The face of natural gas demand is changing. The conventional Local Distribution Company (LDC) load characterized by predictable daily morning spikes and evening peaks is undergoing transformation as more natural gas power plants are constructed throughout the United States. Stricter environmental laws coupled with evolving industrial and commercial demands have given rise to peaker and combined-cycle power plants using natural gas as their source of fuel. This new type of demand is punctuated by the following obligations: Increased loads, Customer specified delivery load profiles, Quick start-up requirements, and Minimum pressure obligations by the pipeline. These are the new services that are being requested by the market from existing pipeline facilities. Meeting these additional requirements gives transient pipeline simulation an opportunity to become a more frequently used tool in the capacity market place. As pipeline transportation planners within the El Paso Corporation, we have experienced a tremendous growth in pipeline projects to deliver incremental natural gas volumes to serve as fuel for new gas-fired power generation. Consequently, it was a business imperative to model and quantify the impact of the power plant load on a pipeline system. This paper discusses the use of transient pipeline simulation in ensuring that the Power Plant Client's needs are met while protecting the pipeline's operational and financial objectives. Transient analysis was used successfully and effectively in this instance to: Design incremental pipeline facilities to meet the new demand requirements of power plants, Identify critical operating conditions for Gas Control to operate the pipeline effectively in delivering these volumes at the needed pressures and hourly rates, and Provide Marketing and Business Development with assessments to adequately price this service of providing a power plant load.
In 2001, the total US net summer generating electric capacity was 848,000 megawatts, an increase of 4.5% from 2000 [Reference 1]. The expected growth by 2020 in power generation capacity is 400,000 megawatts, of which 92% of this new growth load is expected to be serviced by gas-fired turbines. Gas consumption for power generation is predicted to grow from 6 TCF (~ 170,000 million cubic meters) to 17.4 TCF (~ 493,000 million cubic meters) by 2020 [Reference 2]. Assuming evenly daily flow rates over the entire year, this growth equates to 31 Bcf/d (~ 878 million cubic meters per day) of pipeline transport capacity that has to be provided by the pipelines. This incremental transport capacity is 27% of an approximate US pipeline capacity of 113 Bcf/d (~ 3,201 million cubic meters per day) [Reference 3]. While many of the previously mentioned growth predictions were made prior to the US economic slowdown and thus should be tempered to account for the slowdown that has occurred within the last few years, projections for world use of natural gas remains intact and strong.
