You would have surely seen wind turbines on land. Did you know that we have not stopped with land?
Some countries have started putting massive wind turbines in the ocean, sometimes as much a 20 miles from the shore (though most are much closer).
Why would anyone wish to put up turbines in the ocean?
There are some pretty strong reasons for this:
- Lack of land resources – Many countries such as Germany do not have enough land resources to put up large wind farms. Ocean is thus an obvious option.
- Lack of wind resources – Winds over oceans are much stronger than winds on land.
The above two aspects make the offshore wind farms quite attractive.
Typically, offshore wind farms cost significantly higher per MW than do onshore land based wind farms (as much as double or higher), but offshore wind farms also can generate twice as much electricity per MW compared to their land based counterparts. Besides, owing to a more regular wind pattern over sea than over land, offshore wind farms can generate electricity more consistently along a year than can onshore wind farms – which in some regions like south India (where I live) generate most of their electricity during a few months of a year, and that too, mostly during evenings and nights.
As of 2016, offshore wind farms have started popping up in some countries in Europe (UK and Germany are leaders), and in select regions such as China. But their cumulative capacity is still only a small % of that of onshore wind farms. At the end of 2015, onshore wind farms had about 430 GW in installed capacity worldwide, while offshore wind was just over 12 GW, only about 3% of onshore wind farm capacity.
Having been involved in the wind power sector early in my cleantech journey, I was routinely used to hearing about 1 MW and 2 MW wind turbines. So I was surprised to hear about 5 MW wind turbines developed for offshore applications some years back. This size kept increasing, and a few weeks back, I read about a massive 8 MW turbine (32 of them!) being installed in Liverpool Bay!