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HomeMy WebLinkAbout2026-031 Calendar Year 2025 Renewable Energy Supply GoalMay 29, 2026 Report No. 2026-031 INFORMAL STAFF REPORT TO MAYOR AND CITY COUNCIL SUBJECT: Calendar Year 2025 Renewable Energy Supply & Goal EXECUTIVE SUMMARY: For calendar year 2025, DME achieved a power supply of 100% renewable energy. However, the monsoon season in far west Texas in late spring to early-summer of 2025 caused some disruption to solar production due to the cloud cover in the region. DME purchased additional Renewable Energy Credits (RECs) to ensure 100% renewable energy power supply. BACKGROUND: DME previously received approval from City Council to recognize the use of RECs to meet its 100% renewable energy goal as mandated by the Denton Renewable Resource Plan. Calendar Year 2021 was the first year that DME achieved its 100% renewable energy goal and that achievement included the use of RECs. DISCUSSION: DME Renewable Energy Supply Planning – Compliance with the requirements of the Denton Renewable Energy Plan (DRRP) is measured on a calendar year basis. This compliance period is a direct result of the accounting and crediting of RECs by the Electric Reliability Council of Texas (ERCOT) which provides a third-party independent verification of renewable energy credits for all market participants. Consequently, when DME forecast the number of MWhs of renewable energy required to demonstrate compliance with the DRRP, it spans two fiscal years. For calendar year 2025, the number of expected MWhs served for the months of January through September 2025 were forecasted in April of 2024 as part of the fiscal year 2025 budget. The remaining months of October through December 2025 were forecasted in April 2025 as part of the fiscal year 2026 budget. The Energy Management Organization (EMO) uses weather normalized forecasts to predict the amount of energy to be served in the City of Denton and the generation expected from our renewable resources under long-term Power Purchase Agreements (PPAs). Renewable energy output from our contracted resources are a function of wind speed and duration and hours and intensity of solar irradiation during each day. Forecasting these quantities is based upon proprietary algorithms that use historical correlations of wind and sun to forecast output from each of our contracted resources. Given the volatility of weather, the EMO recognizes that forecasts are likely to be off from actuals but in order to maintain the statistical integrity of the load and generation forecasts, this analytical approach is considered best practice in the electric utility industry. May 29, 2026 Report No. 2026-031 For calendar year 2025, the EMO projected that the total DME served load would be 1,891,756 MWh. Actual calendar year 2025 load served was 1,789,266 MWh, or 5.42% less than forecasted. For the calendar year, the EMO projected that renewable energy supply under contract would not be sufficient to meet the forecasted load due to the Delilah solar project delay and eventual default. As DME became aware of the potential shortfall, RECs were purchased from the market to make up the shortfall. Renewable Energy Credit Inventory – ERCOT, as the market administrator for RECs, issues RECs to each renewable energy generator monthly. However, Retail Energy Providers (REPs) who provide contracted energy in the competitive retail market areas of ERCOT are not required to demonstrate compliance with the renewable energy portfolio standards until May 1 of the year following the compliance year. Because the REC market was developed with this compliance date in mind, renewable energy resources do not generally finalize their REC transactions until mid-April of each year. DME’s contracted renewable energy resources do not post their RECs to DME’s REC account at ERCOT until mid-April. Consequently, DME does not know the actual level of RECs officially allocated by ERCOT to each renewable energy resource and those resources are trueing up their ERCOT accounts into April of each year. Actual Load Served and Actions Taken by EMO – As previously stated, DME purchased 1,789,266 MWh from ERCOT for resale to retail customers in calendar year 2025. With an ERCOT REC inventory of 1,175,737 for the calendar year, DME’s account was 613,529 or 34.3% short against the actual load served. To balance the account, DME purchased this shortfall from the market to achieve 100% renewable energy supply for the year and to again achieve compliance with the DRRP goal. The EMO believes the actions taken this year to demonstrate compliance with the DRRP are prudent and consistent with electric industry best practices. The processes and procedures used to demonstrate compliance are fully auditable and are consistent with the findings and recommendations of the City of Denton’s March 14, 2022, EMO audit. The following table provides a historical recap of this goal: Calendar Year Load Served (MWh) Renewable Energy (MWh) RECs w/o Energy (MWh) Total Renewable (MWh) Renewable % 2021 1,593,440 1,343,789 262,800 1,606,589 101% 2022 1,750,135 1,396,335 353,800 1,750,135 100% 2023 1,749,737 1,480,144 269,593 1,749,737 100% 2024 1,776,322 1,375,792 400,530 1,776,322 100% 2025 1,789,266 1,175,737 613,529 1,789,266 100% May 29, 2026 Report No. 2026-031 STAFF CONTACT: Jose Gaytan DME Executive Manager of Power Supply (940) 349-7528 Tony Puente DME General Manager (940) 349-8487 REQUESTOR: Staff Initiated STAFF TIME TO COMPLETE REPORT: 2 hours PARTICIPATING DEPARTMENTS: Denton Municipal Electric