CHARLIE SPARKS

Our Blogs

How to Buy The Best Solar Battery Storage

January 31, 2023
1:26 am

The utilisation of home battery storage is of great interest to those seeking to conserve energy. Solar panels installed on roofs can provide a significant benefit if the surplus electricity is stored in a battery during nighttime hours or on days with reduced sunlight.

Understanding how these batteries operate and the considerations to consider before installation is essential.

In this article,we will go through factors and considerations while buying solar battery storage.

Factors to Consider When Buying a Solar Battery

Capacity rating

The nominal capacity of a battery is typically expressed in kilowatt-hours (kWh) and represents the total amount of energy it can store. Due to the depth of discharge, full power is unavailable, limiting the usable capacity.

Battery size

The universal battery is deemed the optimal selection for many people since most purchasers typically need to gain knowledge of the necessary criteria. Nevertheless, it often has to sacrifice certain features and capabilities to adhere to the essential specifications of varied applications.

Depth of discharge

Most battery types need to remain at least partially charged to prevent damage. There is no risk of discharging lithium batteries to 80-90% of their rated capacity. Lead-acid batteries can typically be discharged to between fifty and sixty percent, while flow batteries allow for a full discharge.

Battery lifetime

The battery’s expected life, including any applicable warranty, can be measured in cycles or years. While the latter figure is usually an estimation based on the battery’s desired usage level, the lifespan should also indicate capacity retention at the end of its life. For lithium batteries, this is typically the case.

Output at peak power

Kwp is the unit of measurement for kilowatt peak solar batteries. This value serves as a comparative metric rather than a unit of absolute measure and indicates the theoretical peak power output of the system during the most optimal circumstances. When selecting a solar battery, the kWp rating informs one of its maximum power output capacity; the more significant the peak power output level, the more advantageous the battery.

Round-trip efficiency

The efficiency of a battery, expressed as a percentage of the energy used to store it, can be calculated by determining how much energy can be output from the battery compared to the initial input energy.

A battery with an efficiency of 90% can store 100 kWh of energy and return only 90 kWh (90 kWh / 100 kWh x).

Opt for batteries with a higher cycle efficiency for cost-effectiveness.

Battery type

In selecting a solar battery, the type/technology should be the primary factor, with a budget and individual requirements taken into account.

Cost

The price point of solar batteries varies significantly. Prices range from $200 to $750 per kWh, with lead-acid batteries typically averaging around $260 and lithium-ion batteries at $271 per kWh.

The batteries range from $5,000 to $7,000, varying depending on the locality and brands available.

Types of Solar Batteries

Lead-acid Batteries

Lead-acid battery technology, long utilised to start cars, is also employed for large-scale storage. With its tried and true performance, this battery remains a reliable option.

Despite advancements in performance and price reductions, lead-acid technology’s long-term viability is still being determined compared to lithium-ion and other technologies.

Lithium Batteries

Today, lithium-ion batteries are the most popular type of battery for residential applications. This technology is similar to smaller electronics such as smartphones and laptops. Amongst lithium-ion chemistries, lithium nickel-manganese-cobalt (NMC) is the most favoured for use in home batteries.

Lithium Iron Phosphate (LiFePO4 or LFP) is a well-known chemical that is less likely to cause thermal runaway than lithium oxide. This event can result in battery damage and fire due to overheating or overcharging.

Frequently Asked Questions

Are batteries worth the cost?

Backup power sources such as batteries can enhance energy independence and, in some cases, reduce electricity costs by providing an alternative to the grid.

How long can solar batteries last?

If you choose to install a home solar battery now, you can expect to need a replacement within 5 to 15 years; however, by doing so, you will ensure that your solar power system remains operational and efficient for its entire lifespan of 20-30 years.

What is the best battery type for solar storage?

Home energy storage batteries often come in three varieties – lead acid, lithium-ion, and saltwater. Generally, lithium-ion batteries are the most suitable choice for a solar panel system, as other types may be more cost-effective.