Wind Power

what are the two types of wind power

HAWTs and VAWTs

what does HAWTs stand for

horizontal axis wind turbine

what does VAWTs stand for

vertical axis wind turbine

advantages of HAWTs

• technology is more advanced and established

• higher efficiency

disadvantages of HAWTs

• stress cracking in base of blades

• teller towers needed

• stronger tower required

advantages of VAWTs

• turbines driven by wind from any direction

• no need for a motor

• quieter

• operate at lower wind velocities

disadvantages of VAWTs

• no very large VAWTs built

• lower efficiency

what are aerogenerators

they absorb the kinetic energy of moving air so air behind turbine moves more slowly

why must wind turbines be spaced out

so they are not in the ‘wind shadow’ of the nearest turbines

what are the locational constraints of wind power

• wind velocity

• isolation

• land use conflicts

what are the different land use conflicts of wind power

• ecological impacts

• land requirements

• telecommunication interference

• public opposition

why is wind velocity a locational constraint of wind energy

• the reliability and strength of wind are affected by latitude

• topography affects the wind velocity as friction slows it own

• higher the wind velocity, the more power produced

what areas are best for wind velocity

• temperate and polar regions

• costal, upland, flat areas, the sea

why is isolation a locational constraint of wind energy

• small-scale can provide electricity for isolated places

• large-scale usually located near electricity grid

why is ecological impacts a land-use locational constraint of wind energy

• locate turbine away from bird migration routes

• located away from high bat populations

• located away from sensitive areas

why is land requirement a land-use locational constraint of wind energy

turbines require a large amount of land to minimise ‘wind shadow’ but land can be used for other purposes

why is telecommunication a land-use locational constraint of wind energy

aerogenerators can interfer with radio and radar systems

why is public opposition a land-use locational constraint of wind energy

some people object so they are located away from scenic and urban areas

what are the new wind power technologies

• blade tip fins

• nacelle brushes

• direct drive turbines

• helical VAWT blades

• wind-assisted ships

what do blade-tip fins do

• reduce turbalence

• reduce wind resistance

• increase efficiency

what do nacelle brushes do

• reduce amount of air escaping between blades and central nacelle

• increase kinetic energy absorbed

what are direct drive turbines

they produce an alternating current to turn the turbines

disadvantages of turbines which direct drive don’t have

• expensive gearbox

• gearbox often breaks down

• friction in gear box reduces efficiency

• tower required to be stronger for extra eight

what are the advantages of direct drive turbine

• have no gear box

• more reliable

• quieter

• cheaper

• generate electrisity at lower wind velocities

• converts direct current into alternating current

what are helical VAWT blades