The twenty-first century has ushered in an increase in the world's dependence on electricity. But with the evident degradation of the environment due to human energy use and global warming, there's been more demand for green fuel solutions.
Techno-enhancements have improved greener energy alternatives like wind and solar. However, as you may know, home energy needs to be harvested and stored for later use. And this is where energy storage systems like batteries come in handy. Here's a guide to battery energy storage systems to help you learn more about this.
What Is a Battery Energy Storage System?
To fully understand a battery energy storage system, you must appreciate how renewable energy works. Renewable energy is the power that comes from a source that continuously replenishes when used. Good examples of such sources are the wind and sun.
Suppose you use solar panels to convert light into electricity; your panels would work well during the day. But at night, you would have no power. You would have to find ways to store energy for a more constant supply of energy for later use. One way to do this is through a battery storage system.
In other words, a setup that allows you to store renewable energy in a battery for later use is what a battery storage system is all about.
Uses of Battery Energy Storage Systems
Battery energy systems have a myriad of residential and commercial uses. They are a preferred source of energy storage because they are rechargeable.
They trap and store energy from the electricity grid, solar panels, or wind generators. One can use the stored energy to provide power for residential or business applications, including the following:
- Off-grid – battery storage systems are also used for off-grid homes in rural areas or city homes that want to claim rebates.
- Peak shaving – is done to ensure that no power is drawn from the grid during peak times. It could help reduce the power utility bill.
- Load shifting – provides an option for businesses to switch from grid to solar, and vis-versa, depending on when electricity is cheapest or more expensive.
- Emergency backup – can maintain a constant power supply even during power outages.
- Renewable integration – allows for a smooth flow of power generation from renewable energy sources for home or business use. It mimics the consistency of grid electricity by regulating frequency and voltage.
- Solar power storage – stores surplus energy from solar panels during the day for use at night.
The Importance of Battery Storage
As highlighted earlier, battery storage systems are an essential alternative to fossil fuels. They make harvesting and storing green energy in homes, offices, and industries easier.
Other advantages of battery storage systems include:
- Money-saving: they could be significantly cheaper than grid power. After the cost of installation, you could say your power comes for free.
- Reliability: they are a convenient electricity backup during power disruptions.
- Safety: they're reasonably safe when installed properly and can be integrated into your electrical wiring.
- Environmentally friendly: they are clean and safe for the environment. And are known to contribute immensely to reducing greenhouse emissions. If you want to help save the planet from the environmental impacts of global warming, consider battery storage systems.
Types of Batteries
Like most other forms of technology, battery storage systems work with different types of batteries. Below are some of the common types of batteries:
1. Lithium-ion
Most modern home battery storage systems use lithium-ion technology. These batteries are made from either lithium-ion phosphate, lithium cobalt oxide, or lithium manganese oxide. They have the following characteristics:
- A life span of between 5 to 20 years.
- Better energy storage and release than most other batteries.
- Comparatively charges faster than other batteries.
- An efficiency rate of 89% to 97%.
- Depth of discharge of between 50% to 90%.
- A life cycle of between 2 000 to 3 000 charging cycles.
- Can operate at a temperature of between 0 to 45 degrees.
- They may require careful installation and monitoring to avoid the risk of fire.
2. Lead-Acid
Lead-acid batteries are the cheapest and most common type of battery. They have been widely used as car batteries, such as AGM batteries, although they can also provide power storage for home backup systems. Characteristics of lead-acid batteries include:
- A life span of between 3 to 15 years.
- An efficiency rate of 80-85%.
- Mostly recyclable.
- Generally safe and reliable.
- A 50% depth of discharge.
- A life cycle of between 1 000 to 1 500 charging cycles.
- Can operate optimally at a temperature of between 10 to 40 degrees.
- Using more than 50% of the charge may affect their life span.
- May require good ventilation to avoid gas build-up.
3. Flow Batteries
Flow batteries are commonly used for large industrial operations but could also be used in homes. They use liquid electrolyte solutions to store energy. Their main characteristics include:
- A life span of more than 20 years.
- About 10 000 charging cycles.
- An efficiency rate of about 80%.
- Environmentally friendly.
- May not be recyclable.
4. Salt Water Batteries
Saltwater batteries have a liquid solution of salt water used to store electricity. Some of their common characteristics include:
- A life span of about 15-20 years.
- Quite affordable.
- 100% efficient.
- Is known to be the most environmentally-friendly battery.
- Very safe.
- Bulky and heavy.
How Battery Energy Storage Works
Battery energy storage systems work in three main simple steps:
- Charging: electricity from either solar, wind or the utility grid is trapped by the battery.
- Optimization: the battery software has algorithms that analyse power generation, usage history, utility rate, and weather patterns and optimizes them.
- Discharge: energy is discharged from the battery storage system for use in the home or business.
How to Choose the Best Battery
There are so many different battery brands on the market you could pick the wrong one if you're not careful. To help you choose better, you could use the following specifications as your evaluation criteria:
- Capacity and power rating – capacity is the total amount of electricity stored in the battery. It's measured in kilowatt-hours (kWh). Power rating is the amount of electricity a battery can deliver, measured in kilowatts (kW). A battery with a high kWh capacity and low kW rating will store lots of electricity but power few appliances. If, on the other hand, it has a low capacity and high-power rating, it will power more devices for a shorter time.
- Depth of discharge (DoD) – most batteries will not use up all their stored electricity. They'll use a specific percentage before they need to be recharged; this percentage is the depth of discharge. The higher the DoD, the better for you. If your 10kW battery has a DoD of 90%, it means you can use 9kW before you need to recharge.
- Round-trip efficiency – is the amount of energy you can get out of your battery compared to the amount you need to charge it. If you need 5kW to charge a battery that will give you a total of 4kW, the efficiency is 80% (4kw/5kw). In other words, the higher the round-trip efficiency, the better the battery.
- Battery cycles on warranty – is the number of times you can charge and discharge your battery on the warranty. The higher the cycles, the better the battery quality.
Conclusion
Now that you know a thing or two about battery energy storage systems, research which one caters to your needs. Remember, each battery storage system may have unique installation and maintenance procedures.
Most manufacturers will also have battery specs and safety information published. Consult a professional before deciding on the right one for your applications.
