In this study we evaluate the economic potential for energy arbitrage by simulating operation and resulting profits of a small price-taking storage device in South Korea’s electricity market. As demand for electricity continues to grow, maintaining a balanced power system at all times has become more challenging in Korea and other developed nations. Along with demand response programs and increased renewable energy utilization, energy storage devices may provide a viable way to contribute to diurnal peak demand shaving. In some parts of the U.S. storage arbitrage has proven to be profitable. Treating a battery’s ability to charge and discharge as a scarce resource, we apply the Hotelling (1931) rule to determine a strategy for maximizing the value of the battery. Results show that present market conditions in South Korea do not provide sufficient economic incentives for energy arbitrage using sodium–sulfur (NaS) or lithium-ion (Li-ion) batteries, with the capital cost of the storage devices exceeding potential revenues.