Ann de Rouffignac
OGJ Online
The Dallas-Fort Worth area of Texas could face a "voltage collapse" as early as 2003, unless new generation and transmission lines are built to serve the region, the Public Utility Commission of Texas warns in a background paper �Meeting the DFW Challenge.�
Despite the absence of public discussion about electric reliability problems in Texas, the PUC is now holding a public forum Nov. 7 to hear proposed solutions from consumer and industry groups. The commission projects a shortfall in electricity during peak times for the Dallas-Fort Worth (DFW) area as early as 2003.
The area is transmission constrained and faces tough new air pollution rules for its small fleet of old gas-fired generating plants some of which may have to be shut down. The DFW Metroplex area imports 65% of its electricity needs from outside the region. If plants are closed, the area could have voltage support problems, meaning reliability could be breached on days of high demand, according to the paper.
The DFW area is classified as not meeting federal clean air act standards (a non-attainment area) for certain air pollutants. Some of the oldest gas-fired plants with the highest rates of Noxemissions will have to be retrofitted or shut down to meet federal guidelines by 2003. Even further reductions in Nox emissions will be required by 2005.
The new environmental rules will make construction of new generation within DFW very difficult, the PUC says. The Electric Reliability Council of Texas (ERCOT) and the PUC are encouraging solutions that will result in reductions in peak demand as well as improvements to transmission and generation.
Tight supply
DFW uses about 15,000 Mw of power but only has 5,800 Mw of internal generation. The balance is imported through the transmission system. Load growth has averaged 2.9%/year over the last 6 years for the Metroplex and is projected to keep growing at 3.4%.
New merchant plants are under construction in the North Texas region but most are being built outside the transmission constrained region of DFW. Inside the Metroplex, there is little land available for greenfield generation projects and the public has little stomach to allow new plants to be constructed. Some of the old gas-fired plants within the DFW area are not attractive investment repowering prospects.
Old plants
Most of the plants that are located within the nonattainment zone of DFW have completed or will soon complete the modifications to reduce Nox emissions to the levels required by the first set of environmental rules. But newer rules require certain DFW power plants to be retrofitted with new Nox reduction devices, reduce output ,or shut down. If the retrofits are not deemed cost effective by the PUC, the costs cannot be collected from customers.
�It is not yet known whether and how much existing generation could fail the retrofit cost-effectiveness test and thus require retirement,� the report states.
The risk of voltage collapse in DFW (shutting down the electrical system in certain areas to avoid a total collapse) is real�especially if many plants are shut down for environmental reasons and the load continues to grow, the PUC says.
Proposed solutions
Transmission alone will not fix the problem in DFW. ERCOT advises the PUC that a certain amount of environmentally acceptable generation will have to be available within DFW to maintain reliability of the system, according to the report.
The PUC says the most well received proposals will be those that include the following:
� Plans that can be implemented between 2001 and 2005.
� Plans that have long lasting operational value.
� Proposals that don�t require issuing a certificate of convenience as in the case of new transmission lines.
� Proposals that don�t require acquisition of new right-of-way.
� Non-traditional proposals that are competitive with traditional solutions.
� Solutions cannot require long outages of either transmission or generation.
� Solutions that cut demand at peak times and promote energy efficiency are encouraged.
� Distributed generation and price-responsive demand mechanisms plans are also welcome.