Battery Storage

There are several key reasons why homeowners are looking at battery storage.

• Self-sufficiency. In general, we see that people want to be more self-sufficient and to run their homes off the electricity thy have produced themselves
• To run their car on sunshine. Even if you are out during the day, you can still use solar electricity to run your car.  Store your generated electricity in a home battery, and then discharge this into your vehicle when you return home.
• To help the grid. Using a home battery reduces electricity demand at peak times (weekdays 16:30-19:30).  That makes the UK’s overall system easier and cheaper to run.  Peak demand also determined how many power stations we need – so if we can reduce demand at peak times we simply don’t need to have as many fossil fuelled power stations anymore
• Riding through power cuts. Some models of batteries allow you to use your stored electricity in the event of a power cut.
• Getting the cheapest electricity. A home battery can allow you to store cheap night-time electricity for use at other times.  It means you always access the cheapest possible electricity, whether from solar or the grid.

The simple answer is that the home battery system stores electricity for use in your home at another time. The demand for energy within the home isn’t at one level all day, especially if there are periods when some or all of the family are out of the house. This means that for some periods of the day, the electricity being generated by their solar panels isn’t being fully utilised. Of course, when the sun goes down or the weather is particularly bad, the solar PV can’t generate electricity, and you need to draw from the grid to power your home. A home battery means that you have solar energy stored to use before you need to take from the grid.

If you currently receive feed-in-tariff (FiT) payments for the electricity you generate with your solar PV, they will not be affected if you install a home battery system. The FiT scheme was discontinued for new home solar PV systems installed on or after 1^st April 2019, but existing qualifying households won’t lose any of these payments for the contract term (usually 20 years from installation) if they do install a home battery system.

Different home battery storage systems may come either ‘AC coupled’ of ‘DC coupled’. A DC coupled battery system, locates the battery between your panels and the inverter (which converts DC electricity to AC electricity for use in the home.  DC coupled systems are more thermodynamically efficient, as you only convert DC to AC electricity once.

An AC coupled battery system has a separate inverter in the battery itself.  Solar DC electricity is converted to AC electricity for use in the home, and if it goes into the battery is converted to DC again.  This is thermodynamically less efficient, but much more flexible.  It allows batteries to be charged from any source, not just solar.  They can be charged from the grid, for example when electricity is cheap, typically when there is a lot of wind power on the national grid.  So it allows you to take advantage of cheap low carbon electricity no matter where it is generated.

It also means that the battery doesn’t need to be installed physically close to your solar PV inverter, which makes installation more flexible. For these reasons, the market is moving towards AC coupled systems as standard.

If your household has very high energy requirements in the evenings, especially during longer winter nights, smaller battery storage systems may not be able to hold enough power for all of your needs all night. For example, if you wanted to run several ‘thirsty’ appliances at once in the evening, such as kettles, microwaves, washing machines, along with TVs, lights, fridges etc, your battery would discharge at a much quicker rate than that of a less busy household with lower energy demands. Home battery systems are also limited to the amount of electricity output they can give at any one time. It’s important to choose a battery storage system for your home which is best matched to your household’s needs. We can help you to find the best home battery solution for your individual circumstances – contact us today for more information.

In terms of the life span of a home battery system, this can vary; depending on the make and model of your battery and the way that you use it. Whilst these types of batteries are designed and optimised to undergo frequent charging and discharging, eventually, over many thousand cycles, the batteries will start to lose a small percentage of capacity. The Puredrive batteries come with a market leading 10 year warranty.

From our own experience of these products and the very slow degradation of the types of batteries used in the home battery systems, the likelihood is that a home battery system will usually significantly outlast the warranty.  It is the same as any other electronic product in this respect – if you bought a TV with a 5 year warranty, you would reasonably expect it to last for 10+ years.

If you’re getting a home battery that works with your solar PV system, you will need to ensure that your installer has the necessary experience to carry out the installation properly, so that all of the necessary elements communicate properly with each other. It is advised that you use an installer with years of experience in both solar PV installations and home battery systems.

Some home batteries can be installed either indoors or outdoors, depending on which system you opt for. Many homeowners choose to install their battery system in their garage, which offers some protection from the elements. The Puredrive battery systems can be installed outside.

It’s very difficult to say how much a home battery will save you, as it is highly dependent on both how much you personally use and how much you can generate.We also know that having the ability to top-up with cheap grid electricity when solar is not available, also massively improves the return on investment. The Puredrive system allows you to do this.

Some home battery systems can power your home in the event of a power cut, but not all products of this type are designed with this capability. The Puredrive battery does continue cooperate during a power cut.