Oct 28, 2020
1.What is an Independent microgrid?
It does not depend on the external power grid and can supply power to the load independently, stably, and for a long time through distributed power sources and energy storage systems.
It can be divided into three types: DC type, AC type, and AC/DC hybrid type.
2.Why develop an independent microgrid system?
(1) At this stage, in economically developed areas covered by large power grids, the power supply cost of microgrids is much higher than that of large power grids, which lacks the economy;
(2) Especially grid-connected micro-grids are easily replaced by large-scale grids and lack competitiveness;
(3) However, in places that are not covered by large power grids, such as islands, remote areas, urban surroundings, tourist attractions, etc., microgrids have advantages, so there is an urgent need to develop independent microgrids.
01. Distributed power supply
(1) Distributed power sources related to independent microgrid
Gas power generation (natural gas, biogas)
Biomass power generation
Ocean power generation
Diesel power generation
(2) Advantages and disadvantages of distributed generation
Advantages: abundant clean and renewable energy can be used.
Disadvantages: Some renewable energy sources are intermittent and random.
(3) Distributed power sources related to independent microgrid
Among them, distributed photovoltaic is the most potential renewable energy, with a wide range of adaptability, few restrictions, rapid technological progress and rapid cost decline, and the most promising application prospects.
Difficulties and countermeasures in the development of distributed photovoltaics at this stage:
Difficulties: difficult to find, difficult to access electricity, slow subsidies, unstable electricity demand;
Countermeasures: An independent microgrid method can be adopted, which does not depend on the power grid; seek suitable electricity demand to truly realize self-generation and self-use.
02. Energy storage system
(1) Energy storage system related to independent microgrid
Chemical energy storage
Lead-acid batteries, lead-acid gel batteries, lead-carbon batteries, lead batteries
Lithium battery: iron phosphate, lithium manganate, ternary, titanate,
Flow battery: full vanadium flow, zinc bromide, a nickel-hydrogen battery, sodium-sulfur battery, zinc-air, lithium-air
Physical energy storage
Pumped storage, compressed air, flywheel, phase change energy storage, supercapacitor, superconducting energy storage, heat storage, and cold storage
The energy storage system is an indispensable part of the independent microgrid and the main reason for the high cost of the microgrid system.
Need to find a way to reduce energy storage into the wood by Dafu
a. Technological progress
b. Business model innovation
(Combined with electric vehicle charging and discharging, and stepped utilization of retired batteries)