Energy Storage and Its Importance

1. What is energy storage?

Answer: Energy storage is the process of converting energy produced at a point to a form which can be used at some future point. It provides supply-demand balance, enhances grid reliability, and allows integrating intermittent renewable sources like solar and wind.

2. What are the technologies deployed in energy storage?

Answer: Energy is stored by the following technologies:

Battery Storage: Electrical energy is stored chemically in batteries such as lithium-ion, lead-acid, and flow batteries. The procedure is widely used in homes, electric grids, and electric vehicles.

Pumped Hydro Storage: Water is pumped to a higher reservoir and then spewed to a lower reservoir to generate electricity. It is the most widely used large-scale energy storage process.

Energy is confined within a rotating body and released suddenly when it is needed. This is best for applications where brief intervals of peak power are required.

Compressed Air Energy Storage (CAES): Air is compressed and stored in the ground, and then used to drive turbines to produce electricity.

Thermal Energy Storage: Excess energy is used to heat material (like molten salts), which can be used later to produce heat or electricity.

3. Why is energy storage important?
Answer: Energy storage is important for the following reasons:

• Grid Stability: Evens out electricity supply and demand fluctuations.
• Renewable Energy Integration: Enables sun or wind power to be used when the sun does not shine or the wind does not blow.
• Backup Power: Acts as a backup power in the event of a grid outage or power failure.
• Peak Saving: Stored energy can be returned during peak demand periods, lightening the load on the grid.

4. What is energy backup?

Answer: Energy backup are systems or solutions employed to provide power when the main power is cut off or the grid is down. These systems play a critical role in facilitating uninterrupted operations in households, offices, industries, hospitals, and critical infrastructures.

5. What are the various types of energy backup systems?

Answer: Different types of energy backup systems include:

A. Battery Backup (Inverters / Solar + Battery Systems): Conserves electricity to be used during power failures. Most common system used in household regions and small offices and is usually paired with solar PV systems. Lithium-ion and lead-acid batteries are normally used.

B. Diesel/Petrol Generators: Runs on fossil fuels (diesel/petrol) to generate electricity. Suits heavy loads like hospitals and industries. It is, however, noisy, contaminating, and costly owing to high fuel consumption.

C. Uninterruptible Power Supply (UPS): Offers short-time backup power for sensitive loads such as computers, routers, and servers. It provides power immediately when the grid goes down.

D. Hybrid Systems: Integrates various technologies such as solar PV, batteries, and generators. It provides flexibility and is well-fitted for long-duration backup.

E. Grid-Tied Backup: Linked to the primary grid with battery backup. Batteries are charged when there is normal supply and utilized during a blackout.

6. What should be taken into account while selecting a backup system?

Answer: Consider the following factors:

• Load Requirement: Which devices need to be powered during a blackout?
• Backup Duration: For what number of hours do you need backup (2 hours or 24 hours)?
• Budget: Cost varies between inverter systems and generators.
• Location: Urban or rural location, grid reliability, and availability of fuel.
• Environmental Impact: Clean options like solar + battery or dirty options like diesel?

7. Why do Nepal need backup systems?

Answer: Although Nepal has improved grid stability, there are rural areas where there are power outages. Natural calamities like floods and landslides could interrupt power supply. Such interruptions affect critical sectors like business, telecom, and the medical sector that require continuous electricity. Having 24/7 electricity in these areas is therefore critical, and backup facilities become essential.

8. Why is solar power and battery backup gaining such popularity?

Answer: The cost of solar power systems and batteries has decreased in recent times. The government, as a part of the Alternative Energy Promotion Centre (AEPC), is promoting renewable energy. Solar and battery backup systems are increasingly being used as long-term solutions due to their cleanliness, quietness, and reliability.