Trevor Mihalik
Executive Vice President and Chief Financial Officer at Sempra
Thanks, Jeff. We continue to see robust opportunities to invest in our utilities and infrastructure businesses, resulting in a $40 billion five-year capital plan, which, as Jeff mentioned, is approximately $5 billion higher than the previous plan. I'll briefly summarize the expected spending at each business. At Sempra California, their five-year $21.4 billion capital plan is aligned with the state's priorities, which include safety, reliability, wildfire mitigation and sustainability with a focus on customer affordability. At Sempra Texas, the $15.3 billion capital plan includes our proportionate share of Oncor's $19 billion plan. Expected spending is in response to robust economic and demographic growth that is occurring across the state.
As Jeff mentioned, we expect this capital plan will likely be revised upward in the future. At Sempra Infrastructure, its new capital plan of $3.6 billion now includes Sempra's proportionate share of Port Arthur LNG Phase one, assuming Sempra Infrastructure's targeted 25% ownership level. To fund this growth, our customary approach is to start by reinvesting operating cash flows and raising debt financing at our regulated utilities in line with our authorized capital structures. We also evaluate other financing options, such as project-level debt and equity and asset sales before issuing common equity at the parent, all with the goal of solving for the lowest cost of capital. This approach is consistent with our past convention, where we've raised efficient financing through various asset and minority equity stake sales and our financing of Port Arthur LNG Phase one.
Overall, this approach of sourcing the lowest cost of capital has allowed us to maintain a strong balance sheet and continue to return capital through our growing dividend, all while providing flexibility to support infrastructure investments and deliver strong financial performance. The key takeaways for me as the CFO is that this is an exciting time for Sempra. And we have improved visibility to a portfolio of opportunities to capture strong growth across this decade. Please turn to the next slide. Over the next five years, our rate base is expected to increase at an average annual growth rate of 9% with over 70% dedicated to electric infrastructure. This growth reflects the positive macroeconomic tailwinds in our core markets and attractive regulatory environments.
Please turn to the next slide, where I'll speak to Sempra California's and Sempra Texas' accomplishments this quarter and their updated capital plans. Beginning with SoCalGas, you'll recall that in late 2022, the CPUC issued its decision for the Angeles Link memorandum account, which also directed SoCalGas to work with the state in its application to the DOE for hydrogen hub federal funding. In doing so, SoCalGas is honored to be a partner with more than 100 other entities to support California's application. According to DOE, clean hydrogen hubs are expected to create a network of producers, consumers and local connected infrastructure to accelerate its implementation as a scalable clean energy source. SoCalGas is excited to support the state's application and looks forward to advancing the development of critical new infrastructure to support cleaner fuels for the benefit of its customers. Further, customer affordability is a top priority.
That's why SDG&E has been working closely with regulators to proactively develop solutions to reduce bills while continuing to enhance customer safety and reliability. SDG&E is advancing several initiatives that we believe will improve the overall affordability of its services. First, it recently filed a joint proposal with the other two large investor-owned utilities in the state to redesign electric rates to include a fixed charge, which is intended to make electricity more affordable and encourage broader support for the electrification across the state. A proposed decision is expected in early 2024. Also, SDG&E announced that it submitted an application to DOE seeking up to $100 million in federal matching funds to support the strategic undergrounding and hardening of overhead power lines in and near federally recognized tribal nations land within a service territory. SDG&E would invest an additional $100 million towards this effort, subject to approval from the CPUC.
Exploring options to tap into federal funding for infrastructure hardening is a great example of how SDG&E is working to advance safety and reliability in a more cost-efficient manner for our customers. Further, the California ISO recently issued a draft 20-year transmission outlook, which included several important projects in SDG&E's service territory that would support further renewable integration and overall grid reliability. Within the draft plan, the projects identified meet both reliability and policy objectives. The estimated cost of these projects are approximately $500 million based on reliability needs and an estimated $3 billion for projects consistent with state policy, which will be subject to a competitive bid process. The draft plan is anticipated to be reviewed by the CISO Board later this month.
We're encouraged to see their outlook is beginning to incorporate the higher expected electrification loads that will be needed to further decarbonize the state in accordance with state policies. Additionally, we expect the ongoing general rate cases at SDG&E and SoCalGas to establish the critical foundation for meeting the future needs of customers. Importantly, our filings are centered around delivering cleaner energy, safely and reliability in alignment with California's sustainability goals. Based on the current schedule, we expect a proposed decision in the second quarter of 2024 with rates retroactive to the beginning of that year. In the meantime, SDG&E is continuing to execute a state-of-the-art wildfire mitigation plan, advancing the integration of utility storage and distributed resources and supporting electrification for the transportation sector.
For SoCalGas, Scott and his team are focused on continuing to make improvements in the safety and integrity of the natural gas system while preparing its infrastructure for the delivery of cleaner fuels. Please turn to the next slide. Moving to Sempra Texas. I'm pleased to report that Oncor is off to a strong start to the year. As Jeff mentioned, Oncor received a constructive final order for its base rate review in April, which preserved Oncor's equity layer at 42.5% and updated its ROE to 9.7%. As part of its decision, the commission recognized Oncor for its track record of excellent reliability of service, even with the extreme weather events that have occurred in its service territory.
This regulatory outcome has bolstered our confidence in the regulatory construct in the state. Having received the final order, Oncor updated its five-year capital plan for 2023 through 2027 to $19 billion with a view toward making critical investments that support growth in the Texas economy and benefits customers through improved reliability of service. Also, as a reminder, as part of Sempra's agreement to acquire Oncor in 2017, we committed to deploying $7.5 billion for the five-year period from 2018 to 2022. At the end of 2022, Oncor had invested nearly $12 billion over that same period or nearly 60% more than its 2017 regulatory commitment.
And now its five-year plan anticipates $19 billion of investments, which is 2.5 times its original regulatory commitment at the time of Sempra's investment. Increases to Oncor's new capital plan are expected to support: growing generation interconnections, which are primarily related to renewables and clean power; strong premise growth; grid resilience and reliability; and technology and innovation advancements on the grid. You've heard us talk a lot about the attractiveness of this market in the past. In part, it's because Oncor benefits from the efficient capital recovery tracker mechanisms that are designed to limit lag associated with its investments.
There is now pending legislation that we are following that could improve Oncor's capital efficiency even further. In particular, SB 1015, if passed, would provide for two DCRF filings per year instead of the one that Oncor currently operates under. Passage of the bill would reduce regulatory lag and further support Oncor's efficient deployment of capital. From an operational perspective, Oncor had another strong quarter with a 41% increase in active and retail transmission interconnection requests at the end of March compared to the same time last year. Also, premise growth continued to be robust in the first quarter, where Oncor connected 17,000 new premises. Please turn to the next slide, where I will turn the call over to Justin to provide an update on Sempra Infrastructure.