Lifecycle Value and Tariff Impact Assessment of Voltage Support and System Strength Technologies in Weak High-PV Power Systems

High levels of photovoltaic penetration and synchronous generator decommissioning are weakening grid strength and increasing voltage support requirements, yet most studies still assess support technologies primarily based on technical performance rather than full lifecycle utility value. The key gap is the absence of a consistent framework that links technical performance to lifecycle cost, tariff impact and investment outcomes across competing technologies. This study addresses that gap by developing a transparent utility-oriented assessment framework to compare Static Var Compensator (SVC), Static Synchronous Compensator (STATCOM), Synchronous Condenser (SC) and grid-forming BESS (BESS-GFM) options in a weak high-PV penetration network. Quasi-dynamic simulations on an IEEE 9-bus system were used to quantify technical benefits, which were then converted into lifecycle financial metrics within a total expenditure (TOTEX)-based model and combined with practical decision criteria through multi-criteria decision analysis (MCDA). The results show that while all four technologies improve system performance, their overall value differs once cost, tariff impact, risk and flexibility are considered. Under the adopted assumptions, STATCOM provides the best overall balance and ranks highest.