Wind Turbine Intermittency

Hello Reader,

I wanted to draw your attention to a New York Times article from the past week that highlights one of the major challenges facing developed countries as we try to connect increasing numbers of wind turbines to national and regional electricity grids. That is: intermittency.

Wind turbines are notorious for generating intermittent energy. From a physical perspective this makes sense, because wind does not blow at the same speed all the time. However, when it comes to the electricity grid intermittency can be a huge issue.

On a very small scale, such as a single isolated wind turbine on a farm, this issue can be over come by simply combining the wind turbine with a battery storage system. In such cases, intermittency is not really an issue unless the wind simply stops blowing for days at a time.

On a somewhat larger scale, such as the current state of the US electricity grid, where wind turbines only make up a small percentage of electricity generation the fluctuations are manageable. That is the gaps in generation caused by wind turbine intermittency can be filled in by other generation sources.

Of course, as the article indicates when wind energy starts to make up larger percentages (e.g. 20%) of generation sources, intermittency can pose serious risks to grid stability (e.g. increasing the risk of brownouts and blackouts). The article suggests studies are testing the possibility of connecting multiple turbine farms together to level off the effects of intermittency and provide a more consistent power source. From a physical perspective this also makes sense because when the wind is blowing in one location it may not be blowing in another and vice versa. This means electricity generation will be averaged out.

While this does appear to be a crucial step towards large scale implementation of wind energy, more infrastructural concerns must be addressed. One such step includes the mass introduction of electrical energy storage, which allows electricity to be produced at one point in time (e.g. when the wind is blowing hardest) and used at another point in time (e.g. when you wake up and turn on your electric razor). Unfortunately, the current structure of the electricity grid is not compatible with this concept. As it stands, electricity must be produced as it is being used and at no other time.

Not only is this an issue for installing wind turbines, but it also has massive impacts on the efficiency of traditional fossil fuel and nuclear plants as well. As such, energy storage is the topic of my postgraduate dissertation. Next week I will post part of my dissertation proposal, which explains more about the issue and the need for research into the field. In the meantime, I encourage you to look into the topic for yourself.

The article I referenced within this post is:
A Grid of Wind Turbines to Pick Up the Slack
By HENRY FOUNTAIN
Published: April 12, 2010
http://www.nytimes.com/2010/04/13/science/13obwind.html

Sincerely,

Sean Diamond