We’ve talked about the use-cases for battery energy storage systems, but what are the qualities that make one battery energy storage system (BESS) better or worse for a given use-case?
Click here to get more.
We’ve made another list!
If you are making an investment case for battery energy storage, how would you evaluate the different technical qualities different technologies might offer and how that could impact the business case for your project. Gridcognition can help.
Battery storage systems can store a lot of energy in a relatively small amount of space. Energy density is a measure of energy per unit of volume. It is sometimes called “volumetric energy density”. There are many different battery chemistries with different energy densities, and even just within the family of Lithium-ion batteries, volumetric density can vary considerable. But as an indication the energy density of a given Lithium-ion battery pack could be around 500 watt-hours per litre (Wh/L). For comparison, the energy density of Diesel might be around 10,000Wh/L (or 10kWh/L).
We can also think about density of battery storage systems by measuring the energy per unit of weight, sometimes called “gravimetric energy density”. As an indication the energy density of a given Lithium-ion battery might be 250 watt-hours per kilogram (Wh/kg), and Diesel for comparison might be around 12,000Wh/L (or 12kWh/L).
Battery storage systems have a cost per unit of energy stored, or $/kWh.
When we are comparing measures of cost, or any of these qualities, we need to be clear about the scope we are considering. Are we looking at just the cost of the battery pack that is one component of an integrated storage system, with the long targeted price of $100/kWh, or are we looking at the designed, installed and commissioned cost of an entire storage system, which could be many multiples more than this.
Battery storage systems also have a cost per unit of power output, or $/kW.
When we are considering the cost-efficiency of a battery energy storage system for a given use-case, it’s important to understand if the use-case is energy-limited (e.g. energy arbitrage or load-shifting) or power-limited (e.g. frequency or voltage regulation).
Power output is a measure of how fast the battery can discharge or charge, usually expressed in kilowatts (kW).
Sometimes we will see power output expressed as a ratio to the storage capacity, or as a storage duration. A charging ratio of 0.5 would represent a battery that could fully charge or discharge in a 2-hour period, or in other words it could maintain its full power output for 2-hours. A charging ratio of 1.0 would represent a battery that could fully charge or discharge in 1-hour.
This can be counter-intuitive because it means that a, say, 4-hour duration battery would be cheaper than 1-hour duration battery, given then same energy storage capacity (kWh), because this implies it will have a lower charging ratio or power output (kW).
Cycle life is number of times a battery can discharge and recharge before it falls below some threshold of useful capacity due to degradation.
The degradation of batteries can be very complex with different degradation characteristics for different chemistries, different environmental conditions, and different applications. In practice it is mostly a factor of time (batteries have a ‘shelf-life’, even when they are only lightly-used), energy throughput (the total volume of energy discharged and charged), and rate of throughput (how quickly the battery is discharged and charged).
When we are planning battery projects for a given application, we need to understand how our application will affect the rate of degradation, or health, of the battery, and how this might relate to the vendor’s warranty for the battery system.
Use-cases like ‘peak-lopping’ require much less throughput or ‘cycles’ than use-cases like energy arbitrage, where the battery might be chasing a dynamic wholesale energy price. So when developing an econo-technical model for a project, you need to consider the value a given use-case might deliver relative to the degredation it will cause in the battery.
There are losses in the process of charging and then discharging a battery storage system. We call the ratio of power absorbed to energy released through this cycle the ’round trip efficiency’. The energy that is used to charge a battery has a cost, and so the value created through the charge and discharge cycle has to be sufficient to compensate for the cost of energy losses (and for the asset replacement cost associated with the degredation of the battery through the cycle). Any econo-technical simulation and optimisation of a battery project must take into account the losses associated with round-trip efficiency.
Different battery technologies can have different safety characteristics that can make the better suited to different applications, but this will often entail trade-offs with the other battery qualities. Some Lithium-ion batteries can exhibit a phenomenon known as thermal runaway, which can lead to fires, as owners of Samsung Galaxy 7 phones became all too aware of. A battery with a lower energy density might have a better safety profile, and so suited, for example, for installation inside a home, but may be bulkier and more expensive as a result.
The performance of batteries, including their safety performance, can be very sensitive to temperature. For some applications, there may be quality tradeoffs required to be able to accomodate different environmental conditions.
Most battery systems have active cooling systems that can be noisy. If you are installing a battery in or near an office or school, noise can be a material issue to consider.
While batteries are generally installed to do a specific functional job at a price, I’m sure the beautiful industrial design of the Tesla Powerwall has been a factor in why its chosen for some applications.
1.Why we should care about energy storage
From the "Energy Storage Grand Challenge" issued by the US Department of Energy, the "Climate Neutral European Hydrogen Energy Strategy" issued by the European Union, to the "14th Five-Year Plan for New Energy Storage Development Implementation Plan" issued by China in February this year, governments all over the world have given huge policy support to the energy storage industry. The direction of the policy is the direction of technological development, capital influx, and talent inflow. It also indicates that the energy storage industry is developing rapidly with the support of various resources.
In fact, energy storage is not far away from us. On the roof, in the car charging pile, there is energy storage everywhere. The most representative is residential energy storage, which emerges as the times require, and producers meet the needs of households by providing energy storage solutions. If the Internet has changed our way of life, then new energy and Renewable energy storage will jointly change our living environment.
The decarbonisation of the power sector is an unstoppable trend, as evidenced by the Paris Climate Agreement and actions taken by many countries. While energy efficiency and renewable energy are the backbone of most decarbonization strategies, energy storage is a game-changer for the power industry and nearly all of its stakeholders. Its falling costs, especially lithium-ion batteries, have made them a commercially viable solution for large-scale renewable energy integration, which in turn has made lithium ion battery storage popular.
Renewable energy storage, whether using wind energy or solar energy, will be affected by the weather. When there is excess wind and light, it will be converted into electrical energy and stored to ensure the stable and normal operation of the power grid system. Therefore, as long as new energy is developed, energy storage must be available.
2. What is energy storage and energy storage system
Energy storage refers to the process of storing energy through a medium or device and releasing it when needed. According to the different forms, it can be divided into thermal energy storage, electric energy storage and hydrogen energy storage. At present, electric energy storage is the most widely used energy storage form at this stage. Electric energy storage can be divided into mechanical energy storage and electrochemical energy storage. The development of mechanical energy storage started early and has a large scale of application. It is a relatively traditional energy storage technology. As a new type of energy storage technology, electrochemical energy storage is mainly known as battery energy storage, including lithium ion battery storage, sodium-sulfur battery energy storage, lead battery energy storage, etc.
Energy Storage System (ESS) is a system that can store electrical energy and supply power, with functions such as smooth transition, peak shaving and valley filling, frequency regulation and voltage regulation. The application of energy storage system covers renewable energy storage such as solar and wind power generation and storage, industrial enterprise energy storage, commercial building and data center energy storage, residential energy storage, etc.
3. Advantages of Battery Energy Storage
Goto Inventronics to know more.
The battery energy storage system has high energy utilization efficiency and fast response speed. And it is more flexible to use, has a variety of applications, and can customize different energy storage solutions. This also shows that the battery energy storage is widely used in emergency situations. For example, residential energy storage can help connect to the power grid and improve power quality, while helping to regulate voltage and frequency.
The battery energy storage system makes energy regeneration a possibility, and also provides a new idea for the future development of energy ecology. In this regard, how to classify and integrate different types of battery energy storage units with different lifespans, and perform differential charging and discharging, optimize battery management, and establish good renewable energy storage is also what we need to pay attention to.
In terms of environmental protection, lithium ion battery storage uses a wide range of raw materials, is environmentally friendly, and is a sustainable renewable energy storage. For electrochemical performance, its battery capacity, energy density, and cycle life are far better than lead-acid batteries.
4. How to choose the suitable energy storage battery
In recent years, the market demand for battery energy storage has been expanding, and the shipment and proportion of lithium battery companies in the field of energy storage are rising rapidly. We all want to have a good residential energy storage, so how to choose a suitable energy storage battery?
First, the choice of batteries. The quality of the battery cell determines the quality of the energy storage lithium battery to a large extent, so when choosing an energy storage battery, don't be greedy for cheap, you must look for brand batteries, and at the same time be based on energy storage solutions.
Second, the choice of protection board. The lithium battery protection board is the brain of the lithium ion battery storage. Whether it can ensure the safety of the battery, the protection board plays a vital role. Therefore, when choosing an energy storage battery, be sure to choose a protection board with better performance and equipment and better reliability.
Third, the production process. Rigorous production process, together with high-quality cells and high-reliability protection boards, can truly ensure the safety and reliability of energy storage battery packs.
Fourth, match the charger. For good lithium ion battery storage, the charger should also be used with a charger that matches the battery. Unsuitable chargers can easily lead to unsatisfactory charging or overcharging, and even cause damage to the energy storage lithium battery pack and cause unnecessary after-sales problems.
5. The main application scenarios of battery energy storage
From the perspective of the entire power system, the application scenarios of battery energy storage can be divided into three scenarios: energy storage on the generation side, energy storage on the transmission and distribution side, and energy storage on the user side. Different scenarios require different energy storage solutions.
Power generation side energy storage
There are many types of demand scenarios for energy storage on the power generation side, including six types of scenarios, including energy time shift, capacity units, load tracking, system frequency regulation, reserve capacity, and grid-connected renewable energy storage.
Grid side energy storage
The application of lithium ion battery storage on the grid side is mainly to relieve transmission and distribution congestion, delay the expansion of transmission and distribution equipment, and support reactive power. Compared with the application on the power generation side, there are fewer types of applications on the grid side, and more from the perspective of effect. is the substitution effect.
User side energy storage
The user side is the terminal of electricity use, and the user is the consumer and user of electricity. The cost and benefit of the power generation, transmission and distribution side are expressed in the form of electricity price, which is converted into the cost of the user. Therefore, the price of electricity will affect the demand of users.
Let's talk about the user side energy storage in detail, because it is the energy storage system that residents can experience best, mainly for end users. The user side energy storage is mainly residential energy storage. In the residential home, renewable energy storage such as solar energy is used to supply power to the family. And at the same time, the electricity is managed, and the excess electricity is stored and supplied to the grid. According to the specific situation of users, tailor-made exclusive energy storage solutions to meet the different needs of users. Its main function is to serve as a backup power source, increase PV self-consumption, reduce demand charge and reduce time-of-use bill management.
6. Top performers in battery energy storage
Whether you admit it or not, the old days dominated by conventional energy sources are beginning to end. A new era combining electric vehicles, new energy, and energy storage is beginning. Renewable energy storage will surely occupy a place in the market of the future.
Tesla is without a doubt the best of the bunch. In addition to reshaping the auto industry landscape by itself, Tesla is constantly pushing the boundaries of its business. Compared with the auto business, including custom energy storage solutions. Tesla's energy layout is mainly divided into two parts, the first is energy storage equipment, and the second is solar roof. The high electricity price in the United States makes the residential energy storage system of "household photovoltaic + energy storage" outstanding in terms of cost performance. By deploying rooftop photovoltaics to drive the installation of energy storage batteries, Powerwall has become the "electric vehicle-photovoltaic roof-storage wall". It is a key part of the energy strategy of the grid system. In terms of product design, Tesla's battery pack is composed of multiple battery packs connected in series, and each battery pack is composed of multiple lithium-ion batteries in parallel, that is, lithium ion battery storage.
As we all know, BYD is a new energy vehicle company from China, and new energy vehicles are its most dazzling business. In fact, it's not just cars, it's also worth mentioning in terms of energy storage. Since , BYD has specialized in the research and development, production, sales and service of battery energy storage, and is committed to providing efficient and clean new energy solutions. Relying on advanced iron battery technology, it can meet the needs of energy storage, peak shaving and valley filling, and peak and frequency regulation. It provides clean energy storage solutions whose key features are safety, efficiency and stability. The China-based company started out as a battery maker and has expanded into a diverse range of alternative energy, electric vehicles and more. The energy storage system of BYD's leading product, Cube, is currently using BYD's ordinary lithium ion battery storage. Recently, the relevant person in charge of its energy storage department said that the company's new energy storage system products based on blade batteries will be launched in China next year. External synchronous listing, its performance and security will be greatly improved.
Panasonic, a Japanese electronics manufacturer that is also one of the world's largest manufacturers of energy storage products, is gaining momentum in the market. Panasonic's EverVolt residential energy storage system is divided into two types: AC coupling and DC coupling. Through its inverter, it can be easily coupled with another energy storage system. The total capacity achieved is significantly higher than the average daily consumption of American household users. power. In addition, when combined with electricity provided by residential solar power facilities, home users can obtain long-term power supply in the event of a power outage. The company recently said it is expanding the development of zinc-air battery technology, a new zinc-air flow battery (ZAFB) designed for large-scale renewable energy storage projects that is safer than lithium-ion devices. At the same time, the energy density of zinc-air batteries is very high, and the same size battery contains twice the energy of lithium ion battery storage.
Pytes, an energy company headquartered in Shanghai, China, formerly known as DLG, has been delivering innovative energy storage solutions around the world for decades. Its energy storage systems have been deployed in more than 40 countries and can be found in some of the most remote places on Earth. Pytes' systems are well known for their safety, reliability, competitive pricing and good services. Pytes' leading product is the E-BOX series, in which the R battery is a high-performance renewable energy storage that is widely used in home applications, small commercial and industrial energy storage systems, and telecommunication stations. Pytes products are sold all over the world and are an excellent choice for many users when building energy storage systems.
7. Cases of residential energy storage solutions
Germany-based IVG Energy Solutions GmbH, which focuses on providing energy storage solutions for households, has been helping households achieve KfW40+ houses recently. IVG understands occupant needs, including location, house size and roof type, and electricity usage, and determines the direction of implementation. Due to the shortage of electricity in Europe, many households have begun to install home photovoltaic energy storage systems. This time is no exception, with IVG opting to install residential energy storage for households.
The key link in the residential energy storage system is the energy storage battery. IVG has found the energy storage battery expert Pytes Energy Co., Ltd. to provide it with energy storage batteries. This time, the batteries installed in KfW40+ houses are exactly E-BOX-R batteries from Pytes.
The battery pack is compact, easy to install, free of maintenance, and could be deployed to the building block of energy storage system by being assembled in parallel. E-BOX-R has a BMS to measure, monitor and manage solar panels and use the system in real time at all times. Moreover, this lithium ion battery storage has a long service life and high safety, and is suitable for most inverters on the market, such as Victron, SMA, and Sol-Ark. In the above projects, the batteries facilitate the perfect matching of Deye inverters to provide sufficient power for the home. After the installation of the home energy storage system, if the residents have any problems, the service engineers from Pytes will patiently and exhaustively solve them for them.
Ultimately, Pytes’ energy storage solutions helped IVG successfully realize three KfW40+ houses. Most houses are installed with 8KW/10KWh (inverter/battery), which is enough to meet the needs of most houses, and a few have installed 12KW/10KWh to meet higher power demands. And because renewable energy storage is more energy efficient, these houses not only meet the standard of KfW40+ houses, but the owners will also be subsidized by the national government and receive up to 45% of the qualified amount!
If you are looking for more details, kindly visit Commercial Battery Storage Systems.