Ultra-capacitor assisted battery storage for remote area power supplies: A case study

Remote areas power supplies (RAPS), with their crucial requirement for good inverter input voltage regulation, differ markedly from other applications such as uninterruptible power supplies (UPS), electric vehicles (EVs) and hybrid electric vehicles (HEVs). Also, the overall cost of remote area power supplies is significantly affected by the life expectancy and the cost of associated battery storage. Ultra-capacitors can be used to smooth battery current demand. A smoother current demand results in a steadier inverter input voltage. There are also claims that a smoother current demand profile improves the life expectancy of lead acid batteries. This case study aims to quantify the potential benefit of ultra-capacitor assisted battery storage. It is shown that significant benefits are possible if ultracapacitors are used together with lead-acid or nickel iron batteries.