Figure 1: Simple lay out of a Micro-grid system (Image credit: Mr Sethi, UPES)

What is Micro-grid?

A Micro-grid is a stand-alone small transmission and distribution network which leverages on decentralized distributed power generation systems and exploits locally available resources. In a way, it is a self-sustained power system which serves various electrical loads in a radial distribution network and can operate in a centralized grid-tied or completely isolated mode.

Figure 1 (Source: UPES) depicts a simple sketch a Micro-grid network. As shown, the network rely on distributed renewable energy (DRE) technologies such as solar PV, biomass or wind coupled with energy storage systems and feed power to local loads through a distribution system. The micro-grid operations can be monitored and handled by remote automated system such as a controller. On consumer side the system allow the usage of advanced metering system through which users’ bills can be generated and typical O&M can be scheduled.

Micro-grids thrive in areas that are remote and lack access to centralized electric grid. In such areas, expanding the central grid proves a comparatively expensive proposition and can be done away with the exploitation of local DRE resources through micro-grid network. Initially the cost of energy service through micro-grid in such areas may prove higher but from an opportunity cost perspective such network remains more attractive than the conventional grid or no power.

Micro-grids can employ various DRE technologies and operating parameters vary accordingly. Economically, technologically and operationally there are many issues which need to be accounted before practical implementation of such a network. Those issues are to be evaluated through economics analysis, power control strategies, grid connection issues, stability and protection issues, operation frameworks, consumer acreage, tariff mechanism, billing and revenue collection methods etc.
 



Figure 2: DRE based system (Solar PV) in a remote village (Photo credit: USAID)

What are the benefits of Micro-grid?

There are many concurrent benefits of a micro-grid. Firstly, it helps in exploitation of local renewable energy resource through DRE based technologies whose deployment may see harnessing clean power generation instead of polluting fossil fuel based generation. It also helps in mitigating global greenhouse gas emission and improved air quality issues locally. In addition, micro-grid can stand as an auxiliary power supplier during hours when grid power is unavailable. Such network can also improve the reliability as well as quality of power delivered.  For remote areas where there is no access to conventional grid, micro-grids can be a real boon for the local community since access to reliable energy can boost (especially rural) communities’ socio-economic development.

What is the status of Micro-grid in India? Who are the major players?

Micro-grid in India was pioneered in 1990s by West Bengal Renewable Energy Development Agency (WBREDA) when it installed a 25KWp solar PV system in Sundarban delta region. Subsequently Chhattisgarh Renewable Energy Development Agency (CREDA) initiated a solar plant in Bilaspur district. By the time of 2001 census, there were an estimated 25,000 remote villages which were considered too remote and warranted off-grid electrification. Thereafter, several micro-grid installation has taken place under the umbrella of Government of India initiatives such as the Remote Village Electrification Pro­gramme (RVEP), the Village Energy Security Program­me (VESP) and Decentralized Distributed Generation (DDG) scheme across various states like Bihar, Chhattisgarh, Sikkim, Madhya Pradesh, Odisha, Ut­tar Pradesh, Uttarakhand, Karnataka and West Bengal.

Apart from the push by Government, there are multiple emerging private players who are active in establishing and maintaining micro-grids in the country. Hush Power System, a company based in Bihar, installed 90 biomass based plants in 300 villages and hamlets. All plants provide power supply through basic micro-grid infrastructure in villages who had earlier experience unreliable grid power or no power at all. Similar efforts are being pursued by a private entity called Mera Gao Power (MGP) who has electrified households in over 500 hamlets in Sitapur and Barabanki districts in Uttar Pradesh through solar PV based mincro-grids. DESI Power, another company dealing in biomass based generation technology, has implemented micro-grids in over 20 sites in Araria district of Bihar.  Other private sector companies that are providing power access in rural areas of India through DRE based micro-grids are Minda Next Gen Technologies, Kuvam Energy, Gram Power, Gram Oorja, OMC power, Greenpeace, Tata solar, ONergy etc.

Role of Energy Storage in Micro-grid systems

Electrical energy storage or batteries are key components of micro-grid systems, especially the solar PV or small wind based ones. The storage system provides valuable functionalities to the micro-grid systems, most significantly in extending the output of the generation plant through dark hours of the day or when the wind is not blowing. Along with a power conditioning unit and inverter, the battery storage systems also serves the purposes of smoothing intermittent power flow from renewable generation, regulating voltage in the system and providing peak shaving. Depending on connectivity of the micro-grid to the centralized grid system, energy storage can also help in resiliency through its ability to offer islanding and black start support.  

According to a recent survey done for the Rockefeller Foundation, in typical solar micro-grid systems serving rural communities in India, the cost of battery back represents anywhere between 10%-20% of the capital expenditures. Most of the current installed systems in Indian rural setups have been conventional lead-acid based and their typical life do not extend beyond 3-5 years. Other prevalent technologies such as advanced lead acid, Li ion or Nickel Cadmium have been found too expensive and impractical in the rural context. However, such a scenario might change in the urban context if campus based micro-grids are encouraged in urban townships and establishments such as SEZs or hospitals etc. since the appetite for investment may be higher compared to a rural setup.

What is the role of IESA in promoting Micro-grid technology in India?

IESA provides a common platform for micro-grid project developers, operators and other stakeholders in the country. The alliance is making conscious effort to bring together the practitioners and researchers alike on a single stage where they can work together to enhance the employability and acceptability of micro-grids across India. The alliance will offer consultations and dissemination of information on following aspects related to uptake of micro-grid:
  • Micro-grid feasibility, design, and implementation
  • Refining the business case for hybrid, renewable energy micro-grids
  • Solar + storage advances
  • Utilisation of energy storage for micro-grid scenarios
  • Micro-grid power control, management, and grid integration
  • Optimising the management of distributed renewable energy resources
  • Effective project evaluation, implementation, and management
  • Project financing
  • Economic and market analysis of micro-grids
  • Standards and interoperability issues
  • Market drivers and opportunities region-wise in the country
The participants of the alliance are envisaged in forms of micro-grid project developers, owners, and entrepreneurs, utility, renewable energy professionals, energy storage providers, researchers and academics professionals, investors and regulatory representatives etc. IESA promises to be a unique platform for all those stakeholder to share knowledge, network for business opportunities and work in tandem to facilitate best practices of micro-grid implementations and maintenance.

IESA Initiative - MICRO (Microgrid Initiative for Campus and Rural Opportunities)



MICRO initiative by CES and IESA addresses the fundamental challenges faced by the developers and funding agencies by creating an ecosystem to make microgrids sustainable and economical. Through this initiative we want to have a real time monitoring system installed at as many microgrids and use the archived data to build analytics for
  1. Optimizing the life of an asset ( specially batteries) 
  2. Predicting failures in advance 
  3. And Deriving the right INR/kWh cost make such micro grids sustainable.
Customized Energy Solutions (CES) was closely watching developments in rural microgrids in India since 2014. CES team was then of opinion that with our expertise in the field of energy storage, we can help in correct sizing of battery and identification of the right energy storage technology which is the pain point in most of the solar and wind based grids and with that can make the electricity affordable for microgrids consumers. But we were touching just tip of iceberg or solving part of the puzzle with this solution. After interacting with many stakeholders across the industry over last couple of years, it was realized that we would need to touch upon a lot of gaps in the industry. The problem areas are not only technical but also social and business related like bill collection, linking of electrification to economic development, aggregation of demand from small microgrids developers for better product options and negotiations. Hence, we decided to come up with a holistic service platform called MICRO.

All the IESA member can be part of this community and help us making the difference.