We adhere to our minimalistic approach when managing electrical energy. The institute is powered entirely by a solar panel array generating less than 0.5 kWp. The solar field is divided into two branches; one comprises seven 50Wp solar panels, resulting in a 350Wp solar power capacity. Energy from this branch is stored in five Li-ion batteries, each with a nominal voltage of 36V (12P10S) and a capacity of around 1 kWh. In our institute, these batteries are dedicated to powering a 230V AC inverter, mainly supplying the fridge and water pump. We strive to operate our devices on DC 12V wherever possible. The DC 12V branch features LiFePO4 (4S) batteries and is supplied by an array of solar panels with a 150Wp capacity.
The inverter, by design, consumes some power when in an idle state, approximately 10W for our setup. To minimize energy consumption further, we employ a remote control to turn the inverter on. The remote control is connected to a relay controlled by the fridge thermostat, ensuring the inverter’s idle time is reduced to zero.
While considering a similar principle for the water pump, utilizing the pressure sensor to turn the inverter on, we opted for an alternative approach. We use a 100L pressure tank for the water pump, providing ample water pressure capacity for temporary usage throughout the day. This pressurization occurs once over time, coinciding with the inverter being on due to the fridge. This setup simplifies the system and reduces the likelihood of potential issues. For more extended or permanent water usage, there is a manual switch to turn the inverter on, serving the dual purpose of meeting the institute’s 230V AC needs for other applications.
