Coupling energy storage systems with renewable generation systems has a variety of advantages including: increasing the penetration of renewables, reducing curtailment, providing energy security, lowering greenhouse gas emissions and providing an array of ancillary services. These advantages are multiplied for hybrid off-grid power systems. However, sizing both the energy storage system for both energy capacity and the power rating can be difficult in these remote locations, as modularity, solution characteristics, transportation and installation logistics must be taken into consideration. This analysis simulates one year of energy generation and load based on real data from the remote community of Old Crow Yukon Territory, Canada. Throughout the year data pertaining to the effect of the energy storage system on the remote power system are collected. This information is used to find the optimal energy capacity and power rating for the remote isolated power system, using a specific energy storage dispatch logic. Seven parameters are used to find the optimal solution: cost of energy, cost of power, cost of fuel, cost of curtailment, cost of reserve, cost of insufficient power, and cost of blackouts. Each parameter is compared on the basis of levelized cost of energy and a specific weighting factor. Three cases are examined for different weighing factors, to demonstrate the flexibility of the approach to serve specific purposes. Case 1 examines equal values across all weighting factors. Case 2 focuses on fuel consumption and curtailment and Case 3 focuses on energy security and reliability.
Remote hybrid power systems that integrate renewable resources, such as wind and solar, in a thermal generation system encounter technical barriers with regards to the depth of penetration of these renewable resources. Some of these barriers can be addressed by curtailing the renewable generation, however with increasing levels of penetration energy storage must be implemented within the system in order to maintain system security and adequacy. These barriers are identified through a logical approach and the level of renewable energy that these barriers reside at is found through QSTS simulations of the remote power system of Old Crow, Canada. This analysis finds that for a remote, isolated diesel based power system the most load that a generator could pick up or shed is approximately 65% of the name plate capacity. Therefore, the size of the renewable resource before energy storage required is dependent on the capacity of the smallest generator to ensure that energy balance and system security are maintained.
