Introduction 2015

Introduction to 46300 Wind Turbine Technology

No. 1 student question

How to pass ?

Mandatory in class test on the last lecture 3th December +

3 reports (1 WT aerodynamics+1 Electrical +1 Structural)

Lecturers: Assoc. Prof. Martin O.L.Hansen Dept. of Mechanical Engineering/ Fluid Mechanics Build. 403 room 224 Aerodynamics and structural mechanics Assoc. Prof. Arne Heide+Nenad Mijatovic DTU Electrical Engineering Generators, converters and electromagnetic components

Rough characterization of Wind Turbine

H

D

Number of blades 1,2,3,4,…. Rotational speed rotor 10-30 RPM Constrained by noise ωR≈70 m/s generator speed variable or fixed 1000-1500 RPM Rated power 500kW to 8MW Upwind or downwind rotor Control: pitch (collective or individual) or stall fixed or variabel speed (generator type)

H/D ≈ 1

Courtesy: Siemens Wind Turbine

Courtesy: Siemens Wind Turbine

P/R2 0.89 1.00 1.25 0.96 1.25 1.3

Rule of thumb for danish site (based on statistics) 1000 kWh/m2/year Another rule of thumb: P≈R2 [kW] Example: A 400kW WT, D=40 m, A=1256 m2 yields 1.26 GWh/year corresponding appr. to 250 households A 3 MW WT thus produces appr. 9 GWh corresponding to appr. 1800 houses A yearly consumption of 5000 kWh assumed

Why wind power !

Pros •Fossil fuel free energy ÷CO2 •Clean •Self suppliant •free of fluctuating fuel prices •Creates jobs •Good in remote areas •Cheap energy •Works excelent with hydro •Desalination •Good business •Other

Cons

•Only when wind/intermittent •Difficult to store energy •Noise •Uggly in landscape •Might disturb migrating birds •Other

∆m=ρAL= ρAVo ∆t

∆Ekin=½ ∆mVo2=½ ρAVo

3 ∆t

P= ∆Ekin/∆t= =½ ρAVo3

Power in the wind

L= Vo ∆t

Vo A

Power~ρAVo3

Example: (BONUS 2MW at Middelgrunden) R=38 m ρ=1.225 kg/m3

Vo=10 m/s Massflow: !!! skgRV

tmm o /555712 ==∆∆

= πρ

P(Vo=10m/s)=1.2MW 43.0321

==o

p AVPCρ

Wind turbine designed for 20 years corresponding to appr. 120.000 hours. A car runs appr. 300.000 km at an average speed of 70 km/hours corresponding to 4000 hours. Robust design is therefore needed.

Key economic figures Cost of wind turbine ≈ 1200 Euro/kW Erection (danish site) appr. 30% of price Grid connection, roads, transportation, foundation etc. Maintenance cost appr. 1.5-2% per year (based on statistics for many danish sites). With these numbers you can very roughly estimate a price on a site in DK

EWEA reports can be downloaded from the internet for those interested in wind energy economics

From EWEA report: Economics of Wind Energy, 2009

From EWEA report: Economics of Wind Energy, 2009

From EWEA report: Economics of Wind Energy, 2009

Yearly income ?

The way it used to be. Fixed tariff

”green certificates” or Renewable Energy Certificates RECs is tradable commodity. Typically one certificate is issued after a production of 1000 kWh. The price depends on the demand for the certificates that can politically determined. E.g. California dictates 33% renewable electricity in 2020

Now the price depend on the free market and varies in Scandinavia with the amount of water available in Norway/Sweden (Nord Pool) 10 Norske øre=1.3 Euro cent Plus some possible ”green certificates”

Free market, fluctuating income

Oil price 59$/barrel Oil price 120$/barrel

From EWEA report: Economics of Wind Energy, 2009

Wind Energy may be even more competitive if the benefit of being self supplied and no risk from possible increase in fuel price is capitalized and/or a tax on emitting CO2 is increased

How to have more wind power installed-

different strategies

Inspired by the book: Wind Energy comes of age, Wiley

by Paul Gipe

Source: Wind Energy comes of age, Wiley by Paul Gipe

Source: Wind Energy comes of age, Wiley by Paul Gipe

Curiosum: Ronald Reagan US president 1981-1989

Source: Wind Energy comes of age, Wiley by Paul Gipe

Status: Where are we now

GWEC reports can be downloaded www.gwec.net

Exponentional growth