One of the most commonly asked questions that we get at Blackwell Energy is Should I get battery storage with my solar panels ? The need for added battery storage totally depends on the property’s ‘load profile, ie. their day-to-day consumption, especially at peak times, not to mention to lifestyle of the home owners. For example , if a homeowner is at work all day and the home is empty ? then storing the electricity produced during periods of low consumption for later use makes total sense. This is also a great way to maximise your system and deliver even greater savings to your home. In this post we try to answer the most frequently asked questions when it comes to adding battery storage to your solar panels
A solar battery is basically a large rechargeable battery pack that is charged using periods when excess power is produced from your solar installation instead of sending that energy back to the grid. During and after your battery is fully charged excess power can be diverted to heat your water as well sold back to the grid automatically. The power is stored in the battery for use after your panels have stopped producing power ( after sundown or later in the evening ). When you battery has emptied itself then the system automatically switches over to the grid. Typically this is at a time when the price per unit rate is lower. During periods of high consumption the battery and grid can work in conjunction without the needs to touch your solar PV system.
Unfortunately the current SEAI Grant only covers the cost of the installation of the Solar Panels, Inverter and related works. The grant is calculated based on the total system size up to 6kW. The current maximum domestic grant available in 2025 is €1,800 whilst the non-domestic grant is up to €162,600
At Blackwell Energy we offer a varied range of battery options depending on each client’s specific needs or preference. With prices varying from brand to brand a typical average price for 5kW battery storage is €2,100 to €3,200. It’s also worth noting that battery systems can only be added to Hybrid Inverters. This type of inverter is slightly more expensive than a regular string inverter. Hybrid inverters typically add €400 to the overall cost of the solar install.
Systems without battery storage sell excess energy produced back to the grid. With varied rates of buy-back from different providers, it can make a lot of sense to store that excess power and use it yourself. Having battery storage added to your solar panels allows you to store the excess energy for use at a time when there is no solar production. While selling energy back to the grid saves you money based on your energy providers buy back tariff, battery storage maximises your solar installs potential by allowing you to use the excess energy in your home or business.
A less known benefit of having battery storage with your solar panels is that you can charge you battery from the grid for use in the mornings. If your energy provider offers a cheaper night tariff, then this allows you to save even more on your energy needs by charging the battery at this lower rate.
This is a question we get asked a lot. Can I power my home or business from my solar battery storage in the event of a power cut ? Unfortunately this is not compliant with current Safe Electric regulations. For safety reasons your inverter cannot supply power in the event of a power cut. It poses a risk to workers repairing the issues on the main grid.
The average lifespan of a solar battery is 10 to 15 years. Given that your solar PV panels come with a standard 25 year warranty you will most lightly need to purchase a replacement battery during the lifetime of your solar panels. Battery lifespan is determined in cycles. Charging your battery fully and using all of its available power counts as 1 cycle. Depending on the type of battery you choose this can range between 6,000 to 10,000 cycles. Warranties on batteries range between 5 to 10 years.
Adding a battery after your initial install is possible but only if you have installed a Hybrid inverter at the time of install. Hybrid inverters are ‘battery ready’ so adding battery storage later is pretty straight forward. It’s worth noting batteries cannot be added to string inverters. To add battery storage to a system with a string inverter would require the inverter being changed.
Low temperatures can affect solar batteries significantly, leading to decreased battery capacity and slower charging rates. This means your solar storage might not hold as much energy as it can in warmer weather, and it takes longer to charge up. It’s worth noting this when deciding where to have your battery installed. Optimal performance is typically achieved between 14-22°C, which does mean outdoor batteries can perform poorly in low temperatures, likewise in non-insulated attics. At high temperatures, solar batteries can degrade more quickly, reducing their lifespan and efficiency. This is obviously less of an issue in Ireland’s oceanic climate, but cool damp weather will reduce performance. Talk to our technical sales team about our battery options which include heat pads (for cooler temperatures) and cooling fans (high temperatures).
Adding battery storage to your home or business when switching to solar helps maximise your properties savings on energy spend. The battery is charged by diverting excess power produced by your system to be stored for use at a later point, typically in the evening times when there is no solar production. Batteries cost on average €2,500 depending on the size and make. The lifespan of a battery is on average 10+ years or between 6,000 to 10,000 cycles. Unfortunately for safety reasons you cannot power your home from your battery during a power cut. Choosing a hybrid inverter when installing solar gives you the option to add a battery at a later point.
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