Wales Diesel-Off High Penetration Wind System - An Emerging Energy Technology Grant Project
The ultimate goal of this project was to revive the wind diesel system in Wales, Alaska so the community could achieve a 50% reduction in diesel consumption. In doing so, the diesel-off configuration could then be replicated in other communities.
In 1995 the Alaska Energy Authority (AEA), Kotzebue Electric Association (KEA), Alaska Village Electric Cooperative (AVEC), and the National Renewable Energy Laboratory (NREL) implemented a high penetration wind diesel hybrid power system to reduce diesel consumption for Alaskan communities. This project was intended to be a technology demonstration and a pilot project for commercial replication in other Alaskan communities. Low penetration systems are, at this point, a mature technology. High penetration systems, however, still have many problems - especially when installed with the capacity to operate in a diesel-off capacity.
Funding was provided by the U.S. Environmental Protection Agency, the U.S. Department of Energy, the Alaska Science and Technology Foundation, as well as KEA and AVEC. NREL created the control systems which were required to integrate system components. KEA and AVEC provided project management including site selection, permitting, and wind resource assessment. The project was commissioned in Wales in the spring of 2001.
The system has degraded in functionality since original commissioning and upgrades are needed including installation of remote access for monitoring and control, increased data logging, and other updated equipment.
Kotzebue Electric Association’s overall goal for this project was to demonstrate diesel-off configuration for a remote wind-diesel high penetration hybrid power system through the retrofit of existing equipment and controls. The scope of work for this project included upgrading the controls and monitoring of the Wales system, as well as restoring the two Entegrity turbines.
The proposed work plan was as follows:
- Phase 1 – Project Design and Engineering
KEA and AVEC engineers will review and recommend system improvements to the power plant, conducting a review of system performance. KEA and AVEC technicians will accompany the engineers to evaluate the system in its entirety to ensure that system relaying and protective controls are operational and to upgrade the wind turbine programming and systems, installing the most current components. A report will be produced specifying necessary work to allow Wales to operate in a diesel-off mode.
- Phase 2 – Installation
Purchase and install new radio links at the power plant, school, and wind site; a dedicated satellite connection for the power plant; new PLCs for the energy storage system, school heating system, power plant, and wind site. Other work may include replacing the existing servers at the power plant and the wind site. Equipment will be ordered after the initial review, to be installed in Wales upon arrival. After the equipment is installed, data collection will begin.
- Phase 3 – Data Analysis
The SCADA system at Wales is to include a system allowing for real time monitoring and remote control of the turbines and interconnections with the turbine controllers. Concurrent data collection from met tower sensors will measure numerous power quality parameters including real and reactive power, voltage, and current on each phases, voltage and current total harmonic distortion, frequency deviation, and voltage imbalance. This data will be collected, analyzed, and reported on a monthly basis throughout the duration of this proposal by KEA, AVEC, or another entity of their choosing. As system performance is studied, further recommendations will be made as needed to optimize the operation of the system.
Once project activities commenced, it was discovered that the system would need significant repairs for functionality beyond those anticipated by the project scope of work and budget. In particular, cracks in the turbine blades were discovered that required time and weather sensitive repairs. Continued delays in repair work due to weather caused the resulting project timeline to fall outside of the EETG overall program timeline. The project was subsequently cancelled pending further review by the Denali Commission, KEA, and other key project stakeholders including AVEC and NREL.
The Wales Wind-Diesel Hybrid Power System was intended to demonstrate the feasibility of retrofitting a village power plant with a high penetration wind-diesel system which allows the community to realize large reduction in diesel consumption. It is one of very few systems in the world which can operate with the diesel off for extended periods of time. The system is in need of repairs and upgrades so that research can continue.
One critical issue that was identified through this attempted project was that of project ownership. While the wind system is owned and operated by KEA, the local powerhouse is owned and operated by AVEC, with much of the wind system being designed by NREL. For future project success, it will take significant cooperation between these three entities, and the alignment of wind generation incentives between the generation asset owner and the local utility. In addition, the community of Wales has had little engagement on the project or its future. The inclusion of the community is similarly critical for the future successful rehabilitation of the Wales system.
Photo 1: A Review of Wind-Diesel Power Electronics in Wales. Courtesy Jason Meyer, ACEP.
Photo 2: The Wales High-Penetration Wind System. Courtesy Jason Meyer, ACEP.
Photo 3: The Wales High-Penetration Wind System. Courtesy Jason Meyer, ACEP.