Largest Power Plants in the World: How many are Solar/Wind?

Zero! But the largest power plants in the world is dominated by Hydro power plants. Not small hydro, large hydro. There are a couple of nuclear power plants also, in that list.

Here's the Countdown for the Ten Largest Power Stations on Earth:


No. 10 - Bruce (Canada); Type: Nuclear; Capacity: 6300 MW.
No. 9 - Sayano-Shushenskaya (Russia); Type: Hydro; Capacity: 6400 MW.
No. 8 - Longtan (China); Type: Hydro; Capacity: 6426 MW.
No. 7 - Grand Coulee (USA); Type: Hydro; Capacity: 6809 MW.
No. 6 - Kashiwazaki-Kariwa (Japan); Type: Nuclear; Capacity: 7965 MW.
No. 5 - Tucuriu (Brazil); Type: Hydro; Capacity: 8370 MW.
No. 4 - Guri (Venezuela); Type: Hydro; Capacity: 10235 MW.
No. 3 - Xiluodu (China); Type: Hydro; Capacity: 13860 MW.
No. 2 - Itaipu (Brazil/Paraguay); Type: Hydro; Capacity: 14000 MW.
No. 1 - Three Gorges (China); Type: Hydro; Capacity: 22500 MW. 

Here's an infographic created by Temporary Power Solutions, showing the largest power stations and some interesting facts about each:

When are we going to see Solar and Wind Power Stations in that list? Let's hope soon enough :)

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Harness the Energy of the Sea Waves - It's possible!

Think about it: Sea Waves are an endless source of energy available in all coastal areas! There are companies that manufacture equipment that can harness the energy of sea waves, now. I am not sure if any of them have operations in India, but it is useful to know what exists. 

Even better than wave energy, maybe the offshore wind turbines. These are large wind turbines that are placed deep into the sea where the wind currents are very high. They are large-scale (MW(s)-sized) and efficient. However offshore wind turbines are very expensive to built and they need specialized ships, equipment and skills to mount and maintain. This technology is outside the purview of many countries, and India is just experimenting with a pilot project.

Wave energy, on the other hand, though is less forceful, has more kinetic energy than wind. Hence it is possible to generate electricity in smaller scale using smaller/inexpensive devices, especially if they are designed and manufactured with local conditions in mind. Also, since waves are available throughout the day, even through their intensity might vary, electricity production can be achieved 24x7. 

In this post, I want to highlight two manufacturers of wave energy harnessing devices (from Scotland, Israel), and one invention from India - IWAVE that converts wave/tidal energy into electricity. 

Aquamarine Power: 

Aquamarine Power, based in Scotland, UK, has devised an interesting technology to harness the energy of sea waves. They call it Oyster wave energy technology. See the above introductory video. 

This device can be placed near the shore (500 meters) in ten-meter deep waters. It is attached to the sea bed and the large even surface plate bends forward and backward as the wave approaches and recedes. It pumps compressed water to an on-shore hydro electric power generating plant using under-sea pipelines, and the hydro plant generates electricity. This power is completely renewable. They say that the device has a life of 20 years and it is possible to maintain/repair/remove the unit whenever required. This is one company that is close to setting up megawatt-scale wave energy farms in the UK. 

You can find more info about them from here: Aquamarine power. 

Eco Wave Power: 

Eco Wave Power, based in Israel, is another company specializing in manufacturing wave energy devices. See the above video for an introduction to their EWP wave energy devices. 

They have two products: The Wave Clapper and Power Wing. They use a combination of uniquely-shaped buoys to convert the motion of waves into electricity. Their system also comes with storm protection and corrosion protection mechanisms. It can be arranged in a flexible modular structure, based on the required capacity. Here also, the energy of the motion of floats is delivered to an on-shore generator via undersea cables, which produces electricity. 

You can find more info about them from here: Eco Wave Power. 

IWAVE:

IWAVE is a device that converts wave/tidal energy into electrical energy, designed by someone from our very own India. This is a floating structure attached to the seabed via cables, and can be positioned approximately 500 meters away from the coast. The energy of the rising wave drives a piston which in turn drives the crankshaft by half a turn. The receding wave helps complete the remaining half turn. This motion drives a generator which produces electricity. This generator can be placed next to the device. 

Have a look at this page for more information about IWAVE. The contact details of the inventor is also available there. 

India has tested two wave energy pilot projects earlier, but has not ventured into commercial wave energy generation. There is a lot of potential as we have 7500 KM of coastal area, but we need to overcome many limitations, including: Technical design that is efficient, cost effective & easily maintainable; ability to withstand high tides and forceful waves; ability to resist corrosion; nonavailability of specialized resources and manpower to design and manufacture, etc. However, wave energy is one renewable energy technology that we can start focusing on from now in order to supplement energy from other renewable/conventional sources. 

If someone wants to design an effective wave energy device, but is finding it difficult to procure modelling software, etc., please have a look at the open source wave energy modeling initiative by the DoE and NASA of US. You can contribute to that project, as well as use it to design more efficient wave energy systems: Details here. 

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Small Pumped Water Storage for storing Electricity?

One of the problems with popular renewable energy systems is their intermittent generation of electricity. Solar panels generate electricity during the day, but the (peak) energy demand is during the night. Wind turbines may generate a lot of electricity during a particular (windy) season, but the (peak) energy demand maybe during the summer or some other season. In many cases, since the electric grid can only accept a certain amount of electricity at any given point of time, excessive electricity generated is often sent to the earth, resulting in wastage. Energy storage systems like batteries are complex, expensive, and in some cases even unfeasible, especially on a large scale. 

What do we do, then?

If you look at a large hydroelectric power station, it basically blocks the course of a river, stores that water in a dam and releases it through turbines/generators, as and when electricity is required. Why not use the same principle with an artificially created (smaller) water storage system, whose purpose is to pump water to a higher elevation when excess electricity is generated/available, and then run that water down-course through a turbine/generator and produce electricity when it is needed?

Agreed, this method would create some loss of electricity (probably about 30% of power would be lost) and requires considerable amount of capital investment, but that's still better than losing electricity. More importantly, electricity can be generated on-demand and whenever required - this is crucial to ensure energy sufficiency at all times. The above embedded video shows a simple (conceptual) example of how such a system can be realized.

There are issues, however. One, a large site should be made ready for this purpose. Two, a lot of water is required and water-loss from evaporation and seepage into the ground needs to be prevented. Three, the site should be near to the solar/wind energy generation facility so that transmission losses are minimum.

We can either construct a pumped water storage system from ground-up, or use a natural site that is suitable for the requirement. Have a look at this site near the sea on an island in Japan that acts as a large pumped sea-water storage reservoir for electricity generation, later on.

Energy storage is an important part of the puzzle that needs to be addressed for renewable energy to be accepted on a larger scale. While batteries are available for smaller systems, large-scale renewable energy generation doesn't allow for long-term energy storage. Certain innovative techniques like storing energy as heat in molten salt have already been implemented for short-term energy storage, in CSP (Concentrated Solar Power) plants but they can hold energy for a very short time (only).

While it is possible to burn coal/oil whenever required, release water in a large hydro-power station whenever required, we can only generate electricity using solar panels/wind turbines, when it is sunny/windy. We should make hay while the sun shines, but we should find a suitable place to store all that hay, right?

Will pumped storage be that facility for storing energy, generated in large capacities, over the long-term? 

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Generating Electricity from Rain Water (Two Ideas)

From time to time, I get certain BRAIN WAVES and I start thinking OUT OF THE BOX. O.K. this time, I have just thought OUT OF THE HOUSE - Generating electricity using rotary turbines and small generators, during rainy days.

Basically, the sun heats up the sea-water and some of it evaporates to form clouds. These clouds contain a lot of potential energy which is released as kinetic energy (rain). That kinetic energy is all ours to take advantage of! Solar energy and wind energy based generation methods work with reduced efficiency during rains and hence we might look to compliment our electricity generation using ideas like these, during rainy days (which - at times - can extend to many hours/many days at a stretch). 

The above diagram shows a rain, house, window, window shade and a rotary turbine fixed at the edge of the window shade. It should be fixed as shown above, exposing one side to rain and the other side below the sunshade. Since rain water falls only on one side (the open side), two blades on that side get pushed by rain water and the turbine starts rotating. As long as the rain continues, this device can generate electricity.

The limitation is, we can only generate small amounts of electricity using such a set-up and hence we may need multiple such turbines to produce any considerable amount of electricity. We need to have low-cost generators in order for this fantasy to become a practicality. All these turbines (attached to generators) can be connected to a battery, where electricity is stored. Now, all you need to do is wait for the rains and you can start generating electricity!

I have also come up with another method of using rain water to generate electricity. In the above diagram, notice that there is a two-story building and a terrace above it. The rain water collected in the terrace is generally allowed to flow into the ground/rain water harvesting pit to recharge the ground water. But, when the rain water flows down, it contains a certain amount of kinetic energy, which can be utilized to generate electricity.

In this case, the storm water pipe is cut to introduce a rotary turbine. When rain water flows through it, it turns the blades of the turbine and flows down. Since the water flows only on one side of the turbine, the blades keep rotating in the anti-clockwise direction. We can have another/more rotary turbines, below, to generate more electricity. The enclosure should be closed to ensure that water doesn't go out it should be sloped in the bottom to send the water to the pipe. Both the turbine/generator and the enclosure could be fixed to the wall. 

That's it - we've got one more way of generating electricity from rain-water! Of course, these are all only ideas and no one has made such devices (I think). 

I don't know what kind of turbines/blades/generators to use with this set-up or how much all that will cost. This is just an open-source idea - anyone can try to expand it further or try to create a working prototype. 

Would you bet on this idea getting a noble prize? Don't!! :P

If you have any (proper) ideas on generating electricity using renewable sources of energy, let me know - solarwindhydroenergy[at]gmail[dot]com. I'll feature it on this site, if I like it. And don't worry too much - your ideas can't be sillier than the ideas I have presented above :)

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GL Garrad Hassan: Comprehensive report on Wave & Tidal Energy

GL Garrad Hassan, has released a comprehensive report on Wave and Tidal Energy in the UK. Though the document is focused on the UK market, the document offers a comprehensive analysis of the marine energy industry and hence might be useful for anyone associated with this renewable energy industry. More importantly, this document should be read by countries/regions having rich marine ecosystems, but are unsure about marine energy implementation. 

This document offers insights on the following topics: Current state and potential of the marine energy industry, risks associated with marine energy industry, possible ways to mitigate the risks, benefits of developing wave/tidal energy, pathway to commercialization, etc. As mentioned earlier, the report is meant for the UK audience, but offers substantial information to members of this industry located elsewhere, as well. 

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Geothermal Energy from deep inside the Earth - Altarock Energy

We know that geothermal energy is a renewable form of energy that can be extracted from certain places on the earth. 

The difference in temperature between the surface and the region slightly inside the earth is already being utilized in various homes for heating/cooling, as the need maybe. Have a look at this video, to get an understanding of this residential geothermal application. It's high time we start using such systems to generate energy. I will write about this in detail later. 

On a larger scale, geothermal energy is extracted from hot springs and molten liquid like lava. But these things depend on locating geo-thermal power stations in the place where hot springs/lava is located. Often, that is a difficult proposition. 

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Atlantis Resources Corporation - Harnessing Tidal Current Energy in India

Hydro Energy is not just about large hydro power dams or micro hydro power plants. Hydro energy is also about Tidal energy, energy from waves, and much more. Atlantis Resources Corporation is a UK-based company that specializes in making tidal current generators to harness the kinetic energy of tidal current resources under seas/oceans.

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Arunachal Pradesh: Micro/Small Hydro Power Plants

Every state in India should follow the example set by Arunachal Pradesh in setting up/ encouraging micro/ small hydro power plants, in varying capacities, all over the state. As you maybe aware, hydro energy is a renewable form of energy and does not contribute to carbon emissions/pollution. In areas where there are perinnial water streams/rivers, there is a lot of energy to be tapped 24x7, 365 days.

It is not always required to construct huge dams to tap the kinetic energy of moving water/ streams/ rivers. Small/ Micro hydro power plants enable people and Governments to generate electricity on a smaller scale (and smaller capacity).

With small/ micro hydro energy generating stations, it is not required to stall/halt the course of a river and there is no damage done to the aquatic life forms (flora and fauna). A separate (small) stream is dug along the sides (of a small stretch) of the river, water is made to flow through rotating hydro turbines that produces electricity, and then the water is allowed to rejoin the river. As you can see, there is no loss of water, either.

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Greenko Group - Owning & Operating Small/Medium Hydro Power Projects in India

Greenko Group is based in UK, but operates a considerable number of small/medium hydro energy projects in India. They own and operate renewable energy projects, especially micro hydro power plants. They are one of the largest operators of small hydro projects in India, but also take up projects in the wind, natural-gas/biomass sectors.

Currently Greenko operates 151.3 MW of hydro energy projects and a total of 229.6 MW renewable energy projects, in India. One of their aims is to achieve 1 GW operational capacity by 2015.

Greenko generally selects river projects between 20-100 MW within a cluster and keep adding more projects under their belt. They are involved in sustainable community beneficial activities in the educational, health-care, safety, rural development and environmental sectors, mainly in rural areas.

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We need more Micro Hydro Power Plants to generate electricity in remote/hilly regions

India has a lot of remote villages/settlements in hilly regions that cannot be connected to the power grid in the near future. Either the villages are so small (and hence powering them up might be economically unfeasible) or the power transmission infrastructure/cables cannot be taken through the mountains/thick jungles. 

In many of these places renewable energy technologies is our only option. We can use solar panels or micro wind mills to generate electricity. But for places that have naturally flowing water streams/rivers, we can also look at installing micro hydro power plants to generate energy. 

Consider this: Most of the villages/settlements are already located near a river because the river provides water for their living/agriculture needs. Most of these streams/rivers/water-falls are perennial. These water bodies have a lot of potential energy (stored in the water accumulated up-stream), which is released as Kinetic energy of the flowing water. This kinetic energy can be harnessed to generate electric power. 

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