As the penetration of variable renewable generation increases in power systems, issues, such as grid stiffness, larger frequency deviations, and grid stability, are becoming more relevant, particularly in view of 100% renewable energy networks, which is the future of smart grids. In this context, energy storage systems (ESSs) are proving to be indispensable for facilitating the integration of renewable energy sources (RESs), are being widely deployed in both microgrids and bulk power systems, and thus will be the hallmark of the clean electrical grids of the future. Hence, this article reviews several energy storage technologies that are rapidly evolving to address the RES integration challenge, particularly compressed air energy storage (CAES), flywheels, batteries, and thermal ESSs, and their modeling and applications in power grids. An overview of these ESSs is provided, focusing on new models and applications in microgrids and distribution and transmission grids for grid operation, markets, stability, and control.

Millions of people have limited or no access to electrical energy. A diverse group of scholars and activists, from individual researchers to nongovernmental organizations (NGOs), civil society organizations, UN, and increasingly to engineering and financial private sector firms, have been working on initiatives to address this issue, which is considered by many a human rights problem. Energy access is not only a challenge for developing economies but is also equally important for service to remote areas such as the Arctic, islands, and communities distant from the grid. Several governments and private institutions, as well as nongovernment organizations around the world, are now funding projects and a variety of initiatives to help impoverished communities, especially across Africa and remote regions, develop clean and sustainable energy systems. The IEEE is actively involved in addressing energy access issues through several initiatives, such as the Smart Village program, focusing on “integrating sustainable electricity, education, and entrepreneurial solutions to empower off-grid communities” (http://ieee-smart-village.org/). In this special issue, we concentrate on highlighting the current state of knowledge associated with strategies for bringing clean, affordable, and sustainable electricity service reliably to energy-limited communities, based on local renewable energy (RE) sources and storage systems. Sociopolitical and economic forces as well as inclusionary and exclusionary culture or practices that often define the technical approaches and solutions offer opportunities for progress on this important problem.

The effect of climate change is significant in the arctic regions of the world, with the carbon footprint from diesel-only based electricity generation in remote arctic communities adding to the environmental degradation through greenhouse gas (GHG) emission, oil spills, and black carbon. Moreover, the dependence on diesel and its associated costs are an economic problem for these communities, particularly in the Canadian Arctic, where governments subsidize this fuel. Thus, this article presents specific studies including new variable-speed generator (VSG) technologies that demonstrate the feasibility, impact, and benefits of introducing renewable energy (RE) together with VSGs in remote microgrids in the Canadian Arctic. More specifically, this article describes a two-step procedure to select remote communities for detailed feasibility studies of deployment of RE sources, including a generation expansion planning (GEP) framework and optimization model for RE and new VSG integration applied to the selected communities, to minimize diesel dependence of isolated microgrids and maximize the incorporation of environmentally friendly generation technologies. The proposed approach is applied to communities in Nunavut and the North West Territories in the Canadian Arctic, based on actual data, to study the technoeconomic feasibility of RE integration and develop business cases for diesel generation replacement with RE and VSG generation in these communities. The obtained optimal plans contain diesel-RE hybrid combinations that would yield substantial economic savings and reductions on GHG emissions, which are being used as the base for actual deployments in some of the studied communities.