why measuring wind

Why measuring wind?

A wind farm is a huge investment, whereas the costs for a high quality measurement are quite low in relation to the overall investment. Nevertheless many project developers and investors don’t want to pay for a high quality wind measurement even if the cost is low compared to the overall investment: is such a high quality measurement really necessary? Why do I have to measure a whole year? Why can’t I use cheaper solutions? What does a cheap, low-quality solution mean for the whole wind power project?

High quality in wind measuring pays off!

Since windhunter started building met masts in 1999, we dealt with these issues in order to offer our clients the best solutions for their successful wind power project. From the very beginning one thing became clear: a high quality wind measurement pays off – even years after commissioning the wind farm!

P=1/2 * (ρ*A*v³)

The reason for putting so much effort in measuring the wind lies in the physics of wind power. You can’t measure wind power nor wind energy directly, so it has to be calculated from measurable parameters like this:

 P=1/2 * (ρ*A*v³)

P = wind power

ρ = air density

A = rotor area

v = wind speed

As often the devil is in the details: here it is the third power of the wind speed. Twice the wind speed gives eight times the power, half the wind speed gives one eighths of the wind power!  This means that even the small errors in wind measurement result in huge errors in the calculated wind power – and this leads to high uncertainties in the energy yield study and in the site assessment. High uncertainties mean a high financial risk. To reduce the uncertainties and the financial risk as much as possible international standards have been set up to guarantee for a high quality and low uncertainties in wind measurement.