M1L10: Renewable Energy-II

In the previous lecture, we tried to cover the scope of solar energy in India. In this lecture, we dig a little into other renewable sources. They include wind, tidal, hydro and piezoelectricity.

If you recall, India has pledged to produce 175 GW of energy trough renewables as a part of INDCs. This can be distributed as follows

100 GW through Solar

50 GW through Wind

10 GW through Bio

5 GW through Hydro

This lecture will be divided into two parts. First it will cover the basics. Later on, it will try to analyze the impact of excessive push for renewables on the economy of India.

Wind turbines can be of two types. Vertical or Horizontal. From UPSC point of view, this doesn’t hold any substance. What matters is how can it help to improve public welfare.

So, where does India stand, when it comes to production of wind-based electricity? Research studies tell us that in order to operate a wind farm, minimum velocity of wind that is required is 2.6 m/sec. India is blessed to get 9 m/sec speed of wind.

However, incase of wind, it has been found that it contributes to changes in weather conditions, albeit at micro levels. In Rajasthan, deaths of great Indian bustard and certain migratory birds is/are also attributed to excessive number of Wind turbines.

Tamil Nadu & Gujarat are the largest wind power producing states. While India is blessed with 7500+ kms of coastline, we haven’t tapped the potential of offshore wind farms

Since, India has such a huge coastline, why can’t we also tap the potential of Tidal energy? After all, tidal energy is the only renewable energy that does not fluctuate from season to season, unlike solar or wind. Lack of progress in exploiting tidal energy can be attributed to multiple reasons, one among which is the limited availability of sites with sufficiently high tidal velocities.

As you can see from the image below, tidal energy too, has its own share of controversies.

1.    Since the rotating blades of turbine, that runs on tidal energy is immersed in water, it accidentally kills swimming sea life. The rotating blades also contribute a constant noise that causes depression in marine species.

2.    Tidal barrage, as seen from the picture below, also inhibits the water, flowing in and out of the bay or estuary

3.    This leads to less flushing that eventually affects the turbidity (suspended solids) of water near the coastal areas and may affect the surrounding ecosystem in the long run.

4.    Salt water causes corrosion in metal parts. The blades are therefore made up of high-quality steel that obviously comes at high cost

Fast forwarding to hydro energy, what image comes to your mind? I am sure it mostly resembles this.

As you can see from this image, we can see that one side of the dam is completely filled with water.

This leads to a phenomenon known as hungry river effect in the downstream. The heavy particles of sand and other debris get settled in the dam, and therefore the water flowing downside gets devoid of such debris. In the absence of dam, this water ideally carries fine sand, which gets deposited on the floor of the river bed and makes it smooth. This fine sand is used by fishes as a breeding ground. Loss of such breeding grounds due to construction of dams in upstream eventually impacts the population of fishes in the downstream. This explains why the population of Hilsa fish has dropped in West Bengal after other states have constructed too many dams on the upstream side of river Ganges.

When a dam is constructed, this fine sand discussed above doesn’t flow downstream and gets settled in the dam. The river flowing downstream of the dam appears to be clean. Now recall the fact, that you have already studied in geography. A river has its own lifecycle. It has a youth age and a mature phase. In its youth, it does more cutting on the sides of the bank. While doing so, the river loses some part of its energy to carry those sediments and particles, that it gathers during its course. In the absence of it, the river becomes hungry for such sediments and flows with more friction resulting in further cutting on the sideways of its banks and downcutting of its bed. This phenomenon is called hungry river effect. Can you connect this concept with recent floods in Kerala?

Now, if you look back at the picture, you will see that the land behind the dam is completely submerged. What does this mean to wildlife and the people? We shall understand this by taking two examples

‘Save the Macaque’

In the 20^th century, the government of Kerala tried to build up a dam on the Kunthipuzha River. The locals and the environmentalists, argued that if the project gets approved then it will lead to submergence of significant portion of Silent valley national park. Now try to recall that this place is home to several endemic species which may be lost forever if the park gets submerged. One among them is Lion Tailed Macaque that is not found in any other part of the world other than Silent Valley--- which is part of the Nilgiri Biosphere Reserve in Western ghats.

So, should the project get approved? The government wanted so, but environmentalists said No. Now, if you remember, the government has come out with a new set of rules known as CAMPA. Let us assume, that in the best-case scenario, the government would have declared that they will do afforestation on the same size of land that got submerged. Which means that the number of trees that will be submerged, shall be counted and shall be regrown at some other place. But does the CAMPA rules clarify if the trees, that shall be regrown to compensate the loss due to deforestation, shall be similar to the ones that got lost? Will those tree species be able to perform the same kind of roles (protective, supportive, cultural, regulatory) that was done by the earlier ecosystem and the forest environment that took thousand’ of years to evolve? Answer is obviously ‘No’. There are multiple other functions and roles that are played by the forest environment and the extensive biodiversity that we find in it, apart from what we know in our textbooks. Once the dam is built, the biodiversity that existed before the land got submerged is lost forever.

Let us jump to another example, ‘Narmada Bachao Aandolan’. In this case, too we find that the root cause of the campaign, is that the tribals and forest dwellers, haven’t receive adequate compensation and the government has failed to rehabilitate their livelihoods that got lost due to submergence of land on which their families dwelled for hundreds of years.

So, the biggest challenge in making huge hydro power projects is the submergence of land and the collateral loss due to it. This collateral loss, includes the impact on protected wildlife habitat the people and the change in the geological features of the land.

Huge dams filled with water also put enormous pressures on the soil below it. This may lead to earthquakes in the future. Now, may I ask, which part of India is more prone to earthquakes? Answer is northern part of India. Why? Because it lies close to a tectonic fault line where the Indian subcontinental plate rubs with the Eurasian plate.

So, let me ask one more thing. India and Pakistan have distributed the six Indus rivers among them. India has been given complete control over Ravi, Beas and Sutlej while Pakistan is given control over Indus, Jhelum and Chenab. In this zero-sum game, both the countries are competing to use more and more water. And for doing the same, they are making hydropower projects. The famous among them, as all of us are aware of are Kishenganga dam, Baghlighar dam, Daimur Bhasha dam etc.  Are the governments of these countries, neglecting the fact that the places where they are building these dams are very close to tectonic fault lines? Google this and let me know on my email.

The government has entasked MNRE to construct hydropower projects below 25 MW and gets funds from Global Environment Facility to do it. Since, the Himalayas are young mountain and the northern states are more prone to earthquakes, the government prefers not to build large dams there. The turbines are designed to run directly on the flow of the river without accumulating the water in a dam. Such projects are called as run of the river hydroelectricity project.

Now refer this graph, that I am sharing below. You will notice one thing. That the Southern states are more ahead in exploiting hydro based electricity than the northern states. May I ask, why? Conventionally, we believed that the rivers in the Northern part of India are more perennial compared to the Southern part of India and therefore Northern states should be ahead in exploiting hydro power.

Let’s clear this misconception.

Rivers in North India get their waters due to melting of glaciers. Rivers in South India get their water directly from the rains. However, this happens in two phases.

One, when the ITCZ shifts above equator and the South West Monsoon winds pour water when they travel northwards and

Second, when the ITCZ shifts below equator and the returning winds bring water with them.

So, rivers in South India are also perennial. We have river Ganges in the North. Can you name me the river which is also known as the Ganges of the South?

Returning back to the question, why southern states are ahead in exploiting hydroelectricity, this is due to the fact the Deccan region of India is a part of ancient Gondwanaland and therefore more stable compared to Northern part of India. Therefore, getting an environmental clearance to make hydropower projects in the South of India is easy compared to the North of India. Adding to this fact, is that protected areas in the South of India are more concentrated in Western Ghats and Eastern Ghats and the remaining landmass is flat. In contrast, the proportion of landmass that comes under protected areas in North India is more than 60%, reducing the overall scope of getting environmental clearance in those places.

So, with this lecture, we studied, the scope of wind, hydro and tidal energy in India. One more thing that is pending is piezoelectricity. And that will mark the end of your lecture. As a homework, you are supposed to make a list of all the steel and aluminum plants that are located close to major hydroelectric projects, so as to get and advantage of procuring electricity at cheap rates. This would be a part of GS1 topic, Factors responsible for the location of industries, primary, secondary and tertiary. For piezoelectricity, pls refer the following.

Piezo electricity is derived from the greek word ‘Piezein’ which means to squeeze or press

Thus, piezoelectric effect is defined as the ability of certain materials to generate an electric charge when they are pressed. They can be effectively used to produce electricity at railway stations, temples, roads etc.