California is the place where the earliest put forward the development of smart grid, but the pace of upgrading has been very slow, it is easy to suspicious: California 2020 can achieve 33% of electricity from renewable sources? The intermittency of renewable energy is difficult to adapt to the conventional power grid that centralize unified transmission. The concept of micro smart grid was born.
The concept of the micro-smart grid was first introduced by California's galvin power innovation corporation. , the company President John kerry said the micro smart grid is repositioning of electricity services, it lets the power suppliers and power consumers in electrical equipment design and planning during the mutual communication, so as to realize a win-win situation to a great extent.
An alternative to a micro grid or a power supplier.
Most of the current smart grids that are being built cannot generate and store enough electricity to connect directly to the grid, and must be connected to the device. In fact, the smart grid has to maintain a stable and complex relationship with the power supply, through the purchase and sale of electricity and the connection and disconnection of the power grid to adjust the power and reduce the pressure on the power grid. Power suppliers can also use it for energy conservation projects, and to mobilize extra power during peak periods.
With these mini-networks, power operators are able to close the gap with school research units and businesses to help them find the best way to manage distributed transmission. Renewable energy is relatively easy to incorporate into the micro smart grid, and the energy storage power is high in the power supplier. The equipment needed for the general smart grid is too heavy to install, so the microgrid is the simplest alternative.
Many American colleges and universities have announced plans for a mini-grid. In particular, Howard university is located in Washington, d.c. The school has just signed an agreement with Pareto energy to develop a device that will provide electricity and heat to the campus. Pareto plans to invest $15 million to $20 million to renovate the school's central system for two years.
The university of San Diego in California is also pushing the micro-grid. The school is considered one of the world's most advanced micro-grids, with an estimated size of 1,200 acres, which can power 450 homes, involving 45,000 users. The research project is part of the California energy commission's "community-based renewable energy security" program to test local energy, particularly on campus renewable energy. The school has installed two gas turbines with a capacity of 13.5 megawatts, a 3-megawatt steam engine and a 1.2-megawatt photovoltaic power plant that can meet 82% of the school's electricity needs.
In addition, the U.S. military has a special interest in micro-smart grid technology, and the military is trying to install a solar microgrid in hunter ligutenberg, near the U.S. base in central California. The system has a capacity of 1 megawatt and is estimated to cost between $5 million and $10 million. Even if there is a drop in the efficiency of the fog, one megawatt can meet the annual demand for 200 homes. The micro grid can guarantee local energy security, supply electricity to the local area during power outages, and reduce the cost of redistributing electricity to the main power grid during peak hours. With its built-in storage and transmission equipment, the grid has become more reliable, more secure, and has reduced its dependence on the outside world, which is the most critical advantage of a military base.
There are many challenges to popularizing the micro-grid on a large scale. The main obstacle is the technical level, which means it is difficult to synchronize with the conventional power grid. In order for the power to be sent to the Internet, voltage, frequency and power are subject to control. Even micro-grid equipment should meet existing standards to maintain grid load balance. Because of reliance on local power supplies, storage devices are the most critical component of the microgrid. Current energy storage is expensive, and maintenance costs will be pushed up once the energy storage device is installed.
