India is building a massive, floating solar power plant

Jul 11, 2014

By Becky Crew

Having already started on their plan to install 10 megawatt (MW) solar plants on top of several canals, India has taken the creative use of space one step further and is planning on floating a power station on one of the large stretches of water in Kerala, a state in south-western India.

This floating solar power technology was developed by India’s Renewable Energy College and the plant is being built by Indian energy company, the National Hydro Power Corporation (NHPC). The first plant is scheduled to be commissioned in October this year.

“NHPC had contacted us for offering technical know-how and installation assistance for their proposed 50-mw plant,” said SP Gon Choudhury, chairman of the Renewable Energy College, to Andrew Tarantola at Gizmodo. “Each station would require around 3000 square feet [914 square metres] of space to generate 20 kilowatt of power. There are many water bodies that could be used for this.”

10 comments on “India is building a massive, floating solar power plant

  • Well, at least global weirding and climate chaos are driving our creativity.

    We’ve got a small pond; with the exorbitant price of energy now, I wouldn’t mind one of these babies being plonked on top of it.

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  • Interesting story. But how much faith can you put in an article by a journalist who can’t convert imperial units to metric?

    Makes me think, “Hmm … what else has the writer got wrong?”

    And if the figure of 3000 square feet is correct, then the power plant produces only about 70 Watts of electrical power per square metre, which means it is only about 7% efficient (assuming that the light power falling on the panels is 1000 Watts per square metre). Perhaps they just use inexpensive solar panels.

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  • The advantage of these systems is that in a large continent with remote areas they are local and can reduce the need for an extensive grid.

    The Indians are also planning and building an Asian tidal and wind power hub in the Gulf of Kutch, with other developments in Scotland, China, Canada, and Australia.

    The primary development site is located towards the centre of the mouth of the Gulf of Kutch, fewer than 17km to the south of Mandvi Beach, which is adjacent to the proposed onshore site at Maska. The Ranwara Shoals, to the north of the site, create a shallow region through which flow is accelerated, resulting in ideal deployment conditions for the tidal turbines. The site experiences less extreme flows than, for example, the Pentland Firth and the Bay of Fundy, and our initial optimisation studies indicate that 1MW AR1000 turbines will deliver the best returns for the project. This work will be further developed during FEED.

    The project has been well supported at state and national level, ensuring expeditious procurement of the necessary approvals. The Gujarat state government has awarded grant funding to GPCL to support FEED studies for the first 50MW of the commercial project and to enable a tariff to be set which will generate sufficient returns to attract investors. GPCL and Atlantis are now working to compile and submit the information required to substantiate the level of the required tidal power tariff.

    The project is currently the largest planned tidal array in Asia, and an important precursor to future development of other opportunities in the state, both offshore and inland. India, and Gujarat in particular, is enacting an ambitious programme of incentives to increase renewable generation capacity to ensure a clean and secure energy future, and this renders it an attractive and important market for Atlantis.

    The potential from tidal power is enormous!


    It is estimated that in the United Kingdom, there is a technical resource of 29TWh per year from tidal currents, of which 11TWh is found in the Pentland Firth in the far north of Scotland.

    In 2010, an Atlantis led consortium was awarded an agreement for lease for the Inner Sound of the Pentland Firth by The Crown Estate. The lease area lies in the channel between the island of Stroma and the north easterly tip of the Scottish mainland, encompassing almost 3.5km2 of fast flowing water. The site capacity is almost twice as large as the next biggest site awarded by The Crown Estate.

    MeyGen Limited, the company behind the project, is 100% owned by Atlantis. MeyGen has an overall goal to deliver a fully operational renewable energy plant of almost 400MW powered purely by the tide, generating the equivalent electricity to power 400,000 Scottish homes.

    The first phase of the project is scheduled for installation during 2015.

    Atlantis also have new models and big company backing!

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  • Although described as ‘massive’, the only thing massive about these power plants is the square footage. 50MW is a small power station; 10MW is tiny. Most of the 17 Hoover Dam units were conservatively rated 92MW, but could could actually produce over 100MW when Lake Mead’s water level allowed it.

    To put these numbers in perspective, I used to be a shift operator of probably the smallest hydro plant in the US to have an operator on duty 24/7, when the plant was online. (It is now on supervisory remote control.)

    The plant controls the water flowing through the Los Angeles Aqueduct as it departs the Owens Valley for L.A. The plant remained an attended station until the turn of the 21st century because it’s in a relatively remote area and supervisory control equipment wasn’t reliable enough to depend on. Emergency shutdown capability is mandatory in case of a catastrophic aqueduct failure. Part of the aquaduct route is through gravity powered inverted siphons.

    The plant is rated 4.5 MW from two horizontally mounted Francis turbines.

    Scroll down to see a schematic profile of the aqueduct system and photos of the small to medium sized power plants along the route. I spent time at three of them, from the Gorge to San Francisquito #1:

    The largest inverted syphon:

    Scroll down to the three Haiwee P.P. data records:

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  • This is a very clever idea, cooling panels this way. (Whilst the water won’t convect the heat away it will conduct it about as well as plaster or earth will.) Solar PV loses efficiency with increasing temperature (about 0.5%/K). It begs the question of the possibility of adding solar gain to the system, mirrors, to increase panel utilisation if the panel temperature can actually be kept down. A supplementary shore based heliostat, or just passive mirrors, positioned for morning use, when coldest, might make more sense with panels cheaply kept cool by the added thermal mass of the water. A few fins on the back of the panels will co-opt larger volumes of water very readily.

    Forced water circulation may just pay for itself…

    Water assetts might be well preserved by simple covering over, reducing evapouration, algal blooms and the risk of becoming disease vectors (eg for malaria).

    Reservoirs might be cheaply co-built with solar PV creating complementary geometries from scratch. Also worthy of consideration are east-west oriented surface mounted water mains pipes covered with PV and with anamorphic reflectors. The water flow will achieve real cooling.

    FWIW I intend to comment occasionally here but only on science and tech.

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  • atheezilla Jul 12, 2014 at 4:36 am

    how much faith can you put in an article by a journalist who can’t
    convert imperial units to metric?

    I’m confused by the numbers from the referenced articles.

    3000 square feet is 279 square meters, not 914.

    The photo in the linked Gizmodo article doesn’t appear to show anything like a solar plant 7 miles square, supposedly required to generate 50MW. But there’s nothing to scale it to.

    Something doesn’t appear to add up. (But I’m no math whiz!)

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  • toroid Jul 13, 2014 at 12:38 am

    I’m confused by the numbers from the referenced articles.

    They author does not seem to grasp the numbers.

    @OP – “NHPC had contacted us for offering technical know-how and installation assistance for their proposed 50-mw plant,” said SP Gon Choudhury,

    For comparison ONE tidal turbine generator (see earlier comment and links) is rated at 1 MW or 1.5 MW.

    A single wind-turbine can be rated at 1 to 3 MW with 4.5 to 6 MW for offshore units.

    The advantage of small local plants is the reduction in the need for network cables.

    However, for somewhere as sunny as India, Liquid-salt Solar Thermal generators are a good option, where there is stable land available for heliostat towers, or parabolic trough systems to give 24 hour electricity.

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  • reply to

    Alan4discussion Jul 13, 2014 at 5:10 am

    I find it interesting that LADWP is eliminating the use of ocean water for cooling when repowering its large coastal gas fired steam plants.

    Apparently the warmed water is harmful to the marine environment. I wonder whether solar powered floating plants bring environmental downsides not addressed in the article.

    It’s amazing new gas fired plants can ramp up from zero to full output in 10 minutes. Scattergood Unit 3 produces 460MW!

    BTW, in the post above (Jul 13, 2014 at 12:38 am) regarding the size of the floating platform I should have stated “seven square miles” not “seven miles square”, which actually is 49 square miles.

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  • toroid Jul 13, 2014 at 10:30 am

    Apparently the warmed water is harmful to the marine environment. I wonder whether solar powered floating plants bring environmental downsides not addressed in the article.

    These photovoltaic panels should reduce the solar heating and temperature of the water under them, as they intercept some of the solar energy which would otherwise go into the water to heat it.

    In tropical areas the downside for aquatic life, is the drop in oxygen levels in water as the temperature rises.

    The high temperatures also increase organic decay further reducing oxygen levels and producing toxic anaerobic conditions. There is unlikely to be much aeration of the standing water in canals.

    Here is a link on tropical fish in aquaria:

    Almost every tropical fish in the hobby can take water temperatures in the high 80-degree Fahrenheit range for a short period of time (perhaps two or three months). Remember, they are tropical fish. The difficulty is not in the fishes’ inability to withstand the temperature, but rather in the side effects of the higher temperatures.

    Increased temperatures bring a decrease in the oxygen-carrying capacity of the water. This means that the aquarium must be clean and have no extra organic material buildups that will deplete the oxygen levels further. The fish aquarium should be well aerated, with lots of surface agitation to ensure that there is adequate gas exchange to release harmful gases and acquire maximum oxygen content under the adverse conditions.

    Where fish live in paddy-fields, the water is shaded by the rice crop. In fast flowing rivers there is active aeration.

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  • Check out Phil’s system. Much better:

    What’s in common is exploiting available shallow water surfaces typically located alongside rural population centres. Objective is low technology to enable very low cost of establishing and maintaining. Very low cost and easily obtainable or substitutable materials. Cost is everything, including reliance on low tech local support.

    A major innovation is cheap Fresnel lenses to augment the efficiency of cheap solar cells. Cells are kept very small and are immersed to reduce temp loading, but not deeply enough to significantly reduce the incident energy. Lenses are very light and nothing much more than polystyrene floats are required to support the system and the in-water cables.

    Shallow water doesn’t generate big enough waves to cause significant damage. Main design issue is direct wind damage that might bend and damage the lens alignment and mountings. (Lenses are connected to stepper motors to track the sun – all coordinated by a cheap PC in a box nearby.) Wind speed is detected and the lenses automatically invert in excessive wind conditions to place themselves under water to eliminate windage and avoid damaging the fragile system. Kind of like an automatically capsizing sailing yacht. Less chance of tearing the sails after tipping over.

    The point of the system is that very little technical knowledge or specialised materials are required. The arrays are enormously scalable.

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