Comparing battery technologies

Until recently lead acid batteries have been the major player in the energy storage industry, particularly for off grid installations but they have serious limitations in terms of requiring customer maintenance and of course they are made from toxic materials.

Recently, Tesla’s lithium ion batteries have received a lot of attention due to their advertised low price and excellent marketing, however the lithium ion batteries are now receiving attention due to their fire risk on the release of embodied energy. Lithium ion batteries have a smaller operating range than most other batteries and won’t operate efficiently above 35 – 40°C. Also, lithium is a toxic material and is in limited supply and at this stage can’t be recycled effectively.

There are some new technologies coming onto the market, such as Redflow’s zinc bromide, Aquion’s sodium ion salt water batteries, improved lead acid and many variations of lithium battery. These each have advantages and disadvantages, both in terms of performance and size.
Depth of Discharge (DOD)

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How much battery capacity do you need?

 

When people start looking at energy battery storage one thing they often ask is I have “x” kW solar on my roof at the moment, how much battery storage do I need?

This isn’t an easy question to answer and there definitely isn’t a one size fits all answer. If someone tries to sell you a battery without asking about your lifestyle and what your needs are then walk away. Chances are they are just trying to sell you their battery and not really working towards what is best for you. The cheapest battery upfront may turn out to be more expensive in the long run if the battery technology isn’t matched to your needs.

The amount of storage isn’t really related to the amount of solar you have on your roof (although it is definitely part of the equation) but it is more to do with how much power you use on a daily basis, how long you want backup power for and what appliances you want to operate from the battery. Continue reading “How much battery capacity do you need?”

Cheaper battery prices can have unforseen consequences

 

There are many things to take into account when looking at an energy storage battery for your home or business. These include safety, performance, operating temperature as well as recyclability and environmental impact.

Unfortunately many people only look at the initial purchase cost of batteries and this is what they use to compare different batteries. This doesn’t take into account what a battery may cost them over its lifetime or the cost to the environment of both the battery’s manufacture and end of life disposal. To make a realistic comparison of a battery’s cost you need to consider its full “cradle to grave” impact on all areas, including its safety during operation and its environmental impact. Continue reading “Cheaper battery prices can have unforseen consequences”

So much conflicting information on battery storage

 

When consumers go online to compare different batteries there is so much conflicting information available it is very difficult to get a clear picture of what is available and to understand what is happening in the industry. What is important is you compare similar products and don’t just listen to what salespeople are telling you.

If a product has been in use for a number of years the quoted figures are more likely to be reliable than if a product is new and hasn’t yet been tested in real life conditions. Generally batteries are tested in factories at 25 degrees. This can produce different results than are experienced in real life when temperatures vary widely.

Currently there are no relevant battery standards in Australia Continue reading “So much conflicting information on battery storage”

What is your Energy Storage Battery Size?

 

Energy storage batteries come in a variety of different sizes and weights and each have different characteristics. Here is a comparison of some of the most common batteries currently available in Australia with comparisons of size for a similar sized 20kWh system. You can see from this image that size is not necessarily a good indication of the power that is available to be used in a battery installation. Some batteries have much better energy density than others with the FIAMM SoNick battery having the best energy density of all, although some of the newer lithium ion batteries also have a very good energy density..

If you have a lot of suitable space to store your battery this may not be relevant but if you are limited in space you may want to consider one of the more energy dense batteries. If there is a possibility of moving house you may want to take into account the battery size as well as its weight if you want to move it with you. Continue reading “What is your Energy Storage Battery Size?”

Why do people look at battery storage?

With battery storage set to grow in the next few years there are many people that are interested in looking at this technology but there are also a wide variety of reasons that people are doing so.

Up until now most people that have used batteries to store their energy have been those that have been in situations where it was not possible, either for economical or proximity reasons to connect to the electricity grid. However, there are now many more reasons that people are considering battery storage and many more questions people are asking about the batteries they are looking at.

Over the last 5 – 10 years there has been a big push to install rooftop solar panels to capture electricity to use on the building the panels are installed on. This was encouraged by governments as they introduced feed-in tariffs to encourage people to install solar. This was so successful, as the general public took up these offers that governments soon decreased the feed-in tariffs and now they are extremely low or non-existent, depending on your state. Continue reading “Why do people look at battery storage?”

Battery Recyclability

 

One of the things that you should consider when putting battery storage on your home is whether or not the battery will be recyclable at the end of its life.

Often, one of the reasons that people put solar panels on their house and put in battery storage to collect the excess usage is to protect the environment and reduce the need for coal powered power stations.

This can be counterproductive if you choose a battery that is made from toxic materials or has components that can’t be recycled. Continue reading “Battery Recyclability”

Battery Operating temperatures

 

Most batteries will operate, with varying degrees of effectiveness in the 5- 35 °C range so are fine for the autumn and spring operating months, however if you want a battery that will also operate efficiently in winter and summer you need to understand how temperature has an effect on a batteries operating capabilities.

The ambient weather temperatures have a large impact on the performance and on the life of most batteries and unfortunately, it’s a characteristic that isn’t often talked about.

The optimum temperature for most batteries to operate at is around 25°C and this is the temperature all battery testing is performed at. When temperatures vary, either up or down there is an effect on the performance and life of most batteries. Continue reading “Battery Operating temperatures”

Battery Drawdown power

 

Energy storage batteries come in a variety of different sizes and weights and each have different characteristics.  Here is a comparison of the 2 safe, recyclable batteries currently available in Australia, FIAMM sodium nickel chloride (SoNick) or molten salt battery and Aquion salt water battery, with comparisons of size for a similar sized system from some other battery technologies.

Another thing to consider is how much power you can actually draw from the battery at any point in time. Our SoNick battery can draw 150 amps for 4 hours continuously but some other batteries are very limited in the amount of power that can be used, maybe only with enough to boil a kettle and little more. Continue reading “Battery Drawdown power”

Battery degradation

Energy storage batteries come in a variety of different sizes and weights and each have different characteristics.  Here is a comparison of the degradation after 10 years of batteries currently available in Australia with comparisons of size for a similar sized  system from other battery technologies.

You can see from this image that different battery technologies have different degrees of degradation over their lifetime. You need to take this into account when deciding the best battery for your needs. If a battery seems cheaper to purchase upfront but has then degraded significantly after a couple of years and may be down to only 50 or 60 % of original capacity after 10 years this will significantly affect how much power you can draw from that battery.

This degradation is also what may make it difficult to add additional batteries to an installation after a few years. In many cases with lead acid and lithium ion batteries you may need to purchase a new system if you want to add extra capacity. Continue reading “Battery degradation”