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What is energy storage?

Energy can be stored in batteries for when it is needed. The battery energy storage system definition is an advanced technological solution that allows energy storage in multiple ways for later use. Given the possibility that an energy supply can experience fluctuations due to weather, blackouts, or for geopolitical reasons, battery systems are vital for utilities, businesses and homes to achieve a continual power flow. A battery energy storage system (BESS) is no longer an afterthought or an add-on, but rather an important pillar of any energy strategy.

What is solar energy storage?

What is energy storage? A solar energy storage system is a technological solution in which batteries charge during the day when the sun is shining, and store and release power for consumption around the clock or on cloudy days. Battery energy storage is particularly effective when combined with solar energy, because solar energy storage mitigates the intermittent nature of renewable power and guarantees a steady supply of electricity. Modern batteries for a home or business solar energy system usually include a built-in inverter to change the DC current generated by solar panels into the AC current needed to power appliances or equipment. Solar battery storage works with an energy management system that manages the charge and discharge cycles based on real-time needs and availability.
Battery Energy Storage Solutions

Battery Energy Storage Solutions

Integrated solutions to save energy and boost your business

What are the main battery storage applications?

Battery storage can be used in many ways that go beyond the simple emergency backup in the event of an energy shortage or blackout. Applications differ depending on whether the storage is being used for a business or a home.


For commercial and industrial users, there are several applications:

  • Peak shaving, or the ability to manage energy demand to avoid a sudden short term spike in consumption
  • Load shifting, which allows businesses to shift their energy consumption from one time period to another, by tapping the battery when energy costs more
  • Flexibility, whereby customers can reduce their site’s grid demand at critical times – without changing their electricity consumption. Energy storage therefore makes it a lot easier to participate in a Demand Response program and save on energy costs
  • Microgrids rely on batteries as a key component, because these grids need energy storage to enable them to disconnect from the main electricity grid when needed
  • Integration with renewable energy sources, since batteries guarantee a smooth and continuous electricity flow in the absence of the availability of power from renewable.

Residential users benefit from battery storage applications by:

  • Self consumption, since residential users can produce solar energy during the daylight hours and then run their appliances at home at night
  • Emergency backup in the event of a blackout
  • Going off the grid, or detaching completely from an electrical or energy utility

What are the battery energy storage benefits?

The advantages of battery storage systems are many. They make renewable energy more reliable and thus more viable. The supply of solar and wind power can fluctuate, so battery storage systems are crucial to “smoothing out” this flow to provide a continuous power supply of energy when it's needed around the clock, no matter whether the wind is blowing or the sun is shining. Plus, they can protect any user from grid fluctuations that could compromise energy supply. Here are some of the advantages of battery storage:
  • Environmental gains

Installing a battery storage system in a home or businesses powered by renewable energy reduces pollution, thereby contributing to the energy transition and combating the effects of global warming.


  • Lower energy costs

Storing low-cost energy and consuming it during peak periods when electricity rates are higher allows a user to shift consumption and avoid higher charges, saving money. The savings are magnified when combined with solar power, which is free.

  • Less dependent on the grid

Battery storage systems guarantee a continuous energy supply, even at times when the energy grid is unstable due to peaks in demand or extreme weather.

  • “Always on” supply

The sun is not always “on.” A battery storage system works round the clock, and therefore compensates for any fluctuations in solar energy supply by storing any excess power in the system.

  • Resilience

A battery storage system provides emergency backup in the event of a power outage, guaranteeing business continuity. 

How does a battery storage system work?

Second life batteries

Second life batteries

Batteries can have a second chance to create sustainable value, enabling a more efficient energy consumption

The operating principle of a battery energy storage system (BESS) is straightforward. Batteries receive electricity from the power grid, straight from the power station, or from a renewable energy source like solar panels or other energy source, and subsequently store it as current to then release it when it is needed. When combined with software, a BESS battery becomes a platform that couples the energy storage capacity of batteries with the intelligence needed to deliver advanced management of energy consumption by harnessing AI, Machine Learning and data-driven solutions. This makes batteries a tool in the effort to offset climate change, because they enable a more flexible way of using energy that lets the user adapt to dips and peaks in demand and supply.
Overall, battery energy storage systems foster the deployment of renewable sources, thereby helping reduce carbon emissions and even deliver lower costs for businesses and households. Enel X works with businesses to ensure that all the energy needs are met, regardless of whether a facility already has a battery storage system up and running, needs to stall a new one, or must add more capacity. Our battery storage system is equipped with our DER.OS optimization software, which is designed to work with all kinds of distributed energy solutions resources and can easily be integrated into existing systems, such as solar photovoltaic systems.

Which are the different meter systems for battery energy storage?

A battery energy storage system (BESS) can be of two types: front-of-the-meter (FTM) or behind-the-meter (BTM). BTM systems are installed on the user’s premises and are typically smaller than a FTM system. A BTM’s main function is to improve the stability of its owners energy supply and cut costs, but if the local regulatory framework allows for it, the batteries can also supply energy back into the grid and thereby become an additional revenue stream. The larger FTM systems are directly connected to the power grid and usually therefore belong to a utility, helping it solve network congestion issues or as an alternative to building new power lines.

How long does a battery energy storage last and how to give it a second life?

Most energy battery storage systems last between 5 to 15 years. As part of the ecosystem of solutions for the energy transition, battery energy storages are tools to enable sustainability and, at the same time, they themselves must be fully sustainable. The reuse of batteries and recycling of the materials they contain at the end of their life are all-around sustainability goals and an effective application of Circular Economy principles. Recovering an increasing quantity of materials from batteries and giving them a second life leads to environmental benefits, in both the extraction and disposal stages. Battery reuse also delivers economic benefits.
Circular Economy

The Circular Economy

A new model for creating value

Can battery storage systems be integrated with a distributed generation system?

Distributed Energy and Infrastructure

Distributed Energy and Infrastructure

Save money and improve the site’s resiliency by generating sustainable power locally

Enel X battery storage systems come equipped with our DER.OS optimization software, which is designed to work with all kinds of distributed energy resources and can easily be integrated into existing systems, such as solar photovoltaic systems. Regardless of whether a business already has such systems up and running in its facilities or needs to integrate them with a battery storage system, Enel X can create an effective solution for all energy scenarios.

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