Signaling that solar generation is set to expand rapidly on the grid operated by the Midcontinent Independent System Operator Inc, MISO has proposed that solar projects be required to register as "dispatchable intermittent" resources.
Renewable generators with resources classified as dispatchable intermittent can make offers in the real-time energy market based on the maximum megawatt level at which the resource can operate for five-minute intervals. The proposal would put solar on the same level as other generation resources, including wind. MISO said the proposal would improve grid reliability, enhance market flexibility and increase price transparency.
According to the Sept. 12 proposal from MISO's Market Subcommittee, the grid operator expects significant growth in solar capacity in the coming years. More than 9 GW of solar projects are close to securing interconnection agreements across the region, 6.7 GW of which are expected to come online in 2020. Nearly 52 GW of solar projects are in the planning phase for interconnection, MISO said.
Currently, 243 MW of solar projects are already registered as dispatchable intermittent resources in MISO, the grid operator said. Under a proposed transition plan, any new solar projects operating before the tariff rule is in place would have a two-year transition period before registration as a dispatchable intermittent resource is required.
Solar projects without a generation interconnection agreement before the tariff rule takes effect would have to register as dispatchable intermittent resources without any transition period, MISO said.
In 2011, the Federal Energy Regulatory Commission approved MISO's proposal for wind projects to register as dispatchable intermittent resources, and MISO's proposal said the grid operator expects the same operational and market challenges in its proposal to fold solar power into the real-time market.
MISO is taking comments on the proposal until Sept. 26 and expects to finalize the proposal by November so it can apply to FERC for a new tariff rule in December.
