Microgrid (MG)

Definition

A Microgrid (MG) is a small, local electric power system that contains its own electricity generation, storage, and consumers. It normally operates while connected to the main Electric Power System (EPS), but if the main grid fails, it can disconnect and continue supplying electricity independently. A microgrid combines DERs (such as solar panels), BESS, and local loads into one self-managing system.

The Problem That Led to It

After DER and BESS were introduced, local areas could generate and store their own electricity. However, they still depended on the main grid. If the transmission or distribution network failed, even a neighbourhood with solar panels and batteries could lose power because it remained tied to the main grid.

Engineers wanted critical places—such as hospitals, military bases, universities, and industrial parks—to continue operating even during a grid outage. This led to the development of Microgrids.

What Problem It Solves

A Microgrid:

• Combines local generation (DG), storage (BESS), and consumers.
• Can operate with the main grid during normal conditions.
• Can disconnect (called islanding) and continue supplying local electricity during outages.
• Improves reliability and resilience.

What Happens If Not Used

Even if a community has solar panels and batteries, it may still lose power when the main grid fails because it cannot safely operate on its own.

Easy Wording

A Microgrid is a small neighbourhood power grid that can take care of itself when the main grid goes down.

Layman Example

Imagine a city connected to the national water supply.

Normally, everyone receives water from the national system.

Now imagine a hospital that also has:

• Its own water well,
• A storage tank,
• Pumps.

If the national supply stops, the hospital disconnects and keeps using its own water.

A Microgrid works exactly the same way, but with electricity.

Technical Example

Normal Operation

Main Grid │ Distribution Network │ ┌──────────────┐ │ Microgrid │ │ │ │ Solar (DG) │ │ BESS │ │ Homes │ └──────────────┘

The Microgrid exchanges electricity with the main grid.

During a Grid Failure

Main Grid ❌ │ (Disconnected)

  ┌──────────────┐
  │  Microgrid   │
  │              │
  │ Solar (DG)   │
  │ BESS         │
  │ Homes        │
  └──────────────┘

The Microgrid isolates itself (islanding) and continues supplying local electricity using its own resources.

Limitation

A Microgrid is limited by the electricity it can generate and store locally. If demand exceeds its available generation and battery capacity for a long period, it may not be able to supply all consumers.