Wind integration
Hawaiian Electric Company (HECO)
In October 2008, Hawaiian Electric Company signed a comprehensive agreement with the state of Hawaii to reduce the state’s dependence on fossil fuels for electricity and ground transportation, as part of the Hawaii Clean Energy Initiative (HCEI). The HCEI aims to accomplish several goals, including:
> Integrate up to 1,100 MW of pre-identified additional renewable energy on HECO’s grids, of which 700 MW is to be integrated within five years
> Construct an undersea cable system that connects up to 400 MW of wind power generated on the islands of Lanai and Molokai to the Oahu grid
> Obtain 40% of electric power from renewable resources by 2030, per requirement
Project
KEMA’s assignment was to evaluate the existing Energy Management System’s (EMS) ability to monitor and control the Oahu power system, to accommodate an increasing proportion of generation supplied from uncontrolled renewable resources. As management and technical consultants, KEMA had to execute specific tasks for this study, such as
> Determine the amount and type of information, calculations, and scripts required to dispatch, monitor, and control Oahu generation
> Recommend improvements to the EMS’ Automatic Generation Control (AGC) process
> Evaluate the effectiveness of plant-level control systems—Local Frequency Control Units—intended to increase the speed of response to large generation to load imbalances
KEMA used its KERMIT tool to simulate the real-power dispatch of a power system, on a one-second time periodicity, over a maximum 24-hour term. KEMA enhanced KERMIT to realistically simulate the Oahu island power system, which is characterized by limited inertia (i.e., kinetic energy). KEMA simulated eight scenarios through KERMIT. Three scenarios were made to calibrate the model so it closely matched actual power system events and to further validate this calibration. The other five scenarios postulated Oahu power system operations with increasing penetration of wind, solar, and other uncontrolled renewable resources through 2030. For these scenarios, KEMA used KERMIT to evaluate the AGC capabilities of HECO’s EMS to determine if conventional generation control functionality would be sufficient to manage normal and exceptional power system conditions.
The analysis considered the effectiveness of tuning the control algorithm to (1) react more or less rapidly to frequency deviation, and (2) vary the control in direct proportion to the deviation magnitude. The analysis also examined the ability of the control functionality to effectively utilize larger amounts of controllable generation.
Benefits
HECO and KEMA determined that the capability to control the power system is limited by the resources available for it to manage. HECO used the study’s results as input for its planning process to fulfill its HCEI agreement.
Client> Hawaiian Electric Company
Project details
> Duration: March 2009 - October 2009