We will be continuing with our exploration of wind energy this week, digging into offshore wind! Just like wind turbines on land, offshore wind harnesses wind power to create electricity. However, the potential energy yield is higher with offshore wind, since wind tends to blow stronger over the ocean than it does over land (Global Ocean Wind Energy Potential). While Americans are less familiar with offshore wind, it is a huge industry in countries across the pond, namely, Denmark, Sweden, the United Kingdom and the Netherlands. The United States has only recently dipped our toe into the waters of offshore wind, but the industry is taking off fast! Between 2019 and 2020, the amount of offshore wind capacity tripled to 6,439 MW (“2019 Wind Energy Data & Technology Trends”). This is enough energy capacity to power over 4 million homes!
Though the basic mechanics of offshore wind turbines are virtually the same as onshore wind, there are a few key differences in how the turbine connects to the grid. Offshore wind farms sit above sea level, but their foundation is embedded in the sea floor (“Offshore Wind 101”). Array cables that connect the turbines together are run under the sea floor and connect to an offshore substation, which stabilizes the energy produced and transmits it to shore (“Offshore Wind 101”). The cables are laid deep enough in the ocean floor so as to not disturb ocean life. Once the energy is stabilized, coastal load centers, which determine where the energy is needed most, distribute it throughout the grid (“Top 10 Things You Didn’t Know About Offshore Wind Energy” 10).
While this may seem like a lot more work than onshore wind farms, there are a multitude of benefits to increasing the amount of offshore wind in the United States. First, offshore wind provides energy at a more stable rate and during peak energy usage. This is because offshore wind is strongest during the day, when usage is strongest, compared to onland wind energy, which is strongest at nighttime (“Top 10 Things You Didn’t Know About Offshore Wind Energy” 10). Offshore wind farms can also be significantly larger than onland farms, since you don't have to worry about noise pollution or spacing. Additionally, since 80% of the U.S. population lives in the coastal and great lake states, offshore wind is a conveniently located energy source (“Top 10 Things You Didn’t Know About Offshore Wind Energy” 10).
You might be thinking, “Wow, offshore wind sounds awesome, why haven't I seen more of it?” and for the most part it comes down to cost. Offshore wind farms are incredibly expensive and can be costly to maintain. These projects take years of planning, starting with financial backing, permitting, engineering/design, construction and then grid tie in. There are many parts along the way that can end a project if they don’t go according to plan. Additionally, offshore wind has been a tough market to crack open in the US, since wind turbines are not very aesthetic to see when hanging out at the beach! More on this next week!
Currently, offshore wind is a largely untapped renewable energy resource in the United States with massive potential. To recognize the advantage of wind power, we can look to Western European countries who have much smaller coastlines but are producing vast amounts of power from offshore wind. By taking advantage of even a small amount of our available coastline, the US could become a leader in the development of offshore wind. However, it is one thing to say that we could, and another to actually achieve this. That is why next week, we will be looking at how the US can place itself to be a global leader, mainly from a policy perspective.