Renewable Energy Wind Energy Liang Li Qing Yu Samuel 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 Turbines Horizontal-axisVertical-axis

Wind Energy Utilization Wind power plants and wind pumping are two main utilization of wind power. Wind Power PlantWind 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 farm R is the capital recovery factor or the annual capital charge rate E is the wind farm annual energy output M 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  Wind power generation  Wind farm construction  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.