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Solar Power Battery Storage - An Introduction

Solar power battery storage is dramatically changing how people use and consume solar power. 

The average household uses electricity first thing in the morning and in the evening hours. Power consumption is typically low during the middle of the day when solar power generation is at its peak, which is not ideal when trying to maximise the benefits of the solar power system.  Changing power consumption patterns isn't always practical, making battery storage a great solution to enable a high amount of solar power consumption within the home. 

Due to falling prices, along with continuous improvements in technology, solar-powered battery storage systems (a.k.a. solar battery banks) are becoming increasingly popular in New Zealand. Approximately one-third of all new solar installations in New Zealand have batteries included in the system.

Lithium-ion type batteries are the most common technology used for solar storage. Tesla Powerwall is one of the big names that is leading the charge in the solar battery marketplace.

How Solar Batteries Work

Prioritised for maximum efficiency, solar power is sent to where it is needed most. 

How Solar Power Is Stored In Batteries

  1. Solar power is sent to any appliance that is on.
  2. Excess solar power charges the battery.
  3. Solar power is drawn from the battery at night.
  4. Any additional power needed will come from the grid.

Why Are Solar Batteries Useful?

Batteries are highly recommended if there is too much solar power exported to the grid during peak power production hours. Solar batteries function by taking excess solar electricity (shown in the yellow bell shaped curve) and storing the electricity in batteries, allowing the user to consume power whenever they like. More often than not, the stored solar energy is used at night when the sun’s not shining. 

Why Solar Batteries Are Needed - Bell Shaped Curve

What Is The Price Of Solar Batteries?

The price range for solar batteries is roughly $6,000 to $20,000 NZD.  Typically the more storage a battery has, the more it will cost.  Other factors that affect the price are the capabilities of the battery, quality of the battery, chemistry used and how long it’s expected to last.

Here’s a quick rundown of  some of the products available on the market along with their estimated price:

Battery Model Usable Capacity Battery Chemistry Power Output Approximate Price
Solax Triple Power 6.3 kWh Lithium Nickel Manganese Cobalt Oxide $6,500 (uninstalled)
Energizer Home Power 12.2 kWh Lithium-Ion Phosphate 3.6 kW $14,000 (installed)
Tesla Powerwall 2 13.5 kWh Lithium Nickel Manganese Cobalt Oxide 7kW peak / 5kW continuous $20,000 (installed)

Please note these prices are rough estimates.  For accurate quotes, fill in our quote request form here for 3 free quotes.  

View and compare more battery storage products available in New Zealand here.

Solar Battery Storage For Black Outs

Solar batteries can be set to power appliances when there is a blackout, or during a power outage. Note: not all batteries offer this feature, be sure to ask when making a purchase.  

Will Solar Power Still Be Exported To The Grid If Solar Batteries Are Installed?

Because such low rates are paid for exported solar power (roughly 8-12 cents per kWh), sending power to the grid is the last priority for the solar power system. 

Solar power will be sent to (1) appliances first (if they are switched on), and then to the batteries (2).  Only if there is additional excess solar power will the system export solar power to the grid.

Where Solar Power Is Directed When Solar Batteries Are Added

Why Install Solar Storage?

A solar battery allows homes and businesses to store excess solar electricity and use it when it’s needed most.  Here’s a shortlist of why this is a good thing:

  • Store excess solar power instead of selling it to the grid for a low price.
  • Ability to keep the lights on and the fridge running during a blackout.
  • Use more green energy; 20% of New Zealand’s electricity is created from burning fossil fuels.  With solar battery storage, you can use more renewable energy.
  • Reduce electricity bills or get close to eliminating them.  Solar batteries will help the household use more of the solar energy created, which means less demand for grid power.

Read more about the benefits of solar battery storage here?

Should You Install Solar Batteries In Your Home?

For Power Security - Yes!  If you are sick of power outages, or the idea of not having power for a day makes you nervous, then absolutely, solar batteries can be sure to provide a home or business with power during a blackout.
For Financial Return - Maybe not quite yet.  A solar battery is likely to reduce a solar power systems return on investment and lengthen the payback period.  
To Reduce Power Bills - Yes!  A battery will reduce those pesky power bills on top of the savings already made with a solar power system.

Lithium-ion Battery Technology

Battery storage technology; it's a race to develop the ultimate solar battery storage system. Lithium-ion battery technologies are the most common battery on the market. Lithium-ion batteries are smaller, lighter and store more energy than traditional lead-acid batteries.

Lithium-ion batteries are found in mobile phones, laptops and electric vehicles - increased demand for these products has prioritised economies of scale for lithium-ion, with the cost dropping roughly 20% each year.

Retrofitting Solar Storage Batteries

Fear not, savvy and smart early adopters of solar technology. Existing grid-connected solar power systems can be retrofitted to include a solar battery bank.

Having a battery ready system is an excellent option if a user is considering adding solar storage at a later date.

Read our blog articles about solar battery storage here>

Read about grid-scale batteries in New Zealand here>

Get 3 free quotes for solar + battery storage here>