What exactly is CREZ? Why did the Texas Public Utility Commission (PUC) go through the CREZ process?


Senate Bill 20 (SB20) was introduced in the first special session of the 79th Legislature and was passed overwhelmingly in the House and unanimously in the Senate. This legislation implemented recommendations from the Governor’s Texas Energy Planning Council to continue and expand the state’s successful Renewable Portfolio Standard (RPS) program and encourage the continued development of the State’s vast renewable energy resources. The RPS target has always been intended as a floor, not a ceiling, allowing renewable energy development in Texas to grow. Since this visionary program was initiated, Texas has become a worldwide leader in renewable energy production.

SB20 additionally required the Texas Public Utility Commission (PUC) to consult with the Electric Reliability Council of Texas (ERCOT) and other appropriate regional transmission organizations to designate the best areas in the state for renewable energy development. These “Competitive Renewable Energy Zones (CREZs)” would be designated where both the renewable resources were optimal and land areas were sufficient to generate power from renewable energy. The PUC was then to develop a plan to construct the transmission infrastructure required to deliver the power from these CREZs to electricity customers across the state of Texas.

In designating the CREZs, the PUC was also required to consider the level of financial commitment by generators for each zone to determine whether to designate an area as a CREZ and grant a certificate of convenience and necessity (CCN) to a transmission service provider (TSP) for the construction of transmission lines. If the PUC issued a CCN, or ordered a utility to construct or expand transmission facilities, such construction and expansion could be included in the utility’s rate base. It is important to note however, that the CREZ process was never intended to exclude other areas of the state from wind energy development. The map on the left illustrates the original twenty-five CREZ nominations identified by ERCOT. Each of the original twenty-five CREZs is capable of generating 4,000 MW of clean, renewable energy. Wind developers were then asked to submit their top preferences for CREZ areas and provide evidence of financial commitment to develop these areas.

Developers predominantly prioritized areas where existing facilities and planned expansions faced transmission constraints, or areas where no transmission infrastructure was available at all. The map on the right shows the final five CREZs designated by the PUC based on this feedback and additional information provided by market participants. These five CREZs will have transmission capacity to accommodate a total of 18,500 MW of wind energy (6,000 MW is already in operation).

Potential Electricity Production on Windy Lands in Texas

Texas is blessed with abundant amounts of renewable energy resources. In wind energy potential, Texas ranks second in the country, only behind North Dakota. These maps illustrate the vast parts of Texas that can capture this powerful resource for the benefit of the entire state.

Wind Class Meters/Second (m/s) Miles per Hour (mph)
Class 2 5.6-6.4 12.53-14.32
Class 3 6.4-7.0 14.32-15.66
Class 4 7.0-7.5 15.66-16.78
Class 5 7.5-8.0 16.78-17.90
Class 7 8.8+ 17.90-19.69

Wind Characteristics 80 Meters above Ground

In 1995, the Texas State Energy Conservation Office published a study on renewable energy resources in Texas. The study analyzed characteristics of wind 50 meters above the ground. Today, the typical commercial wind turbine stands 80 meters above the ground. Even at the lower height of 50 meters, the table below points out that Texas contains enough class 4 resource to produce all of the electricity currently consumed in the state. Even when utilizing only class 5 and 6 lands, wind power could generate a significant portion of the state’s electricity.

An interactive map may be found at The West Texas A&M University’ Alternative Energy Institute.


Wind Power Class (at 50 meters) Area (km2) Percent of State Land Potential Capacity (MW) Potential Production (Billion kWh) % of Texas Electric Consumption
3 143,400 21.13% 396,000 86 371%
4 29,700 4.38% 21,600 48 100%
5 5,000 0.74% 21,600 48 21%
6 300 0.04% 1,600 4 2%
Total 178,400 26.29% 524,800 1,143 493%

Source: Texas State Energy Conservation Office


As manager of the State’s largest power grid, the Electric Reliability Council of Texas (ERCOT) was designated to collect wind data and nominate a number of CREZs (Competitive Renewable Energy Zones) based on transmission cost calculations for each CREZ.

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