Are Solar Batteries Worth It? 3 Things to Consider BEFORE You Buy A Battery

Solar batteries can take up to half of the total cost of a solar system. In this post, I cover the three key things you need to know before getting a battery. Let’s dig in.

1. Do you need batteries?

Most suppliers and installers in Zimbabwe would say yes. It’s a sound investment that will pay you back in less than 10 years. But batteries are not cheap, and you should get them only if:

  1. You don’t already have an existing ZESA connection and getting connected costs more. Examples of this would be a newly built home, a home in a remote area, or a safari lodge. For these, you would need batteries in an off-grid system. You can find out more in my guide on off-grid solar systems.
  2. You need a backup power supply in case of load shedding or a blackout.
  3. You want to save on your power bill by reducing how much grid-supplied electricity you use.

2. Are there other options?

There are alternatives to getting a solar battery. You can either get a solar system WITHOUT batteries or get a backup generator. It all depends on what you’re trying to achieve.

Reducing your electricity bill

If you’re trying to cut down your electricity costs, then a solar system without batteries will work. This is a grid-tie solar system.

Grid-tie solar is cheaper since there’s no battery. The disadvantage is, without batteries, your system provides electricity in the daytime only.

This makes it better suited for homes with an existing ZESA connection. When the sun sets, you switch over to the utility. Here’s a basic guide on grid-tie solar systems.

Backup power supply

If you need backup power, you could just get a generator. They’re cheaper upfront and they provide more energy than batteries. You could get a solar system and a generator instead of batteries but there are a couple of reasons this is far more expensive and not practical in the long run.

  1. Generators need refuelling and maintenance. Batteries recharge using solar and they need little to no maintenance.
  2. Batteries have a 50% longer lifespan (5-10 years) than generators.

These are the key factors. Here’s my post on backup power systems for a more detailed comparison of batteries vs backup generators.

Off-grid system

For an off-grid system you could also get the solar and generator system. But this setup has the same flaws I highlighted above. It’s expensive and impractical.  

3. The type of battery

If you’ve looked at your other options and decided on getting batteries, the only thing left is to pick the right one. The type of battery is important because it determines:

  1. How your solar system will perform.
  2. How much the system will cost in total.

For performance

Lithium batteries are unbeatable. They have the biggest energy capacity, they’re smaller and they weigh less. These are the batteries used in electric vehicles. Here’s a complete guide to lithium batteries.

Sealed lead-acid batteries are the second-best option. They have less energy capacity than lithium. There are two types to choose from, namely gel and AGM batteries. Here’s a comparison of gel vs AGM batteries for more.

Flooded lead-acid batteries perform almost as well as sealed lead acid. They have one disadvantage. They require maintenance. Here’s a basic guide to flooded lead-acid if you want to know what type of maintenance.

For price

Flooded lead-acid is the cheapest solar battery. Then comes sealed lead acid which cost a little more. Lithium batteries are the most expensive.

Once you know what to look for picking the right battery is easy. Specifications like capacity, efficiency and how many appliances it can support. Here’s a detailed guide to choosing a solar battery.

Conclusion

Solar batteries can save you money and give you peace of mind of having power when you need it. But you don’t always need one.

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