Current Utilities Infrastructure Projects

The university has added approximately 2 million square feet of new facilities since 1998 that stressed the Utilities and Energy Management Department's ability to address the reliability and cost effectiveness, to which the campus has grown accustomed.

The primary issues affecting reliability and cost were a wooden cooling tower (#1), built in 1958, that supports two steam turbines and other key plant ancillary equipment, the 2 x 56 MVA Harris Substation that had exceeded the N-1 reliability standard for stand-by power from Austin Energy and related switchgear, some of which was over 50 years old. In addition, firm capacity was 48 MW, which is less than the campus peak electrical demand of 56 MW. This was compounded by key generation equipment that dates back to 1945 and a tradition of only one campus-wide electrical outage in 35 years.

The department thus embarked on three interrelated projects worth $45.7 million to replace Cooling Tower #1, upgrade the Harris Substation and related switchgear in the substation and power plant to address 30 years of projected campus growth, and the addition of a new 25 MW steam turbine.

These three projects were extremely challenging technically and because systems had to be replaced without affecting service to the campus. To accommodate tight time constraints, phasing in of new equipment, and coordination with energy supply to the campus, the projects were managed in-house. The engineering design contracts were broad to proceed from feasibility studies to commissioning services seamlessly, the large equipment was pre-purchased by the university using best value procurements and provided to the contractor, construction contracts and equipment deliveries were carefully structured to address risk, the transfer of accountability of delivered equipment, and construction phases.

Cooling Tower #1

This wooden tower originally was originally constructed in 1958 and was becoming very unreliable. For example the tower was constructed with wooden pipe headers that were leaking more water than not. This project was challenging because it was located between two power plant buildings and was surrounded by live plant systems. The new tower also had to be increased in capacity to handle the addition of the new 25 MW steam turbine, in addition to existing systems, and still fit in the existing tower footprint. This project was completed in August 2003 using a fiberglass tower and is automated to interface with the existing power plant control system.

Harris Substation and Switchgear Upgrade

The existing substation consisted of a 2 x 56 MVA transformers and related distribution switchgear on a site slightly less than one acre. It is located between a dormitory, parking garage, 9,000 ton chilling station, and law school. To upgrade to the needed 4 x 50 MVA transformer Gas Insulated Switchgear (GIS) technology was the only system that could fit in this limited area. Typically, an open-air type outdoor substation of this size would require a footprint of 3.5-4 acres. An alternate site was not possible due to existing underground distribution interfaces at the existing substation that would be too costly to relocate.

Before we could begin, the 69 KV portion of the substation belongs to Austin Energy (AE), so a construction agreement with AE was necessary that included the requirement of GIS equipment. The construction delivery process was complex because AE and UT used their own general contractors, and then there was a need to use AE's contractor to perform some work for UT. A single contractor would have made managing the project easier, but available funding for both parties and project time constraints made a single contractor delivery difficult.

Also, to replace the substation, twelve sections of switchgear at the substation and power plant had to be replaced. This was a major challenge since campus loads will not tolerate any outages. This forced careful scheduling being accomplished in 15 stages so that all electrical service can be maintained, and campus generators kept on-line, thanks to the existing installation having redundant switchgear line-ups.

The finished substation has N-1 redundancy through 2030, was completed on-time and within budget, without having impaired the delivery of electricity to the campus (except for a two hour outage affecting 40 buildings caused by a tripped 1965 gas turbine), electrical equipment on the campus electrical grid can be operated with or without generation, and includes a Supervisory control and Data Acquisition System that will trend, and archive operating data and allow for future control considerations.

New 25 MW Steam Turbine

The Hal C. Weaver Power Plant consisted of 85 MW of generation with equipment that ranged in age from 1988 to 1945. Firm capacity remaining, should the largest generator fail was 48 MW. With a campus load peak of 56 MW and projected load growth of a peak of over 60 MW in the next eight years it became important to improve total and firm capacity. Also because of the increased load, the existing 25 MW steam turbine could never be shut down for maintenance.

This project to install a new 25 MW steam turbine allows for a back up to the largest existing 1978, 25 MW steam turbine. The new turbine is about 9% more efficient than the existing unit, improves the firm capacity to about 73 MW, and pays for its own debt service over the life of the turbine with efficiency savings.

The installation of the new turbine was very challenging due to tight space constraints within the existing plant. The site chosen is an addition to building PPA that houses existing generation, but within the footprint of the power plant complex. The turbine project required a temporary closing of 24th Street which is key transportation artery of the campus, shipping the turbine from Germany via river to seaport and from US seaport via truck to Austin, erecting a temporary 70 ft high, 300 ton gantry crane to place the turbine on a 5 ft thick concrete table top 20 ft in the air, and running up to 30 inch diameter piping from the new cooling tower, two buildings away from this site.

End result of this project is a new state of the art steam turbine housed in building that blends in with the surrounding campus that will support the campus load for many years to come and as the cost of natural gas escalates over $4.00/ MMBTU will reap savings beyond the debt service.