Offshore Wind Can Be a Winter Powerhouse for Maine

Saving budgets and lives

In 2013 and 2018 Maine and New England have faced threats of electric power brownouts or even blackouts as demand soared during brutally cold winter weather while natural gas and even oil supplies for power generation became dangerously low. The real-time wholesale power price increased almost tenfold to $0.30+/ kWh hour, not including transmission and distribution. Businesses and factories were forced to curtail heavy electrical power use, sometimes having to shut down altogether.


It is precisely at this time when the strong winter winds from the Northwest (The Montréal Express) enables offshore wind to run at maximum power just as homeowners suffer from extreme budget-busting “degree days” of heating costs. By using a heat pump with a “Coefficient of Performance” (COP=BTUs of heat delivered to home per BTU of energy consumed) of 4, electric power at $0.15 / kWh is equivalent to being able to buy heating oil at $1.50 / gallon. Over the course of a harsh winter, an average family could save $500-$1000 if heating oil were priced at $2.50 per gallon. And it is important to keep in mind that over the last two years we’ve seen oil increase from $30 a barrel to $60 a barrel, and just 10 years ago it was $120 a barrel. A return to the $90 per barrel range is all too likely for many reasons. That’s when heating cost pain turns into torture.


Each 8 MW offshore wind turbine running at maximum output could supply power for heat pumps in 2000 homes. A midsize 500 MW commercial offshore wind farm with sixty-four 8 MW turbines running at maximum output could provide power for 128,000 homes with heat pumps. On an annual average, offshore wind turbines can run at approximately 42% maximum capacity due to the intermittency of wind. But in the winter months, this can be closer to 60% or above. This is the so-called “capacity factor”.


Although the capacity factor is not 100% this offshore electricity generation can be a power grid lifesaver and can help keep electric power costs down. Natural gas and oil-fueled power plants have their own intermittency problems when during extreme winter natural gas is withheld from power plants and diverted to use solely in home heating. This 2018 winter shows that in this stressful case when oil power plants day after day are forced to take on a 30% share of power generation even their oil storage reserves can be emptied. That’s when things get really ugly. Oil usually is called upon for only 1 to 5 percent of the total Maine generation capacity. The plants are old and inefficient. The fuel is expensive. And the CO2 released jumps by at least a factor of 2 compared to natural gas.  Natural gas usual carries about 50% of the Maine load for these reasons. Offshore wind can prevent resulting brownouts and blackouts by significantly taking over for oil and natural gas and allowing them to rebuild their fuel storage supplies. With enough offshore wind in place, the polluting inefficient oil generating plants would simply not have to be used. Beyond all that, days of sky-high wholesale power prices are avoided by turning to offshore winds.  The average kilowatt hour prices the utilities can demand from the PUC are held at a reasonable level. Such winter usage price spikes can affect rates throughout the year because of the way utility rates are set.



Far more so than onshore wind, offshore wind is tremendous for filling this “emergency generator” role. As is shown on the recent snapshot of wind conditions when the wind onshore is 10 mph on average, offshore this will be 20 mph or much more. This doesn’t mean just twice as much power from the wind available for each turbine. In fact power available goes as the cube of the wind speed. So twice the wind speed means that eight times as much power can be extracted. And the winds are far more constant and predictable offshore.

This translates into very serious economic value per turbine and for a 500 MW wind farm with 64 turbines. At full output and for a wholesale price of $0.10 /kWh an 8 MW turbine will generate $800 of revenue per hour or $19,200 per day. For a whole 64 turbine 500 MW wind farm this would be $51,200 per hour or $1,229,000 per day. Over the course of a year the average fraction of maximum output available from a turbine, the capacity factor, will be between 40 and 50 percent. At a 40% capacity factor a single turbine will generate revenues of more than $2.8 million per year. The whole 500 MW wind farm will have revenues of $180 million per year. This goes to pay for the overall construction costs plus interest handled in a financial structure that amounts to a mortgage. Using the MAV design at least roughly half of the overall original construction costs of $2.5 billion for a 500 MW offshore wind farm will go to Maine companies and workers.


The following is a dynamic link to current wind speeds in the Gulf of Maine:


Interested Maine residents, students, etc. can see real-time what an electricity problem is brewing with the cold weather after they install the following app on their own phones: