Scientists have simulated a 4G and 5G cellular base station in Kuwait, powered by a combination of solar energy, hydrogen, and a diesel generator. The lowest cost of energy was found to be $0.0714/kWh.

Researchers from Kuwait’s Kuwait University have proposed operating 4G and 5G cellular base stations (BSs) with local hybrid plants of solar PV and hydrogen. Numerically simulating a few configurations for such a station, the team has considered net present cost (NPC), the cost of energy (COE), and CO2 emissions. The simulation took place under the conditions of Hawally, a city in the east of Kuwait.

“Renewable energy sources (RESs) such as solar and wind can be used to power BSs and offer sustainable and environment-friendly alternatives to traditional grid power or diesel generators (DGs),” the academics said. “The use of RESs in powering BSs can also help reduce operational costs and increase network availability, particularly in remote areas, where access to grid power may be limited or unreliable.”

The PV power in the simulation was based on 285 W panels with an efficiency of 17.41% or 665 W and 21.4%. The storage was based on a battery bank (BB) with 244 Ah, and the inverters were assumed to have an efficiency of 95%. A DG system with a minimum load ratio of 25% was also implemented for times when renewable production does not meet demand. Electrolyzers with 85% efficiency were also assumed.

“The BS load profile was acquired for the period from November 2021 through October 2022,” the group added. “The DC annual average energy is determined as 122.11 kWh/day, while the AC annual average energy is obtained as 110 kWh/day. In turn, the total average energy amounts to 232.11 kWh/day. The DC peak power is 15.10 kW, and the AC peak power is around 13.6 kW.”

Per the simulation results, when 285 W is used, the optimized size of the system uses 194 panels for a total capacity of 55.1 kW, along with DG of 34 kW, fuel cell (FC) of 5 kW, electrolyzer of 5 kW, hydrogen tank of 15 kg and a convertor of 12.7 kW. The yearly PV production, in this case, is 97,923 kWh, and the FC is 766 kWh. Its NPC is $160,075, COE is $0.0945, and yearly CO2 emission from the DG is 5,317 kg.

However, when 665 W is used, the optimized size of the system uses 95 panels for a total capacity of 63.1 kW, along with DG of 34 kW, FC of 5 kW, electrolyzer of 5 kW, hydrogen tank of 5 kg, and an inverter of 13.5 kW. The yearly PV production, in this case, is 114,304 kWh, and the FC production is 832 kWh. Its NPC is $121,014, COE of $0.0714, and yearly CO₂ emission from the DG is 3,257 kg.

“When constraining the DG capacity in the PV-HFC-DG-BB model, the simulations show that constraining DG to lower values than the unconstrained ‘Base’ case can lower the NPC (up to 7.71%) as well as system area (up to 9.93%),” the group added. “In fact, when using a DG with small capacity, the system will be forced to increase the FC energy production, which leads to a significant decrease in the CO2 emissions (by 51.12%) while improving the renewable energy fraction (by 1.44%).”

The system was presented in “Hybrid solar PV/hydrogen fuel cell-based cellular base-stations in Kuwait,” published in the Journal of Engineering Research.

Looking forward, the scientists said they want to consider hybrid PV-wind-HFC systems in on-grid and off-grid system configurations, as well as the use of PV panels with higher peak output power. “It would be interesting to study the potentials of utilizing a wind turbine by incorporating it into the hybrid solar PV/HFC electric system across various locations in Kuwait,” they added.