Small scale wind energy W. Hulshorst Jan. 2009

Agenda Types of small scale wind energy systems 2) How to estimate the energy output 3) Aspects on the location 4) Case study with RETscreen

Types of small scale wind energy systems

2) How to estimate the energy output

3) Aspects on the location

4) Case study with RETscreen

What is Small Scale WE? Exact definition is not always clear: According IEC 61400:2007: turbines with swept rotor area < 200 m2 are classified as small scale turbines Non universal definitation is often based on the kW: system that is self yawing (tail vain) and < 100 kW.

Exact definition is not always clear:

According IEC 61400:2007: turbines with swept rotor area

< 200 m2 are classified as

small scale turbines

Non universal definitation is

often based on the kW:

system that is self yawing (tail vain)

and < 100 kW.

Wind energy for remote area’s Off grid systems Weather stations Wind – PV Wind – Diesel

Off grid systems

Weather stations

Wind – PV

Wind – Diesel

Wind energy on buildings Horizontal Vertical In between?

But also integrated

Power curves

Wind distribution To estimate the annual energy: Power Curve Wind distribution At most locations the wind- distribution can be described as a weibull distribution At higher heigts the wind speed is often higher. That’s the reason why we build wind turbines on a tower Restrication could be the weight of the generator/alternator

To estimate the annual energy:

Power Curve

Wind distribution

At most locations the wind-

distribution can be described as

a weibull distribution

Urban wind characteristics small wind turbines require less wind & land resources than large turbines, so their installation is feasible in a wider variety of locations. However small scale wind projects in urban area’s do face some constrains: Lower annual mean wind speed Turbulance Potential difficulties in obtaining planning permission

small wind turbines require less wind & land resources

than large turbines, so their installation is feasible in a

wider variety of locations.

However small scale wind projects in urban area’s do

face some constrains:

Lower annual mean wind speed

Turbulance

Potential difficulties in obtaining planning permission

Site conditions effects output

Location Output of energy depends on the windspeed The windspeed increases significantly near the top of a hill and the air flow should be free of obstacles. Existing obstacles, such as buildings, trees can significantly affect wind speed. Locate as far as possible from obstacles Alternatively, the turbine height can be increased to compensate the lack of distance

Output of energy depends on the windspeed

The windspeed increases significantly near the top of a

hill and the air flow should be free of obstacles.

Existing obstacles, such as buildings, trees can

significantly affect wind speed.

Locate as far as possible from obstacles

Alternatively, the turbine height can be increased to

compensate the lack of distance

Locations

Other issue’s It is recommended that the wind turbine is located reasonably close to the point of energy use or to the grid connection. Noise and visual impact are particularly sensitive issues in a residential area. Both can be subjective and hard to judge.

It is recommended that the wind turbine is located

reasonably close to the point of energy use or to the

grid connection.

Noise and visual impact are particularly sensitive

issues in a residential area. Both can be subjective and

hard to judge.

Some interesting websites General information about renewables: www.leonardo-energy.org Information about wind manufacturers in Europe: www.urbanwind.org www.allsmalwindturbines.org Windspeed in different countries: www.windatlas.dk

Thanks for your attention Walter Hulshorst Econ International B.V. PO box 5035 6802 EA Arnhem The Netherlands T: + 31 (0)61 047 45 77 F: + 31 (0)26 381 64 82 E: walter @ econ-international.nl W: www.econ-international.nl