Wind Energy - Resource Analysis

Site-specific Investigations

Network Characteristics at the Injection Point

Analysis of transformer/feeder/transmission capacities, voltage variations, fault levels and other grid characteristics (including upgrades or reinforcements, if need be) that are relevant for the design and future operation of wind parks at the selected site or, for that matter, the points at which the loads of the wind parks will be injected into the transmission network.

Site Conditions

Site-specific examination of ground and soil conditions, accessibility (e.g. roads), availability of ancillary material and equipment (e.g. cranes), environmental hazards, climatic risks, legal constraints (e.g. property rights), licensing/authorization procedures and other factors or obstacles that affect the suitability of the selected site (the partner will bear the cost for soil bearing costs, as well as topographic surveys, if needed).
Site-specific examination of environmental and social aspects. The study shall contain information on national regulations on the requirements of an environmental (and social) impact analysis or, if national regulations are not available, it shall follow international recommendations.

Wind Regime

Preparation and processing of available wind data for estimating the daily, monthly and seasonal electrical output of the wind farm (calculate a norm year by correlation of measured wind data with long-term meteorological wind speed data). Determine the impact of wind parks on the short-term and long-term scheduling of existing power plants with a view towards minimizing system generation costs. Estimate the savings/benefits attributable to wind park integration such additional capacity available during peak load periods.
Correlate monthly diurnal wind speed patterns with monthly load curves based on hourly wind and load data.
Depending on the availability and quality of repeated samples of the probability distribution of the wind speed at the selected sites, the study should also perform wind reliability/predictability calculations that can be used to approximate the capacity credit (load carrying capability) of the wind farm.

Evaluation of Wind Potentials (Example from Namibia)

The evaluation of the wind potential in Walvis Bay and Lüderitz in Namibia was carried out under two different aspects that required also different approaches and methods:
A. Evaluation of daily and annual characteristics in the wind speed distribution and comparison to the load characteristics in Walvis Bay and Lüderitz

• statistical analysis of long and short term data
• daily, seasonal and annual wind speed patterns
• firm power probabilities for at least certain hours per day.

B. Design of wind park alternatives and calculation of its annual energy yield (various scenarios).

For these calculations the wind atlas model and the related WASP model and WindPro sofware program were used. Within these calculations also a sensitivity analysis concerning a well-suited type of wind turbine for the site in question was undertaken. The wind park calculations were then based on the identified turbine. The evaluation of the wind potential was based on measured data from 10 m height, which had been collected intermittently by MME during the past 2 years.4 In addition, long term meteorological data of the past 20 years as provided by the Namibian Weather Bureau and the South African Weather Bureau
were also considered.

The resulting wind potential in 50m height is characterised as follows

Site	Annual Average m/s	Energy Density kWh/m2/a	Weibull Parameters a,k
Walvis Bay Saltworks	6.8	3047	A = 7.73 k = 2.17
Lüderitz Golf Course	7.5	4936	A = 8.4 k = 1.70

Further Information

• Portal:Wind
• Gasch Bewertungsmethoden für Sites (Gasch Kapitel 4)
• Capacity Building - Wind Energy
  
• Ecological Aspects - Wind Energy