The 35,000 MW project, which the Government of Indonesia declared in 2015, was a massive development of a new power plant installed in the Indonesia power system. Along with this 35,000 MW project, there are 108,000 MVA development of new substations and 46,000 km of new transmissions, which benefit and impact the future of the Indonesian power system. Currently, 35,000 MW projects are rapidly studied and discussed, but there are none in-depth-studies for the relation between 108,000 MVA and 46,000 km of circuit projects with 35,000 MW project itself. This paper discussed several points: the progress projects and their impact on the power system, quantify the economic benefit of each power plant, substation, and transmission project. The Monte Carlo simulation performs to describe the uncertainty conditions from investment cost, capacity factor/loading, generation production cost, and electricity sales tariff. The simulation can produce a range of economic benefit probabilities from each project. The assessment result showed that several projects were postponed, and a few projects there are not financially viable and are very vulnerable to input variable changes.