Global warming is the main driving force behind worldwide interest for the generation of bulk electrical energy from renewable sources. As a consequence of advancements in solar cell fabrication and converter technology, solar PV has emerged as one of the most promising renewable sources for bulk power generation. If the current commissioning rate continues, PV power would lead to the modification of several aspects of power system and could influence the stability of the system. This paper extensively reviews the technical challenges, on particular, the stability issues associated with the integration of large-scale PV into the power system. In addition, the paper also reviews the dynamic model of large-scale PV for stability studies as well as the grid codes for large-scale PV integration into the system. Finally, this paper summarizes the research findings about the technical solutions to overcome the power system stability challenges regarding the large-scale PV integration into the transmission and sub-transmission or medium voltage distribution system.

A review of key power system stability challenges for large-scale PV integration

https://docs.lib.purdue.edu/cgi/viewcontent.cgi?article=1144&context=coolingpubs

Thermal analysis of solar thermal energy storage in a molten-salt thermocline

As a result of the increased awareness of the dangers posed by global climate changes (mainly caused by growing global energy consumption needs), the quest for clean and sustainable energy future is becoming of paramount importance. This can be largely realized via a large-scale integration of variable renewable energy sources (RESs) such as wind and solar, which have relatively low carbon footprints. In many power systems, the level of integration of such resources is dramatically increasing. However, their intermittent nature poses significant challenges in the predominantly conventional power systems that currently exist. Among others, frequency and voltage regulation issues can, for example, arise because of improperly balanced and largely uncoordinated RES supply and demand. Generally, the higher the integration level of intermittent power sources is, the higher the flexibility needs are in the system under consideration. Flexibility, in a power systems context, refers to the ability of such a system to effectively cope with unforeseen changes in operational situations, which are mainly induced by the inherent uncertainty and variability arising from the supply side, demand side or any other external factors. In the absence of appropriate flexibility mechanisms, it is increasingly difficult to manage the imbalances between generation and demand as a result of their natural variations in real-time. This paper presents an extensive and critical review of the main existing and emerging flexibility options that can be deployed in power systems to support the integration of “carbon-free” and variable power production technologies. Starting from a broader definition of flexibility, we highlight the growing importance of such flexibility in renewable-rich energy systems, and provide insights into the challenges and opportunities associated with various flexibility options provided by different technologies.

A comprehensive survey of flexibility options for supporting the low-carbon energy future

https://northumbria-test.eprints-hosting.org/id/document/267323

A two stage hierarchical control approach for the optimal energy management in commercial building microgrids based on local wind power and PEVs

To realize the synergy between plug-in electric vehicles (PEVs) and wind power, this paper presents a hierarchical stochastic control scheme for the coordination of PEV charging and wind power in a microgrid. This scheme consists of two layers. Based on the non-Gaussian wind power predictive distributions, an upper layer stochastic predictive controller coordinates the operation of PEV aggregator and wind turbine. The computed power references are sent to the lower layer PEV and wind controllers for execution. The PEV controller optimally allots the aggregated charging power to individual PEVs. The wind controller regulates the power output of wind turbine. In this way, a power balance between supply and demand in a microgrid is achieved. The main feature of this scheme is that it incorporates the non-Gaussian uncertainty and partially dispatchability of wind power, as well as the PEV uncertainty. Numerical results show the effectiveness of the proposed scheme.

Stochastic Coordination of Plug-In Electric Vehicles and Wind Turbines in Microgrid: A Model Predictive Control Approach

I am pleased to offer this issue devoted to the integration of wind-generated power into the electric grid. This is our fourth look at this subject, each coming at two-year intervals. When we last looked, wind power constituted 1.5% of worldwide electricity usage (according to 2008 figures); that number has grown to 2.5% (per 2010 figures). Several countries have achieved relatively high levels of wind power generation, notably Denmark (21%), Portugal (18%), Spain (16%), Ireland (14%), and Germany (9%). During that same period (2008–2010) China has installed approximately 30 GW, a almost four-fold increase in wind generation.

Windy conditions [From the Editor]

Whether we're talking about the "smart grid" or the "intelligent grid" or, as we have chosen to call our issue, "the-next generation grid," the electric grid of the future is a subject that's certainly on the front burner. The topic attracted attention during the recent U.S. election campaign, and statements by President Obama suggest the issue will become a priority during his presidency, even in these troubled economic times.

Beyond the gridlock [From the Editor]

The guest editors of this issue, Ralph Masiello and Mani Venkata, have titled their guest editorial "Microgrids: There May Be One in Your Future." Their answer is a resounding yes, and the articles they are introducing offer proof of this conclusion. After citing multiple reasons for reaching that conclusion, they offer "there is enough activity in the microgrid world today that multiple market research studies are touting billions of dollars of microgrid business in the next few years." That claim will be backed by the information contained in the seven feature articles that cover the theme of our issue. An overview of the technical articles and features presented in this issue is then given. Next, predictions regarding increased solar activity in the foreseeable future abound this year are briefly discussed along with the upcoming IEEE Power & Energy Society (PES) elections.

The Future of Microgrids: Coming to a Neighborhood Near You [From the Editor]

The rise of the sun [From the editor]

The six articles in this issue examine the need to make power system grids more resilient against the forces of nature and catastrophic climate-related events. These articles provide a penetrating look at the catastrophic events themselves as well as ensuing responses and the plans either formulated or in place to mitigate future events.

Mel Olken

Papers

Windy conditions [From the Editor]

Beyond the gridlock [From the Editor]

The Future of Microgrids: Coming to a Neighborhood Near You [From the Editor]

The rise of the sun [From the editor]

The Resiliency of the Grid: Putting the Plans in Place [From the Editor]