Detailed Explanation:

Correct Answer: ✅ Option 4 (All Four)

Distributed Energy Resources (DERs) are small-scale energy generation, storage, or management systems located close to consumers rather than large centralized power plants. They help improve grid reliability, energy efficiency, and renewable energy integration.

✅ Battery Storage – Correct: Stores electricity locally and supplies power when needed, making it a key DER.

✅ Biomass Generators – Correct: Small-scale biomass-based power plants can generate electricity near consumption points.

✅ Fuel Cells – Correct: Fuel cells produce electricity in a decentralized manner and are widely recognized as DERs.

✅ Rooftop Solar Photovoltaic Units – Correct: One of the most common DERs, generating electricity directly at homes, offices, and industries.

Short Notes: Distributed Energy Resources (DERs)

• DERs are small-scale energy resources located near end-users.

• Include both energy generation and energy storage technologies.

• Common examples: rooftop solar, battery storage, fuel cells, biomass plants.

• Reduce transmission and distribution losses.

• Improve grid resilience and reliability.

• Support integration of renewable energy sources.

• Can operate independently or alongside the main grid.

• Important for the development of smart grids and decentralized energy systems.