The effect of energy storage on the Residual Load Duration Curve (rLDC) of a system with high Renewable Energy contribution

Abstract

This paper evaluates how energy storage acting in a system with a very high contribution from variable Renewable source can reduce peak loads. The methodology uses observed demand and renewable generation data to construct scenarios of increasing renewable contribution complemented by energy storage. The analysis is based on the concept of creating load duration curves for the period over which a set of storage technologies can act to reduce peak loads by storing energy during low loads. The models used here are developed on the premise that different types of storage are deployed for different purposes. For the scope of this work, three types were used. The first to manage loads within a day, the second acting over a period of a week, and the third at a much longer, seasonal scale.

A model for optimum prioritisation of energy storage use. I: Optimum local use of local generation

“…That initial rapid change gradually reduces suggesting that the marginal benefit of increasing the storage tails off rapidly at around the 10 to 20 MWh storage size. With the mean half-hourly consumption (Table I), this equates to a scale of 13 to 26 hours, confirming a common observation [2,14] that much of an ESS addresses the daily demand and generation cycle. Addressing imbalances across several days or weeks requires significantly larger capacities.…”