Ascend Helps NorthWestern Monetize Risk In S.D. Resource Plan

Ascend Analytics recently put its PowerSimm Planner software to great success for NorthWestern Energy in its formulation of a 10-year integrated resource plan (IRP) for South Dakota.

PowerSimm Planner helped NorthWestern realize value of adding highly flexible peaking resources to its generation fleet in the SPP and MISO market. Despite these markets having some of the lowest average energy costs in the country, Ascend uncovered a hidden opportunity to realize additional value through internal combustion units (ICU’s).

The ICU’s (Wartsila 50SG) attributes of no start-up costs and small heat rate penalty at minimum load provide substantial economic operating advantages over standard combustion turbines (GE 7FA).  These advantages are realized through capturing the more dynamic price signals of the 5 minute real-time energy market for energy and ancillary services.

“NorthWestern’s decision to enlist Ascend to provide the analytics for its South Dakota integrated resource planning (IRP) further solidifies our position as a leader in electric utility planning sing sophisticated modeling software to help power companies more cost-effectively predict and monetize unique opportunities,” Ascend Analytics President Gary Dorris said.

It marks the company’s second such collaboration with NorthWestern.  Last year, Ascend provided modeling support for NorthWesterns successful bid to acquire $870 million of hydroelectric generation in Montana.

NorthWestern also used PowerSimm to model supply portfolio, regional commodity prices, and energy resource characteristics in South Dakota.  The software introduced “meaningful uncertainty” into future simulations, capturing both the expected costs and risks of its portfolio there.

Traditional resource planning tools lack the sophistication of PowerSimm and fail to capture the extreme volatility and value of more flexible generating resources.  Other software planning models for IRPs fall short recognizing the value of flexible generating assets.

NorthWestern Energy concluded that current peaking options such as GE 7FA are not cost competitive with more flexible internal combustion engines (Wartsila 50 SG).  The additional value of a flexibility added an order of magnitude increase in profits.

Check out Ascend’s contribution to NorthWestern’s South Dakota resource plan via the utility’s website: Chapter 4 — Portfolio Modeling and Analysis

For more information, please contact Ascend Analytics at (303) 415-1400 at