Microgrids are becoming increasingly popular as a way to improve energy efficiency and reduce reliance on traditional power grids. These small-scale systems generate and distribute power locally allowing for greater control and flexibility in energy management. However, as with any new technology, there are both advantages and disadvantages to consider when implementing a microgrid. This article will provide a full review of the benefits and drawbacks of microgrids, examining their potential impact on energy production and distribution, as well as their overall cost-effectiveness.
Advantages of Microgrids
Microgrids can provide several advantages, including:
1. Improved power reliability
Because microgrids can operate independently from the main grid, they can provide a reliable source of power during grid outages. This can be especially beneficial in emergency situations or for critical facilities such as hospitals and emergency shelters.
For example, during Hurricane Sandy in 2012, Princeton University’s microgrid remained operational even when the surrounding area lost power. The microgrid provided power to critical facilities on campus including the emergency operations center, health services and a residence hall that was used as a shelter. This allowed the university to continue operating and providing essential services during the storm.
2. Enhanced energy security
Microgrids can be powered by a variety of energy sources, including renewable energy sources such as solar or wind power. This can reduce a community’s reliance on fossil fuels and enhance energy security.
For example, in the United States, the island of Hawaii has implemented a microgrid powered by a combination of solar, wind and battery storage. The microgrid, located on the island of Molokai, provides reliable and sustainable energy to the local community reducing their dependence on diesel generators that are expensive and contribute to air pollution. The microgrid has also improved energy resilience allowing the community to maintain power during power outages and natural disasters.
Another example is the Brooklyn Microgrid in New York City which is powered by solar panels installed on rooftops and other locations throughout the community. The microgrid allows members of the community to buy and sell energy locally creating a more sustainable and decentralized energy system. This microgrid is an example of a community-driven initiative to increase energy security and reduce reliance on non-renewable energy sources.
3. Increased energy efficiency
Microgrids can be designed to optimize energy use resulting in increased energy efficiency and potentially lower energy costs for users. Widespread application of modular microsources may contribute to a reduction in energy prices in the power market with an appropriate economic balance between network investment and distributed generation utilization.
For example, consider a microgrid installed in a residential neighborhood that includes rooftop solar panels, battery storage and a smart energy management system. The microgrid can supply electricity to the neighborhood during times of peak demand or when the main grid experiences a power outage.
The smart energy management system can optimize the use of energy by balancing the supply from the solar panels and the demand from the neighborhood. The excess energy generated by the solar panels can be stored in the batteries for later use, reducing the dependency on the main grid and potentially lowering energy costs for the users.
Moreover, if the microgrid produces more energy than the neighborhood needs, the excess energy can be sold back to the main grid contributing to the reduction in energy prices.
Overall, the application of modular micro-sources in a microgrid can contribute to a more efficient and cost-effective energy system.
4. Improved power quality
Microgrids can provide clean and stable power which can be especially beneficial for facilities that rely on sensitive electronic equipment. An example of this would be a hospital that relies on stable and reliable power to operate critical medical equipment. In the event of a power outage, a microgrid can provide backup power ensuring that the hospital can continue to operate without interruption.
5. Environmental benefits
The environmental impact of micro sources is expected to be smaller than with large conventional thermal power stations. Physical proximity between consumers and micro sources might help increase consumer awareness toward a more rational use of energy. The reduction of greenhouse gas (GHG) emissions could mitigate the alleged effects of climate change due to the creation of technical conditions to increase the connection of RES at the LV level.
Disadvantages of Microgrids
However, there are also some potential disadvantages to consider with microgrids:
1. High initial costs
The initial costs of developing and implementing a microgrid can be high which can be a barrier for some communities or organizations. The high installation cost for microgrids is a big disadvantage that may be reduced if some form of subsidy from government bodies is obtained to encourage investment, at least for a transitory period, given the current official environmental and carbon capture goals.
2. Technical difficulties
These technical barriers are mostly related to the relative lack of experience and technical knowledge to operate and control a significant number of micro sources which require extensive real‐time and offline research on issues such as management, protection and control of microgrids. Also, specific telecommunication infrastructures and communication protocols must be developed to help manage, operate and control the microgrids. However, some of these technical difficulties are in the way of being overcome as more research and demonstration projects are being set up across Europe, the United States and Asia.
3. Limited scale
Microgrids are typically designed to serve a relatively small area or group of customers so they may not be suitable for larger communities or regions. An example of this is a microgrid installed in a single building or campus such as a university or hospital. These microgrids can provide reliable and resilient power to a specific building or campus but may not be able to meet the energy needs of a larger community or region. For larger areas such as cities or towns, a larger-scale power grid may be more appropriate.
4. Complexity
Microgrids can be complex systems that require careful planning and management to operate effectively. An example of this can be seen in the case of the Brooklyn Microgrid in New York City. The microgrid is designed to provide energy to a local community but its operation requires coordination between multiple stakeholders including the utility company, regulators and the community members who participate in the grid. The system must balance the supply and demand of energy, manage the flow of electricity between different sources and consumers and ensure the safety and reliability of the grid. This requires careful planning, monitoring and management to ensure that the microgrid operates efficiently and effectively.
5. Regulation
The development and operation of microgrids can be subject to a variety of regulations at the local, state and federal level which can be a challenge for some communities or organizations. In some countries, there is a lack of legislation and regulations for the operation of micro sources. However, in Portugal, for instance, there is already specific legislation addressing the connection of microgeneration to the grid that establishes the tariffs to be paid to microgeneration adopting an avoided cost strategy leading to subsidized tariffs.
6. Standardization issues
As this is a comparatively recent area, standards are not yet available for addressing power quality, operation and protection issues, for instance. This constitutes a serious obstacle to the massive deployment of microgrid technologies.
