The key technologies of smart microgrids mainly include the following: (I) Renewable energy generation technology At present, smart microgrids are mainly based on a variety of renewable energy sources, and the power input is mainly photovoltaic, wind power, hydrogen energy, natural gas, biogas and other mature power generation technologies. (I) Key technologies of energy storage Energy storage is an indispensable part of microgrids. It can play a role in peak shaving and valley filling in microgrids, greatly improving the utilization efficiency of intermittent energy. With the continuous development of science and technology, the current energy storage mainly includes battery energy storage, flywheel energy storage, superconducting magnetic energy storage, and supercapacitor energy storage. The more mature energy storage technology is lead-acid battery, but it has the problems of short life and serious lead pollution. In the future, the marketization of high energy storage, low cost, and high-quality performance graphene batteries will bring spring to the energy storage industry. The current development cost of energy storage technology is relatively high. Countries around the world are working on this technology, but they all have a common goal, which is to achieve the goal of "low cost + high energy storage". (II) Smart microgrid energy optimization dispatching technology Different from the traditional power grid dispatching system, the smart microgrid dispatching system belongs to the horizontal multi-energy complementary optimization dispatching technology, which can fully explore and utilize the direct complementary substitutability of different energy sources, and can not only realize the output of heat, electricity and cold, but also realize the energy exchange of light/electricity, heat/cold, wind/electricity, direct/alternating current. The stratification of various energy sources in the source-storage-load links realizes orderly cascade optimization dispatching to achieve the best energy utilization efficiency. (III) Smart microgrid protection and control technology There are multiple power sources and multiple loads in the smart microgrid. The changes in loads and fluctuations in power sources need to be regulated and controlled by the energy storage system or the external power grid. The regulation, switching and control of these power sources are completed by the microgrid control center. In addition to monitoring the power parameters, switch status, power quality and energy parameters of each new energy generation system, energy storage system and load, the microgrid control center also needs to save energy and improve power quality.

     In recent years, with the growing awareness of climate change, the international community has actively sought to achieve a win-win situation between the economy and the environment to reduce environmental pollution and reduce carbon emissions. In this context, renewable energy has become a sustainable energy solution, including photovoltaics, wind power, hydropower, geothermal energy and biomass energy. Compared with non-renewable and limited resources such as fossil fuels and coal, nature continuously produces renewable energy, and its replenishment rate is much higher than the consumption rate, which is more environmentally friendly. Therefore, renewable energy has become a focus of today's society and is regarded by various countries as an important carbon reduction development project.       One of the most well-known renewable energy sources is photovoltaics. Photovoltaics uses photovoltaic panels to capture and then convert it into electrical energy. In recent years, the price of photovoltaic panels has continued to decline and the technical maturity has continued to improve, making photovoltaic power generation systems more and more accessible and can be used to power homes, businesses and even entire communities.       Another common renewable energy source is wind power. By setting up wind turbines, wind power causes the blades to rotate to generate kinetic energy, which is then converted into electricity. Wind energy is widely favored in the global energy industry. With the advancement of technology and the realization of economies of scale, the cost of wind power has gradually decreased. Many countries and regions have been able to produce wind power at competitive prices, making wind power generation a cost-effective energy option. In addition, wind resources are widely distributed around the world and can be developed in many regions, which can help non-oil mining countries reduce their dependence on imported energy and increase the stability of energy supply.        In addition, renewable energy also includes biomass energy and geothermal energy. Biomass energy is obtained from plant and animal debris, such as burning wood to generate heat. Geothermal energy converts geothermal heat into mechanical energy, and then converts mechanical energy into electrical energy.        In general, renewable energy has an important impact on achieving energy transformation and mitigating climate change, while also creating a sustainable future. With the continuous advancement of technology, policy support and market promotion, renewable energy will continue to develop rapidly and become an important force in dominating the future global energy system.