The proposed screening-level renewable energy zone (REZ) analysis tool aims to assist resource planners and regulators in evaluating the relative attractiveness of geographically broad renewable resource options in a simple, transparent manner. The tool would calculate the delivered cost of in-state and out-of-state renewable energy resources from identified REZs to load service entity areas. It would also highlight opportunities for transmission collaboration between load service entities and potential competition for limited renewable resources. The tool would utilize default assumptions that users could modify to evaluate different scenarios.
6. Power Delivery Tool Development: Review of Previous Work Lawrence Berkeley National Laboratory Black & Veatch Generation & Transmission Modeling Work Group
24. Wind Solar Load Flow CASE A WREZ Delivery Scenarios Other CASE B CASE C INCREASING COMPLEXITY Gas-at-load Remote Gas
25. Screening-Level REZ Analysis Tool: Straw-man Proposal Lawrence Berkeley National Laboratory Black & Veatch Generation & Transmission Modeling Work Group
47. Primary WECC Transmission Paths BUCKLEY SUNDANCE FT. PECK PEACE CANYON MICA VANCOUVER SEATTLE PRINCE RUPERT AREA AREA COLSTRIP BOISE PORTLAND AREA MALIN TABLE MTN ROUND MTN SALT LAKE CITY AREA MEXICO EL PASO AREA DEVERS LUGO SAN FRANCISCO MIDPOINT AREA LOS ANGELES AREA ALBUQUERQUE AREA NAVAJO DENVER AREA MOJAVE HOOVER PHOENIX AREA LANGDON HOT SPRINGS HELLS CANYON CHIEF JOSEPH BURNS PINTO FOUR CORNERS SHASTA LANGDON CANADA UNITED STATES
-Important to consider how the objectives of these analyses overlap with the objectives of the REZ tool - All of the analyses, to some degree, consider the bus-bar cost or a resource that requires new transmission, the cost of the new transmission, and the value of the energy sent over the transmission line -The first two that will be discussed are analyses that were not done using spreadsheet models, but they do address the question of how to determine which renewable resources and transmission lines are most attractive -Next two models focus on California as the load, then evaluate various options to obtain renewables (both in-state and out-of-state) -Final two models focus more on evaluating specific transmission lines (single source, single sink)
Overall, the idea of a transmission line is that you want to access distant resources that are more valuable than local resources. Build transmission lines if the value of the power accessed is more than the delivered cost of that resource. Three key components to this decision: bus-bar cost, transmission cost (sum of two is delivered cost) and market value adjustments
First two: non-spreadsheet analyses that provide useful guidance on what is driving transmission development ERCOT evaluated different transmission options to various CREZ zones to determine which options were most economically attractive. Value analysis: very detailed production cost modeling of new wind in each CREZ Bus-bar cost: simplistic assumptions for wind capital cost Cost of transmission: detailed power flow and economic dispatch modeling or several different transmission solutions for each resource level and location (over 60 transmission upgrades were considered for one CREZ alone!). Transmission criteria was that it reduce the level of wind curtailment to below 2% for all wind
Based on their results, I estimated the relative ranking of each option in $/MWh of wind terms. Ranking was based on the formula: Bus-bar cost + transmission cost – market value adjustment. Options that are most attractive have lowest ranking cost
WinDS is a optimization model – similar to NEMS but it includes detailed modeling of wind. ReEDS is under development and includes multiple resource types Wind resources are selected if that wind resource is the least cost option including transmission cost. Up to 10% of existing transmission capacity is assumed to be available for wind for free Additional transmission capacity can be built at cost of $1,600/MW-mi – no lumpiness: same cost multiplier for 500 MW of wind from WY-CO as 1500 MW of wind from WY-CO
Note that some new lines are built to transfer <500 MW of wind (i.e. Arizona)
No we get into spreadsheet based tools. RETI and E3 compare options from various regions in the West, delivered to California load zones. Relative ranking of different options is based on delivered cost adjusted for market value (energy and capacity – no integration costs) RETI Transmission costs: All out-of-state transmission costs based on pro-rata share of 500 kV transmission line. Line utilization based on capacity factor of resource (assumes no curtailment). No lumpiness of transmission costs.
General framework employed in RETI is similar framework we propose to use for each load zone (i.e. we propose to perform a RETI-type analysis for each of the 20 load zones)
E3 analysis is very similar to RETI, with a few major exceptions Market value adjustments in E3 are based on capacity and integration costs only. Integration costs (only for wind) increase with more wind penetration in CA – no benefits of diversity are accounted for Resource selection: Resources are grouped into zones – i.e. B.C. has predefined mix of hydro and wind (user examines them jointly, not individually user cannot easily examine just wind from B.C. without hydro. (Multi-technology zones) Cost of transmission : very lumpy – 250 MW of wind in B.C. triggers new 500 kV line with all cost assigned to 250 MW of B.C. wind
Very high cost options (far right are due to lumpiness of transmission – bus-bar cost is sub $100/MWh but total delivered cost Is > $300/MWh due to assumption of new line being built to accommodate small resource
Next two examples are tools that are better suited to determine the delivered costs based on specific transmission lines (not generic $/MW-mi assumptions) FEAST determines the delivered cost (source) and compares it to the resources displaced at the load (sink). FEAST framework can work for any source-sink pair, but tool only evaluates one pair at a time.
Useful interface for exploring contribution of each component to the value analysis of the transmission line. Bottom right two columns: Do benefits (Value of resource – Cost of Resource) exceed transmission cost? Key feature of model – disconnect line utilization from capacity factor of resource - 1200 MW of wind can be put on 1000 MW of transfer capacity – higher line utilization Limited options can be evaluated in tool – options can only be evaluated one at a time.
Another transmission line-centered analysis. No market value adjustment, only calculates delivered cost Also allows transmission utilization to be different from resource capacity factor.