A DC Microgrid is a localized group of electricity sources and loads that normally operates on ‘island mode’ and disconnected from the centralized electrical grid in the mainland. Its main advantage is that it can function independently.
In this way, a microgrid can effectively integrate various sources of distributed generation, especially Renewable Energy Sources (RES), and can supply emergency reserve power by incorporating batteries within it.
DC microgrid, as a source of power, connects solar panels in series in order to generate power at a comparatively higher DC voltage, which can be transmitted over a small distance. Multiple solar power plants are strategically placed at specific locations within the grid, instead of a single centralized grid, so as to minimize distribution losses.
Houses tap into the distribution line with the help of junction boxes and charge controllers for each home. The microgrid charge controller installed in each house steps down the higher DC ‘grid’ voltage, to 12/24/48 V DC as per individual requirement, which is used to charge the storage battery and power the energy efficient DC loads in house.
During the daytime, the controller uses power from the DC grid to charge the battery as well as power the DC loads. During night time, the battery power is consumed to run the DC appliances.
The main advantages of DC Microgrid over traditional AC grid is that the cost of electrification is much less for individual households, considering there is no need for transmission over long distances. Additionally, it is more efficient, low maintenance and highly reliable.
It is a simple, reliable, cost-effective, scalable and efficient solution to provide electricity to people living without access to electricity.
Cygni 4, 8 and 12 home DC Microgrid System
We at Cygni Energy, have developed a much smaller model of microgrid solution for rural homes. Instead of having a single generation point and distributing it across the village, we create a microgrid at a cluster level. Each Cluster can be a group of 4, 8 or 12 homes which are powered by Cygni IBIS system. With the pilot project implemented with IITM, Cygni is ready to deploy the solution. The image below reflects the proposed solution, with a central generation and storage system. The power generated is then distributed to homes. Each home has an IRU (Inverterless remote unit) which can be used to control supply at the home level. Each unit is provided with GPRS and Bluetooth connectivity for data transfer. The solution also provides a provision for remote monitoring via management server or Cygni Android App.
With the system described above, power costs for homes could be drastically reduced and become affordable in the presence of a 24/7 grid, grids with a significant amount of load shedding or even in the absence of the grid.
These homes use energy efficient DC powered Appliances and with green energy at each home, India is on its way to becoming a green nation.