Zonal and Nodal Modeling – What They Are and Their Functions
MARKET SIMULATION MODELING: Zonal and Nodal Modeling – What They Are and Their Functions
By Jason Atwood | Director of Business Development firstname.lastname@example.org
Part 2 of 4.
Are regional results sufficient or is greater granularity needed? Understand the two types of modeling and when they should be used.
Zonal modeling is a high-level perspective of the power planning grid. It examines a region of the country, which could be a state, multiple states, or a portion of a state(s). In grid planning, zonal analysis can be used for timeframes including current day to 30- plus years into the future to forecast generator operations, energy, capacity, and ancillary service prices. Zones are connected by links that represent the maximum amount of energy that can flow between them. Analysts can identify congestion between zones by examining the flow of these links but cannot determine congestion within a zone because the detailed transmission grid is not modeled. To analyze congestion within a zone, the user must examine the grid from a nodal perspective.
Resource expansion planning begins on the zonal level to determine which generation technology type is needed for future years, the forecasted costs of construction, and the appropriate time to build a generator. Upon these determinations, generators should be modeled and analyzed at the nodal level.
Nodal analysis introduces a power flow model into the simulation process which allows the examination of the grid at the bus (nodal) level. Nodal analyses are often used to examine one day to five years into the future. Beyond five years, nodal simulations are typically performed on a single year such as the tenth of fifteenth year in the future. LMPs are determined for each bus in the simulation including marginal congestion and marginal loss components. The congestion component allows the development of a transmission hedging strategy for financial transmission rights (FTR, CRR, TCR, ARR). In addition to providing pricing at each bus, nodal analysis can forecast pricing for each zone or modeled trading hub to determine a basis differential between a proposed generator bus and hub/zone. Transmission flows can be considered on each line or flowgate in the study. Nodal simulations determine where forecasted transmission congestion may occur and provides projected costs for it. They also provide data on generator operations and curtailment to help developers steer clear of chronically congested areas of the grid. Modeling details such as nodal topology and granular time steps are required to perform transmission planning. EnCompass software is fully integrated and can import the generation expansion plan into the market simulation model. It helps with resource adequacy decisions such as Loss of Load Hours (LOLH) and Loss of Load Expectation (LOLE). EnCompass also models daily gas prices and has hourly and sub-hourly solution intervals.
Both zonal and nodal analysis forecast price, fuel usage, emissions, and generator operations. However, nodal simulations provide a granular level of detail. Considering the millions of dollars required to construct generation, the additional steps of modeling on the nodal level should be performed to help mitigate the risks of siting a generator in a sub-optimal location.
Hourly and sub-hourly results provide beneficial information especially to companies that develop and operate their generation facilities. Sub-hourly simulation capability during the planning phase provides detailed forecasts of unit commitment and dispatch levels, which is most beneficial to facilities that can start and stop quickly. Once a generator is operational, sub-hourly simulations are pertinent in analyzing energy and ancillary service prices.
Whether analyzing generation, transmission or both, modeling the market is crucial for long-term power operation planning with multi-million-dollar assets.
The EnCompass software product is the industry leader in representing North American power markets and offers the ability to easily and thoroughly analyze changing market structures, zonal or nodal powerflow transmission representations, environmental compliance programs, price forecasting and resource planning applications. Don’t be limited by insufficient or outdated power planning software or software designed for different markets. Call or email us to schedule a demo to see what EnCompass can do for your organization.
Anchor Power Solutions provides planning software and consulting services for the power industry with a focus on market price forecasting, economic transmission analysis, integrated resource planning, budgeting, and risk analysis. Anchor Power Solutions developed EnCompass Software to accomplish all these functions in a single, easy-to-use system. For a custom demonstration, contact email@example.com.