Lisa Barton
President at Alliant Energy
Thank you, John. It is an honor to be entrusted with the future growth and stewardship of this industry-leading company. Since joining Alliant Energy it has been abundantly clear that our organization lives and delivers on its purpose, day-in and day-out. In fact, the organization's commitments and alignment with its purpose is what drew me to Alliant Energy. I recently had the opportunity to meet with our team in Janesville, Wisconsin and was struck by the level of engagement and ideas our frontline teams brought to the table to better serve our customers.
As you know, we are actively undergrounding our lines to provide greater reliability and system resiliency. In this conversation, our employees were offering suggestions to prioritize the undergrounding of overhead facilities located in backyards. They were sharing how these facilities can be difficult to get to require specialized equipment and due to the nature of the terrain restoration can be time-consuming factors that can be avoided by undergrounding. I appreciated their ideas and focus on our customers, with the goal to reduce outages and restoration times, a notable example of the level of engagement and the connection with our purpose to serve our customers and build stronger communities.
Our teams' passion for innovation and dedication to serving our customers and communities is consistent across the company in both Iowa and Wisconsin. And it's precisely why it is a true privilege to take on the role of CEO and to serve as a member of our Board of Directors. Before going into the capex plan I would like to underscore our organization's ongoing role of being at the forefront of the clean-energy transition, by providing our customers with access to a cleaner and more diverse energy mix. In 2022, approximately 40% of the energy we supply to retail customers was generated by zero fuel-cost renewable resources. This number will quickly grow with the addition of 1.2 gigawatts of solar set to be in service by the end of 2024.
Across our portfolio of new generation we are successfully bringing projects online investing in energy security, creating local jobs, and providing valuable tax revenues for the communities we serve. In Wisconsin, we expect to bring approximately 600 MW of solar online by year end. In Iowa with an advanced ratemaking ruling in hand for our planned 400 MW of solar we will continue to expand our investments in resilient, clean energy resources for our customers and communities by bringing this new generation online. In addition to solar we made great strides in our energy storage plans during the third-quarter.
We commissioned our first microgrid project in Richland County. We secured regulatory approval in Wisconsin for 175 MW of battery storage projects in Wood and Grant counties which will be paired with our solar investments. In addition, we secured approval for 99 MW of battery storage at our Edgewater Generating Facility site to take advantage of our existing interconnection and additional tax credits associated with repurposing a brownfield site. These storage projects, strengthen the performance of our generation portfolio increased, grid resiliency, and improve reliability. These investments tied to the capital expenditures, John mentioned which are essential to deliver a diverse mix of energy with the enhanced reliability, our customers depend on.
Looking-forward, we have refreshed our capital expenditures plan over the next four years by $600 million. These investments expand our dispatchable generation resources include wind repowering for approximately 500 MW of our legacy wind fleet bringing efficiency savings to our customers and additional tax benefits through the Inflation Reduction Act. This plan reflects increased investments in American Transmission Company to support expansion of transmission within the State of Wisconsin and underscores our commitment to enhancing grid resiliency and undergrounding.
Our updated customer-centric capital investment forecast through 2027 contributes to a solid 8% rate base growth through 2027. Approximately 55% of our investments over the next four years will be in generation, a strong demonstration of our commitment to a diverse clean, reliable, and resilient energy future for our customers. We take considerable pride in the balance of resources in our generation portfolio. We will continue to invest in renewables over the Five-Year planning period. We also recognize our resource plans need to address MISO's resource adequacy needs.
This is why you see greater additional capital expenditures for gas projects, when compared to prior plans. In 2024, we will continue our transparent process to engage with regulators and stakeholders as we update and revise our resource plans to adapt to changing reliability needs. Our plans include new dispatchable natural gas resources, capacity and efficiency improvements, and investments to ensure resiliency and availability of fuels during extreme weather and other disruptions. Specifically, our focus will be on improving the capacity and efficiency of our existing units in both Iowa and Wisconsin as well as repurposing sites where coal units will be retiring in the next five years.
We will be investing in new flexible natural gas resources to complement our investments in battery storage and renewables. We will also invest in reliability, natural gas supply in both Iowa and Wisconsin to address concerns about reliability and resiliency during extreme weather. This includes exploring opportunities to enhance resiliency through gas, LNG, and electric storage technologies. Now switching to regulatory matters. First, we appreciate the certainty the IUB's advanced rate-making decision provides. Last month the IUB approved a minimum ROE of 10.25% over the 30-year life of 400 MW of solar. We remain confident in the advanced ratemaking process and look-forward to submitting additional filings following our stakeholder and regulatory engagement process next year.
Staying in Iowa, we recently filed our forward test year rate review. Our forward-looking electric and gas rate review focuses on our plans to strategically invest in a cost-effective and diverse energy mix coupled with grid modernization to deliver and more reliable, sustainable, resilient and secure energy future for our Iowa customers and communities. With our steadfast focus on keeping customer value top-of-mind we continuously strategize to take proactive measures to manage costs and to meet customers' ever-changing energy needs. This is the reason why we have asked for a two-step increase. The investments we are making in this state[phonetic] are expected to reduce the number and duration of outages, improve safety, lower operating maintenance and fuel expenses, while reducing the impact of fuel price volatility.
Shifting gears to our rate review in Wisconsin. The procedural schedule is now complete and we await a decision from the PSCW to place new rates into effect on January first. We believe the PSCW staff testimony was constructive and gave the commission, a good starting point for their decision. I will now turn the call over to Robert to provide insights regarding our financial results, guidance and a few additional regulatory matters.
