Wind Turbine Ramp-up

Challenge

A reality of life in the renewable energy business: Providers of alternative energy (such as wind turbine generators) are subject to being “curtailed” or temporarily shut down by the power grid operators. In these cases, the wind power is available but it is not dispatched to the power grid. These curtailments happen for a number of reasons, including a reduction in the demand for power, transmission congestion or lack of transmission access.

Renewable energy companies are entitled to charge back the traditional utility for revenue lost during the period of curtailment. But in the case of wind turbine generators, it takes time to get the wind turbines up and running at full capacity after being shut down. The ramp-up period can take six to eight hours, another period during which the wind provider is not making money. It is difficult if not unworkable to use spreadsheets to accurately identify the curtailment periods needed for accurate chargeback.

A wind energy company was experiencing curtailments roughly once every two days at a cost of several hundred dollars per day, adding up to lost revenue of roughly $3,000 per month per windfarm. The company was unable to quantify its commercial losses during curtailment. It needed a more accurate way to quantify the period of curtailment and ramp-up to ensure accurate chargeback.

Solution

Using Seeq, the wind turbine generator was able to calculate its wind generation potential based on wind strength and direction. It used Seeq to identify the ramp-up period, compare potential versus actual power generated and quantify losses for more accurate chargeback.

Using Seeq, the team can easily identify the curtailment periods and quantify losses. Previously, the team had done this calculation using Excel spreadsheets—a time-consuming and cumbersome process for a single turbine. Using the old process, it was unrealistic to scale these calculations across an entire fleet of turbines. Now, the team uses Seeq combined with OSIsoft PI Asset Framework to quickly and easily identify stoppages for a fleet containing hundreds of wind turbines, greatly simplifying the chargeback process.

Results

The wind turbine generator can now calculate its commercial losses during ramp up across its entire fleet of wind turbines. This enables the company to pass charges onto the grid operator. The wind turbine generator was able to recapture an excess of $30,000 per windfarm per year thanks to accurate chargeback calculations and can now scale these calculations across additional fleets of turbines.

Data Sources

• Process Data Historian: OSIsoft, PI, MySQL
• Asset Structure: OSIsoft, Asset Framework

Data Cleansing

• Filtering of curtailment conditions less than a specified amount of time
• Filtering of turbine performance when a unit is offline

Calculations and Capsules

Power generation potential is calculated from wind speed and direction using modeling. Seeq allows multiple conditions to be created to analyze the total power generation potential lost during wind turbine ramp-up period and are then totaled and displayed.

• A condition is created for periods of generation curtailment using capsules.
• A ramp-up condition is created that determines the time from the end of a curtailment period to the time the turbine reaches its generation capability.