Challenges in the Marine Environment
By moving into the marine environment the cost and complexity of any operation increases dramatically over land based work. This is due primarily to the absence of a fixed surface to operate from and the fact that any operations on the sea floor must be performed remotely. The constant motion of the sea surface through waves and currents also complicates the ability to precisely position components. Therefore, it is important to design structures and devices with ease of installation, operations and maintenance in mind.
By design, energy capture devices and in particular MHK devices, will be located in particularly energetic locations. This is a double edged sword, in that while the resource will be high, there is a natural variability that means storms will subject devices to extreme forces. As an example, the energy present in a wave varies approximately with the square of its height, so while a particular location may have an annual average wave power of 25kW, a typical annual storm could provide 1MW, thus any device or structure in the marine environment must be designed with inherent survivability during operation.
Furthermore, due to the scope and inaccessibility of the underwater environment, flora and fauna (plants and aquatic life) are difficult to investigate and determining impact of any intervention can be difficult. Another challenge is that land ownership will be either by the state or federal government and particularly in the US, many parties will have jurisdiction and thus obtaining the required permits can be significantly more challenging than on land.