SOLAR ENERGY- A GAME CHANGER FOR CIAL

Electricity has become an integral part of the day-to-day life of every human being. This form of energy has influenced the human life to the extent that one cannot even imagine a world without electricity.The ease of conversion into other forms of energy such as mechanical, light, sound, heat etc. and the availability of efficient methods for its transmission from the place of generation to the place of utilization are the two unique features behind the universal acceptance of electrical energy. No other form of energy is as flexible as electrical energy. Till the last few years, the demand for electrical energy has been met mainly from various types of generating stations such as thermal, diesel, nuclear and hydroelectricpower plants. They make use of the chemical energy stored in coal, diesel, radioactive elements etc. or the potential energy of the stored water in the dam. This was sufficient prior to few decades. However, due to the tremendous increase in population and the development taking place in the agricultural, industrial and service sectors, the demand for electricity often exceeds the capacity of the existing plants.

In the state of Kerala, only one third of the required electrical energy is produced within the state. Rest of the requirement is being met by the purchase of energy from the central grid. Though the land is suitable for more hydroelectric power plants, the public protest and the prevailing environmental norms hinder the successful implementation of such projects. Moreover, the drastic changes in the monsoon being observed since the past few years, has been affecting the generation from the existing hydroelectric power plants. Owing to higher running and maintenance cost, and environmental pollution thermal and other similar power plants are not generally preferred. In addition, the fuel for such plants such as coal, diesel, natural gas etc. are nonrenewable and hence their availability cannot be guaranteed forever. In this context, emphasis must be given to the energy generation based on renewable energy sources such as solar, wind, biomass, tidal etc. Among these solar power plants are more popular due to the following features; greater reliability, low maintenance cost, pollution free operation, easy enhancement of capacity, modularity etc.

Cochin International Airport ventured into the field of solar energy by installing a pilot power plant of 100kWp capacity on the rooftop of the international arrival terminal in April 2013.  The tender for the work was awarded to M/s Vikram Solar Private Limited. The plant generates an average of 400 units of electricity everyday which is utilised for running the AC power plant situated on the top of the terminal building. In the month of November, CIAL installed another solar power plant of 1MW capacity near the premises of CIAL Academy building and became the pioneer of megawatt scale solar PV project in the state. The EPC work for the project was awarded to M/s Emmvee Solar Power Private Ltd., a Bangalore based company. The average daily generation from this plant is about 4000 units.

14.4 MWP SOLAR PV PROJECT

The total yield from 100KWp and 1MWp solar PV power plants constitutes only a meagre portion of the total electricity consumption of the airport from the state electricity board. The airport daily requires around 48,000 units on an average for its normal operation. The entire demand had been met from the energy supplied by KSEB, for which CIAL had to spend more than one crore rupees every month. In addition, the electricity tariff decided by KSEB varies from time to time and could have posed higher monetary burden on the airport. Under these circumstances, it was the concept of our Chairman and Managing Director, Sri. V.J. Kurian IAS to make the airport grid neutral by commissioning a solar power plant of adequate capacity. The endeavour was taken up by the newly formed subsidiary of CIAL, called CIAL Infrastructures Limited.

I.  12MWp Soalr Power Plant

A detailed load flow analysis and arrived at a designed capacity of 12MWp, with a provision to increase the capacity by another 2.4MWp. Around 45 acres of land was identified near the cargo building of the airport for this purpose. The land was meant for the expansion of the cargo building in the later years. However, due to the proximity of the runaway, it was kept unused since the commissioning of the airport. The tender for the DSITC works of the plant was awarded to Bosch Limited. The work was commenced in the month of February 2015 and completed within a short span of six months, despite of the monsoon season started during the progress of the work.  The plant was inaugurated by the then Honourable Chief Minister Sri. Oommen Chandi on 18th August 2015.  Average daily generation from the plant is around 48,000 units. The plant enabled CIAL to become the first fully solar powered airport in the world. CIAL received great applause in the national as well as international level for its remarkable achievement in the field of sustainable development.

The plant essentially consists of 46150 solar panels of 260Wp capacity, which convert the solar energy into DC electricity. The panels are connected in series-parallel configuration to attain the desired voltage and power levels. The DC electricity being unsuitable for direct consumption or injection into the grid, it is converted into AC form by means of 10 central inverters of 1MW capacity each. The outputs of every two inverters are connected to a 2MVA transformer for enhancing the voltage level to 110kV, which in turn are connected to the state electricity grid through the 110kV substation of CIAL.

In localities with either no grid connectivity or intermittent grid failure, battery storage systems may be installed along with the solar plant to store the electrical energy generated during day time. The stored energy can be utilised during ‘non-sunshine’ hours and night. However, owing to the high capital expenditure and difficulties associated with their routine maintenance, we have not employed storage systems in this plant. Instead, we utilise the ‘banking’ facility provided by KSEB for the renewable energy developers. In this scenario, the excess energy generated during day time can be injected into the grid and can be taken back as and when required without remitting any excess charge. Any excess units fed to the grid will be paid by the electricity board at the end of the solar calendar (October-September) as per the prevailing average pool purchase cost. This ‘banking’ policy enables the airport to be grid-neutral even without any battery storage system.

II.  2.4 MWp Extension plant

The 2.4MW plant is an extension of the 12MW solar plant and is commissioned in the month of March 2016. As this expansion had already been proposed during the design of 12MW plant, the work was allotted to M/s Bosch Limited, the EPC contractor for the 12MW plant. The plant occupies an area of approximately 9 acreslying near to the former plant, where around 9000 solar PV modules are installed. Two numbers of 1MW central inverters are installed to carry out the DC to AC conversion, which are subsequently connected to a 2MVA transformer and finally to the 110kV substation of CIAL. Average daily generation from the plant is around 10,000 units, which will be used for meeting a part of the energy demand of the new international terminal after its commissioning.