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Comparative Investigation of System-Level Optimized Power Conversion System Architectures to Reduce LCOE for Large-Scale PV-Plus-Storage Farms

Conference · · IEEE Energy Conversion Congress and Exposition (ECCE)
 [1];  [2];  [2]
  1. Georgia Inst. of Technology, Atlanta, GA (United States); Georgia Institute of Technology
  2. Georgia Inst. of Technology, Atlanta, GA (United States)

PV-plus-storage (PVS) has become a prevalent configuration for newly commissioned large-scale solar projects. However, the optimal power conversion system (PCS) architecture has not been investigated yet. This paper first validates the limited impact of inverter cost on LCOE and then explores a system-level optimized PCS architecture with extended LCOE reduction to proliferate large-scale dispatchable solar energy. Two state-of-the-art architectures including central inverters (CI), traditional 480/600 V string inverters (SI) are compared with newly proposed medium voltage string inverters (MVSI) and multiport DC transformer (MDCT). With verified layouts and single line diagrams (SLDs) of 20 MW PVS plants, the losses and costs breakdown of different architectures are extracted and the PCS related LCOEs are derived. In this analysis, all electrical bill of materials (EBOS) elements, inverters, battery storage and its associated components, are included, whose losses and costs are obtained from markets, manufacturers, and literature. Besides, the sensitivities of PCS-related LCOEs to Inverter-Loading-Ratio (ILR) are also investigated. Here, the results show that compared with CI and SI with 1.5 kV PV, 4 kV MVSI and 34 kV MDCT present an extended LCOE reduction across all ILR from 1.0 to 3.0, making them economically favorable candidates for PVS farms.

Research Organization:
Georgia Inst. of Technology, Atlanta, GA (United States)
Sponsoring Organization:
USDOE Office of Energy Efficiency and Renewable Energy (EERE), Renewable Power Office. Solar Energy Technologies Office.
Contributing Organization:
First Solar; Oak Ridge National Laboratory (ORNL); Southern Company
DOE Contract Number:
EE0008351
OSTI ID:
1923367
Journal Information:
IEEE Energy Conversion Congress and Exposition (ECCE), Journal Name: IEEE Energy Conversion Congress and Exposition (ECCE) Vol. 2021; ISSN 2329-3721; ISSN 2329-3748
Publisher:
IEEE
Country of Publication:
United States
Language:
English

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