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HomeMy WebLinkAbout2004-0204 Study Session PacketCiTY OF SHLAND CITY COUNCIL STUDY SESSION AGENDA Wednesday, February 4, 2004 at 12:00 p.m. Council Chambers, 1175 East Main Street 1. Electric System 10-Year Planning Study Report. 2. Update on the Stormwater Management Plan. In compliance with the Americans with Disabilities Act, if you need special assistance to participate in this meeting, please contact the City Administrator's office at (541) 488-6002 (TTY phone number 1-800-735-2900). Notification 72 hours prior to the meeting will enable the City to make reasonable arrangements to ensure accessibility to the meeting (28 CFR 35.102-35.104 ADA Title I). CITY OF SHLAND Council Communication Title: Dept: Date: Submitted By: Reviewed By: Approved By: Synopsis: Update on the Stormwater Management Plan Public Works/Community Development February 4, 2004 (~tudy Session) James Olson /~ I Paul Nolte [/] / Gino Grimaldi~/x~-/~ James Harper of Tetratech/KCM Inc. and Greg Stabach of Rogue Valley Council of Governments will present an update on the status of the City's Stormwater Management Plan. Recommendation: It is suggested that Council support the efforts of the Consultants and Rogue Valley agencies in the development of a Stormwater Management Plan to ensure continued practices for regional,water quality improvement. Fiscal Impact: $100,000+ over 5 years Background: Ashland has a long standing reputation of being vitally concerned with the environment and especially with our surface waters, Years ago we began taking steps to improve storm water discharges and now have moved into a higher gear in that regard. In December of 2002 the City was notified by DEQ that Ashland had been designated by federal regulations for inclusion in the National Pollution Discharge Elimination System (NPDES Phase II) permit program for "small" municipal separate storm sewer systems (MS4s). This designation required the City to acquire an NPDES storm water permit. The permit application and fee was submitted to DEQ on March 10, 2003 as required. Under the conditions of the permit the City has been given 12 months to develop a stormwater management plan. Since five other agencies (Medford, Central Point, Talent, Phoenix and Jackson County) in the area are facing the same requirements it was determined that the best course of action would be to select a consulting engineering firm and develop the required plans with a regional outlook. The six agencies selected Tetratech/KCM to assist in the development of the stormwater plan. RVCOG was also contracted to provide assistance in the public outreach and public education element of the plan. A stormwater advisory team (SWAT) was formulated with representations from each of the agencies to administer the contract and develop the plan. Although each agency will be required to submit its own plan much of the effort will be from a regional viewpoint. C:\W1NDOWS\TEMP~CC Stormwater Mgmt Plan 2 4 04 Study Session.doc The final plan must include the following elements: -Stormwater Public Education and Outreach Program -Stormwater Public Involvement and Participation Program -Illicit Discharge Detection and Elimination Program -Construction Site Stormwater Runoff Control Program -Post-Construction Stormwater Management Program -Pollution Prevention in Municipal Operations Program The City will have five years to fully develop, implement and monitor the effectiveness of its stormwater management plan. _ The Public Works and Planning Departments have been working together to implement various elements of the program. The Phase II requirements have provided a legal background for implementation of a Riparian Ordinance which is crucial for stream protection. Planning began this work several months ago by contracting with Fischman Inc. to conduct a riparian corridor mapping and inventory. This work is now basically complete and the drafting of the ordinance should be completed within the next six months. Attachments: Copy of Phase II permit form C:\WINDOWSWEMP\CC Stormwater Mgmt Plan 2 4 04 Study Session.doc NATIONAL POLLUTANT DISCHARGE ELIMINATION SYSTEM GENERAL PERMIT APPLICATION FOR SMALL MS4s Oregon Department of Environmental Quality 1. t~gaiName: City of Ashland 20 E Main Street, Ashland, OR 97520 2. Type of Entity: [] Federal [] State [] County [] City [] Special District [] Other: Responsible Official: Gino Gfimaldi Organization: City of Ashland Mailing Address: 20 E Main St Title: City Administrator Telephone #: 541 488-6002 City, State, Zip Code: Ashland OR 97520 Primary Contact: Paula C. Brown Organization: City of Ashland Mailing Address: 20 E Main St Title: Public Works Director / City Engineer Telephone #: 541 488-5587 City, State, Zip Code: Ashland OR 97520 5. Invoice to: Paula C. Brown Billing Addre~ss: 20 E Main st Telephone #: 541 488-5587 City, State, Zip Code: Ashland OR 97520 LOCATIONAL INFORMATI°N a) The Urbanized Area within which the MS4 is located (or municipality if not located within an Urbanized Area): b) The latitude and longitude of the approximate center of the applicant's MS4: Latitude Longitude 421 11 44 (N) 122 41 45(W) Deg. Min. Sec. Deg. Min. Sec.' 2. Is any portion of the MS4 loc. amd on Tribal Lands? [] YES [] NO 3. Name of receiving water(s): Ashland Creek, Bear Creek Medford 4. Does the applicant plan to rely on another governmental entity(s) satisfy any permit obligations? [] YES [] NO If"YES", which entities will be sharing permit responsibilities: See Attached Exhibit 5. Attach a summary of thc actions you will take to develop a Storm Water Management Program Plan, and an associated timetable for completing these~cUons. See attached Exhibi.~ 'B' I hereby certify that the information contained in this application is true and correct to the best of my knowledge and belief. In addition, I agree to pay all permit fees required by Oregon Administrative Rules 340-045. This includes a renewal application fee to renew the permit and a compliance determination fee invoiced annually by DEQ to maintain the permit. Paula C. Brown P.E. Name of Legally Authorized Representative (Type or Print) ..~horized Representative Public Works Director / City Engineer Title Date t IL [ t;Ui' Y DEQ/WQ/SWlvI-KM-00447.doc (12/02) - I - EXHIBIT A CITY OF ASHLAND, OREGON NPDES GENERAL PERMIT APPLICATION SECTION B-4' QUESTION: Does the applicant plan to rely on another governmental entity to satisfy any permit obligation? RESPONSE: The City of Ashland views the issue of storm water pellution prevention and water quality improvement as a regional responsibility that cannot be adequately addressed on an individual basis. The City of Ashland intends to work closely with the following communities to develop its program: · City of Medford · City of Central Point · City of Grants Pass · City of Talent · City of Phoenix · Oregon Department of Transportation · Jackson County In addition the City of Ashland expects to rely heavily on the Rogue Valley Council of Governments for information, support, assistance and training. It is further anticipated the RVCOG will provide much of the public / community outreach program. EXHIBIT B ACTION PLAN FOR DEVELOPING a STORMWATER MANAGEMENT PLAN FOR THE CITY OF ASHLAND · research and identify targeted audiences and goals RVCOG/Public Works Administration July 1, 2003 · research media options including utility billing stuffers, newspaper articles, RVCOG I Public brochures, workshops and local cable access outlets October 1, 2003 Works Administration · research and obtain authorization to use educational material from other RVCOG / Public jurisdictions July 1, 2003 Works Administration February 17, Public Works submit ~ of 2004 Administration · develop storm drain system map w/outfall locations November 1, 2003 · develop procedures for inspection and detection of illicit discharges December 1, 2003 · outline elements of illicit discharge ordinance and enforcement program December 1, 2003 · submit proposal for illicit discharge program to council (as part of SWMP) February 17, 2004 GIS Specialist Public Works Administration / Public Works Administration I Planning Public Works Administration develop inspection protocol and ordinance compliance mechanisms · develop procedures for construction site plan review · conduct preliminary training for inspectors (coordinate with planned DEQ training) I· ~ submit prOposal for construction erosion control program to council (as part of SWMP) ' September 1, 2003 September 1, 2003 November 1, 2003 November 10, 2003 February 17, 2004 Engineering / Planning / Building Engineering I Planning / Building Engineering I Planning / Building Engineering / Planning / Building Public Works Administration develop a riparian protection ordinance February 1, 2004 Planning o research and evaluate BMPs to be included in a post-construction stormwater run- off policy · outline process for ensuring compliance with regulations and long term maintenance · submit proposal for post construction stormwater management program to council · inventory all municipal operations that may contribute to or minimize storm water pollution February 1, 2004 February 1, 2004 February 17, Z004 August 1, 2003 Engineering / Planning Engineering / Planning November 28, 2003 Public Works Administration Public Works Superintendent · research pollution prevention options implemented by other jurisdictions AugUst 1, 2003 Engineering · evaluate and select recommended pollution prevention measures October 1, 2003 · conduct training for municipal maintenance employees submit proposal for pollution prevention program to council (as part of SWMP) February 17, 2004 Public Works / Engineering Public Works Superintendent Public Works Director * 1,3 ':' ';' Overview Stormwater Management Control Measures Program Overview Control Measures: Public Education and Outreach Public Involvement and Participation Developing a Stormwater Education Program Stormwater Education Develop and education and outreach strategy Stormwater brochures Education with school districts Work with volunteer groups Stormwater displays Websites Public Involvement and Participation Public Meetings News Releases What's Being Done... ? Stormwater Open Houses (Ashland and Medford) News articles and television interviews Distribution of educational materials Presentations, seminars, and workshops Website and brochure development Involving local schools Outreach Materials Examples Education poster from Storm Water O~n Hous~ 2 How you can help Here are some tips from the Environmental Protection Agency to reduce your conthbution to pollution in local streams and rivers. For more information contact Craig Harper or Greg Stabach at Rogue Valley Council of Governments, 664-6676. Auto care -- repair auto fluid leaks sod re cycle used auto fluids. Lawn care -- use pesticides an d fertilizers sparingly, if at all. Septic syste ms -- have systems inspected ever y 3 years. Landseapi ng -- plant native plant and grass area s instead of covering large areas with concrete and asphalt, so rainwater can soak into the ground. Pet waste can be a major source of bacteria and excess nuuients in Io cai waters; picking it up and flushing in toilet is the b cst solution. Keep vegetation along strea mbanks -- keep livestock away from streambanks and provide them a water source away from waterbodies. 3 4 5 Forebay (scaling pond) at North. Mountain Park in Ashland Managing Stormwater and Watershed Health Goal is to improve water quality 6 Electrical System 10-Year Planning Study CITY.OF ASHLAND Ashland, Oregon . REPORT EGON ~ December 2003 Electrical Systems Analysis, Inc. P'repared By: Jerry Witkowski, P.E. David Castor, P.E. 1. Introduction A. Purpose The purpose of this study is to perform an electrical system evaluation and develop an orderly, economical improvement plan for the City of Ashland. The evaluation and improvement plan are intended to help assure that the City's electrical system has the operational capacity, reliability, and flexibility to meet its planning criteria. The study identifies and recommends system improvements that allow the City to supply adequate and quality power to serve customers into the intermediate future (10 years) and practical improvements that should be applicable for providing service into the long-term future. The study provides recommendations for modifications to existing facilities and new construction as required to meet projected system loading and growth economically, so that no facilities become obsolete early-on in their service lives. In addition, the study considers impacts to the City's distribution system caused by known planned PacifiCorp and Bonneville Power Administration (BPA) facility modifications. The recommendations presented in this report should be used as a guide by City management and staff in planning and implementing electrical system improvements. Improvements are suggested based on projected system load growth and changing electrical industry conditions to improve service quality and reliability and to comply with construction, operating, and safety standards. This study was conducted based on the best available information at the time. Some assumptions were necessary and are noted in the report. Any changes in equipment or system configuration from the data used in this report may require a change in recommendations. Except where noted, this study evaluated the system as it was configured at the time the study was performed. With the passage of time, conditions generally change, and these changes can affect the feasibility or practicality of making certain system improvements. Because conditions do change, this report should be reviewed and updated periodically since changed system conditions may affect the economics or integrity of the recommended plan. By following this approach, the City will maintain a valuable, up-to-date tool to aid management and staff in the process of system operation, planning, and expansion. B. Project Authorization In January 2003,the City of Ashland authorized ESA to conduct a study of the City's electric distribution system. The study consists of various tasks as described in the ESA December Proposal to the City of Ashland with modifications as negotiated during the project kick-off meeting which took place January 6, 2003. This report contains the results of the City's Electric Distribution System Study. 1-1 C. Scope of Work The following is a summary of the scope of services performed in this study. Load Forecast Evaluate the City's system-wide growth patterns based on historical, recent (last 10 year period) and expected future growth, from data to be provided by the City's Electric Department and population projections from the Community Development Department. Evaluate past electric energy and demand uses to forecast future loading (presented in summation tables). This data was then used to estimate future feeder and substation peak loading through system analysis and to determine recommended system improvements. System Planning Criteria Establish realistic planning criteria and objectives upon which short-term and long-term planning should be based. These planning standards are used to determine loading guidelines, the appropriate level of backup under outage conditions, economic conductor sizes, acceptable voltage drop levels, and improvement timing. · Transmission and Substation Evaluation Evaluate the existing transmission system facilities serving the City for interconnection and switching flexibility, looping capabilities, isolated segments, and overall operation and performance for power supply and delivery to the City. Also, evaluate the existing substations serving the City points-of-delivery for equipment ratings, capacities, and configurations. This effort is to include consideration of reliability, protection components, protection philosophy, interruption frequency and duration, power availability and the ability to serve growth, and operation and maintenance programs. · Analysis of the Existing System Evaluate the ability of the existing electric system to provide economical, high quality service in terms of component loading, voltage levels, line losses, power factor, and reliability in the short-term and intermediate future. This effort includes a review of the existing system performance based on the following criteria: - System reliability - System capacity ~ System flexibility - System and feeder peak loads System construction practices Operation and maintenance policies Environmental sensitivity System equipment aging Identification of trouble spots and poorly performing equipment Review adequacy of system record keeping 1-2 The purpose of this analysis is to determine cost-effective measures that can improve system performance. · Power Flow Analysis Analyze the City's electric system circuits by the use of computer modeling software. The system was modeled on a system-wide single-phase basis using ASPEN DistriView. The power flow analysis modeled the system for the following conditions: 1. Base Case lA-model the normal system configuration under recent peak load 2. Base Case lB - model the normal system configuration under light load 3. Case 2 - base case modeled under normal system configuration, recent peak load and cold weather conditions 4. Case 3 - 5 year growth case modeled under projected peak load and cold weather conditions 5. Case 4 - 10 year growth ease modeled under projected peak load and cold weather conditions 6. Loss-of-Substation Cases 5-1 through 5-4 - model the base case as a sectionalized system under peak load with each substation source out-of-service 7. Loss-of-Feeder Cases 6-1 through 6-10 - model the base case as a sectionalized system under peak load with each distribution circuit's source out-of-service The Power Flow analyses were performed for the conditions noted above to identify the system configuration voltage drops, real and reactive power flows, and system losses at system busses as labeled. The results are presented in the Power Flow Chapter with detailed analysis output reports. · Short Circuit Analysis A short circuit analysis was performed under the Base Case configuration to update all fault availability values at system busses. The results are presented in the Short Circuit Chapter with detailed fault data examples and analysis output reports. · Protective Device Coordination Use of the short circuit analysis results for comparison of calculated fault values with equipment ratings was performed to assure satisfactory system protection. These values are compared to evaluate the adequacy of existing system protective devices and settings with Time-Current Curves prepared using ESA's EasyPower software. For each distribution feeder a time-current curve coordination chart showing the devices listed bglow is presented: PacifiCorp and BPA Transformer damage curve Conductor or insulation damage curve Maximum available short circuit symmetrical and asymmetrical fault current Time-current curves of PacifiCorp and BPA primary protection devices Time-current curves of PacifiCorp and BPA secondary protection devices Time-current curves of City's major backbone protection devices 1-3 The results are presented in detailed tabulation with recommended settings for existing protective devices. In addition, analysis of coordination charts and recommended protective device changes that will improve system reliability are included. The development of a fusing application guide for the sizing of downstream fuses is also inserted. Prepare Electric Distribution System Study Report A report summarizing the results of the study is provided which includes: Documentation of references, planning criteria, related calculations, computer reports, and techniques used in the analysis. Analysis and evaluation of the existing distribution system, identification of alternative improvement options, and suggested areas that need focused attention. A list of conclusions, recommendations, and proposed system improvements with projected construction timing and estimated costs. System maps and analysis plots showing the configurations and results of the various study cases, including recommended system improvements. 1-4 2. Summary A. General In general, the City of Ashland owns and operates the electric distribution system and serves customers within the city limits and most customers within the Urban Growth Boundary (UGB). The present number of City electric customers is approximately 10,100. The City's electric service area is currently completely surrounded by the Pacific Power (PacifiCorp) Medford service area. At this time, the City has an exclusive power purchase agreement with Bonneville Power Administration (BPA) who has a General Transfer Agreement with PacifiCorp. All power used by the City is wheeled over the PacifiCorp transmission system and delivered through two PacifiCorp owned substations (Ashland and Oak Knoll) and the BPA owned Mountain Avenue Substation. Presently, the electric utility industry cohtinues to change due to electric restructuring and deregulation, with the intention to move toward a more competitive environment. Although legislation was passed in the 1992 Energy Act, deregulation is still not complete. Failing markets, bankruptcy, and abandonment of the trading sector, all coupled with the scarcity of inexpensive power have created distrust and slowed the political and public will to complete deregulation. In some parts of the country, government agencies and investor-owned utilities are none the less being required to provide open-access to their transmission facilities and to publish open-access tariffs for use of their transmission systems. The result has encouraged regional transmission operators (RTOs) and independent system operators (ISOs) to have single tariffs in their boundaries, with a goal of making it economical for power to ~,. ~ ~':'.~)n~ ~,. i : '~. The Federal Energy Regulatory Commission Standard Market Design (FERC SMD) has also recognized the perceived need for independent customer representation through energy service providers (ESPs), and although some energy service companies are moving ahead in formulation and marketing, these activities are quite slow. In Oregon, the passage of House Bill 1149 to form such operations in this state awaits action having been shelved due to the uncertainty caus¢,~ problems noted above. While restructuring of the electric industry is expected to have some effect on thc ' ~ , ,ver supply provider, industry-wide it is generally thought that existing municipal uti! .a as the City of Ashland, will continue to serve exclusive service areas. Reviews of typic,~i cnt surveys indicate that residential, commercial, and small industrial customers do not want the risk of making power purchasing decisions and prefer their power supplier make those choices. We feel that existing municipal distributing utilities will continue to provide distribution facilities and services fdr power delivery to most end-use consumers. In some instances this includes present substations to transform power from transmission voltage to distribution voltage, and includes the trend toward acquisition of such facilities to provide services. In the City's case, PacifiCorp and BPA currently own the existing transformation facilities and deliver all City consumed power, with the exception of the small amount of City hydroelectric generated power. Because restructuring of the electrical industry has resulted in the unbundling of services and charges by transmission and substation providers, many cooperatives, municipalities, and public 2-1 utility districts have begun to purchase substation facilities allowing them to take high voltage power delivery and avoid transformation charges, such as are currently being paid by the City of Ashland. We believe as loads increase, it may be to the City of Ashland's advantage to finance the purchase and expansion of the Mountain Avenue Substation and reduce load on other substations. This independence should result in better rate control and lower rate services to Ashland customers. Evaluation of the Ashland electric distribution system indicates that its historical peak demand (44.6 MW) has not been exceeded since its occurrence in December 1990. The most recent system peak, 42.1 MW, occurred in January 1998, and although no new peak has been recorded since 1990, energy sales have continued to increase. Energy sales have increased without the occurrence of a new peak demand since 1990 because of the mild weather trends in the northwest. Weather data reveals that the coldest temperatures in the last fifteen-year period occurred in the winters of 1989 and 1990, followed by the winter of 1998. There is a strong correlation between temperature and peak loading. The?efore, the modest continuous increase in energy usage has created the potential for new peak loading on City circuits at cold temperatures. This condition, coupled with the potential for new peak loads on the PacifiCorp circuits served from the Ashland and Oak Knoll Substations, suggest that a new system peak demand could occur any winter, if an extended low temperature period occurs. A peak demand of 50 MW is forecast under cold weather conditions at the present time. Although the City of Ashland electric distribution system has historically been a winter peaking system, over the last 1 O-year period summer peak loads have increased at an average annual rate of 3 percent, twice the rate of the average annual energy consumption growth. This increase in summer peak conditions has been caused by very warm summers, growth, and additional air conditioning loads. If this trend continues the City could expect that the summer peak demand may equal the winter peak demand around 2010 to 2012. This condition and its impacts are discussed in detail in Chapter 4. At this time there is sufficient transformation capacity (substation transformer ratings) available to serve the City's system into the long-term future, except under single-contingency conditions (the loss of any single major system component) as identified in this report. Single-contingency limitation plus the existing PacifiCorp transmission system and substation service reliability concerns are summarized below and described in greater detail in Chapter 4. The conclusions and recommendations throughout the remainder of this section are based on analysis of the existing system and the development of a plan to optimize effective use of the existing electrical facilities. The steps necessary to prepare the City's electric distribution system to operate adequately under additional loading through the implementation of feeder load transfers, circuit load balancing, conductor segment replacements, and interconnections to sectionalize circuits under various outage conditions are also addressed. B. General Conclusions and Recommendations The following general conclusions and recommendations are the outcome of this study. This discussion is followed by specific system improvement recommendations outlined in Table 2-1: 2-2 System Observations At the present time the City's electric system is providing quality service to its customers. There are, however, some operating situations and switched configurations under which service may be limited and result in low voltage and component overload conditions. There is also feeder load disproportions and phase imbalances that add to these limitations. Improvements to eliminate these conditions can be made and are addressed in this report.. The Bonneville Power Administration 1996 Wholesale Power and Transmission Rate Schedules include a Reactive Power Charge that was modified effective October 1, 1999 and revised August 2000. The new policy requires that BPA customers maintain their electric system power factor between a bandwidth of 0.97 lagging during peak period hours (heavy load hours (HHL) - 7 a.m. thorough 10 p.m.), and 0.97 leading during offpeak period hours (low load hours (LLH) - 11 p.m. through 6 a.m.). This policy revised and reduced the previous 0.95 power factor bandwidth requirement. Although this policy is not being enforced at the point-of-delivery (POD) substations at this time, it may eventually be passed thrbugh the PacifiCorp system. We have obtained the City's system reactive power data, available from BPA's meter extraction site, and concluded the new BPA reactive power policy requirements are occasionally being violated by the City's load. Evaluation of this condition is discussed in this report. The City may want to consider modification to its Electric Ordinance so that the reactive power policy stipulates updated requirements and guidelines to which City electric consumers must adhere. This policy should be in line with the new BPA reactive power requirements and will allow the City to in effect pass-through poor power factor charges to their source. This will offset City incurred penalties or corrective facility costs such as capacitor bank installations. With the ever-increasing requirements for utilities to deliver high quality electric power and because of the potential for industrial and commercial power users to cause system disturbances that can affect sensitive customer loads, we suggest the City also consider the adoption of a Power Quality clause to its Electric Ordinance. The language should specify how to regulate non-linear loads in accordance with IEEE requirements and guidelines. With the Distributed Generation technology coming of age, and the substantial increase in the potential for consumers to place small-scale power generation sources on-line, thereby creating possible unstable interconnections to the utility grid if not properly isolated, we suggest the City also consider the adoption of a Generation Interconnection clause to its Electric Ordinance. The language should specify how to regulate the interconnection of customer owned electric power generation to the City's electrical system in accordance with IEEE requirements and guidelines. With fluctu, ating external power supply and transmission costs on the near horizon the concept of pass-through consumer revenue billing with a linkage to time-of-use metering should be evaluated. It may be determined that this application is only reasonable for larger industrial and commercial customers or certain customer classes. The City may want to consider the adoption of language in its Electric Ordinance that will allow pass-through billing when the need arises. 2-3 Transmission Observations Under normal conditions, power is delivered to the City of Ashland from PacifiCorp's 115 kV Transmission Line 19 operating between the PacifiCorp Lone Pine Substation and the COPCO facility. Line 19 is tapped and becomes PacifiCorp Line 82, providing service to PacifiCorp's Oak Knoll Substation and continuing to PacifiCorp's Ashland Substation. Between the Oak Knoll and Ashland Substations Line 82 is also tapped serving the Bonneville Power Administration's (BPA) Mountain Avenue Substation. These three substations are the points-of-delivery (POD) for the City of Ashland. PacifiCorp's transmission service to the Ashland Substation is looped, but at two voltage levels. Power is delivered from the south at 115 kV from the Oak Knoll and Mountain Avenue Substation Line 82 direction, and from the north at 69 kV from PacifiCorp's Line 3 direction. From Ashland Substation, PacifiCorp's Line 3 circuit goes north to the PacifiCorp Talent Substation and continues to Voorhies Crossing where it becomes Line 79. Line 79 then continues to PacifiCorp's Belknap Substation and its 69 kV origin at the PacifiCorp Lone Pine Substation. PacifiCorp's Lines 19 and 82 are constructed and operated at 115 kV; and Lines 79 and 3 are constructed at 115 kV with the exceptioh of an approximate 1.3 mile section between Voorhies Crossing and Belknap Substation that remains constructed at 69 kV, and both Line 79 and 3 circuits are operated at 69 kV. The 115 kV Line 82 normally serves the entire City of Ashland load consisting of 10 distribution feeder circuits and local PacifiCorp load consisting of 2 distribution feeder circuits. Presently, this combined load can conceivably reach 60 MW and is supported from what could be considered a 'radial' tap because of weakness within the 69 kV backup system. This 115 kV tap can adequately support an approximate 100 MW summer load and 149 MW winter load. However, the 69 kV backup system can only adequately support an approximate 60 MW summer load, and 90 MW winter load. Because these transmission lines must also support the PacifiCorp load at the Talent, Belknap, and Foot Hills Road Substations, under worst-case winter and summer loading conditions this 69 kV backup source cannot be relied upon to adequately support peak loads without significant load shedding. PacifiCorp's 2003 Medford Area Transmission Planning Study indicates under an outage condition of the Oak Knoll 115 kV Line 82 tap, the 69 kV Lines 79 and 3 can incur overloads between an approximate 140 percent to 160 percent, between the 2003 and 2007 planning period. PacifiCorp recognizes these system deficiencies as the 'weakest spot' in the Medford transmission system, resulting in low voltages and significant overloads during summer peaks. PacifiCorp's study offers a recommended improvement to convert Line 3 (Voorhies Crossing-Talent) and Line 79 (Belknap-Voorhies Crossing) to 115 kV in addition to relocating the Ashland Substation 115-69 kV transformer to Bleknap, and performing other necessary switching construction. PacifiCorp's current planning study suggests that without these improvements the following deficiencies ar, e likely to occur with service from the 69 kV source: Winter - The 69 kV source to Ashland from Lone Pine can support winter peaks between the years 2003 and 2007, although it will likely require manual transformer tap adjustments at Ashland Substation to modify voltage levels and avoid capacity limitations. 2-4 Summer - The 69 kV line will not support summer peaking load during the same period, and significant load may need to be shed. The approximate load that may require shedding from this transmission system and time schedule is as follows: 2003 - Shed 29 MW from these circuits. 2007 - Shed 48 MW from these circuits. PacifiCorp has stated that this condition has existed for many years and that presently the PacifiCorp-BPA General Transfer Agreement does not require a backup source. Although PacifiCorp considers the 69 kV Line 79/3 a backup source, it does have a planned construction schedule to upgrade these facilities as mentioned above, planned to occur in 2006.. The City's most recent winter and summer peak loads are 35.9 MW and 38.6 MW, respectively. In addition, PacifiCorp serves approximately 9 MW of local average peak summer load from the Oak Knoll and Ashland Substation facilities. Therefore, should there be a loss of Line 82 the majority of load to be shed would be from service to the City of Ashland customers. This Scenario would suggest that of the projected load to be removed from service in the Ashland area, approximately 12 to 20 MW based on the PacifiCorp study would be City of Ashland load equivalent to approximately 55 percent of its customers. The PacifiCorp planning schedule assumes some system improvement is implemented prior to 2008, although the actual timing and completion of such plans is dependent on PacifiCorp funding. Failure to meet the improvement schedule will require a well-planned system load shedding scheme or alternative system improvements. Under the normal service configuration, PacifiCorp's 115 kV transmission system (Lines 19 and 82) has adequate capacity to support the Ashland area loads, and service integrity is improved by the fact that the tap point (Line 82 at Line 19) is looped at 115 kV from the north and south. However, the fact that Line 82 could be considered a radial tap presents exposure to the City of Ashland because of the limitations of the 69 kV backup source (Lines 79/3). This condition will worsen as loads increase and it is expected that if the stated amount of load shedding (20 MW) becomes necessary it will present severe hardship on the City of Ashland customers. We suggest that contingency plans based on load shedding be considered unacceptable to the City, and further suggest that the City continue to pursue investigating alternative solutions that avoid the need for load shedding for any single contingency failure. Transmission Recommendations Although the PacifiCorp transmission system has generally provided reliable service to Ashland in the past, the vulnerability to service interruption and projected load growth emphasize the need for transmission improvements. A failure of Line 82 combined with the Line 79/3 backup facility limitation make portions of the Ashland region susceptible to prolonged outages under the load shedding contingency. Should PacifiCorp's planned construction activities be delayed, alternative solutions the City may want to consider are suggested in this report. One option for consideration is to construct and own or lease a new backup transmission segment tapped from PacifiCorp's Line 19 to provide a reliable transmission loop to the Ashland Substation. Construction of an approximate 2.1 mile 115 kV tap from PacifiCorp's Line 19 to Line 82 at the Ashland Substation would provide a 115 kV backup source to the three area substations. 2-5 The option to construct a City of Ashland 115 kV interconnection to provide two independent 115 kV sources to the Ashland area may be more cost-effective than upgrading the PacifiCorp 69 kV line facilities and substation equipment. Since the City owns property that would accommodate a right-of-way for such a circuit, this approach seems a reasonable solution should other action fail to occur. In addition, PacifiCorp's planned schedule to upgrade the 69 kV transmission facilities to 115 kV may not align with the City's objective of providing its customers with reliable backup power. Any delay in the timing of PacifiCorp improvements will increase concerns for backup reliability to the City. Therefore, we encourage the City to be proactive in negotiating with PacifiCorp to see that these construction improvements take place as planned. Should the City decide to make any transmission construction improvements related to the backup source for reliability enhancement independent of PacifiCorp, the improvement costs will likely needto be borne by the City. However, any transmission improvements made by the City of Ashland would also benefit PacifiCorp, and the possibility of construction alternatives and cost sharing should be investigated. There may be other alternative solutions to improve the weakness of the backup source and all options and costs should be thoroughly explored and discussed with PacifiCorp including maintenance and operation responsibilities prior to taking any action. Cost estimates for alternative improvement options are provided in Chapter 4 and in Table 2-1 of this chapter, with additional detailed descriptions presented in the Appendix. Substation Observations Three substations currently provide distribution service to the City of Ashland customers. The City itself owns no primary transformation facilities. PacifiCorp owns the Ashland and Oak Knoll Substations providing service to the City of Ashland distribution points-of-delivery (POD). At the Ashland Substation the City takes delivery from a PacifiCorp secondary breaker which feeds a City owned distribution rack and four City distribution circuits. At the Oak Knoll Substation, PacifiCorp provides the City service from three distribution breaker positions to three separate POD and City distribution circuits that originate outside the substation. At the third facility, Mountain Avenue Substation, the substation site, the high voltage equipment, the control building and ancillary components are owned by the Bonneville Power Administration (BPA). The City takes delivery at the secondary voltage, owning the voltage regulator, distribution rack, and feeder getaway facilities. The Ashland Substation transformer T-3499 is loaded to near capacity under summer conditions and an objective of this study is to transfer some load to the neighboring Mountain Avenue Substation. The PacifiCorp Oak Knoll Substation has adequate capacity and also has switching flexibility should any device fail or need to be out of service for maintenance. However, a loss of transformer T-3856 under peak summer conditions could create an overload condition on transformer T-3234 in the near future. An objective of this study is to assure adequate feeder sectionalizing will be in place to allow the transfer of load to neighboring substations should such an event occur. The Mountain Avenue Substation distribution rack is configured with an auxiliary bus allowing a flexible switching arrangement so that load can be transferred from one circuit to another within 2-6 the substation. However, a loss of transformer T-1537 for any reason will require the transfer of load to neighboring substation feeders. Additional information regarding substation equipment, ratings, loading, and capacity is presented and discussed in the Chapter 4 and other parts of this study. PacifiCorp has indicated that if any Ashland or Oak Knoll Substation transformer fails, necessary action would be taken to transfer load to surrounding operable feeders and substations. PacifiCorp has an official time limit of 20 hours for installing an emergency mobile transformer. BPA has indicated that in the event of the Mountain Avenue Substation transformer failure, action would be taken to transfer load to PacifiCorp's Ashland and Oak Knoll Substations. BPA has stated that it may take a long as 48-hours to ready, deliver, install, and energize a mobile transformer for Mountain Avenue once notice was received. At this time PacifiCorp has indicated there are no immediate planned modifications to either the Ashland Substation or the Oak Knoll Substation facilities that serve the City of Ashland, and at this time BPA has indicated there are no modifications planned for the Mountain Avenue Substation. The substation facilities serving the City have provided reliable service in the past and pres: ~'~ ¥ have adequate capacity available to meet City loading into the 10-15 year intermediate futm ~ provided there is no loss of service from any one transformer. However, as the intermediate future approaches loss of a transformer or its removal for maintenance could expose the City to the possible inability to serve load. This single contingency shortcoming suggests the need for additional transformer capacity, which should be considered in the intermediate (1 O-year) future, but the specific timing of any improvement is load dependent. The City should be aware that the time required for the planning and implementation phases of such an improvement, could be two to three years depending on negotiations and available funding. The Ashland Substation, located close to the City's load center, is fairly congested with little room for expansion. The Oak Knoll Substation, located in the southeast region of the City's service area has capacity for load growth in its vicinity, but has limited ability for expansion that could easily reach the City's concentrated load center. Neither the Ashland Substation nor the Oak Knoll Substation, are good options to handle additional load in the core of the City. The most practical substation facility for consideration of future expansion is the Mountain Avenue Substation. This newest substation is centrally located to the City's load and consists of a s i:,~ with suitable space for expansion and has been constructed to accommodate expansion. Substation Recommendations Because the City takes delivery of power at the distribution voltage level (12.47/7.2 kV), it must pay a monthly transformation charge for all energy purchased. We believe it may be to the City's advantage to purchase and own the Mountain Avenue Substation. Such purchases from BPA are common in the northwest. Although ownership would obligate the City to provide substation operation and maintenance, the potential savings from offset transformation costs could prove worthwhile, and allow the City to continue offering consumers favorable rates in the future. We suggest the City investigate this option by beginning negotiations with BPA regarding the value of the substation facility, and the City develop its own cost estimate for comparison and further negotiation. An economic comparison should be performed to determine the cost-benefit and payback period for such a purchase. 2-7 Some of the benefits of expanding the Mountain Avenue Substation which also impact the concept of City ownership of the Mountain Avenue Substation are listed below: It is close to the center of load growth · Avoids further feeder congestion at the Ashland and Oak Knoll substations · Allows the City to own the centrally located substation if it chooses to do so · Facilitates the development of a 115 kV transmission loop · Strengthens the distribution feeders' ability to backup and sectionalize · Strengthens the ability to carry peak load with one other substation out of service · It is an existing substation with sufficient room for expansion It does not involve acquiring a new substation site It does not require extensive planning or permitting Distribution Observations The following comments describe general observations of City's electric distribution system. Additional comments and recommendatibns are presented in the following section: 1. Distribution feeder loading is dispersed unequally with some feeders supporting as much as 100 percent of the recommended feeder load under peak conditions and others supporting less than 10 percent of suggested feeder loading. Should loss of a feeder or complete loss of a substation occur, feeder sectionalizing, in some cases is not adequate to transfer load to adjacent substations or feeders under peak conditions. Some City feeders have controllers that provide individual phase load current indi This data and City line-logger circuit tap measurements indicate there are segments in the system with poor load balance. Primary concerns of system load imbalance problems include: a. Unbalanced circuits create unequal phase voltages. b. Unbalanced phase voltages can cause additional negative sequence current to circulate in three-phase motors creating over-heating. The potential for high neutral current is created which increases losses, (' :. , :rose possible negative effects on ground relaying or mis-operation, and can cause operating problems, arcing and safety concerns. Feeder imbalance can result in one or two phases being overloaded and create low voltage conditions. Underground cable neutral corrosion has occurred in the City's electric system on older cable installations. This loss of neutral can degrade protection and create an unsafe operating condition. We have previously provided the City with information of test methods to identify the loss of concentric neutral cables. 5. The electric distribution system includes City served PacifiCorp loads and PacifiCorp served City loads are interspersed throughout the system. If practical, these loads may be 2-8 more efficiently served by one power provider. If this is not pos. sible, an agreement should be reached to ensure energy billing is accurate and compensates for peak demand, transformation charges, losses, and reasonable administrative services. The City may also choose to install primary metering between these interconnections, or at least monitor PacifiCorp loads with line-logger measurement, to get an indication of the tap loading percentage in comparison with the feeder load. Distribution General Recommendations The following comments describe the general evaluations, guidelines, and recommendations for the City's electric distribution system: The City should enhance the distribution interconnections between feeder circuits to improve feeder transfer speed and reliability during emergency switching. This should include the installation of group-operated air-break switches at appropriate locations along main feeders to improve operational flexibility and sectionalizing. Where applicable, load-break switch installation should be considered to allow the transfer of loads between feeders without an outage. Under normal loading and configuration conditions feeders should be limited to a peak load of 7.5 MW. This will allow feeder load levels to be increased temporarily to approximately 11.0 MW under emergency or sectionalized loading conditions. o The City should standardize applications of overhead and underground conductor types, sizes, and application as shown in Tables 5~1 and 5-2 of Chapter 5. These include 750 kcmil Al URD, 500 kcmil AL URD, and 4/0 A1URD underground cables and 556.6 kcmil AAC, 336.4 kcmil AAC, and 4/0 AAC overhead conductors adopted for main 12.47 kV feeder getaways, circuit backbones, and major tap connections. These conductors and applications are practical and economical sizes. Because of its light loading, use of the existing Ashland Substation N. Mountain Feeder as an Express Feeder interconnected to the Mountain Avenue Substation for the purpose of transferring either the North Main Feeder or Business Feeder load, could be enhanced with the installation of transfer switches placed outside the Ashland Substation. o In addition to the transfer switches mentioned above, construction of an express feeder from the Mountain Avenue Substation would eliminate the potential to overload the S. Mountain Feeder, presently the interconnection tie to the Ashland Substation N. Mountain Feeder. This would allow considerable sectionalizing flexibility and backup capacity. Poor load balance conditions can be avoided if the system is properly balanced. As loads are transferred or feeder circuits upgraded according to the recommendations of this report, circuit phase balance should continue to be monitored. The City should continue taking load readings on each feeder at major tap points to detect load characteristics and unbalanced loading. If feeder unbalance is greater than 10 percent additional phase transfer at single-phase taps and the distribution transformer level should take place to equalize circuit loading. Field load measurements and load balance evaluations will be an ongoing process, and the transfer of additional loads may be necessary to maintain proper load balance within each circuit. 2-9 o o Redundant sources should be available to critical loads, such as the Ashland Community Hospital and Southern Oregon University. Ideally each source would come from a separate substation. To prevent loss-of-neutral corrosion the City should adopt the practice of installing jacketed concentric-neutral URD cable. Three-phase circuits should contain 1/3 concentric neutrals sized at 1/3 of the phase conductor, and single-phase circuits should contain a full concentric neutral. We suggest the City schedule testing of areas determined to be susceptible to this problem and develop a program and timetable for the replacement of the defective cable segments. All new construction, system replacements, or expansion additions should conform to the design standards established in this document. 10. The City should continue the development and design of construction assembly units and specification standards to ensure consistency with all new construction. Typical construction unit drawings should include material lists and be implemented to establish standardization and consistency for work order preparation, warehousing, and construction practices. 11. The City should develop, document, and keep up-to-date circuit-switching plans. In addition, the adoption of cut-sheets should be prepared describing the "preferred" method for removal of any circuit feeder or substation from service and the transfer of load to the other circuits. The circuit-switching plans should indicate how to switch circuits in the event of equipment failure or outage to minimize the number of customers interrupted and the interruption duration. The plan(s) should indicate how load is to be transferred quickly to other feeder(s) during planned and emergency outages. The plans should also include any voltage regulator tap adjustments, protective device modifications, and manual settings that might be necessary prior to load transfers. 12. The City should continue the distribution feeder component numbering pattern used in the mapping system to facilitate feeder and equipment identification. Unfortunately, some system component identification numbers are duplicated on different maps, so any database created with these numbers should include a key map number for reference to ensure a unique component identifier exists. 13. The Electric Mapping System has been enhanced extensively through the process of this study with City staff verification of inconsistencies and missing data. A standard process should be developed to ensure that the mapping system accuracy is maintained and updated as system modifications and expansion take place. 14. The City should monitor and log the electric system monthly and annually to evaluate performance. This report contains examples of record-keeping tables and files to assist the City with downloading and organization of feeder load rending and characteristics. 15. The City should regularly evaluate the system protective devices and coordination. This should consist of the use of the short circuit analysis results where necessary and include the following practices: Compare annual peak load currents with equipment ratings and device settings. 2-10 16. Verify existing fuse types, sizes, and short circuit ratings, and replace equipment having inadequate interrupting ratings. The City should, establish a procedure that occurs every few years to allow the evaluation of the system protective devices. This evaluation should include the following: Install and replace fuses in accordance with a fuse application guide, such as McGraw-Edison's Distribution System Protection Manual and examples included in this report. Be consistent in the use ofNEMA "T" type fuse links or existing City "K" type fuse links for Protection of taps along main distribution feeders. It is suggested that the use of'preferred' fuse sizes be used and the use of 'non-preferred' fuse sizes be avoided to enhance coordination. The City should be aware that "T" type fuse links have a less inverse characteristic than "K" links, providing better coordination with relaying at the substation. Selection of fuses should be sized on a full-load current carrying basis, sized for the connected kVA. Fuse selections must also be capable of handling transformer in-rush current (approximately 1 O-times full load current for 0.1 seconds). · Use fuses to protect all new tap lines, especially underground taps. Employ operating procedures to ensure that the correct size and type of fuse is installed when replacing a blown fuse. A tagging scheme, such as pole tags, indicating the correct type and size of fuse are recommended. Where possible, size fuses for underground taps so that an underground fault will blow the fuse before the first operation of the substation breaker or recloser to avoid reclosing into a permanent underground fault. If loads increase it may become practical for the City to consider the installation of additional vacuum load-break and fault-interrupting pad-mounted switchgear at major underground sectionalizing locations. These devices allow the elimination of traditionally fused switchgear with the replacement of equipment that offers much greater flexibility in service operation and maintenance. These devices typically accept two or more sources, include load-break source switching, and offer vacuum fault interruption through single-phase or three-phase electronic selectable trip settings for circuit taps. At overhead locations that require overcurrent protection where the necessary fuse cannot carry full-load current and coordinate properly with substation relay devices, it may be practical for the City to consider the installation of three-phase electronic reclosers or sectionalizers. Reclosers provide a range of flexible settings and reclose sequence but are costly filed devices. The sectionalizer devices are more cost effective and can sense fault current to isolate the downstream circuit and minimize the number of customers experiencing interruption. Their drawback is that they require manual reset. 2-11 17. 18. 19. 20. Where practical, the City should continue its implementation of the practice of joint utility installation for underground facilities with other utilities/public works projects to coordinate construction and minimize construction cost. When timing is practical, on an annual basis, the City should perform thorough "infrared" testing and inspection of its system. A poor connection can become hot before failure and can be detected by infrared (thermal) testing from a safe distance. An estimated 20 percent of all outages in the electrical utility industry are caused from equipment having loose or faulty connections. It appears there are detail drawings, or material list for the Ashland Substation City owned distribution rack. When time allows, the City should develop such drawings and material list as necessary to assist with operation and maintenance. To assist with the preparation for the next long range planning Study, the following guidelines are suggested to monitor outage occurrences: In addition to completing outage/failure field reports and monthly/annual tabulated summaries, the City should prepare outage and equipment failure reports that include outage details such as: cause, frequency, duration, location, and number of customers interrupted. Equipment and component failure detail records such as equipment type and failure cause should be tracked and recorded to evaluate the selection of devices and their performance. These reports should be maintained in accessible files and analyzed annually to determine how the frequency and duration of outages or failures can be minimized through effective system design, operation, and maintenance. This information should also be logged by year and placed in appropriate data files, analyzed, and shown on an outage map to allow troubled areas, equipment, and circuit segments to be quickly identified. These guidelines and the suggestions listed in Chapter 6 regarding outage monitoring should be consistently followed. This will help assure that capital improvement expenditures are invested in a cost effective manner. C. Specific Recommendations As a general recommendation, the City should adopt the planning criteria and implement the system improvements as presented in this report and specifically in Table 2-1. Improvements should be made as necessary to serve the actual load economically, while at the same time meeting prudent service quality and reliability standards. This report should be reviewed and updated approximately every two years to ensure that decisions regarding improvements are based on current system conditions. All new facilities should be constructed in accordance with the latest expansion plan to ensure that no facilities become obsolete early in their service lives. 2-12 Specific recommendations resulting from this study are intended to meet normal load growth requirements and resolve specific operating deficiencies. All cost estimates shown are in 2003 dollars and are based on work performed by a contractor after competitive bidding. Refer to the "Construction Cost Estimate" section in the Appendix for an explanation of the cost estimating development and application. The improvements listed in Table 2-1 are grouped and identified as General (G), Transmission (T), Substation (S) and Distribution (D), and organized by improvement periods labeled Immediate, 5- Year Intermediate, and 1 O-Year Intermediate time-frames. Some improvements are expected to be performed by City crews and are identified as 'crew-time'. A potential improvement spending and time-frame schedule should the City decide to follow the general suggestions and recommendations included in this report, less the construction of the 115 kV transmission loop (T-I) and the purchase of the Mountain Avenue Substation (S-2), results in the following approximate capital improvement forecast: Immediate to 5 Year Intermediate Improvements = $775,000 5 to 10 Year Intermediate Improvements = $785,000 If it becomes necessary for the City to construct a 115 kV transmission loop such as described in the suggested improvements a likely cost for this construction improvement (T-I) is estimated at $600,000, but it may be possible to negotiate some cost sharing with PacifiCorp. In addition, if the City decides to move forward with the purchase of the Mountain Avenue Substation, improvement (S-2), an approximate value of this facility is estimated at $1,000,000. After review of all recommendations, it is suggested that the City prioritize the accepted improvements into one-year and five-year improvement plans to best match manpower and available resources. This will allow the City to implement improvement projects in an orderly fashion while managing normal day-to-day activities. 2-13 City of Ashland Electric System 10-Year Planning Stud)' By Jerry Witkowski/ESA Dave Castor/ESA Electric System Study · Objective - Provide High-Quality Reliable Power · Approach Prepare Load Forecast Develop Planning Criteria Evaluate Transmission/Substation/Distribution Perform System Modeling Analysis Identify Improvements · Conclusions and Recommendations Load Forecast Method · Historic Data: Population-Energy-Demand Energy = accumulated consumption (kWH) Demand = system peak @ time interval (kW) · Weather Impact on Average Electric Use · Forecast Basis - Population/Energy Relationship · Result - Projected Growth = New Demand Moderate Growth (recent demand 1998) Cold Weather Impact (historic demand 1990) Population Growth - Energy Use - Peak Demand Historic (1987-2002) Year Peak(MW Energy (kWh) Populabon Annual Energy Usage and Population Growth Year Ashland Population Projection Ashland Coincident Peak Demand City of Ashland Peak Demand and Average Monthly Temperature Ashland Average Monthly Temperature Population Growth - Energy Use - Peak Demand Forecasts (2000-2020) Forecast Results Monthly Load Summary Planning Criteria · Single-Contingency Reliability · Winter and Summer Equipment Ratings · Equipment Capacity (Normal-Emergency) Substation/Feeder/Conductor Loading · Voltage Levels i City of Ashland ,u .i' ' PacifiCorp Medford Area ', ~ .'a' ~-,::~ Transmission System Transmission Capacity PacifiCorp Medford Area Transmission System Transmission Alternative Monthly Peak and Load Curtailment Transmission System · Normal Configuration: 115 kV - Line 82 Winter 149 MW / Summer 100 MW · Backup Configuration: 69 kV - Line 3 Winter 90 MW / Summer 60 MW · Single-Contingency Exposure (Summer) Loss of Line 82 = Ashland Load Curtailment · Conclusion - City must be able to serve load Promote PacifiCorp 2006 Improvement Plan Alternative Action = City Transmission Line Substation Load Data Capacity Available to the City Transformer Load Data Transformer Capacity - City Demand Transformer Capacity/Forecast Comparison 4 Substation Systems · Ashland Substation Limited Capacity Limited S~vitching Flexibility Aged Equipment · Oak Knoll Substation Sufficient Capacity Flexible Switching Remote from Load Center · Mountain Avenue Substation Sufficient Capacity Close to Load Center Easily Expanded Distribution System Evaluation · Feeder peak loading vs capacity · Feeder configuration · Feeder switching flexibility · Feeder backup/transfer reliability · Identify problem areas Existing Substation Facilities ~,',,..r.. :~, ~ ~.~' ~,~ I s.~ ~.~.: ~ ....~.. j Capacity of Overhead Conductors Analysis Methods Power Flow Analysis · Model Existing System Identify spot load and distributed loads Analyze existing and forecast loading Identify overload & low voltage conditions · Rearrange System Configurations Analyze with improvements Analyze loss-of-substation = load transfers Analyze loss-of-feeder = load transfers Analysis Methods Short-Circuit Analysis · Determine fault currents available · Compare SC current & equipment ratings · Assure protective devices sized correctly Protective Device Coordination · Assure protective devices coordinate · Evaluate each feeder component TCCs Power Flow Example Example - Power Flow Results · Analysis software checks calculated feeder current against assigned maximum current · Overloaded sections are highlighted · Also evaluates low voltage conditions Short-Circuit Example Base Case - Cold Weather Conditions 6 Five Year Case - Cold Weather Condition Ten Year Case - Cold Weather Condition  ] ~,-.City of Ashland '; r-~ I T~ting Circuit Map ', i - ~ ~-- :l City of Ashlanxt..~_ Proposed 10-Year Cir~RLt-Map Recommendations General Comments: · Consider Load Curtailment Plan · Prepare Planned Switching Procedures · Ordinance Considerations and Standard Compliance Reactive Loads Non-Linear Loads Distributed Generation Interconnects · Review Development Charges · Record Keeping Practices Recommendations Transmission System: · Promote PacifiCorp 2006 Improvement · Lack of PacifiCorp Action ~ City Action · Alternative City Transmission Loop · City Transmission Loop Benefits PacifiCorp · Negotiate Cost Share Recommendations Substation Systems: · Ashland Substation - expansion limitations · Oak Knoll Substation - location limitations · Mountain Avenue Substation Load Center Location + Expansion Potential Consider Purchase - transformation savings Evaluate benefit/cost - payback period Possible Negotiations with BPA Add Nexv Feeder Circuit < 5-years Expand Facility 10-15 years - Load Dependent Recommendations Distribution System: · Equalize Feeder Loading · Correct Feeder Phase Imbalance · Circuit Conductor Replacements · Shift Loads · Improve Switching · Circuit Extensions · Redundant Sen'ices to Critical Loads · Add New Feeder Circuit from MAS · Limit Feeder Maximum Normal Loading Conclusion Present Distribution System ~ Good Service System Improvements Future Reliable Service and Satisfied Customers 8