Storing Solar Energy: Everything you need to know

Written by Tania Tahseen
Cover Image for Storing Solar Energy: Everything you need to know

While solar panels can be great companions to a healthy rooftop, they’re typically most efficient during the warm days of summer. And if you have a high electricity demand at night, oftentimes there simply isn’t enough sunlight to supply that demand. In this case, storing energy in batteries or other more efficient sources will allow you to draw power later in the day when it is needed most.

The Indian power ministry said a few days ago that they are looking to delicense the installation of stand-alone energy storage systems. If this will happen then new opportunities in the energy sector, particularly energy trading will emerge.

This blog explains solar energy storage, its benefits, how it works, and how it can help.

What is a Battery Energy Storage System?

A high voltage battery energy storage solution(BESS) is an energy storage system that utilizes a high voltage system to store renewable power. High-voltage batteries can store a large amount of energy, so they play a vital role in securing the reliability and stability of our electricity networks when they are needed most. BESS is an energy storage system capable of storing electricity generated by solar panels, wind turbines, and other types of renewable energy sources on demand. With a standalone energy storage system, electricity can be stored at low tariffs and sold back at high tariffs to the grid.

A BESS is a hybrid system that incorporates both low- and high-level software as well as hardware. It contains the following items:

  • Battery
  • Battery Management System (BMS)
  • Inverter
  • Energy Management System (EMS)

Depending on its functionality and operational conditions, a BESS may additionally incorporate a fire control system and an external cooling system. The monitoring and control units of the safety systems monitor the BESS's characteristics and respond to emergencies, ensuring that it functions safely.

Uses of Energy storage

Batteries are versatile energy storage devices that can be employed for a range of applications. Commercial uses include peak shaving, load shifting, emergency backup, and various grid services. Residential uses include self-consumption, off-grid energy storage, and emergency backup.

Energy storage systems for the residential sector:-
  • Emergency Power Backup: Battery energy storage provides the peace of mind that comes with keeping the lights on during a power outage. Energy storage is a safe and smooth alternative to small generators, which are one of the most polluting sources.
  • For off-grid energy solutions: Batteries are essential for a solar-powered off-grid home. Lithium battery energy storage has far more capabilities than lead-acid batteries. Modern systems are easier to set up, configure, and scale, as well as substantially cheaper and safer per kWh of storage.
  • For surplus power storage: Homeowners can also utilize energy storage to store extra energy generated by solar panels during the day and use it at night.

Energy Storage Systems for the Commercial Sector:-

  • Peak Shaving: In a corporate setting, peak shaving is the most essential application of energy storage. If a firm is on a demand charge utility tariff, demand charges can account for anywhere from 30% to 70% of the total utility bill. Solar panels alone aren't often sufficient to keep these firms afloat. During peak times, however, battery energy storage systems can ensure that no electricity is used from the grid above a predetermined level.
  • Load Shifting: Businesses can adjust their energy consumption by charging batteries with solar energy or when power is cheapest, and by discharging batteries when power is more expensive. This is especially handy in rural locations or where net metering is not a possibility.
  • Emergency Backup: Using the emergency backup, battery energy storage systems, such as the uninterruptible power supply (UPS) under your desk or in your server room, can keep operations running during power outages.
  • Microgrids: Microgrids can be created in conjunction with renewable energy sources thanks to energy storage. Because of its scalability and turnkey simplicity, battery energy storage systems are economically viable. Decentralized or off-grid microgrids can be used in large commercial buildings or even entire communities.
  • Grid Service: Utility-scale clients can benefit from battery energy storage in a variety of ways, including reserve capacity, frequency regulation, and voltage management.

Comparing Battery storage technologies:-

The most common solar battery types are lithium-ion and lead-acid, with lithium-ion batteries holding more energy and lasting longer. Solar battery companies usually prefer lithium-ion batteries because they can store more energy, hold that energy longer than other batteries, and have a higher Depth of Discharge.

Lithium-Ion battery

The lithium-ion battery is currently the most competitive and desirable type of battery available. Its lightweight, compact size, and high power output make it ideal for portable digital devices.

Lead-Acid battery

Lead batteries are environmentally friendly and have been used in off-grid applications for years. They are commonly used in backup power systems to provide primary energy access when a grid connection is not available. Due to their low DoD value and shorter lifespan, battery cells need to be replaced more frequently than they were before advancements in technology and battery design.

Solar powered storage: how it works

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There are two ways in which solar energy could be stored. A coupling is the way your solar panels are connected to your battery storage system. The solar panels create DC electricity, and that DC electricity must be converted into AC electricity before it can be used by your home. However, solar batteries can only store DC electricity, so there are different ways of connecting a solar battery into your solar power system.

A DC-coupled system works as follows:

1. Sunlight hits the solar panels and converts its energy to DC electricity. This is stored in a battery that can store 100% of the total energy received at any given moment.

2. The DC electricity then leaves the battery and enters an inverter to be converted into AC electricity that is used in your home.

An AC-coupled system works as follows:

1. Solar panels convert sunlight into DC electricity when it hits them.

2. Inverters convert DC electricity into AC electricity for use in homes.

3. The excess electricity is then converted into DC electricity by another inverter.

4. Battery-stored energy must pass through another inverter to become AC electricity if it is to be used by the house.

The sun offers a limitless supply of clean power, but harnessing it can be a challenge. Luckily, several options for commercial and residential storage offer proven solutions for storing solar energy. As solar energy becomes a more prominent and prevalent source in the energy mix, storage solutions are becoming an increasingly valuable requirement. A variety of battery options are available, with both commercial and residential options being available to satisfy customer needs.

You can contact us to know more about how you can install solar with a storage solution.