As a result, the off-grid solar segment, powered by solar panels, inverters, and battery storage, has grown by 63% to reach a value of $3.1 billion in 2022.
Battery storage isn’t only for off-grid solar setups; it’s also an excellent way to maximize the energy created by your solar panels and ensure you can keep your appliances running during a power outage.
Deep-cycle solar batteries are the best choice for storing solar energy, but you’ll find a confusing array of solar panel battery storage options available when you set out to supplement your solar panel system.
Keep reading to discover the secrets to selecting the best one for your needs.
Solar Battery Type
Deep-cycle batteries differ from most batteries in that they can discharge a lot of energy compared to other batteries. They’re also rechargeable, unlike some types of batteries.
Choosing the best one for you is an exact science, depending on factors like the characteristics of your solar installation, your expectations, and the size of your home.
For instance, if you have a large home and lots of appliances, you need a high-capacity battery that can store enough energy for prolonged use. If you’re on a budget and simply want to enhance your solar panels’ usefulness, you could make do with a smaller one.
Lithium deep-cycle solar batteries are the best option for homeowners as they can last for up to 5,000 cycles.
Apart from the tips mentioned below, it’s also a good idea to read some online reviews to help you decide which brand of battery is best for you.
A battery’s capacity determines how much energy it can store for future use. Capacity is usually expressed in kWh, which represents the relationship between power and time.
The more power you use, the sooner your battery will go flat, and vice versa. In this sense, battery capacity is a little misleading, as it’s unique to every home.
As an example, a 5 kW, 10 kWh battery can run an AC for just two hours, but it can keep 20 lightbulbs blazing for two full days. Installing multiple batteries will increase your battery capacity and power ratings exponentially.
You should disregard batteries with a usable power capacity rating below 10 kWh. These aren’t suitable for most homeowners’ needs.
Solar batteries usually have two power ratings: a peak power rating and a continuous power rating.
The former refers to how much energy it can release to power appliances that need a burst of energy to get started, like air conditioners. Continuous power rating is the power output available to keep appliances running at a steady rate, e.g. a refrigerator.
Manufacturers express a battery’s power rating in kilowatts or amps. This affects how many appliances you can run at once when using battery power.
You can calculate your home’s power needs by adding up the power consumption of all your appliances. You can usually find these details printed on a sticker on the back of the appliance.
Most homeowners find that batteries with a peak power rating of 7 kW and a continuous power rating of 5 kW are sufficient for their needs.
Round Trip Efficiency
Roundtrip efficiency refers to how well a battery and inverter combination convert and store electricity. It refers to the energy recovery efficiency of your battery.
All electrical processes result in some losses, so you’re bound to lose a few kWh of electricity between your inverter and your battery. Roundtrip efficiency enumerates this loss by referencing how many units of electricity you’ll get out of a battery for every unit you put in.
For instance, if your battery/inverter system can return 4.5 kWh after receiving a charge of 5 kWh, its round-trip efficiency is 4.5/5, or 90%.
Always choose a battery with a round-trip efficiency of at least 80%. They’ll cost a little extra upfront, but they’ll save you more money over time.
There are three ways to measure battery lifetimes. These are:
- Expected years of operation
- Expected throughput
- Expected cycles
Battery cycles refer to how many times you can charge and discharge a battery. Throughput, expressed in kilowatt-hours, refers to how much electricity can pass through a battery during its lifetime.
Both of these factors impact how many years the battery should last. You can calculate this lifespan by dividing the throughput by the usable capacity of the battery.
This will provide an estimate of how many full cycles you’ll get from the battery. When you divide this by the number of days in a year (365), you’ll get the expected lifespan of the battery in years.
All solar batteries manufactured in the US must meet strict safety requirements to achieve certification for installation in homes and businesses.
Always check that you’re installing batteries approved for the purpose you intend to use them for.
Solar Panel Battery Storage Costs
Solar batteries cost between $9,000 and $14,000 to install, but they do qualify for the 30% federal solar tax credit.
There is also considerable competition between installers, so shop around until you find a solar contractor with good deals up for grabs.
When comparing battery prices, you should also consider the Cost of Operation. This refers to the cost of one kWh over the battery’s lifetime and involves comparing the battery’s expected lifetime with its output.
You can also compare the capacity of the batteries based on their prices to get a cost per kilowatt.
Making the Most of Solar Savings
Solar panel battery storage is an excellent way to get more out of your solar panels. Instead of using power from the grid when the sun goes down, you can call on the power stored in your batteries to keep things running at home.
Battery storage adds value and appeal to your home if you decide to sell it, and provides a backup in the event of power outages. When you follow these tips for finding the best battery for you, you’re bound to maximize all these benefits.
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