"There are hundreds of microgrids around the world that are running, and their numbers are still growing. In the practice of various microgrid configurations including grid connected and independent systems, we can have the opportunity to see the ability of microgrid to integrate high proportion of renewable energy. The research of the project "Rocky Mountain Institute director Kaitl yn Bunker and Clinton Island climate action project manager Siana Teel ucksin energy and the important role of" micro grid in global energy transformation in said.

No matter the size of the country, the stable power supply is the most basic guarantee of economic development and peoples daily life. Although temporary blackouts will only bring some inconvenience to family life, but for hospitals and military bases and other critical facilities, power outage is likely to cause interruption of important services or military tasks, and then endanger human life safety. Microgrid, a small network that provides power for local demand, is one of the effective ways to avoid this risk.

"There are hundreds of microgrids around the world that are running, and their numbers are still growing. In the practice of various microgrid configurations including grid connected and independent systems, we can have the opportunity to see the ability of microgrid to integrate high proportion of renewable energy. The research of the project "Rocky Mountain Institute director Kaitl yn Bunker and Clinton Island climate action project manager Siana Teel ucksin energy and the important role of" micro grid in global energy transformation in said.

The study says that in recent years, the cost of solar and wind power has decreased significantly, which means that solar and wind power already has the same cost competitiveness as traditional fossil fuel power generation technology. This allows microgrids to achieve clean energy goals in an economically viable way, while completing the main task of stabilizing power supply.

Quickening the transition of island microgrid

The microgrid can be connected to a larger grid. When a large-scale power failure occurs, the microgrid can interrupt the connection with the main power grid and continue to operate independently, ensuring the power supply of household and commercial services in its service area. The reliability is higher, more sustainable and lower cost. These advantages make grid connected microgrid utilization rate increasing, and at the same time, promote the transformation of independent microgrid.

A number of developing island countries have played a certain role in the 2016 Paris conference of States parties, and are actively implementing the transformation of the power system, making full use of local renewable energy. Solar photovoltaic, wind power and energy storage technology can help independent microgrid fulfill the international climate commitment, improve energy independence and reduce carbon emissions.

The study believes that more sophisticated control technology is needed to ensure the stable operation of the system with the increase of the proportion of renewable energy in the microgrid. Take the island as an example, and the whole country (and its economy) depends on the only power grid. Power grid engineers and operators are shouldering the important task of maintaining the stable operation of an independent microgrid, which will affect the operation of the country as a whole.

The common challenge of grid connected and independent microgrid

The study says that although the grid type and the independent microgrid are obviously different, they have a lot in common. These generalities make the experience of various micro grid projects learn from each other to speed up the rising trend of various micro grid learning curves.

The advantage of grid connected microgrid is that it can rely on large power grid as backup in normal operation time, and at the same time, they are similar to the technology applied to independent microgrid, and are faced with similar challenges -- how to ensure reliable, sustainable and low-cost power supply. In the design of grid connected and independent microgrid, it is a major challenge to maintain a correct balance between the volatility and the stability of energy. In addition, the other problem is how to find an economic balance between cost reduction and construction of large-scale standby energy to ensure reliability.

Like the island power grid, the traditional grid connected micro grid is also largely dependent on all kinds of fossil fuel power generation technology, especially diesel power. Their back-up systems are often dominated by gas generation, fuel cell and cogeneration technology. With the steady decline of the cost of renewable energy technology and the increasing recognition, management and affirmation of the value of distributed energy, the carbon emission intensity of grid connected microgrid is getting lower and stronger. Meanwhile, the sources of power generation are more and more abundant. Another problem of grid connected microgrid is the need to design control systems for two main operating modes. For example, the University of California at San Diego microgrid has proven to be able to operate normally when it is connected to a large grid and its isolation.

Common opportunities for various scale grids

Because the independent and grid connected microgrids have similar goals, technologies and challenges, the designers of the two microgrids have the opportunity to fully communicate with operators and learn from each others best practices.

The study considers that considering the serious consequences of power failure in grid connected or stand-alone microgrids, we must have a careful study of the design of microgrid structure, the selection of power sources, integration and control. In addition, grid operators are seeking innovative and proven solutions, and have begun to try to apply new ways of operation, including closer coordination with users.

Considering the many aspects of grid owners and operators must evaluate, and the opportunities that microgrid can provide, we can predict that microgrid can play an important guiding role in the transformation of global power system. The study says developed countries have always been leading.