Recently we took two polls on the topic of onshore versus offshore wind farms and what most people prefer. One poll was specifically for wind technicians and the other poll was for whoever had an opinion on the subject. The results were very interesting with 70% of those who responded to the poll saying they preferred onshore and 45% said they preferred onshore. Of the few who voted for offshore, one person said they prefer wind farms that are offshore because they can generate more energy than onshore, but is that true? Can offshore conduct more energy? If so, why?

In the United States, Offshore Wind Farms are a new idea, but to the rest of the world, (especially in the United Kingdom), their residents are used to seeing wind turbines on their coast. In fact, the largest offshore wind farm is located off the coast of England. The Walney Extension Wind Farm generates about 660 megawatts; that’s about enough electricity to power 600,000 homes in the UK!

Now, there are many different components when it comes to comparing onshore and offshore wind farms. When scouting out a location for a “normal” wind farm, location is key. The three most important qualities for land that has the potential to host a wind turbine are:

Wind Speed– does the location of the land conduct enough wind?

Proximity to a substation and power lines, this is how the energy will be transferred.

Acres– for a wind farm, the area needs to be large because the average height of a wind turbine is about 328 feet.

For an offshore wind farm, this is where people will say it is more flexible because it doesn’t have to follow as many rules. You won’t be able to find landlines or substation, and you do not have to worry about the land size. The turbines you see in the water are about 540 feet tall, which is 212 feet taller than your average turbine. However, just like the onshore farm, the offshore farm does have several major requirements.

Money: It is going to cost a lot of money, more than your average wind farm because of the different components: size, transportation, and labor. Also, the site location is in the water, so the turbines need to be carried to site by ship.

Technology: The turbines need to be “planted” in deep water, although, some can float or are attached down by wires; floating devices are still in the works and for places like California to have offshore farms built, those “floaties” will be essential to the project.

Storage:  Offshore wind can generate more energy, but it takes a little longer than an onshore farm to collect that energy. Normally, the location where the energy is transferred to is close by, but since the wind farms will be in the water it’ll need extra time to transfer. However, an average wind turbine has a capacity of 2.5-3 megawatts. An offshore wind turbine has a capacity of 3.6 megawatts. Not only the capacity is larger, but winds tend to blow harder and more steadily than on land.

The idea of offshore wind farms should be welcomed, but we cannot forget about our beautiful onshore farms! There’s going to be a lot of back and forth about which one is better, but here at Alcen Renewable, we’re looking forward to another way the United States can produce clean energy for the future.