We paid a visit to our neighbor Scituate, MA’s recently installed 1.5 megawatt windmill. Conveniently, we were able to read its output meter. We were curious, and likely some townspeople in Scituate will be curious too, how much energy it has produced since its inception at the beginning of April, 2012. The meter told the story, have a look for yourself (sorry our image can’t be bigger).
If you can make it out, you’ll see it says “849,467” That is telling how many Kilowatt-hours of electric energy production came out between beginning of April and 21st of July. The total length of time here is 111 days. So let’s do a little processing of these numbers.
Utilities measure energy to include the hours — hence Kilowatt-hours, not simply Kilowatts. On this basis, we have 849,467 (divided by) 111 days (divided by ) 24 hours giving us an average power over those one hundred eleven days = 318.9 KW. This can then be re-expressed as a percentage of the machine’s maximum (‘rated’) power output. Which in this case is 1.5 megawatts, or 1500 kilowatts. So then our final calculation is the following: 318.9 (divided by) 1500 = 21.3 %.
OK, let’s proceed the 5 miles or so northward to Hull. They will have experienced roughly the same winds during those same 111 days . How did Hull, with its 1.8 megawatt machine do, how was its production, in that very same period of 111 days since early April ? We have a reliable answer, thanks to the good MMWEC people in Ludlow, Mass, relayed to us further from the Wizards Corner people at hullwind.org . The output from Hull Wind 2 in that same period was 700, 181 KW-hrs. Hull’s calculations therefore run this way. 700,181 (divided by) 111 (divided by) 24 = 262.8 KW (avg.) This average, divided by the rated capacity of 1800 KW gives Hull’s Capacity Factor : 14.5 %
This proves that Scituate’s new wind turbine has outperformed Hull 2 during this exact period. Interestingly enough, the Hull 2 turbine came rated at a slightly higher maximum capacity (1.8 megawatts, compared to 1.5 megawatts). So we theoretically would have found Hull’s machine outproducing Scituate’s. But many factors go into all of this, including the height above ground of the turbine’s nose-cone. Notus1 in Falmouth is at 77 meters, while Hull’s is at 60 meters. That Falmouth machine’s output is web-available at www.powerdash.com/systems/1000196. Admirable transparency there at Notus1 !