Xcel’s Colorado unit describes changing mix of power sources

Some changes in how it plans to retire or fuel switch coal-fired capacity and how it plans to add new wind capacity are covered in an Electric Resource Plan update that Public Service Co. of Colorado filed Oct. 31 with the Colorado Public Utilities Commission.

In October 2011, this Xcel Energy (NYSE: XEL) subsidiary filed its 2011 ERP, with the Oct. 31 filing an update of that plan.

Phase 1 of the 2011 ERP is still under review by the commission with hearings that began on Oct. 29 and are scheduled to end Nov 9. So, this update summarizes the existing status of the ERP under the limitation that more certainty will not materialize until the conclusion of the Phase 1 review process.

The ERP update noted two recent developments in the context of the utility’s resource position.

  • On July 5, the company filed an application with the commission seeking approval for: retirement of the 109-MW Arapahoe 4 coal unit no later than Dec. 31, 2013; a new ten-year, 118.8-MW purchase power agreement with SWG Arapahoe LLC, under which PSCo will purchase the output from Arapahoe Units 5-7 from Jan. 1, 2014, through Dec. 31, 2023; and a natural gas sales agreement with SWG Fountain Valley Gas LLC, under which Public Service will sell natural gas for the Fountain Valley generation facility.
  • On July 5, PSCo also filed an application with the commission seeking approval to acquire the gas-fired Brush generating units 1, 3 and 4.

PSCo’s current power supply portfolio consists of both company-owned plants and purchased power capacity and energy. In 2013, these sources will provide approximately 7,384 MW of net dependable capacity.

New additions recently approved by the commission as well as proposals which have not yet received approval include:

  • The company’s Arapahoe 4 coal unit is currently scheduled to switch to gas-only generation by Jan. 1, 2014, and operate as a gas peaking unit through 2023 under the commission-approved the Clean Air-Clean Jobs Act docket. PSCo has however filed an application with the commission to retire Arapahoe 4 by Dec. 31, 2013, and replace the capacity with the PPA agreement with SWG Arapahoe and the gas sales agreement.
  • The current PPAs for the three Brush units terminate in 2017 (Brush 1 and 3) and 2022 (Brush 4). PSCo applied with the commission to terminate the existing Brush PPAs and assume ownership of the assets.
  • The company requested approval of a 150-MW energy exchange agreement with PacifiCorp replacing the 176-MW Long Term Power Supply Agreement. The commission has approved the energy exchange agreement.
  • In 2012 several PPAs expired as planned. In August, the PPA with Fountain Valley expired and in September the PPA for Valmont 7 and 8 and Arapahoe 567 expired. Together these three PPAs supplied about 440 MW of net dependable capacity.

The status of projects selected to meet resource needs, including PSCo-owned owned generation and new generation agreements, are as follows:

  • The 2009 All-Source Solicitation resulted in the selection of 700 MW of additional wind and 60 MW of central solar. The Cedar Creek II (250 MW) and Cedar Point (250 MW) wind projects both entered service in late 2011. The remaining 200 MW of wind capacity was filled by the acquisition of Limon I in the 2011 Wind RFP. Limon I is scheduled to enter service no later than the end of 2012. Two 30-MW central solar plants, Cogentrix of Alamosa and San Luis Solar, entered service in early 2012.
  • In August 2011, PSCo requested approval, which it later got, for a PPA for 200 MW of wind from the Limon II wind project outside the ERP process. The Limon II wind facility is scheduled to enter service no later than the end of 2012.

As noted in the 2011 Phase 1 filing, the company has submitted both a ‘Wind Induced Coal Plant Cycling Cost Study’ and a ‘2GW and 3GW Wind Integration Cost Study’ with the commission. The company said it plans to use the results from both studies as part of the bid evaluation process in Phase II of the ERP.

About Barry Cassell 20414 Articles
Barry Cassell is Chief Analyst for GenerationHub covering coal and emission controls issues, projects and policy. He has covered the coal and power generation industry for more than 24 years, beginning in November 2011 at GenerationHub and prior to that as editor of SNL Energy’s Coal Report. He was formerly with Coal Outlook for 15 years as the publication’s editor and contributing writer, and prior to that he was editor of Coal & Synfuels Technology and associate editor of The Energy Report. He has a bachelor’s degree from Central Michigan University.