Midcontinent Independent System Operator (MISO), an American regional transmission organisation, has secured approval from its board of directors to invest $10.32bn in 18 transmission projects in the US Midwest subregion.

The organisation said that the board of directors’ approval was unanimous for the investment in the Tranche 1 portfolio of long-range transmission projects. Put together, these projects will have over 3,218km of transmission lines.

MISO is planning four tranches of projects under its long-range transmission planning (LRTP) process. Tranche 2 will be focused on the MISO Midwest Subregion, Tranche 3 will be on MISO South, while Tranche 4 is planned to address the limitations on exchange of electricity between the subregions of MISO Midwest and South.

The organisation said that the critical transmission projects are required to start integrating new generation resources as outlined in its member and states plans. The projects will also help boost resiliency in the face of severe weather events, said MISO.

It claimed that existing transmission corridors have been used for planning the portfolio of transmission projects. This will bring down the impact on local areas and communities, reduce construction costs, and quicken time for implementation, said the organisation.

MISO CEO John Bear said: “We appreciate the spirit of collaboration and the hard work that MISO members and stakeholders have invested in these projects and look forward to continued discussion around future tranches.

“We also recognise the effort and strong support for LRTP from various regulators and policymakers in the states – including state utility commissions and governors.”

The largest of the 18 planned transmission projects in Tranche 1, in terms of investment, is the Tremval – Rocky Run – Columbia project. Involving an investment of $1.05bn, the Tremval – Rocky Run – Columbia project is targeted to begin operations in 2029.

Another project in Tranche 1 is the $970m Iron Range – Benton County – Cassie’s Crossing project, which has an expected in-service date in 2030.