Small scale wind energy

W. HulshorstJan. 2009

Agenda

1)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 assmall scale turbines

• Non universal definitation isoften 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

Wind energy on buildingsHorizontal 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 towerRestrication could be the weight of the generator/alternator

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

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

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.

Some interesting websites

General information about renewables:www.leonardo-energy.org

Information about wind manufacturers in Europe:www.urbanwind.orgwww.allsmalwindturbines.org

Windspeed in different countries:www.windatlas.dk

Thanks for your attention

Walter HulshorstEcon International B.V. PO box 50356802 EA ArnhemThe Netherlands

T: + 31 (0)61 047 45 77F: + 31 (0)26 381 64 82E: walter@econ-international.nlW: www.econ-international.nl