The Cost of Solar Batteries: Are They Worth The Investment?

Solar batteries, like the Tesla Powerwall, make up a large part of the cost of a solar energy system; as such, thorough research should be done to determine if you need batteries. And if so, which battery storage system best suits your requirements and budget.

🔑 Key Considerations:

1️⃣ Decide upfront what your system expectations are. For example, save money, provide backup power convenience, or off-grid living? 

2️⃣ The type you choose affects the cost of a battery significantly.

3️⃣ Installation and other potential hidden long-term costs associated with solar battery installation must be factored into the overall cost.

4️⃣ Consider the benefits of tax credits, rebates or subsidies, and net metering.

The experience gained through my job as a solar panel system supplier and installer over the past five years places me in an excellent position to offer some recommendations on the subject.

So let’s dive into it!

🔋 Solar Battery Costs

Installing a solar battery system is worth the investment, provided you choose the suitable batteries for your needs. 

A battery backup offers many advantages. However, it’s a reality that not all solar energy systems need backup.

A grid-tied system without battery backup can save you money if you live in an area with a stable grid connection and possibly offer net metering.

Fortunately, most solar power systems are battery compatible, so that batteries can be added in the future.

Many solar system owners follow a phased approach where a backup system consisting of an inverter and solar battery is installed, and solar panels are added to the system at a later stage.

The alternative is to invest in solar panels and an inverter first, run grid-tied, and invest in batteries later.

Batteries are a significant enhancement for any solar panel system since excess solar energy is stored in the batteries for later use.

When paired with solar panels, the solar system generates electricity from the sun, which powers your home, charges the batteries, and can push power back into the grid.

During the day, the sun provides the homes power needs. Once the sun sets, the power draws from the batteries.

If the battery power gets depleted, you will start drawing power from the grid utilizing the credits generated by feeding into the grid during the day.

If your system is correctly sized, the credits generated by feeding onto the grid will equate to the power used at night, resulting in a minimal electricity usage charge, if any.   

Off-grid living requires solar panels and solar batteries that provide power for use at night and during inclement weather conditions.  

💰 The Upfront Cost Of Solar Batteries

The cost of the number of batteries suited to use in energy storage systems varies vastly depending on the type and size battery batteries you choose.

Lead-acid batteries start at around $200, while quality Lithium-Ion batteries can cost up $30 000 or more.

As with many things, “you get what you pay for” is true. Therefore, choosing the correct battery for your needs is critical in ensuring a viable return on investment.

The lower-priced lead acid batteries, which include flooded, gel, and AGM batteries, are attractive when input costs are assessed.

Lithium-Ion batteries are significantly more expensive upfront than traditional battery types but last substantially longer.

The average lithium-ion battery lasts 10 to 15 years or longer before declining in performance, while conventional batteries seldom last longer than five years. Often even less.

Compared to traditional energy sources such as gas, natural gas, oil, coal, and nuclear, the cost of solar production is, on average, over thirty percent cheaper per kilowatt hour for commercial power suppliers. 

For domestic solar plants, the cost of generating your power is determined by many factors directly related to the system you’re running, and the local solar incentives authorities offer.

The type of system: 

  • Is it a backup system only?
    No solar input means the battery is charged from the grid, so there is no saving.
  • Do you have solar panels that subsidize the cost?
    Solar panels save you money, green energy.
  • Does the system have batteries to store excess power for later use?
    Batteries allow you to use stored energy at night, saving money.
  • Is it a Grid tied system that only saves money in the day?
    Only save money when the sun shines.
  • Do you run off the grid?
    Off-grid affords complete grid independence but doesn’t allow any credits through feeding back into the grid.
  • Does your system qualify for tax credits or rebates?
    Varies from State to State.

Solar batteries significantly reduce the cost of generating your power at night. The only other viable choice is using a gas-powered generator requiring constant refueling.

Extrapolate the cost of running the generator over the lifetime of a lithium battery (10 to 15 years), and the batteries become a viable alternative. 

Although solar batteries have become significantly cheaper over the past two decades, they still make up a significant portion of a solar system’s overall cost. Factors affecting the price of solar batteries are:

  • The type of battery (Materials from which it’s made)
  • Expected battery life (Cheap batteries usually don’t last as long before needing to be replaced)
  • The efficiency of the battery (More efficient batteries tend to be pricier)
  • Kilowatt-hour rating (Size)
  • The battery Brand (Premium brands demand higher prices)
  • How many batteries do you require (More backup capacity requires more batteries)
  • Depth of discharge (Higher DOD command a price)
  • Length of the warranty (Long warranties generally support premium products which are higher priced.

The depth of discharge (DOD) of solar batteries varies significantly. DOD, or how far the battery can be discharged before it stops providing power, is a significant factor to consider when purchasing a solar battery.

Lead acid batteries are highly likely to sustain internal damage, reducing their ability to store energy when discharged to more than 50% of their capacity. Lithium batteries generally have a DOD of between 80% and 100% without damage. 

Not only does this affect the potential costs of calling a technician to assess why the batteries are not charging or lasting as they used to. It also means that additional batteries would be required to deliver the desired power, increasing costs.

Battery prices vary significantly; however, with the vast choice of batteries available, it’s possible to find the correct battery for your needs at the right price.

Lithium-ion batteries, for example, last for many years, so although they’re more expensive to buy upfront, they offer the lowest long-term storage solution. 

The Long-Term Cost Of Solar Batteries

Replacing batteries is something you don’t want to do often. Solar batteries are generally made to last for many years; however, all batteries have a limited useable lifespan. Therefore, choosing a battery that lasts the longest and delivers the most cycles is essential.

Batteries are an asset in a solar system as their ability to store energy for later use means you’re saving money while not having to draw power from the grid. The batteries also provide power to your home if the grid fails.

All solar batteries are not equal. Some types, such as flooded lead acid batteries, work superbly well for solar applications; however, they must be maintained regularly to ensure they last as expected. 

Despite the regular maintenance on lead acid batteries, the available cycles are much less than those offered by lithium alternatives meaning you’d have to replace your battery bank at least once, maybe more, before replacing a lithium battery. 

Call-out fees when requiring a battery specialist to provide the service can run into thousands over the battery’s lifetime.

Purchasing a maintenance-free battery is a great way to save future maintenance costs and inconvenience. 

💭 Other Potential Costs To Consider

Buying a solar battery is only part of the cost as the battery or batteries (depending on the system sizing) need to be installed. Installation fees can cost hundreds or even thousands of dollars depending on the work required.

Battery installation is best left to trained technicians as, in most instances, it’s not just a plug-and-play process.

The warranty may also be voided if a solar professional does not install the battery.

For a solar system to save you money, the best option is to run solar panels in conjunction with solar batteries.

Solar panels generate power during the day. The power is stored in the batteries for the evening, and excess energy can be fed into the grid, potentially saving more money.

Solar panel costs depend on the size of the PV array that suits your needs. According to Forbes, the average solar system costs $16 000 in the US, including installation. The average return on investment is about seven years. 

📖 Related Article: New vs. Used Solar Panels

Solar panels require virtually no maintenance other than cleaning if they get dirty. Having no moving parts and being firmly attached to your roof of a ground structure ensures they last for many years.

They have an average useful life of 25 years, meaning you’ll be generating “free” power from the sun for an additional 15 years or more after the initial cost is recovered before needing to consider replacing the solar panels.

A helpful tip is to ensure local support for solar batteries and other components to resolve potential problems within a reasonable period. 

👍 The Benefits Of Investing In Solar Batteries

Investing in solar batteries offers significant benefits, including Environmental benefits. Traditional means of generating power are notoriously harmful to our environment, not only in terms of extracting the required raw materials from the earth but also in terms of air and water pollution and water use.

An additional benefit of installing solar batteries in your home is the convenience of not having power outages and direct savings to the homeowner resulting in increased value.

Having uninterrupted power in areas where the grid may be unreliable is a significant draw card for any potential property owner.

Convenience is often overlooked when considering battery backup for a system. There’s no better feeling than not knowing that the grid power has failed and your home’s lights are on while the neighborhood is in the dark.

Constant, uninterrupted power has become a necessity of life due to our reliance on continuous connectivity (Wi-Fi, etc.), and backup solar batteries provide this solution while saving you money on your electricity bill.

Batteries provide stable power when running through an inverter, significantly reducing the possibility of sensitive electronic equipment being damaged by power surges. Home appliances last longer when running off a stable power supply. 

FAQs

How Many Solar Batteries Are Needed To Power A House?

The frequently asked question can only be answered by determining the home’s power needs. The best solution is to enlist the help of a solar professional. 

Factors that need to be factored into the equation are:

  • Stored kilowatt hours required (determines battery sizing)
  • Whether the battery is charged by the solar, grid, or a combination of both.
  • The type of inverter (Is it compatible with the battery)
  • The type of battery

How Many Years Does A Solar Battery Last?

The type of solar battery determines how long it’ll last. Solar batteries can last from a few months to 25 years or longer.

Battery life is measured in cycles ranging from 200 cycles for a lead acid battery to 6000 plus cycles for a lithium-ion type battery.

A cycle is the equivalent of one complete discharge and back to fully charged. On average, one cycle is used per day.

🔑 Key Takeaways

Investing in solar batteries is expensive and requires weighing the pros and cons before investing.

1️⃣ Solar batteries cost anything from $200 to $30 000 or more, which excludes maintenance costs over the life of the battery and excludes the initial installation costs.

2️⃣ Solar batteries are not all the same in terms of type and size, capacity, efficiency, DOD, and maintenance requirements and differ vastly in how long they last, so research is required.

3️⃣ Solar batteries offer numerous benefits. They save you money on your electricity bill. They provide continuous power by storing power for later use. Solar batteries keep the lights on when grid power is interrupted and offer significant environmental benefits. 

The next step in becoming part of the solar battery evolution is contacting your local solar system installer to accurately assess your power needs.

Once your energy backup requirement is determined, choosing the most appropriate storage solution can begin.

📖 Read Next:
Battery technology: LFP vs NMC
AGM vs Gel batteries
AGM vs Lithium batteries

I’m the website operator and editor here at ALTA Devices. The solar revolution is the most exciting thing to happen in a generation! I’ve written extensively on solar, electric vehicles, and the electrification of the marine industry. You can find out more on LinkedIn below: