The repeating of the common points in the two cases: offshore and onshore occurs in this EIA, however, this is necessary even though some of the points are more specific for one or the other cases.


General Environmental Situation:

The wave power output of the area that has shown interest in, either for offshore or onshore devices is vital. Location is extremely important for offshore and onshore devices because of differing characteristics of local wave generation and form. An example of this is that in strong wave location, waves devices can get damaged causing a disturbance to the environment with an oil leak etc. This is explained with greater depth in the offshore assessment.

However other examples are that wave devices can not be installed in a protected area not only because of the fauna and the flora and but also because of archaeological site. There has been a lot of studies done about the local fauna and how wave devices will affect them. An example of this is the migration of fish and questions over possible similarities with wind turbine and bird migration. This will have the direct affect of not allowing wave devices in the areas where salmon and herring (in Scotland) spawn, and their migration route.

Even though wave devices are environmentally friendly electricity generators, at any point environmental should be respected as a vital part of our life.


Construction and Maintenance:

The land transport is an important part for the installation of any onshore wave devices, because of the use of a lot of concrete, which needs be forwarded to the site. This is the case with some common onshore wave devices such as OWC or the Tapchan Not only the concrete that should be moved by road, but also the turbine and the entire appliance units for the grid connection. This may invole the necessity to construct a road. Later on, during the device running period, construction and maintenance will inevitably occur, with resulting transport issues.

Offshore device directly mounted on the seabed will involve different consideration. They appear more likely to give rise to significant environmental consequences during installation and operation.
These could represent a permanent and possibly undesirable change to the environment unless some technically and economically acceptable method for their removal at the end of their service life can be devised.

Construction and maintenance’s team will need to get regular access to the wave device and too the grid connection by land. This is only for onshore wave device. For the offshore one, it is a little bit more complicated because it depends of waves and also about the weather. The actual maintenance jobs would not be particularly attractive involving long journey to the station by helicopter or ship.
This will involve cramped working conditions, exacerbated in the case of floating device by their pitching and rolling.


Endangered Species:

The site required for the wave device will be dependant upon the localised environment. It considers the fauna and the flora, and to try’s to preserve them. One of the most concerned fauna is the shellfish, their spawn place and how will they be affected. The flora can often include some special orchid or other plants that are limited to the habitat niche that they occupy.

The fauna and the flora need to be looked at specifically because fauna and flora can get damaged through the land use, and also during the construction and maintenance.


Visual Intrusion:

The onshore wave device the view impact can be quite important, because the wave device is attached to the cliff. In the case of the OWC , the body of the OWC is attached to the cliff and the turbine is on the top of the cliff. This position increases the visual impact. Further additions to the visual impact is the onshore installation of transmission systems.


Coastal Erosion:

A chain of wave devices like Salter’s Duck or Cockerel Raft (The Pelamis is not concerned in that case, because it is facing the wave and offer is smaller cross section than the body) can alter the environment a little bit. They affect the environment because the devices are creating a barrier protection to waves.

The floating device barriers with low freeboard well out to sea would probably have little or no effect on the coastline but a station of bottom mounted device might (OSPREY). A decrease in the wave energy incident upon shore and shallow sub-tidal areas could result in changes in the density and species of organisms they support. In some shell-sand beach, any decrease in wave activity and wave steepness could deposit more sand on those beaches if sufficient sediment is available.


Grid Connection:

Grid connection is dependant upon the location and on the type of wave device being utilised, the grid connection will be related in expensive to the type of device used. In the case of the offshore device, a sub-marine cable needs to link the device to the grid. That sub-marine cable can, at anytime, affect the environment as well as the grid connection. It is going to be an obstruction on the view of the landscape. Furthermore teams of maintenance will need to come and check it quite often, which will considerably affect the quietness of the place.


Emissions:

One of the primary advantages of wave energy. Similar to other renewable energy, is that they are not producing any emissions only during the operation time. Consequently, wave devices are considered to be environmentally friendly. The type of electricity produced is known as green electricity.

The example below covers emission factor and emissions during the construction phase, of the oscillating water column (OWC) in Islay (Scotland).