St. Panteleimon Monastery is located on a narrow peninsula (eastern part of the Halkidiki Peninsula), where the climate is subtropical. The population is about 2,000. Decentralized energy supply systems equipped with solar energy and organic fuel metering systems are employed.
The monastery’s energy demand was met by an autonomous hybrid energy system consisting of diesel generators, solar (photovoltaic) installations, and an energy storage system (lead-acid batteries) to supply nighttime loads. The total generation capacity is 420 kW, and the total battery capacity is 430 kWh. The average daily consumption was estimated to be up to 1000 kWh.
The energy balance research studied several days as examples, each with different conditions.
The operator can disconnect the diesel generators, while other functions are limited to monitoring the currents and voltages in the photovoltaic (PV) plants’ circuits and the overall load. The system has hardware capabilities but lacks software for centralized control and monitoring of the PV plants and the energy storage system (based on SMA equipment). The settings of the existing system are considered suboptimal, leading to inefficient use of electricity from the PV plants, constant “charge-discharge” cycles of the battery banks, frequent use of diesel generators (sometimes operating in suboptimal modes), and low overall system efficiency. There are opportunities to expand the automated control system (ACS) by revising the control cable lines for SMA equipment and developing appropriate software.
An assessment of the solar and wind energy potential and the technically achievable and economically viable potential of plant and animal biomass, household waste, and hydroenergy has been conducted.
A set of measures has been proposed to improve the energy supply system. Adjusting the automated control system (ACS) is recommended to reduce battery energy use. The replacement of the existing distribution panel with a new one, equipped with telemechanical switches and a computer interface, is planned. To expand the ACS capabilities and optimize its performance, it is necessary to revise the existing SMA equipment cable lines, connect the equipment according to the operating manual, and add bus translators. To further expand the ACS capabilities and optimize its performance, it is proposed that the existing cable lines for SMA equipment be revised, the equipment be connected according to the operating instructions, and bus translators be added.
The main criterion for the system’s performance was meeting the nighttime loads, minimizing unused electricity from the PV plant, and reducing the use of diesel generators.