India is blessed with a coastline of about 7600 km surrounded by water on three sides and has good prospects of harnessing offshore wind energy. Considering this, the Government had notified the “Nationaloffshore wind energy policy”as per the Gazette Notification dated 6th October 2015. As per the policy, Ministry of New and Renewable Energy will act as the nodal Ministry for development of Offshore Wind Energy in India and work in close coordination with other government entities for Development and Use of Maritime Space within the Exclusive Economic Zone (EEZ) of the country and shall be responsible for overall monitoring of offshore wind energy development in the country. National Institute of Wind Energy (NIWE), Chennai will be the nodal agency to carryout resource assessment, surveys and studies in EEZ, demarcate blocks and facilitate developers for setting up offshore wind energy farms. Ministry set a targetof 5.0 GW of offshore wind installations by 2022 and 30 GW by 2030 which has been issued to give confidence to the project developers in India market.
The wind resources assessment carried out by the National Institute of Wind Energy (NIWE) gives total wind energy potential at 302 GW at 100 meter hub height. Out of the total estimated potential more than 95% of commercially exploitable wind resources are concentrated in seven states (Andhra Pradesh, Gujarat, Karnataka, Madhya Pradesh, Maharashtra, Rajasthan and Tamil Nadu). The precious land resources required for onshore wind projects are gradually becoming a major constraint. With exhaustion of best windy sites, we expect upward movements of market determined tariffs for onshore wind energy in future.
Offshore wind power offers a plausible alternative in such a scenario. Absence of any obstruction in the sea offers much better quality of wind and its conversion to electrical energy. Offshore wind turbines are much larger in size (in range of 5 to 10 MW per turbine) as against 2-3 MW of an onshore wind turbine. While, the cost per MW for offshore turbines are higher because of stronger structures and foundations needed in marine environment, the desirable tariffs can be achieved on account of higher efficiencies of these turbines after development of the eco system.
Globally offshore wind is about two decades old history with the first offshore wind turbine in Denmark in 1991 which has been decommissioned in 2017. As of now the total installation is about 28.308 GW in 17 different countries of which important ones are- UK (9945 MW), Germany (7507 MW), China (5930 MW), Denmark (1701 MW), The Netherlands (957 MW), Belgium (1556 MW), Sweden (202 MW). Capacity additions in last three years stands at 50% of the total capacity out of which 4679 MW commissioned in 2019, 4792 MW in 2018 and 4495 MW in 2017.
Facilitating Offshore Wind Energy in India (FOWIND)
Is a project implemented from December 2013 to March 2018 by a consortium led by Global Wind Energy Council (GWEC) and supported by European Union (EU) to assist India on its offshore wind power development and in turn contribute to India’s transition towards use of clean technologies in the power sector. The project focused on the States of Gujarat and Tamil Nadu for identification of potential zones for development through techno-commercial analysis and preliminary resource assessment. The outcomes of the FOWIND are summarized in the following reports.
First Offshore Wind Power project in India (FOWPI)
Is another project getting implemented from December, 2015 by a consortium led by COWI and supported by European Union with an objective to provide assistance up to the stage of Pre-Financial-Investment-Decision (Pre-FiT) and provide general assistance for capacity building of Indian stakeholders within offshore wind sector. The following reports are already published under FOWPI project.
Identified Offshore Wind Zones for Initial Project Development
Based on the preliminary assessment from satellite data and data available from other sources eight zones each in Gujarat and Tamil Nadu have been identified as potential offshore zones for exploitation of offshore wind energy. Initial assessment by NIWE within the identified zones suggests 36 GW of offshore wind energy potential exists off the coast of Gujarat only. Further, nearly 35 GW of offshore wind energy potential exists off the Tamil Nadu coast.
Offshore Wind Resource Assessment through LiDAR
The offshore wind energy potential estimation carried out through satellite data needs to be validated through actual ground measurements in order to make the data bankable. Ministry has decided to launch a measurement campaign deploying Light Detection and Ranging (LiDARs) at the identified zones off the coast of Gujarat and Tamil Nadu. One LiDAR was commissioned in November 2017 for Offshore Wind Resource assessment in identified zone-B off the coast of Gujarat nearly 25 km away from the port of Pipavav and collection of data started since then. It is planned to install additional five LiDARs (Two for Gujarat and Three for Tamil Nadu). One year data collected from the deployed LiDAR has been analyzed and the report is published at NIWE’s website. The raw data can be accessed from NIWE website ( https://niwe.res.in/department_wsom_lidar_raw_data.php) As per the report, the annual average wind speed at the locations is observed to be 7.52 m/s at 100m hub height.
Oceanographic, Geophysical and Geotechnical studies
In addition to the wind data, the viability of offshore wind projects also largely depends on the condition of site in terms of oceanographic data, geophysical and geotechnical data. Ministry has planned to carry out the required study in this regard through NIWE and provide the basic data to the stakeholders before commencement of the bidding so as to mitigate the risks. Geo-physical Survey for 70 Sq. km (Gujarat) has been done through an EU funded project and additional area of 295 Sq. km aggregate a capacity of installation of 1.0 GW off Gujarat coast is under progress with the help of NIOT (National Institute of Ocean Technology, Chennai). In addition NIWE will also, carry out Geophysical and Geotechnical studies in a selected area off Tamil Nadu Coast
The first 1.0 GW offshore Wind Energy Project
The first offshore wind energy project of 1.0 GW capacity is planned in the identified zone-B off the coast of Gujarat in order to bring the economy of scale and localization of necessary ecosystem for offshore wind energy sector. In principle (stage-I) clearance as per the National offshore wind energy policy from relevant Ministries/Departments for a 1.0 GW offshore wind energy project in Zone –B off Gujarat coast has already been obtained. Further, stage-II clearances required for carrying out required studies/surveys for the selected areas already been obtained by NIWE and NIWE is in the process of collecting geophysical and geotechnical data. Expression of Interest (EoI) for the first offshore wind project of 1.0 GW capacity off Gujarat coast has been floated on 10.04.18 by NIWE. Thirty five International/Multinational and Indian Developers/OEMs have participated in the EoI and subsequent consultation process who provided their inputs for bidding process.
Guidelines for Offshore Wind Power Assessment Studies and Surveys
The ‘Guidelinesfor Offshore Wind Power Assessment Studies and Surveys’was approved and issued by NIWE in September, 2018 to facilitate stakeholders who are interested for carrying out the study/survey activity for development of offshore wind energy project.