To provide added assurance of grid reliability in the face of ever-greater use of renewable resources, Portland General Electric (PGE) on Tuesday proposed an updated integrated resource plan (IRP) for Oregon, with more than half of added power supplies coming from natural gas-fired or other forms of dispatchable generation.

While the IRP emphasizes more efficiency use, demand response and renewables, or “sustainable” resources, PGE CEO Jim Piro also noted that the plan addresses the need for safe, reliable and affordable forms of power supplies, too.

The latest IRP calls for 375-550 MW of year-round, baseload resources.

“This plan reflects our assessment of the best balance of cost and risk for our customers as called for in the PUC’s IRP process,” said PGE’s Maria Pope, senior vice president for power supply. Pope said PGE has identified strategies designed to reduce environmental impact while meeting customers’ needs for affordable and reliable power.

The IRP includes a four-year action plan for acquiring new resources, analyzing long-term expectations for the power utility’s resource needs and its portfolio performance. It calls for adding by 2020 a minimum of 135 average MW (aMW) of energy efficiency as well as up to:

Along with seeking this mix of resources, PGE has to pay close attention to energy management, a challenge of adding more renewable resources while still incorporating the gas-fired and other baseload resources needed to balance increased increments of wind and solar power on the grid, Pope said.

During the recent third quarter earnings conference call, Piro noted the company needed to continue to develop “flexible, dispatchable resources” that could be ramped up and down quickly to complement renewable power and ensure reliability.

Oregon Public Utility Commission (PUC) staff and stakeholders have six months to review, comment and make recommendations on the proposal before making a final determination to the commission.

If the IRP is finalized, PGE and the PUC would work out a bidding process to solicit project proposals from the renewable, hydroelectric, gas-fired generation, geothermal power, energy storage, and merchant power sectors.