How do I choose which home battery suits me best?
This is a complicated subject with lots of angles to be considered. What I intend to do is list the main topics that most people should consider and give a “battery 101” answer to them. Having addressed them all simply then I will consider them in more detail in further blog posts to give a fuller and more in-depth response with examples of scenarios where relevant.
The key thing to remember with a home battery system is that it is a tool to be used, a bit like a smart heating control – if you do not set it up to make the best use of it than it may not do all you wish however capable the system itself is….
Please note that my recommendations and comments made here are from real life experience working with customers but each scenario will be different so you should as always make your own decisions. It may well be helpful to talk to a professional system designer or building services engineer – not just a salesperson. Salespeople, unfortunately, may sometimes tell you what you want to hear to make the sale.
As such it is always good to ask for the evidence of why they suggest what they do. A decent design engineer or surveyor will be more than happy to evidence their thought process and will appreciate good questions and customer participation.
Please also forgive the use of technically incorrect language for all those physicists and engineers out there – I know energy is not consumed 😊 – this is designed to be user-friendly.
Here is a list of topics to be covered in short blogs that are going to be available on our website at www.poweri.co.uk
Before committing to a purchase, Speak to an experienced surveyor or design engineer (not just a salesperson) who can analyse your electricity consumption patterns, predicted production (if you are looking at solar) and lifestyle habits to ensure maximum efficiency and that all your needs are met.
An in-depth energy analysis Can’t ever be 100% accurate, but should help to make sure that your system gives you the benefits you need
Be warned, depending on the type of battery you’re looking at, the usable storage capacity may be 20% or even 50% lower than the headline figure on the label.
There are many factors that will influence this – from battery chemistry, where it is installed around the property, Depth of Discharge of the battery and the age of the battery as it wears will influence the capacity available to you. Again, if you have an experienced surveyor/engineer they will automatically be discussing these issues with you. If a person does not reference the “useable” capacity as part of discussions then alarm bells may start to ring.
A home battery will be limited in how fast it can deliver the energy it stores. This will vary from as little as 750 watts to a peak of 7Kw on current domestic batteries. As you can see one value is roughly a 10th of the other so the answers can vary massively and yes it truly matters. There is no point having a battery that can only provide 750w if you need 3kW (Roughly what it takes to boil a fast kettle). You may never be able to fully use a battery if it’s too slow acting. It really depends on when you use most of your electricity and how much you pay for it at those times. Again, talk to your surveyor/design engineer – they should be raising this as an issue as a matter of course.
Not necessarily. Some battery systems can be configured to run with the grid supply off, others cannot. Some will still run the house (or some dedicated part of the house e.g. lighting) and others will not. If this is wanted be clear to ask for it and what you want it to do. A good surveyor/design engineer will normally discuss this.
Most batteries are affected by the ambient temperature of the location they are installed in. They ideally like to be in the same conditions that you like…. living room temperature ranges for maximum lifespan. Where you locate them often matters… lofts and other places that can get too hot or too cold are a concern in most cases. There are exceptions to this but if the battery is kept in the wrong place it may not work properly. Speak to your experienced surveyor/design engineer.
This is the most variable topic since this has nothing to do with engineering nor physics but the arcane world of customer service. Basically, the answer is a resounding no…they are not all equal. What you get in the real world can vary massively and ALWAYS check how the company who installs the systems supports the manufacturer’s warranty. There is no point getting a new product from the manufacturer if no one will install it, and no point getting a battery from a good installer but the manufacturer warranty is poor.
If the detailed workings of how a battery will save you (and possibly earn you) money, you need to read the dedicated post on this subject – that is too big to summarise here. The short answer though is carefully…
Yes, there are. A bit like economy 7 or 10, there are now “Smart meter” only tariffs” out there that offer a very low night rate and a very high evening rate (such as the Green Energy “Tide Tariff”). Having a battery means you can buy the electricity when it’s very cheap, and use it when it’s very expensive saving a lot on electricity.
Plus, future tariff changes could see you getting paid to allow the grid to access your battery to help them out.
A complicated subject – simply put though, any technology that allows a more efficient usage of renewable generation, greater individual awareness of energy consumption and allowing the grid to be more flexible through things such as demand side response- DSR – is a good thing. Roughly, when electricity is cheap, it’s likely to be greener because less gas and coal is being used at those times. See here for a website showing you where your electricity comes from now.
Installing solar panels and a battery system on a property shows a person who is not just talking the talk but walking the walk. Call it “Eco-bling” if you like but it is always nice to get peer recognition for doing a good thing that also saves you money whilst saving the planet…
Don’t just take our word for it either. For some independent information on battery storage, the links below provide a lot of useful information on energy storage guide , best practise storage guidance document at the bottom of the page and the BRE Solar Storage guide link – 7th down the page.
Written by John Rowlatt