Renewable EnergyWind Energy

Liang LiQing YuSamuel Marin Calvo

Department of Technology and Built Environment, University of Gävle, Gävle, Sweden

VS

Traditional Energy

● Energy Crisis● Green House Effect● Acid Rain● Low Efficiency

Wind Energy

● Clean● Inexhaustible source ● Low Maintenance Fee

Uneven radiation from the Sun create air flow – this is wind!

Any object which has motion has kinetic energy.

Characteristics of Wind Energy

● Wind Speed -- The rate of the motion of the air in a unit of time, unit m/s, (Wind speed is divided into 17 classes).

● Wind direction -- The direction from which the wind is blowing. There are 16 azimuths used to indicate the direction of wind (S,SSW,SW,WSW,W and etc.).

●Wind energy density -- The amount of kinetic energy as wind flows through a unit area vertically.

Wind TurbinesHorizontal-axis Vertical-axis

Wind Energy Utilization

Wind power plants and wind pumping are two main utilization of wind power.

Wind Power Plant Wind Pumping

Other utilization of wind power: heating, sailing and etc.

Cost Calculation

The cost per unit of electricity generated, p, by a wind farm can be estimated using the following formula: p = CR/E + M

C is the capital cost of the wind farmR is the capital recovery factor or the annual capital charge rateE is the wind farm annual energy outputM is the cost of operating and maintaining the wind farm per unit of energy output.

Chapter 3

Wind Power of the world

3.1 Development and utilization of wind energy in China

3.1.1 Wind power generation

3.1.2 Wind farm construction

3.1.3 Future development and problems in China

3.1.1 Wind power generation

From 80s, the 50W-200W micro wind-power generator

Currently there are about 30 manufacturers of micro wind-power generators across the country

produce an annual output reaching 10,000 units total generating capacity of 17 MW now 140,000 units of this type of generator that

have been successfully applied

3.1.2 Wind farm construction

now 160 wind power generating plants in place with the maximum capacity of any single unit being 500 kW, total capacity 30 MW, and annual electricity generation approaching 80 GWh.

3.1.2 Wind farm construction

The Dabancheng Wind Farm in Xinjiang is the largest in China, with its installed capacity exceeding 10 MW.

At present, there are more than 10 wind farms being planned.

3.1.3 Future development and problems in China

Total installed wind power capacity to 30,000 MW by the year 2020

A lack of specialized

3.2 Wind Power in other countries

The European community set up a project to develop renewable energy in 2001, aiming to make electricity produced from renewable sources contributes 12% of the whole European electricity system requirements.

In 2002, total electricity production by wind was 32000MG, while the countries belong to the European Community accounted for 74% of the whole world.

Chapter 3 Advantages & Disadvantages of Wind Power

3.1 Advantages:

Renewable Decreased Dependence on Fossil

Fuels Reduces Greenhouse Gas

Emissions New Jobs & Economic

Development in Rural Areas

3.2 Disadvantages:

Transfer Geography Noise Required Land Space and

Competing Uses Killing Birds

INTEGRATION OF WINPOWER IN THE GRID

Integration of windpower in the grid

Problem of integrate large amounts of wind generated electricity:

The Grid: electricity balance

Variability of wind

Ways to reduce the problem of variability

Wind Forecasting

Storage

Distributed production and interconnection

Wind Forecasting

Makes wind energy more reliable

Reduction of the reserve capacity

Storage

Systems to storage electricity overproduction

Nowadays: hydropower (80%) and air compressed (75%)

Distributed production and interconnection

Distributed production:

Distributed production and interconnection

Interconnection: West Denmark

Annual Report 2004 [Online]. (Eltra) Energinet.dk, Transmission System Operator of Denmark, Fredericia, 2005.