Generation Interconnection Facilities Study For Prepared for: Prepared by: SCE&G Transmission Planning May 27, 2015
TABLE OF CONTENTS General Discussion... Page 3 Generator Interconnection Specifications... Page 3 Scope of Work, Cost Estimates and Time to Complete... Page 4 Summary... Page 5 Figure 1 Engineer Single Line Layout... Page 6 Figure 2 Site Location... Page 7 Figure 3 SCE&G owned 46kV Switching Station General Arrangement... Page 8 Figure 4 SCE&G owned 46kV Switching Station Switching Configuration... Page 9 2
Generator Interconnection Facilities Study For Project in SC A Generator Interconnection Facilities Study follows the previous Generation Interconnection System Impact Study, and specifies and estimates the cost of the equipment, engineering, procurement and construction work needed to implement the conclusions of the Generator Interconnection System Impact Study in accordance with Good Utility Practice to physically and electrically connect the Interconnection Facility to the Transmission System. A Generator Interconnection Facilities Study also identifies the electrical switching configuration of the connection equipment, including, without limitation: the transformer, switchgear, meters, and other station equipment; the nature and estimated cost of any Transmission Provider's Interconnection Facilities and Network Upgrades, if necessary, to accomplish the interconnection; and an estimate of the time required to complete the construction and installation of such facilities. General Discussion has requested a Solar Photovoltaic (PV) plant in Hampton County. This solar facility has a total generation capacity of 8.16 MVA, consisting of (12) Schneider Electric Conext Core XC680-NA 680 kva solar inverters. group has requested an in service date of 10/1/2016 and that this generation be interconnected to the existing SCE&G 46 kv transmission system at a site near the. A previous Generator Interconnection System Impact Study was conducted to determine the ability of the SCE&G transmission system to interconnect the Generator to the Transmission System and to address any identified power flow, short circuit and instability issues. In that System Impact Study, facilities were identified that would require modifications in order to provide the requested Generator Interconnection. This Facilities Study identifies the cost and scheduled completion date of those modifications needed to provide the requested Generator Interconnection. Generator Interconnection Specifications The solar generation facility design consists of the following information: MVA: 8.16 MW: 8.16 PF: 80% lead/lag GSU: 46/26.56 kv (Wye-Wye) Speed: N/A 3
Scope of Work, Cost Estimates and Time to Complete The Table below includes the scope of work, cost estimate and time to complete for the transmission improvements required to provide the requested Generator Interconnection. Time to Complete includes design, drafting, ordering equipment, issuing drawings for construction, issuing drawings, lead time for equipment and construction. (Note that the installation of some equipment may require planned outages of transmission facilities. The ability to schedule an outage and perform the installation is subject to review and is based on transmission system conditions at the time of installation.) Scope of Work Estimated Cost 1 Complete 2 Time to Make modifications to the SCE&G transmission system to provide a radial Generator Interconnection off of the adjacent to project. (See Figure 1, 2, 3 and 4) - Construct an SCE&G-owned 46 kv switching station including, but not limited to, a 46 kv Circuit Breaker, structures, foundation, switches, PT s, CT s, batteries, revenue quality metering, SCADA, station service, lightning arresters, gravel, fencing and ground grid. - Install a Triple Suspended Pull Off (TSPO) wood pole in the center line of the line adjacent to project. Install two spans of transmission conductor from the TSPO to a structure in the SCE&G-owned 46 kv switching station. This cost assumes the SCE&G-owned 46 kv switching station is adjacent to or within 150 ft of the R/W. The cost does not include R/W procurement due to the unknown location of the station. - Make modifications at the Transmission Substation to accommodate reverse power flow through the transformers. $712,300 10 months $65,000 8 months $8,000 3 9 months TOTAL Required for Generator Interconnection $785,300 10 months 1. Estimated Costs based on future required In-service date. Costs do not include site cost, site preparation, road access or Right of Way procurement if needed. 2. Time to complete based on normal lead times for structures and major equipment and timing to allow an off-peak outage of the Estill-Estill 46 kv line. Time to Complete does not include time to acquire site, prepare the site and/or acquire Right of Way if needed. 3. The need for this modification exists in higher priority generator interconnection requests and may be completed as part of a generator interconnection that has a higher position in the generator interconnection queue. If the higher position generator interconnection request continues, then this modification may not be required as part of this generator interconnection. 4
Summary This Generator Interconnection Facilities Study has identified the cost and scheduled completion dates of the modifications needed to provide the requested Generator Interconnection. The 10 month Time to Complete, as shown above, will commence after all appropriate agreements have been signed. 5
6
7
8
9