How does solar energy storage work? This is a question that many people are asking. Solar power has been increasing in popularity for quite some time now, but how it works and the process of storing this energy remains largely unknown to many potential customers. This article will answer these questions and more, so read on!
Solar panels store energy in batteries available in various forms, with lithium-ion and lead-acid the most popular. Your energy requirement will be used to decide how big of a battery capacity is needed and how long the entire system will last between charges.
You can have a look at our post on how many solar panels to charge a 200ah battery if you want detailed instructions.
Steps on how solar panels store energy:
Solar panels collect sunlight and convert it into usable electricity.
Most panels use the photovoltaic effect, whereby sunlight is absorbed by semiconductors in a solar cell and converted to electricity.
Solar panels can convert as much as 23% of the sun’s energy into usable energy, depending on some factors.
The electricity is then fed into an inverter, where the direct current (DC) is converted to an alternating current (AC).
The purpose of this switch is to make electricity compatible with home appliances. Direct current cannot be fed straight into home appliances, as the voltage is either too high or too low for most products.
The inverter also allows you to connect multiple panels and control how much power is generated. Smart inverters also include monitoring services, such as how much electricity is produced and how it flows into your home.
The smart inverter can then connect to an app on your phone, allowing you to control how much power is used and how it flows back into the grid.
Electricity is then sent to a solar charge controller.
The role of this device is to monitor how much electricity is made and how much can be stored. If the amount generated exceeds how much the battery can store, the excess energy will be diverted to a circuit breaker. This ensures that the battery is not overcharged.
Overcharging a battery can be damaging, as it can degrade its life and ruin how well it stores electricity. The charge controller also prevents short circuits. Connecting too many appliances or using faulty devices can cause short circuits.
Short circuits are a huge fire hazard, so the battery must be carefully monitored for excess energy production.
The battery then stores electricity for your home or business, ready to be used whenever you need it.
Batteries are rated in kilowatt-hours and can store enough power to last several days without sunlight if necessary.
The most common type of battery in a solar setup uses lead-acid, but lithium-ion batteries are also becoming increasingly common. Li-ion batteries are more efficient and lighter than lead-acid batteries. They also do not require regular maintenance, such as checking the water levels in lead-acid.
However, they are usually more expensive to buy up front, with prices varying depending on how much power you need.
This is why it’s important to calculate how much power you frequently use and how long you need the battery to last.
A good rule of thumb is to get enough panels or solar batteries to provide enough energy for three days without sunlight, if possible.
When you need to use your power, electricity is taken from the battery and directed to household appliances.
This can be when there is a power blackout or at nighttime if your home is off-grid. During a power outage, the battery will immediately kick in and provide enough electricity for critical appliances such as your fridge and TV.
Different types of solar batteries
Lead-acid Batteries
All lead-acid batteries have the same basic chemistry. Their terminals are connected to lead metal plates while separated by an electrolyte solution containing sulfuric acid in between them.
Flooded lead-acid batteries are the most common type of battery found in residential solar setups. They are relatively cheap to buy but do not last long.
The only real advantage of lead-acid batteries is their lower cost than lithium-ion batteries, but even that advantage disappears.
Disadvantages of lead-acid batteries include the following:
1. The lead plates will begin to corrode over time, and this causes a build-up of lead sulfate on the plates, which makes them increasingly difficult to recharge. This process can be slowed down by regularly checking how much water is in each cell and refilling it if there is no liquid left.
2.Lead-acid batteries have a depth-of-discharge (DoD) rating of only 50%, meaning that they can only be discharged to 50% of their capacity before they need to be recharged again. This means practically you can only use around half or less of the energy stored in them. They can also be damaged by undercharging, overcharging, and overheating.
Lead-acid batteries can only be discharged for 1000 to 3000 cycles before they are considered dead. A typical lead-acid battery costs around $200 to $300 but can be much more expensive depending on how much power you need, how big the battery is and how it’s configured.
3. Unlike lithium-ion batteries, lead-acid batteries pose a fire hazard, and they need to be kept cool regularly.
They can lose charge more quickly in high temperatures and need to be kept at a certain level of acidity or permanently lose their capacity.
4. Lead-acid batteries are also heavier than lithium-ion batteries.
5.Flooded lead-acid batteries are maintenance-heavy, as you have to check how much water they need and whether the plates are corroded. The batteries also tend to get damaged easily if tipped over or exposed to excessive heat.
Lithium-ion Batteries
Lithium-ion batteries are a much better option to use as solar batteries. One of these advantages is that they do not need to be maintained as often or any differently than other batteries.
They also can tolerate deep discharge without much issue. Lithium-ion batteries can typically discharge 80% and up to 100% of their storage capacity without being damaged or having their lifespan negatively impacted.
This means that if you need 10 kWh of battery power storage for your house, a 10 kWh lithium-ion battery is enough, but you would have to buy 20 kWh of lead-acid batteries if you need 10 kWh of daily power for your house.
Typical lead acid deep cycle batteries only last a few thousand 50% DoD cycles, whereas lithium ion batteries are usually rated for 10-15,000 DoD cycles. This means they will last longer before they need to be changed out or retired.
One disadvantage of lithium-ion batteries is that they cost more than lead-acid. However, when you consider how many more discharge cycles lithium-ion can do and how much longer the battery lasts overall, the cost is more than justified, and you end up saving more in the long run.
How long can solar panels store energy?
Solar batteries are rated in KWh, and the amount of time they will last depends on how much energy they can store and how fast it is used.
For example, a 10kWh battery might last 3 to 10 hours if it’s providing all the electricity you need for your home or business 24/7. This means that solar batteries must be sized properly to provide enough electricity when needed.
If you only need power for a few hours in the evening, a smaller solar battery will be enough. A solar battery bank should be considered if you need continuous or close to continuous power.
How long will it take for the batteries to recharge?
A typical lead-acid battery can be charged in about 6 hours. Lithium-ion batteries need less, and Tesla Powerwall can be charged in about 10 hours.
Lithium-ion batteries charge faster because they have a higher energy density, meaning that more power can be stored within the same sized battery. They also have lower internal resistance to provide over 80% of their capacity without being damaged.
Lead-acid batteries have a much lower energy density and can’t be charged without being damaged. A typical lead-acid battery will handle only 25% – 50% of its capacity before its plates begin to deteriorate.
Lead-acid batteries are also not designed to be fast-charged. Lithium-ion batteries can be fast-charged, and they don’t need to cool down after being charged.
An ideal lead-acid battery should last up to a thousand cycles, while most lithium-ion batteries can handle much more than that before the capacity starts to deteriorate.
How much do solar batteries cost?
The cost of a solar battery depends largely on its chemistry and the type of system it will go into. Residential grid-tied solar panels are usually paired with lithium-ion batteries, ranging in price from $7,000 to $14,000.
The federal government offers a tax credit for both residential and commercial solar battery systems. Solar installation companies, like SolarColorado.com, usually price match the tax credit and offer financing plans for solar batteries so you can offset some or all of your up-front costs.
How long do solar batteries last?
Lithium-ion batteries have a lifespan of about 15 years, according to SolarScape. The more you use your battery, the faster it will wear out. There are two ways you can extend your lithium-ion battery’s lifespan: 1) don’t overcharge it and 2) keep it cool. Most lithium-ion batteries come with a temperature sensor, which will shut down the battery if its internal temperature rises above 120 degrees Fahrenheit.
How do solar batteries work?
Grid-tied solar panels have an inverter built right into them that takes in the direct current (DC) electricity produced by the solar panels and converts it to alternating current (AC) electricity compatible with the power grid.
When a solar battery is paired with grid-tied PV solar panels, it works as a backup energy source to provide AC electricity when your home’s electricity goes out or if you are using more power than your system.
Solar batteries are an investment in the future, and they might cost more initially, but you will save money over time.
Solar Battery Technology Improvements
Technology is also improving how quickly solar panels store energy. Lithium-ion batteries have a DoD of up to 80% or more, meaning that they can be discharged to 80% of their capacity and retain much more of their capacity than lead-acid batteries.
For example, Tesla Powerwall is currently the best-selling home battery storage product on the market. It’s also one of the leading commercial and industrial energy storage systems and an attractive option in off-grid living.
Portable solar batteries have also become more common in the last few years, and they are handy for off-grid applications. They come with lithium-ion batteries as well as lead-acid alternative options.
They can be taken to remote locations like cabins or hunting lodges without needing electrical generators or permanent wiring. Portable solar panels for sale are also ideal for construction sites, cabins, camping, and treks, while compact solar generators can be used to charge phones or laptops on the go.
It is important to consider the different types of solar batteries available before making a purchase. Lithium-ion batteries are usually more expensive, but they have a longer lifespan and better storage capacity. In contrast, lead-acid batteries tend to be cheaper upfront with shorter life spans but higher energy density.
