Wind Energy

With the increasing demand for clean energy wind energy has become a big industry.  Vista Data Vision software includes a Wind Energy tool that allows you to quickly estimate the Electrical Energy a windmill could generate if it were placed near a given Weather Station.

The Wind Energy report in Vista Data Vision is used to estimate the Electrical Energy that could be produced if a windmill generator were installed using wind information from a given wind sensor but shifted up to a new level.

Download a Free Trial version of Vista Data Vision and start calculating your wind energy now.

How does it work?

1. In db.data.browser or on a web interface, enlarge graph which includes Wind Speed data.
2. From the functions menu at the top, select Wind Energy. New window opens.
3. Shift the wind speed sensor to new higher level (where wind is stronger), choose diameter of rotor, Air Density, Efficiency of the system and the operating wind speed range of the wind generator. The estimated electrical energy produced for the wind speed data on display is calculated as well as estimation of a one year of electrical production.
4. That's it!

 

The purpose of the Wind Energy calculation sheet is to estimate the electrical energy that could be produced if a wind-powered generator were installed at the same location as a wind speed sensor.

The amount of wind energy depends on wind speed and the swept area of the rotor wings.  Of the two, wind speed has the greatest effect.  If you double the size of the swept area, you double the energy collected.  If wind speed doubles, the energy collected is increased by the factor of 8.

The equation for wind power is: P = 1/2 * rho * A * V3 * N
Where
P   =  Power in watts
rho = Air density (1.22 kg/m3 at sea level)
A   = rotor swept area in m2
V   = wind speed in m/s
N   = efficiency of the system (rotor, gearbox, bearings, generator)(0,3 typical)

Most often, a wind speed sensor is installed in 10m height but could be lower or higher.  However, wind speed usually increases as height above ground is increased.  Therefore, wind turbines are installed as high up as possible.

The equation for estimated wind speed at new height is: Vr/Va = (Zr/Za)^(1/7)
Where
Vr = Calculated Wind Speed at new height
Va = Wind Speed as measured by wind sensor
Zr = New height for wind sensor
Za = Current height for wind sensor

 

Wind Energy Calculations

Wind Speed:  Select wind speed sensor from the drop down list.
Upper Limit:  This is the upper operating wind speed limit of the wind generator, typically 25 m/s.
Lower Limit:  This is the lower operating wind speed limit of the wind generator, typically 4 m/s.
Height 2:  This is the new height you want to transform your wind speed measurements to.  Typical height for 650kW to 2MW wind generators is 44 to 80 m.
Height 1:  This is the current height of your wind speed sensor.  It is not uncommon for such sensors to be located in 8-12m height.
Rotor Diameter:  This is the diameter of the rotor.  For 650kW to 2MW wind generators, you may expect 50 - 80 m diameters.
Air Density:  Average value at sea level is 1.22 kg/m3.
Efficiency:  This is total efficiency of the system (rotor, gearbox, bearings, generator).  Typical value may be 0,3.


Calculated fields:
MWh:  This is the electrical energy in MWh for the time period selected.
LF%: This is average Power produced as percentage of maximum Power in kW
Max kW:  This is maximum Power in kW produced when wind speed is at maximum.
Avg kW:  This is average Power in kW produced for the period selected.
kW/A:  This factor is calculated for reference, as it is common for kW/A to be calculated for an area.
days:  Number of days in the time period selected.
MWh/year:  This is estimate electrical production in 365 days, if the period selected is typical for the whole year.