Techno-economics and environmental analysis of energy storage for a student residence under a South African time-of-use tariff rate

Abstract

Time-of-Use has been introduced in South Africa as part of demand side management measures. Battery energy storage (BES) can take advantage of energy price arbitrage under favourable pricing regimes. However, the challenge is to what extent will the introduced policy favour the installation of BES at residential accommodations? The tools to assess suitability of installing BES exist but they come at a cost. In this study, we improved upon existing methodology and implemented it in Microsoft Excel to assess techno-economic viability and environmental benefits of using BES. The approach showed that none of the three BES technologies investigated was economically viable at the prevailing average rate of 0.1442 $/kWh for peak electricity. The Monte Carlo simulation implemented suggests that the minimum mean price of peak needed for the BES system to break even range between 0.2560 – 0.2919 $/kWh. At 50% discount in storage medium cost and 100% increase in the price of peak, the BES will only break even when the average price of peak is 0.2043 $/kWh at maximum cycling cost that range between 0.1077 – 0.1560 $/kWh. The study concluded that reduction in the cost of storage medium has more impact on economic viability than increasing only peak price of electricity.