Your solar panels are converting light into electricity. This means that they are generating electricity during the day, when the house is often empty. Most commonly, this electricity is fed back to the grid.
It stands to reason that it would be better to use more, if not all, of the electricity which your system is generating and the obvious way to make that possible is efficient battery storage. The question is, how much does solar panel battery storage cost?
Light, efficient, eco-friendly battery technology is advancing very fast in response to market demand. It is not by any means cheap yet, but prices are falling as the technology improves and battery storage is beginning to offer a genuine option for increasing savings, reducing your dependence on the grid and further reducing your carbon footprint.
Once you are sure that you are a good candidate to benefit from adding battery storage to your solar panels, the key factor in calculating the cost and potential return lies in the size of battery you will need and the amount of surplus electricity you generate.
What is your load profile?
Homes with 2.5kW to 4kW solar panel systems are generating somewhere between 1,700kwh and 3,400kWh per year. Suitability to benefit from adding or including battery storage will depend on what is called your Load Profile. Put simply this is the way in which you consume your electricity. If you are already using all or most of the electricity you generate then battery storage will bring you little value. If, however, you are generating a significant amount of your electricity when you are not in your house to use it then battery storage becomes a better option.
A qualified solar engineer will help you to work out the potential advantages and identify the best type of system to suit your needs. This will include choosing the size of battery you require to store your excess solar electricity. Installation costs tend to remain similar no matter the size of the battery. The size of the battery will, of course, affect the cost. Accurate costings are surprisingly difficult to find so our thanks go to Hero Renewables and AES Solar for helping us to compile the following guide pricings.
Tesla Powerwall 14kW
The new Tesla 14kW Powerwall battery will cost you approximately £6,500 including installation.
The German company Sonnen, offer a modular system starting at 2kW with additional 2kW batteries available up to a total of 16kW. Approximately £3,200 will install the basic 2kW system including inverter and controls which can take you up to the full 16kW. Each 2kW add-on will then cost a further £850.
The LG Chem range includes 3.3kW, 4.2kW and 9.8kW options for which you can expect to pay £2,200, £3,300 and £5,500 respectively. You should add approximately £1,000 to these prices for installation.
A typical warranty period will be 10 years and the life-expectancy of the battery will be something similar. Some manufacturers are predicting a longer life-expectancy and you should also remember that the life of the battery will be affected by the way it is used. What is clear is that your batteries will need to be replaced within the life of your solar system.
Calculating the savings you can expect from adding battery storage is complicated and requires both the expertise of a qualified installer and knowledge of your own particular system and load profile. If you think that battery storage would be a viable option then your next step should be to book a visit from a solar specialist who will be happy to do the calculations with you and advise you on your best options.