EnerNex Corporation, together with its strategic partners WindLogics and AREVA, has contributed significantly to the state of the art for assessing the impacts of wind generation on control area performance and economics.
In early 2004, the project team was assembled for the first time and selected by Xcel Energy to assess the economic and technical impacts of 1500 MW of wind generation in their Minnesota control area by 2010, when the hourly peak load is projected to reach 10,000 MW. The analytical methodology developed for the project proved to be a very significant step forward in this type of study. WindLogics performed an assessment of the wind resource in the region and researched forecasting opportunities and challenges. Most significantly, they were able to create a very high fidelity and high resolution chronological wind speed data base for the geographically diverse development of wind generation facilities defined for the study. This data set, based on recent historical years, was combined with Xcel system data from those same years to create an exceptional “picture” of what the Xcel system operators would have seen had that wind generation already been built.
Further innovations were devised in terms of the analytical methodology for the study. Because of the nature of the underlying wind and system data sets, it was possible to “simulate” the operating environment and procedures utilized by Xcel operators. By appropriately defining a series of comparative cases, the expected operation cost increases incurred by Xcel energy for managing the variability and uncertainty of wind generation could then be calculated.
Areva T&D provided expert advice in the likely structure and operation of the developing wholesale energy markets in the region. In addition, modifications were made to their Dispatch Training Simulation (DTS) platform to allow it to be used for simulations of power system operation with and without wind generation at high resolution but over long time periods.
The results of the study were well received by the clients as well as the formal technical review committee which had been convened to oversee the project from the beginning. The project team was then engaged again by Xcel Energy, this time to conduct a similar assessment for the Public Service Colorado control area in and around Denver. The second study brought some new analytical challenges. At the current time, Public Service Colorado’s supply portfolio consists of nearly 50% gas-fired generation. Along with the questions regarding increased production costs due to the variability of wind generation, there was concern for how the relative unpredictability of wind energy deliveries would affect the process for nominating next-day gas deliveries for the generation fleet. The basic method used in the first Xcel study was extended to consider this critical fuel supply question, and allowed the economic impact of wind generation on the fuel acquisition process to be calculated as part of the overall integration costs.
As in the first study, a technical review team consisting of wind energy stakeholders and public utility commission representatives was assembled to oversee the project. Study results were then used by Xcel Energy to inform their strategy in an all-source bid review process.
Both of the studies for Xcel were highly visible efforts with a variety of viewpoints among the parties with some stake in the outcome. The EnerNex project team welcomed the insight, suggestions, and critiques of the project stakeholders, as it is our view that such levels of engagement and openness lead to a much better project outcome.
