The Electric Reliability Council of Texas Inc. added 535 MW of new gas-fired capacity in March, while generation interconnection requests for wind and coal projects surged, according to a monthly status report from the grid operator's system planning division.

According to the report, which also details activities related to new transmission and generation development as of March 31, the 535-MW Cedar Bayou 4 combined cycle in Chambers County, Texas, was the sole power plant to enter commercial operations in March. The power plant is jointly operated by NRG Energy Inc. and Optim Energy LLC, which is co-owned by PNM Resources Inc. and Cascade Investment LLC.

Total installed wind capacity remained unchanged at 8,065, since no new wind generation was energized in March, according to the report.

In total, four new generation interconnection agreements were signed in March, including: Invenergy LLC's 300-MW Sterling Energy Center wind farm in Sterling County, Texas; NRG Energy subsidiary Padoma Wind Power LLC's 150-MW Langford Wind Power project in Tom Green County, Texas; TECO Energy Inc.'s 50-MW gas-fired Texas Medical plant, also known as TECO Central, in Harris County, Texas; and E.ON AG subsidiary E.ON US Holding GmbH's 200-MW Panther Creek 3 wind farm in Concho County, Texas.

As of March 31, ERCOT is now tracking 51,897 MW of generation interconnection requests for wind capacity, a 2,141-MW increase from 49,756 MW as of Feb. 28. Generation requests for coal projects jumped to 9,731 from 8,126 MW, while gas requests rose to 27,488 from 27,187 MW in February.

In total, 105,175 MW of generation requests are in ERCOT's queue, up 4,052 MW from the previous month's report.

The report also detailed a number of transmission projects being reviewed by ERCOT's Regional Planning Group, noting that system planners are reviewing $1.01 billion of potential transmission improvements, up from $772 million being reviewed in February 2009.

American Electric Power Co. Inc. subsidiary American Electric Power Service Corp. submitted a $214 million project to construct several improvements in the Corpus Christi area. The project is in the comment period.

CenterPoint Energy Inc. submitted a $26.6 million project to expand the Zenith substation, add one 800 million volt-amperes autotransformer, connect Zenith to existing circuits near the Gertie substation and upgrade/reconfigure nearby 138-kV circuits. The project is in the ERCOT Independent Review.

The ERCOT board completed review of the Lower Colorado River Authority Transmission Services Co.'s $18.6 million project to upgrade and convert a 27.7-mile Flatonia-Moulton-Henkhaus-Shiner-Yoakum Gartner Road 69 kV transmission line to 138 kV. A Regional Planning Group acceptance letter was also completed for that project as well as for Energy Future Holdings Corp. subsidiary Oncor Electric Delivery Co. LLC's $15 million project to add a 138/69 kV autotransformer at Stanton East into the Spraberry to Big Spring 69-kV line and to rebuild the 138-kV line from Stanton East to Big Spring Switch.

ERCOT moved two projects to the independent review category from the comment period: the Lower Colorado River Authority Transmission Services Co.'s $11.6 million project to construct a new 6.2-mile transmission line from Highway 123 to Cushman substation, and its $12.9 million project to construct a new 7.8-mile transmission line between the existing GPI and Parkway substations. And ERCOT moved one project to the independent review category from the study period: a $4.3 million project submitted by Austin Energy to relocate the Decker to Techridge circuit to new right-of-way so that the existing structures can be utilized for the new Gilleland to Techridge circuit.