The second residential solar revolution has begun – home battery energy storage. Solar + storage has arrived on our doorstep and Energy Matters Australia is ready to welcome it!
A Change On The Horizon
While the option to buy home energy storage has been possible for a number of years, the deep cycle batteries and other components required have been expensive, cumbersome and required a degree of knowledge to operate and maintain the equipment. This has meant residential energy storage has been largely confined to off-grid applications and storage enthusiasts up until now.
The rapid evolution of lithium-ion batteries and associated technology is changing all that. The new generation of energy storage is cheaper to buy, streamlined and better looking.
A Bit Of Battery History
Lead-acid based deep cycle battery technology has been around for over 100 years, but in the 1970’s British chemist Stan Whittingham and his Stanford University colleagues discovered a way to make an electrode that could store lithium ions within layers of titanium sulfide – and in a way that a battery could be rechargeable.
However, the batteries also had a tendency to vent (basically, explode). Even if this didn’t occur, the batteries would rapidly break down.
In 1980, John Bannister Goodenough found a cobalt-oxide cathode to be more stable and able to store twice to three times the energy of any other rechargeable room-temperature battery. As a result, smaller batteries could be made.
Today, while lithium-ion battery technology has evolved, the lithium-cobalt-oxide cathode remains a crucial component in most of these batteries.
It’s for this reason Goodenough has been hailed an energy storage super-hero. It didn’t make him a particularly famous or rich one though – he’s reportedly never received a cent of royalties for his efforts. True to his super-hero status and even at the age of 92, Mr. Goodenough is continuing to work in the field.
Advantages Of Lithium-ion Batteries
Lithium-ion batteries power all sorts of devices – power tools, notebook computers, tablets, cell phones and electric cars. They have some distinct advantages over wet-cell lead acid batteries, such as you’d find in your car.
- Higher energy density
- Lower self-discharge
- Lower maintenance
- No “memory effect”
- Increased cycle life
Home Energy Storage Comes Of Age
Lithium-ion based residential energy storage has been around for a couple of years. There are also open concepts that work with most battery technologies and any existing grid connect inverter, such as SMA’s Sunny Home Manager Flexible Storage System.
However, the battery system that sparked the current storage revolution is the Tesla Powerwall; now available via Energy Matters .
Fronius has also released its own full energy storage solution featuring the Fronius Solar Battery.
View our home solar storage range.
How Home Battery Energy Storage Systems Work
At its most basic, new generation home energy storage is quite a simple concept, but involves some very high-tech equipment.
Here’s how residential battery storage works using the Tesla Powerwall battery system and SolarEdge components as an example.
- Solar panels convert sunlight to DC (Direct Current) electricity.
- Any surplus DC electricity charges the Tesla Powerwall.
- The inverter converts the DC electricity to AC (Alternating Current) for use in the home.
- The inverter (a special type is needed) can also convert AC to DC to charge the PowerWall using cheap off-peak mains power.
The Powerwall model for daily use is single and three-phase compatible; has a 7kWh capacity (6.4kWh usable) and a 3.3kW continuous/peak output capacity. It is a wall mounted, liquid thermal controlled unit weighing around 100kg – which is pretty impressive when compared to much heavier traditional deep cycle batteries.
With the Tesla Powerwall, multiple batteries may be installed together – up to 9 units for the 6.4kWh battery. That capacity would provide the average Australian household with more than a couple of days power supply purely from battery storage. Currently there are no inverter manufacturers supporting multiple installations, but SolarEdge is expected to provide this functionality sometime in 2016.
For most households however, such a big storage system wouldn’t be necessary considering mains grid power will still be available to act as a backup to a solar panel system in an extended heavy cloud event. Blackouts of more than a few hours are also becoming an increasingly rare event in Australia.
How Much Energy Could You Save With A Battery System?
You could reduce your mains grid electricity consumption by 80% with a solar + battery system. Please note however, that this is based on standard system installation in Sydney.
Your home will require an assessment and any savings will depend on your actual individual circumstances (which may vary over time).
If you’re curious about getting a rough idea as to how much you could reduce your reliance on electricity companies through implementing a solar + storage solution, try our new online calculator.
It’s very easy to use – just enter your latest bill cost or average daily consumption, input your town or suburb and choose from a wide range of systems to base the calculations on.
Want Home Battery Storage?
You’re not alone – many Australian households have expressed a desire to buy battery storage to reduce their dependence on the traditional power companies that have had a stranglehold over them for decades!
View our full range here – or contact our friendly battery experts on 133 SUN for advice.
You can also register for announcements by clicking here.
If you’re considering going solar but buying battery storage in the future, acquiring a battery-ready or upgradeable system is important – chat with our storage experts about your needs by calling 133 SUN.
Thinking Solar? Think Ahead
it’s important to think ahead when buying solar – install a battery-ready solar panel system of suitable size if your ultimate goal is to add energy storage. Not all solar power systems will be easily upgradeable.
A battery compatible solar power system is more than just about components – it’s also about positioning and wiring. Few solar installers have this knowledge currently ; but the Energy Matters team does.
Learn more about battery ready solar power systems.
Go Solar Now – Or Wait?
There is a very important potential benefit of going solar now with a battery-upgradeable system and it relates to subsidies.
Subsidisation of solar power systems is based on renewable energy certificates (known as Small scale Technology Certificates these days – STC’s). The value of these certificates fluctuates with market conditions. Currently, their value is quite high; but as we’ve seen in the past, their value can plummet and this can lead to a significant decrease in the amount of subsidisation of a system.
Regardless of market value, current subsidy levels will be reduced in the not-too-distant future.
The other major advantage of installing solar now instead of waiting is you’ll start saving on electricity bills sooner!
Save today and store tomorrow!
Home Battery Systems And Feed In Tariffs
Whether the installation of a home energy storage system will affect your feed in tariff payments will depend on the state you are located in. Learn more about the current state of play in this article (current September 2015). For many battery system owners, the issue of feed in tariffs will become a less important consideration considering they’ll be storing much of their surplus.