Garrad Hassan and Partners has conducted an investigation into how operational wind farms have performed in terms of availability. This paper outlines some of its key results.
The investigation used Garrad Hassan's experience over the past decade assessing the performance of over 14, 000 MW of operating wind farms which is approximately 15 % of the total worldwide installed capacity.
Garrad Hassan has gathered together significant information on the performance of wind farms when conducting analyses on behalf of lenders, owners and other parties. With this information, the authors created a database which consists of over 1000 wind farm years of availability statistics with all major turbine manufacturers represented in the dataset. The availability information covers more than 250 wind farms across Europe, US and Asia with periods of operation ranging from 1 year up to 15 years. It is this database that has been used and referenced in this paper to draw relevant observations and conclusions.

View full abstract

As the level of penetration of wind energy into individual grids has increased it has become necessary to make wind energy appear much more like conventional plant and hence to forecast the power production of wind farms. Historically there have been a number of studies investigating the possible methods of forecasting and the accuracy of their predictions. However, there have been a limited number of studies investigating the potential benefit of forecasting. This paper aims to address the issue by quantifying the potential financial benefits of forecasting for both individual, and portfolios of wind farms in the UK and Spain.
In the UK the market conditions are such that the benefit of forecasting wind farm production has been evaluated based on open market prices. For the Spanish case there is a more structured wind energy trading system whereby participants in the pool market are required to forecast. For both the UK and Spanish cases the trading calculations use data from online forecasting services combined with assumptions of the market conditions.
Based on the forecast data analysed and the assumptions used, there is the potential for increasing the value of wind energy in the UK and Spain by the amounts shown below

View full abstract

In Japan, wind turbines have been surrounded with the strong transient conditions of a gale/blast, and typhoon that were caused to the damage, and to decrease the durability and performance of the turbines. Therefore, the simple mechanism of pitch control system of the turbine blades was required that easily follow and correspond to the abruptly transition of the wind condition. A new proposed passive pitch control mechanism to protect the over speed and the blade stall is using to the resultant force of the drag and lift of sub-blades linked to the main-blades pitches sustained by springs to the normal pitch angles. The aerodynamic performance of the wind turbine with pitch controlled sub-blades are examined by experiment and investigated theoretically, using to the only similarity parameter S (solidity) as a basic study. Consequently, the passive pitch control mechanism presented here is cleared to be effective for avoiding the excess-run of the turbine and the blade stall due to the gale/blast.

View full abstract