Rethinking the traditional roles and interaction between the transmission and distribution grids is necessary to enable the envisioned high-DER future. As variable DERs provide additional services to the distribution grid, more accurate real-time forecasting is needed for the ISO or RTO to issue dispatch instructions. ISOs/RTOs also need additional visibility into distribution grid conditions. DERs have also begun to sell power directly to the wholesale market, but this function still requires electricity to be transferred across the transmission-distribution interface onto the transmission grid. In considering participation in multiple energy market, DER providers need additional information to optimize their market opportunities. Increasing levels of DER will require increased levels of operations and communications coordination to maintain safe and reliable grid operations.
More Than Smart operates a T-D Operations Interface Working Group, comprised of the California ISO, state utilities, and DER providers that evaluate a potential operations framework for coordination between the transmission and distribution grids.

The T-D Operations Interface Working Group originated in January 2016. 

Meeting Presentations and Material: