This paper presents a fuzzy logic-based algorithm developed for battery storage power management (BSPM) and demand side power management (DSPM) for the School of Renewable Energy Technology (SERT)-Smart Grid (SSG) at Naresuan University in Phitsanulok, Thailand. This algorithm enables lower cost operation of the SSG by utilizing the time of use electricity-pricing concept and thus is called the Fuzzy Low-cost Operation (FLO) algorithm. After applying the FLO algorithm to the SSG, the BSPM can strategically handle fluctuating PV production by intelligently alternating between absorbing power during high solar irradiation periods and discharging power to the load during peak consumption times. The FLO algorithm also empowers the SSG's DSPM to decrease the peak load by using SERT's building energy management system to disconnect noncritical load as desired, for example lighting, air conditioners, and dummy heater load (used for research testing purposes). Research results show that the FLO algorithm successfully decreased SERT's annual electricity bill by 17.58%, equivalent to a grand total of $ 9148 in annual savings. Of 17.58% in savings, 5.78% came from modifications to the BSPM and 11.81% came from modifications to the DSPM. The average monthly savings correspond to $762 ($250 from BSPM and $512 from the DSPM), significant savings that without the FLO algorithm would not be available.