The rooftop on-grid PLTS system is commonly used by people from the household,commercial, to industrial sectors to reduce electricity bills from PLN. Based on PERMEN ESDM49 of 2018, the export value of electrical energy to the PLN electricity grid is 65%, and if energyexports are greater than energy bills, the rest will be stored and accumulated in the followingmonth. This is only valid for a maximum of 3 months, in the 4th month the remaining energyexport savings will be eliminated. Determining the right PLTS capacity makes the contribution ofPLTS in making bill savings more optimal. The office of BAPPEDA LITBANG Probolinggo Citywas used as the research location. The PLTS Scenario 1 design uses a capacity according tothe energy needs of the office, which is 21.6 kWp, and the PLTS Scenario 2 capacity is greaterthan the office energy requirement of 32.4 kWp. Based on the investment feasibility analysisusing the NPV, PI, and DPP methods, it shows that the Scenario 1 and Scenario 2 PLTSdesigns are feasible to run. PLTS Scenario 1 and Scenario 2 investment is Rp. 267,000,000and Rp. 395.85 million, respectively. The benefit of saving bills for 30 years of PLTS operation,in Scenario 1 is Rp. 406,863,069 or 152% of the total investment, while Scenario 2 is Rp.595,619,904 or 150% of the total investment.

The use of renewable energy is a solution in the application of clean andenvironmentally friendly energy, one of which is the use of solar power with the PLTS system. Inthis study, the PLTS system planned at TOSS Werdi Guna is a PLTS-On Grid system without abattery with a ground mounted installation, the aim is to reduce the cost of electricity bills. PLTSplanning at TOSS Werdi Guna has a capacity of 32.6kWp with a number of 86 modules anduses 1 inverter unit with a capacity of 33kW. The energy production produced by PLTS for ayear is 52,955kWh. The total investment cost required is IDR 580,469,095 with a paybackperiod of 7 years and 4 months.

Utilization of renewable energy as a source of electrical energy is an environmentallyfriendly energy development, one of which is the use of solar energy by developing solar PV onthe roof of buildings as a medium for installing solar modules. In this study, a rooftop solar PVplan was carried out at the Nangka Utara gas station as a source of electrical energy whichaims to reduce the cost of PLN electricity bills. The rooftop solar PV system at the Nangka Utaragas station uses an On-grid solar PV system without batteries, using 36 units of 415 Wpmonocrystalline solar modules and one 15kW inverter unit. Planning for rooftop solar PV of theNangka Utara gas station with a capacity of 14.9 kWp with the resulting energy production of20.43 MWh per year. The initial investment cost required is IDR. 101.179,000 with a paybackperiod of 5 years and 8 months.