Domestic Battery Storage

Share on facebook
Share on twitter
Share on linkedin

Battery Storage 

Today, homes and businesses in the UK are gradually shifting from depending on the national grid to individual sources of electricity generation. 

Solar panels are a great tool in generating renewable electricity independently. 

When it’s first introduced, solar panels were known with the setback of not being able to produce electricity to use in the evening and at night when sunlight is no more available. 

Solar battery storage was introduced as an accessory to help store electricity generated during the day for later uses at night. 

With this, solar panels can generate electricity during the day, and instead of wasting excess energy, they can send it to the installed solar battery to store.

This article takes a look at solar storage and all you need to know about it.

Are Solar Batteries Cost-Effective?

Solar battery costs vary and depend on certain factors. Factors contributing to the costs of solar battery storage include the battery technology, its lifespan, and storage capacity. 

However, most solar battery storage systems cost between £1,200 and £6,000 in the UK.

Also, the need to regularly replace solar battery storage is another factor to consider. 

A typical battery storage system can last between 5 to 15 years, which is often lower than the average solar panel lifespan. 

This means you’ll have to change your battery storage after some years, increasing your annual costs.

Why Is Solar Battery Storage Essential?

Though the system of pairing battery storage to solar panels was introduced not long ago, it’s an efficient system that has proven its benefits in four different ways:

It Stores Energy

The first advantage of solar battery storage is how it stores energy for later use. The storage stores electricity generated during sunny hours for later use. 

With this, owners can use their solar panels to power their appliances after coming back from work in the evening. 

Some solar batteries are so powerful that they can store electricity for months. This means that homeowners and businesses can use their solar panels even on cloudy days. 

However, the amount of energy stored will depend on the battery capacity.

It Lowers Energy Costs

Other than using solar battery storage to store electricity generated by solar panels, the storage can also store electricity from the grid. 

With this, owners can store electricity during off-peak periods and use it later during peak hours. With this, you cut back on how much you pay for electricity.

You Can Sell The Energy

If the battery has a high capacity that it can store a lot of energy, owners can convert excess energy to money by diverting the stored energy to the electrical grid when the price goes up. 

You’re Independent Of The National Grid

It usually feels great to go independent with your electricity generation. 

With solar battery storage, you can produce your electricity yourself and don’t have to depend on the national grid to supply you electricity any longer. 

However, you must install the right number of solar panels with a powerful battery storage system.

Who Is It Ideal For?

Since battery storage can store energy from any source, it won’t be wrong to say the system is for everyone. 

However, solar battery storage is best combined with a solar PC array. 

This means that you enjoy the system best if you have a solar PV array already. If you don’t have solar panels installed, you can consider investing in them.

The two systems will help save how much you spend on electricity and make you go renewable. 

If you’re planning to go renewable, a combination of solar panels and battery storage is a great option to consider.

When buying a solar battery storage system, you’ll come across several options. 

Each option has a different lifespan, ease of installation, eco-friendly efficiency, and other advantages.

How Much Do Solar Batteries Cost?

As mentioned earlier, solar battery storage systems are available with different options at different prices. 

Depending on chemical composite, life cycle, and capacity, the cost of solar battery storage can fall between £1,200 and £6,000. 

Solar battery storage systems are a bit expensive for now. This can be attributed to the newness of the technology. 

High prices were once the situation of solar panels. The prices were extremely high when the technology was first introduced, but as time went on, the prices declined. 

As such, we can expect the same fate for solar battery storage technology.

The two common chemical compositions of battery storage are lithium-ion and lead-acid. 

Though lithium-ion batteries are more expensive than their counterparts, they’re the most common choice in the UK. 

This can be credited to their longer lifespan and higher usable capacity.

Battery Material

The material composition of a battery says a lot about it. Battery material determines the battery’s lifespan and discharge rate. 

Lithium-ion batteries are the best for both specifications. 

Lithium-ion batteries can discharge between 70% and 90% and have double lifespans of lead-acid batteries. Lead-acid batteries can only discharge around 50%. 

It’s worth noting that the higher the discharge rate and lifespan, the higher the price. 

As such, you can expect lithium-ion batteries with higher prices than lead-acid batteries.

Capacity

A battery capacity is in two forms: storage capacity and usable capacity. 

While storage capacity means the total amount of energy the battery can store, usable capacity means how much of the stored energy you can use.

These two metrics are measured in kilowatt-hours (kWh) and influence battery prices. The larger the capacity, the higher the price. 

Going for a larger capacity means you can store and use more energy, though priced at a higher price.

Lifespan

A solar battery’s lifespan depends on its life cycle. 

The more cycles it can provide, the longer the battery performs. Typically, a solar battery can serve for up to 15 years. 

After this, a new solar battery storage system becomes the best option, adding up to future costs.

Installation

The installation cost of a solar battery storage system usually depends on the size. Some brands offer to install the system for free, though. 

However, it’s best to plan to install both solar panels and battery storage at the same time, as this helps minimize the costs of hiring an installer.

How To Lower Your Costs

Knowing how to lower your costs with solar battery installation is excellent. 

This relieves you of the exorbitant price of buying and installing the system. The good news is, there’re funding for solar battery storage in the UK.

The most common way to save money on solar battery storage is to sell energy to the grid. 

This is made possible through the Smart Export Guarantee (SEG). 

Though each supplier has its export tariff, common tariffs in the UK fall in the neighborhood of £4 and £6 per kWh.

The Feed-in Tariff was an excellent scheme that rewarded homeowners for using solar panels and other renewable energy systems. 

However, with the introduction of SEG, FIT was terminated in 2019. With this, the FIT doesn’t process new applications. 

Only those who had been registered before the termination are still receiving payments, and this will last until their agreements come to an end.

Solar Battery Storage: Types

RV/ Marine Solar Batteries

These are perhaps the least effective solar batteries available today. 

They’re most suitable for RVs and boats since it’s used when no other form of electricity is forthcoming. 

They’re generally known for lower capacity for continuous service.

Flooded Type

Followed by marine solar batteries on the lifespan ranking are flooded type batteries. 

The batteries have longer lifespans than marine batteries and are relatively pocket-friendly. 

The batteries are a variant of lead-acid battery technology, with caps for adding water.

However, the batteries come with the disadvantage of emitting gases. As such, they’re more recommended for outdoor use. 

A venting system is therefore necessary if they’re used indoors, as the gases emitted can be explosive and toxic.

Gel: this is a better option than the flooded-type battery. A gel battery doesn’t emit gases and therefore doesn’t require venting. 

As such, the batteries can be used indoor. This elongates their lifespan, as they are not exposed to the harsh weather conditions that flooded type batteries are exposed to when used outdoor. 

Absorbed Glass Mat Batteries (AGM)

These are the best types of solar battery storage systems. The batteries are sealed, meaning that they don’t emit gases while charging. 

They share the advantages of sealed gel-type batteries but with higher quality. 

Other attributes of these batteries that make them better than other types include higher voltage maintenance, lower self-discharge, and longer lifespan. 

With all these advantages, it’s not surprising that they’re the most expensive of all types of solar battery storage.

What Is The Lifespan Of A Solar Battery?

As mentioned earlier, the lifespan of solar battery storage varies. 

Depending on the chemical composition and type, a solar battery storage system can last between 5 to 15 years. 

As a guide, lead-acid batteries last for 5 to 8 years, while lithium-ion batteries have lifespans between 11 to 15 years. However, a battery lifespan is influenced by the weather condition it’s used.

What Is Depth Of Discharge (DoD)

As it’s harmful to use your phone battery to 1% percent, it’s harmful to use your solar battery to a certain level.

Depth of discharge defines the amount of the charge in the battery that can be used before it’s recharged again. 

This varies from battery to battery and is important to maintain a battery’s lifespan. 

You shorten your battery’s lifespan by using 100% of the charge or using it below the DoD limit before recharging it again. 

For example, when you own a 5kW battery storage system with 80% DoD, it means you have to charge it before using 4kW of the charge. 

The more you keep to this practice, the more you elongate your battery’s lifespan.

The impact of not keeping to this practice is more harmful in lead-acid batteries than in lithium-ion batteries. 

Lithium-ion batteries have higher tolerance levels and can handle higher temperature levels. 

These advantages contribute to lithium-ion batteries being a better choice than lead-acid batteries.

What Is The Best Solar Battery?

When buying a solar battery storage system, you have many options to choose from. 

Always keep in mind that the brand you choose contributes to what to expect from the battery. 

Each battery has specific life cycles, warranty, cost, usable capacity, and depth of discharge.

Most lithium-ion batteries on the market have a warranty of 10 years and depth of discharge up to 90%.

Investing in solar battery storage will make your electricity generation easier and your life comfortable. 

However, it’s important to cleverly choose the best one, as making a mistake in the selection phase can hurt in the long run. 

Solar Battery Technologies

As repeatedly said in this guide, a battery’s technology determines what the battery offers. 

There’re different battery technologies, and the common and most significant ones are lithium-ion and lead-acid.

Lithium-ion

Lithium-ion batteries remain the most common battery technology available today and take the largest share on the market. 

This technology is the same as lithium-ion batteries in laptop computers and smartphones. 

Depending on the brand, lithium-ion batteries are of different chemistry. Tesla and LG Chem are known for lithium nickel-manganese-cobalt (NMC). 

Lithium iron phosphate is another common chemistry and is adapted by Sonnen and BYD. 

This chemistry is regarded as a better option than NMC for a lower risk of thermal runaway. 

This means that lithium iron phosphate (LFP) are less prone to fire outbreak and damage that can generate from overcharging and overheating.

Pros 

  • They have higher charge-discharge cycles
  • They have higher DoD, which can be up to 90%
  • They can withstand a wide range of ambient temperature
  • They have longer lifespans, which is often up to 10 years

Cons

  • They require being recycled regularly to recover metal and toxic landfills. 
  • They are often expensive than their counterparts on the market

Lead-acid

Also known as advanced lead-acid, they’re based on the same chemistry as car batteries and are more cost-effective than lithium-ion batteries. 

However, besides lower prices and continuous improvements, lead-acid batteries are not a great fit to compete with lithium-ion batteries.  

Pros

Lower price: the most significant – and perhaps the only – advantage of lead-acid batteries over lithium-ion batteries is lower prices.

Cons

  • They have shorter lifespans, as they’re sensitive to high ambient temperature
  • They have lower charge cycles than lithium-ion batteries
  • They’re usually bulky.