Prof. Dr. P. K. Jena* in Bhubaneswar, September 9, 2016 : In recent years, the Ministry of New and Renewable Energy, Government of India, is motivating the state governments to harness the renewable energy resources particularly the solar energy. In this regard, recently I came to know from some news paper that, the Govt. of Odisha is planning to set up a 1000 MW Solar Park and for this the state government is unable to acquire a 5000 acres of land.

In view of global warming and climate change, it is essential that, in Odisha as well as all other states of India, in order to save our people from the sufferings of global warming, should concentrate on harnessing and utilizing renewable energy resources particularly that from the huge solar energy available to a tropical country like ours.

But, in a densely populated country like India, because of the difficulty in aquiring the required land and also high cost of the land, it is advisable to harness solar energy through floating solar power plants on the top of water bodies which are abundantly available without any cost. It has been estimated that, for producing 40 – 60 megawatt (MW) solar energy, the amount of land required is about 1 sq. Km (250 acres).

Harnessing solar energy through photovoltaic (PV) solar panels is being practiced on the land mass in a very big way in most of the developed as well as the developing countries including India. But, in densely polluted country like India, solar PV installation has the burden of intense land requirement incurring very high cost. In order to expedite the programmes for harnessing solar energy while conserving the large areas of the valuable land, it is essential to install Solar PV system on water bodies including rivers, lakes, lagoons, canals, ponds and even waste water treatment plants.

Installation of a ‘Solar PV floating’ power generation unit is to translate the combination of the PV plant technology and the floating system technology. In this programme, a floating body including the structure and floater is constructed over which the PV model is installed. The floating system can adjust to water level fluctuation while maintaining its position as per the direction of the sun with provision to protect from strong wind and other similar obstructions. The floating solar PV system placed on the floating system includes floating structure, PV panels, inverter mechanisms, transmitter of power to grid, control mechanisms and monitoring mechanisms. The energy generated is transmitted to load or grids by cable submerged in water.

Harnessing solar energy through solar cell on the top of water bodies has got a number of advantages over those on land:
 It can avoid the huge areas of costly land while vast areas of water bodies can be available with practically free of cost for harnessing solar energy..
 Water bodies can provide water needed for cleaning of solar panels as and when required.
 The solar panel helps in stopping evaporation of water from the water bodies.
 Solar panels on water bodies are kept cooler and thus their ability to generated power is increased by as high as 16%.
 The longivity of the solar panels is increased by keeping these cool on the water bodies.
 The solar panels obstruct growth of the algae on water bodies and keep water less polluted and
 Solar panels over water bodies facilitate the development of fish and other aquatic lives.

Presently, projects on floating PV power plants are being set up in a big way in various countries. The sun baked desert areas and tropical regions should be prime spots for these “Floatovoltaic” projects where the solar energy can be harnessed with maximum efficiency while preventing evaporation of water bodies. It is reported that, the most attractive point of this Floating PV is the extra energy which it can extract from the sun compared to terrestrial PV in a similar climate. The world’s first floating solar power unit was installed in 2007 in California to produce a total of 4 MW power.

It is reported that, during this year, a water utility in Britain has installed a 6.3 MW farm on a reservoir near Heathrow Airport. Japan a highly populated country of the world is going ahead in a big way in this programme. The solar power company Kyocera has installed recently a 13.4 MW project on the Yamakura dam reservoir which is reported as the largest floating solar installation in the world till now. It generates enough electricity to meet the power requirements of around 5,000 families. The dual energy and environmental benefits of floating solar energy plant is becoming more popular all over the world including Australia, Brazil, China, England, Japan, South Korea, India and USA.

It is very heartening to note that, in recent years the Government of India is going ahead with ambitious programmes for setting up floating solar plants. India’s first floating PV power plant of capacity 10 KW was established in Rajarhat New Town in Kolkata in December 2014.In Gujarat a 1 MW Canal Solar Power project on a branch of Narmada canal has been installed. Besides supplying power, this helps to save 90,000 litres of water per year by avoiding evaporation.

It is further reported that, the Gujarat State Electricity Board has set up a 10 MW plant over a 3.6 kilometre stretch of the Sardar Sarovar Canal System. Another floating solar power plant of 100 KW is being set up at Loktak Lake in Manipur. This project for installation of floating solar plant has been commissioned by Manipur Renewable Energy Development Agency (MANIREDA). A large floating solar power plant of 50 MW is being planned to be set up in Kerala. The Central government is recently promoting similar projects in other parts of the country to construct 50 MW solar power plants on canal top and another 50 MW at canal-bank.

Odisha has 480 KM of sea shore, a large number of rivers and net work of canal systems. In view of this, there is a great scope for Government of Odisha with the help of Ministry of New and Renewable Energy, Government of India, to set up floating solar energy plants on these water bodies to produce large amounts of clean energy while saving the huge areas of valuable land and also substantial amounts of water from evaporation.

(*Prof P K Jena is former Director General, Council of Scientific & Industrial Research, India)