Thursday, May 5, 2016

Gas Turbine Power Plant - Low Cost and Renewable Friendly

Subtitle: CCGT at One-tenth That of Nuclear

A few weeks ago, Siemens AG announced the award of an $800-plus million turnkey contract to supply a Combined Cycle Gas Turbine (CCGT) power plant to produce 940 MW for Lordstown, Ohio.   The new power plant is to have a 2-1 configuration, with two gas
Aerial view of a CCGT near Houston, TX
with 2 gas turbines (upper right) and 1 steam turbine
Dedicated cooling tower is at lower left
turbines supplying heat to a heat recovery steam generator that provides steam to a steam turbine.  Each gas turbine and the steam turbine have their own generators.  From the news release (see link):

"Siemens will deliver a complete power plant solution for the (Lordstown) facility, which will feature the record-breaking H-class (gas turbine) technology designed for fast, flexible operation to support renewable integration. The scope of supply includes two gas turbines, one steam turbine and three generators. Slated for operation in summer 2018..."

A bit of math shows that the plant's capital cost is approximately $900 per kW, which is less than one-tenth that of a new nuclear power plant (those costing upwards of $10,000 per kW).   The construction time is also a bit more than two years, which compares more than favorably to a nuclear power plant that typically requires ten years or more.    This power plant is essentially the same size as a new nuclear power plant, with 940 MWe compared to a Westinghouse AP-1000 of 1100 MWe.  

And importantly, the CCGT plant will achieve a bit more than 60 percent thermal efficiency.  The heat rate (LHV) is 5690 Btu/kWh.  

Also, the plant will have design and control system features to provide load-following so that renewable energy systems can be more easily integrated into the grid.    In the Ohio-Pennsylvania region, the renewable energy is mostly wind-turbines. 

The plant is located between Cleveland, Ohio and Pittsburgh, Pennsylvania near the states' border.  The local grid is the PJM, a major grid on the US East Coast.  PJM has wind-turbine resources that can produce in excess of 5,000 MW.  see link to PJM website.

This is exactly as predicted on SLB. (see link)  This is the future of Midwest and East Coast generation, as coal power plants are retired, nuclear power plants are retired, and CCGT with wind-turbines are installed.  

UPDATE:  The installation of CCGT for power production is nothing new; that is not the point of this article.  Such plants have been built for decades, including the one in the photo above, which was built in 1980 in a chemical plant near Houston, Texas.  The pictured CCGT actually has a much higher thermal efficiency of more than 80 percent because the steam to the chemical plant is provided from the steam turbine.    

This article is primarily a reference to show to the nay-sayers (and they are legion) that modern CCGT plants are being ordered and built, they cost less than $1000 per kW, they do have 60 percent or higher efficiency, and they are specifically designed to complement the variable output of wind-turbines.  

One minor point was corrected in this update: the CCGT for Lordstown's construction period is a bit more than 2 years, not a bit less.  --- end Update. 

Roger E. Sowell, Esq.
Marina del Rey, California

copyrignt © 2016 by Roger Sowell, all rights reserved

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