the country recognizes the advantage of diversification to strengthen its energy supply structure and is also looking to increase the number of small and medium hydropower producers government of japan planning and integrating a large number of small power generation plants utilizing different resources and dispersed over broad geographic regions has helped support a more stable supply that incorporates variable renewables in some areas furthermore the introduction of increasingly affordable battery storage enables variable renewable energy such as solar and wind to become dispatchable resources which are able to store surplus generation and then supply power systems when demand is present technology for batterybased energy storage systems is improving and costs are projected to continue to fall pointing to the growing potential for increased renewable energy uptake