Offshore energy for the remote islands of lakshadweep

Abstract

Conjoining the available energy with renewable energy will allow us to utilize the renewable energy sector efficiently by reducing the current prices of electricity. Keeping this in mind, the island administration wants to shift towards renewable energy as the present diesel-electric system is posing a severe threat to its fragile environment of the island. Wind resource assessment was carried out and observed that wind energy has potential for energy generation. In the present paper, an attempt is made to study suitable substructure concepts along with detailed installation methodology for Lakshadweep. As these islands do not have the facility to handle more than 2 tons. It would be challenging to arrive at site-specific installation methodology for an offshore wind turbine. The aerodynamics loads are estimated by open source code ‘FAST’ and the hydrodynamic loads by Morison’s equation. These loads are transferred to structure and then to the soil, where its interaction is modelled as three nonlinear orthogonal springs. The behaviour of structure under combined loads is analysed using Finite Element Method. It is proposed to construct the gravity-based foundation onshore in lagoon side of the island, launched into the sea using hydraulic jacks, tow using tug and ballast at the proposed location. So, it is essential to identify the natural frequencies and Response Amplitude Operations (RAO) to understand the behaviour of foundation during towing. The draft of foundation is estimated under static condition and RAO’s are obtained using panel method. © Springer Nature Singapore Pte Ltd. 2019.