Choosing a Solar Battery - options beyond Tesla
Updated: Dec 2, 2019
Solar batteries can offer significant benefits for homeowners in terms of solar storage and economic savings, but with their significant price tag they don’t always make financial sense for everyone.
Here is a rundown of what they are, who benefits from them, the different types and what your options are when it comes to the three big players in the solar battery storage market.
What is a solar battery
Solar batteries essentially maximise your ability to use the electricity produced by your solar panels. Often we need more electricity in our homes when our solar panels are generating less power i.e night or overcast days. Battery storage allows you to store energy when the solar panels are working their hardest i.e the middle of the day, for use when you actually need it. Genius!
Benefits of solar batteries
From an economic standpoint solar batteries cost more than a standard diesel generator but the solar batteries provide a clean source of renewable energy. Storing clean energy makes it available around the clock and the ability to store solar energy for use at a later point in time reduces your carbon footprint.
Great back-up during power outages
If you suffer from frequent power outages and you’re using solar panels you will lose power because you’re still connected to the grid. When you add a battery to your system, you can use the stored energy in the battery even when the grid is down.
Forget about peak electricity periods
Store power when the cost of electricity is cheaper and use the stored energy during peak periods. Further savings can be made by charging your battery from the grid at off-peak rates.
Types of battery storage
There are two main types of battery storage available for household energy storage; lithium-ion and lead-acid batteries.
Lithium-ion batteries are a popular choice for homeowners with solar panels. Lithium-ion technology is used in mobile phones and portable devices like laptops and tablets. Due to increased production they can now be manufactured in larger sizes suitable for storing solar energy and this has impacted a reduction in costs although they’re still more expensive than lead-acid batteries. Other advantages of lithium-ion batteries are a higher storage capacity, smaller environmental impact, longer life cycle and reduced maintenance due to its inbuilt battery management systems. One of the perceived disadvantages of lithium-ion batteries is the waste, but although limited there are recycling programs available in Australia. It is important to note that lithium-ion batteries must be recycled by a lithium specific recycler such as Envirostream.
Lead-Acid Batteries are based on the technology used in car batteries, but with thicker electrodes. Commonly you’ll find lead-acid batteries used on solar panels in rural homes where it’s too expensive to be connected to the grid. Lead-acid batteries are a relatively cheap alternative to lithium-ion batteries but they require regular checks and maintenance and a lower percentage of the energy stored can actually be used.
Besides the lower cost, some other advantages of lead-acid batteries is that due to the fact that the technology is understood and there have been many recent advances they are easy to acquire across Australia, and perhaps their greatest advantage is that they are readily recyclable with 98% of the battery being classified as a recyclable material.
The Three Front Runners
When you mention battery storage most people will automatically think of Elon Musk’s Tesla Powerwall, but there are multiple options on the market and it’s worth researching what best suits you, your budget and your solar storage requirements. The three major players LG, BYD and Sonnen have made Australia one of their primary markets. Luckily for homeowners the competition means lower prices, better technology and warranty offerings.
LG RESU HV is a lithium-ion battery and has had great success in on grid home energy in Australia. Ulike many batteries on the market it t can be installed both indoors and outdoors, it requires no maintenance, and if you’re short on space then this could be the best option for you. LG RESU HV claims to be the most compact and energy dense battery systems available. The current warranty on the LG RESU HV is lower than other leaders in the market at 60% of it’s nominal energy output for 10 years.
BYD is the world’s largest manufacturer of rechargeable batteries. BYD batteries are lithium iron phosphate, which means it’s extremely unlikely that these batteries will overheat or catch fire, and they have shown high reliability and efficiency amongst many industry reviews. There are 2 product lines - the high voltage (HV) and the low voltage (LV) B-Boxes, each with a variety of storage capabilities. BYD batteries have a higher power output and their peak power is excellent. High power output means electricity doesn’t get drawn from the grid when household demand is high, or, if used off grid, its managing loads is easier. It’s important to note that BYD batteries can only be installed indoors and cannot be exposed to water. In terms of warranty the BYD HV (which we use) gives 10 years but doesn’t specify its limits on use, which it definitely has.
German company Sonnen is the new star in the battery storage market and the good news is that they’re now manufactured in Australia. Sonnen is recognised as the safest home battery on the market due to its use of lithium iron phosphate cells, the safest most durable cells around. It’s also the smartest battery out there. Sonnen’s software works out when certain appliances can run at home, intelligently manages your energy accordingly and users can configure the system with their smartphone. Sonnen also run a community program that allows users to buy and sell power from each other across the grid. Sonnen provides the best warranty on the market at a guaranteed lifetime of 10,000 cycles or 10 years.
Your battery storage needs will differ depending on a variety of individualised factors, we always recommend speaking with a battery expert to determine the best fit for your home.