. photovoltaic and solar thermal energy conversion is less than 40% today i.e. if we assume that sun is directly overhead at any given instant of time even then less that 40% of the area exposed will yield us the actual conversion of solar energy to electrical energy.

Two basic types of Solar PhotoVoltaic Panels available in General as per Quora.

How Solar Thermal works as per solarquotes.com.au.

There are many other aspects today that need to be sorted out from electrical power perspective i.e. energy transmission, storage and consumption. There are special tubular batteries used for storage of electrical power from photovoltaic solar panels however the solar thermal energy is connected directly to the grid. Also the power output from the photovoltaic is in DC mode or Direct Current mode which needs an inverter set to be consumed in AC or Alternating Current format.

Solar Energy has already become one of the main stays of renewable energy transformation scenario and mostly its based out of photovoltaic mode as Solar Thermal conversion is only feasible in limited areas. The existing conundrum of carbon footprint and associated use of fossil fuels causing pollution are the main targets which might eventually help the environment but we are far off from having a complete replacement. As of today, the developed and developing economies are relying more heavily on electricity which is making a per capita energy requirement going higher by the day which is currently being met by the non-renewable sources of energy with contribution from renewable sources to the extent plausible however not all economies are completely into it as of today.

As more and more electrical based appliances are coming into being wherein transportation sector has taken a giant leap in EV or electric vehicles it might be possible to cater to the growing pollution issue if and only if we build upon solar or renewable sources of energy. Having said that it doesn't mean having solar in such quantities is coming without any pollution, getting high efficiency solar panels needs a lot of treatment and equivalent energy spent on it however given the options today it is definitely a safe bet. So also the CSP or concentrating solar panels wherever applicable can be implemented to complement the base loads of consumption the only issue is, they can work at maximum efficacy for only a few hours in a day so challenge for the same is still working towards increasing the efficiency.

Energy ... the What ?

Firmness of soul in man is real excellence; Others are trees, their human form a mere pretence.

Energy is mental wealth; those men who are destitute of it are only trees in form of men.[Thirukkural 600]

We are all acquainted with the word "Energy" but believe me nobody knows it all ... Do you ? How about the words from great physicist engineer and inventor Nikola Tesla 

“If you wish to find the secrets of the universe, think in terms of energy, frequency and vibration.”  

There has been many attempts made over the years and a lot of work has gone into explaining it but let me take a stab on it and present my point of view here.

Let's travel back in time, right to the origin of time which has been postulated for humanity as the Big Bang ... The point in time wherein the space, energy, time and everything we know came into being. If you google it a bit, it will tell you that this point came from something called initial singularity or at least the theory of General Relativity suggests as such. So you see, what we have is the best possible theory to suggest what could have happened without a definitive proof but here is another food for thought - suppose we knew everything about energy could we tie to space and time and thereby the origin of universe ? Perhaps.

So coming back to the topic at hand ... what's energy ? Energy is simply the state of imbalance of equilibrium; the greater the imbalance realized the greater the energy. Ain't that simple ? Take a pair of tongs they are in equilibrium from our perspective as we pick it up. Hold it by the handle and flick it with your finger [imbalance] and try to relate the above statement. The vibrations that can be visible at the end is the direct resultant of energy you transferred to the tongs via the flick to achieve a direct frequency of the vibrations you can see, hear and feel even on the handle which is trying to keep it steady.

We can ponder over energy and try to understand what is the equilibrium that this universe is trying to arrive to i.e. will there be a point in time wherein we achieve that singularity again ? what is the state of this singularity where the energy exists while being compensated for corresponding mass ? Can we call that singularity the equilibrium state of all energy that exists as we know it ? Can there be a single equation which can define all types of energy that we know in this universe ? I believe before we start learning about energy we should learn about equilibrium and how it relates to the work as we know it.

Coming back to the real work applications and making use of the energy we will be walking through a few blogs on utilizing this naturally existing imbalance to good effects without hurting nature so that would be Renewable Energy, by definition, since most of it can be assumed to be available forever in human years but not on universal scale definitely. Even our sun, the source of solar energy is also aging.