The ultimate guide to decide whether you should invest in solar energy or not.

Is it worth investing in solar energy?

Global warming and shortage of fossil fuel are the two major issues we are facing currently. Reducing the wastage and usage of the energy will definitely help, but to fix the problem, we need to opt-in for the alternate energy sources. To decide whether a person should invest in solar or not, one need to learn or gather enough factual information. Solar energy is the emerging source of non-conventional energy. The main reason behind writing this article is to make you aware about solar energy in aspect of some important statistical data for India. After reading this article, you will have your most doubt clear. So please stick to the article to get the bonus tip to buy solar panel at the end.

Table of contents

1. Why Solar Power generation?

2. India’s Solar power potential of 10 major states.

3. Solar trend from 2010 to 2020.

4. Total on-grid and off-grid solar energy extractors in India.

5. Future of Solar energy in India.

6. Questions / Answers

7. Conclusion

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Major Take away :

• Total reserve of coal and other resources to generate electricity is estimated to last about 150 years, if it is consumed at same rate. we are in need to find optional resources to generate electricity.

• India has the lowest cost of capital per megawatt worldwide. The installation rate has risen tremendously over the last five years , as a result of which installation costs have decreased by 89% in the last decade and are projected to decrease further by the same rate until 2050!

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Why Solar Power generation?

1) There are limited electricity generation sources.

The conventional energy sources are limited. Example of such are Coal and petroleum which has been used as primary sources of energy production.

According to the sources, total coal reserve in the world is about 1.1 trillion tonnes; which can last up to 150 years, if it is being used at same rate as of now. Whereas, The proven oil reserves in the world is about 1.50 trillion barrels oil which can last up to 43 years as of year 2020.

2) The pollution caused due to excessive use of coal and fossil fuels by various power plants have resulted in the increase of global warming issues.

Therefore, we must always look for a potential opportunity to overcome the current issues and find optional sources of energy that could fulfill the future demand of electricity for the next generations by turning towards the use of renewable energy sources such as solar energy, wind energy, geothermal energy, bio-gas energy etc. But for each renewable source, it requires specific condition to generate these energies.

For example to produce solar energy it requires sunny days, as it is derived from the Sun. if we are planning to install solar energy extractor for your home/small business, you must consider the geographic location of your house. If it is located in south region which could be considered the best location due to its Consistent and decent intensity of the solar radiation availability which is the best choice for the solar extraction. Another example would be wind energy. The factors affect heavily on the wind flow and the large area required to install the windmill. The wind mill are suitable for commercials purposes as in Wind Mill Farms but not for household or domestic purposes due to the noise produced by the turban machinery and space required to install it. In a country like India, the most suitable potential energy is solar energy due to it’s geographic location on the Earth. India has about 300 clear sunny days out of 365 days of a year. India holds 4th position in the world to produce the solar energy due to the geographical location. International contribution in solar energy. As a result India can produce almost 100% energy in about 300 days. Solar panels also produce energy in cloudy days just with less efficiency.

“It is being measured that if we could collect solar energy falling on the earth for an hour, then we can produce enough energy to meet the requirement of the entire Earth. 430 Quintilian joules of energy falls on Earth each hour.”

India’s Solar power potential of 10 major states

Potential solar power VS Installed solar power in top 10 state of India

The potential energy can be calculated by considering fact that, in any part of India, 4 to 7 Kw h of solar energy is being received per square meter. The chart above shows us the total potential for solar energy in particular state in blue, where the yellow bar shows the existed installed solar panels as of march 2020. sum of all ten states solar power potential is about 560.7 MW (mega watt). In reality these states have only installed 24.02 GW of energy; Whereas, the total capacity of India's installed solar energy is about 35.12 GW as of June 30,2020. Solar energy is being used at a small scale just about 4.28% of the total potential energy. The highest potential of solar energy can be seen in Rajasthan among all ten states whereas Jammu-Kashmir stands second in this list. Gujarat in this case comes at 6th rank in the list of highest potential solar energy states with a capacity of about 35.77 GW out of which 2.9 GW has been extracted. Karnataka stands out as highest solar energy extractor in the country.

Solar trend from 2010 to 2020

solar capacity installed per year

cumulative solar energy installed since year 2010

The solar projects were announced in India in year 2009-2010. from then till now India has exponentially made a growth in solar power generation installation. The above shown data are taken as a reference from MNRE (ministry of new and renewable energy of India). The data shows the growth of solar equipment installation has been increasing epidemically since year 2010. The bar chart shows the installation capacity each year, which has increased aggressively till 2018 with temporary drop for a year and started gaining the numbers again. The highest installed capacity was in year 2018. it was about 9.4 GW in year 2017-2018. from this data we can predict the future to grow at same rate until 2050. India still has about 96% capacity of solar energy potentially.

Second line chart shows the cumulative solar installation over last ten years. Which gives the glimpse of how future of solar will be.

Total on-grid and off-grid solar energy extractors

1) on-grid power as of march 2020 in India stands at 35.8 GW out of total potential of 748 GW considering 3% loss of area to cover solar PV.

2) The below shown is the pie-chart of total number of solar Equipments registered as of March 31, 2020 it is just the emerging state with such a good numbers which proves that we definitely have a bright future for solar powered Equipments.

Total off-grid solar appliances registered as of march 31, 2020.

Future of Solar energy:

India has the lowest capital cost per megawatt globally. Installation rate has been enormously increasing since past five years as a result the installation cost has decreased by 89% in last decade and further expected to decrease by the same rate until 2050! The government of India has estimated 20 GW capacity till 2022,which is already been achieved in 2018 making us four year ahead of the schedule. This shows us the figure of rate of installation of solar panels. The next target is of 100 GW solar energy till the year 2022 which shows the future of the solar power that will defeat the conventional energy production.

Recognizing the potential of solar energy and the damage we have been doing to the environment, some Indian states has cancelled the plans to build coal fired power plants. And also according to sources, various coal mining projects has been stopped. On top of that, Indian government aims to install 40 GW of rooftop solar panels and electrify 18000 villages. India is expected to expand the growth of it solar market by 90% this year and the central government has already announced incentives to reach their targets.

Q /A

first question arises after reading the article is that Should you install solar energy?

Yes you should, Below are the reason why you should invest in solar energy,

1. Solar energy equipments are durable.

2. It emits very less carbon, which helps reducing the effect of global warming, acid rain and pollution.

3. It is a one time investment as the maintenance cost required is very low.

4. The installation Solar energy is quick method.

5. It Saves a lot of money in long run.

Factors you should consider before you buy a system for your home

1. The capital investment cost is high, but it will eventually paid off within 7 to 8 years. If you are moving out sooner within a period of five years then you may want to think about it again because ROI is higher (about 8 years).

2. The efficiency depends on the weather and location, therefore to install the system one must ensure the location. If your location does not have good exposure to sunlight or weather does not provide clear sunny days then you may want to find another solution.

3. Requires large space to install depends on the energy requirement. Make sure you have enough space to install off-grid solar system / on-grid panels.

4. The solar panel degrades over the time and can reduce the efficiency of the solar panels. The degradation rate of the panels are 0.8% per year. Over 25 years of periods the average solar panel degradation reaches about 20% of the efficiency achieved when bought.

How many panels are required to power a house depending 100% on solar?

It depends on how much energy do you consume. By taking the example of general electricity usage of an ordinary house or you can consider your house requirement and you can calculate accordingly. Basically a solar panel produces 300 watt an hour. 10 hours daily sunlight can produce 3000 watt an hour i.e. 3 Kw h. Each unit consumed is 1 kw; if you are consuming 15 units means you need to install 15 kw h solar system. If 1 panel produce 3 Kw h then to produce 15 kW h you need 5 solar panels.

What if your system produces more power than you need for your house hold?

OR

What is net metering?

Net metering (also known as net energy metering or NEM) is a solar incentive that allows you to store energy in the electric grid. When your solar panels produce more electricity than needed, that extra energy is sent to the grid in exchange for credits. During night or the other times when the solar panels are under producing, the energy is pulled from the grid and uses these credits to offset the costs of that energy.

How long does it take to install a solar power to your residential place?

It is the quickest energy to install and extract. It can be installed for houses within few hours or latest two days. The documentation work may take longer but installation is pretty straight forward and easy.

Life expectancy of a solar panel

OR

How long does a solar panel lasts?

Generally speaking a solar panel lasts about 25 years on paper, but in reality they last about twice of what they have claimed. That means you can consider them producing power for about 50 years. It’s almost half of our life. But yes you can not get same amount of output after a certain period of time of as compared to the time when you bough it. Considering the degradation rate is about 0.8% with any local brand. If a brand new solar panel produce 100% output then after a period of one year the panel will give 98.2% output.

How much profit can you make by installing solar power generation system?

The definition of ROI (return on investment) is time span required to gain the invested amount back from revenue generated out of installed system. The return on investment period in solar energy based project could be long term, but it gives surety to earn profit about about 250% considering its total life span of 25 years (stated on paper). The ROI in solar panel is ideally estimated about 7 to 8 years in India after considering all the factors such as less effective electricity generation in cloudy days, degradation of solar panel efficiency about 0.8% each year of average type of solar panel and all maintenance cost.

Conclusion:

Sooner or later we will all have to opt-in for the optional energy sources as the reserve of coal and petroleum is about to finish and we are facing global crisis of temperature rise due to pollution produced by the power plants by burning coal and fuels. The best solution is to find a best non-conventional source of energy suitable for your location. Solar energy has huge potential for power generation in almost every country. The return on investment period is longer, but has higher reliability and less maintenance which can make it best option for domestic as well as industrial purpose. One must go ahead and install solar power generation system after determining the benefit of it.

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(Bonus)

TIP if you have made a decision to invest in solar (green) energy.

• If you have decided to buy a solar system you must consider consulting few solar companies and take quote of the cost estimate. This would save you about 10% of the total cost.

• Also Brand is not always considered as best but instead quality of the product, because branded systems could be expensive, it is not just the quality but also the high advertising fees they pay which reflects in their products prices. So choose the product wisely, don’t only consider the brand.

Paper Airplane

Figure: 1 Click the image to read PAPER AIR PLANE _1 Article.

In previous article, I've mentioned that angle of attack is 15 degree! some of you would have question that why is it between 15° to 18° only? If with the higher angle of attack, we can produce more lift, then why not 45, 60, 90 degree? why only about 15-18 degree is preferred?

Fig.2_As a result of Coanda effect

The above image shows that the air passing over the Aerofoil is deflected downwards, but why is that happening? does the shape is magical/enchanting? do they have gum over the wings? kidding 😅,but yes in a way the shape could be called magical. there is a theory which can make this statement more logical. Stick till the end, because I am going to share you this interesting science fundamental in much easier way.

you can skip the bracket below if you do not want to read in depth, you can directly read the topic of the article written after brackets. ⏩

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Let's see mathematical formulae to create a lift to better understand what I am going to write down in the article.

Lift (L) : (0.5) x Density x {(velocity) (velocity)} x (Area of the wing S) x (Coefficient of lift, CL)

1) So according to the formulae, if we increase the density of the air then we can increase the lift, which we can not control. so we can not consider density to increase lift.

2) If we increase the velocity of the plane, it highers the lift, but it is not more practical and smooth. How? first of all it is a slow process and has very low control over the lift and hence, low control over the plane maneuver. it could cause discomfort to the customers as it makes plane fly with sudden altitude change. because we are increasing velocity which means drag will also increase. so this is not so considerable parameter either.

3) plane wing area, well this is much of design perspective, we know that the wider the wing span better the lift will be, but we also have to consider the stresses acting on wing while the plane is in the air. the plane wing could just cause a failure due to buckling force. so we better stay off changing the wing span.

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4) at last, We have Co-efficient of lift. this is the factor we could consider increasing lift. the co-efficient of lift is the measure of how much lift a wing can produce. co-efficient of lift is linearly proportional to angle of attack for the normal flight condition. Angle of attack is defined as angle between the relative wind or Incoming wind and the Chord line of the wing. so normally we can change the lift performance by varying angle of attack or the design of the aerofoil.

Now what is Chord line right? It is the imaginary line connects the leading (front facing) and trailing (back side) edge of the wing's cross section.

Wing's cross section usually known as Aerofoil shown in above figure. The most reasonable AOA (angle of attack) is 15 degree, but it could be higher up to 18 degree. depends on aerofoil shape. What if it goes above that? plane enters in to stalling state. Stall is the state when, The amount of lift airplane produces decreases and due to which Drag increases. To understand how state of stall occurs, we need to understand the Coanda effect.

Answering our second question, Why does the Air or fluid changes the direction of it's flow path? It is due to the Coanda effect.

let us think of it at molecular level, take a look at below image.

DO IT YOUR SELF✅

you can do this experiment by your self, take a piece of paper, hold it with your hands as shown in figure. Now blow the air above the paper. you will notice that paper will try to move upwards. how did that happen? This effect is called Coanda effect. when you blow the air, it has high velocity compared to atmospheric air. higher the velocity lower the pressure. In addition to that, the high velocity air drags the air particles from nearer layer of the atmospheric air with it which creates vacuum (shown in figure with hatch lines). "V"states shows a region where vacuum is being produced. due to particles being dragged by Higher velocity air, blown by a person creates low pressure at region-2. The paper is light and free to float, so air molecule from region 1 (high pressure region) pushes the paper towards low pressure region which makes paper tend to move upward, when we blow the air. this effect is called Coanda effect. but what if paper is not free to move and fixed from both end?

Then the air from higher pressure region (region 2) will push the higher velocity air as shown in figure towards the curvature and deflect the direction of the air. Here region 1 also has higher pressure than the pressure near the curve of the paper, but air pressure from region 1 can not interact with low pressure region as paper is fixed and air can not move through the paper. This is what exactly happen with the Airplane wings and the Air flowing through it. It deflects the air and air exits at downward direction which is known as down wash. Another example of this effect is when you bring the plastic water bottle under a (laminar flow) tap water, the flow will deflect towards the bottle curvature as soon as it comes in a contact of the bottle. the image is shown below.

click the link to read in other words!

Now, let us move to the first question. why Angle of attack is ideal at 15 to 18 degree? at about 15 degree the air molecules follows the Coanda effect and move along the curvature of the wings which creates lift. but if angle of attack is more than 18 degree, air at the trailing edge started to get separated from the wing surface and become more turbulent. This state is shown below in very last condition. The separation point move further towards leading edge as the angle of attack increases (the situation of stall starts at critical angle of attack). In the last condition, air is not leaving in downward direction, which will not create down wash and no pressure difference will be created which definitely going to decrease the lift force.

It is similar to the hand which is kept out of the window of the car and if u turn your palm from facing road to facing towards incoming air. you will definitely feel the drag. same thing happens with wings. as angle increases the wind will resist and stop producing the lift.

Trunk Call: Explained !

What is trunk call?

A long distance call made within country used to call a trunk call.

HOW DID IT WORKED?

A Line Diagram to understand the system

Before STD (Subscriber Trunk dialing) has even started, there were time when there was a middle ground for Phone calls. which connects two person's call, named telephone exchange.

Telephone Exchange station

Closer look at of telephone exchange circuit board

ones you subscribe to the service, the one end of the telephone line connects to your telephone and another end of the line connects to the telephone exchange.

In the early days of telephones, you couldn’t dial a number yourself. You had to call an operator at the telephone exchange of your phone company to connect you for any phone call. Later on, you could make local calls yourself, but had to call the operator to connect you to someone whose phone was connected to a different telephone exchange in the same city or elsewhere. The two telephone exchanges were connected by a trunk line. the trunk line is the bundle of small wires brought together to make a thick single wire. trunk as a word means the main, core, or central part, before subsidiary parts diverge. A tree trunk, not the branches. the line was pretty thick almost like the tree trunk. this was the reason it called trunk line, and call made through trunk line called trunk call.

Telephone Trunk line

Individual circuits in that trunk are not dedicated to a particular subscriber but can be used by any subscriber as and when needed. The number of circuits in such a trunk is less than the number of subscribers connected to the exchange, because not all subscribers are supposed to need a trunk circuit at the same time. If more subscribers would need to use a trunk circuit at the same time than there are circuits in that particular trunk, some of them would get a ‘busy’ signal because all trunk circuits would be in use. This is just the rough information of how it works. The actual system is much more complicated!

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Bonus

Know more:

S.T.D : Subscriber Trunk Dialing

I.S.D : International Subscriber Dialing

P.C.O : Public Call Office