The main benefits and applications of a home battery
The applications and benefits of a home battery are numerous and can be useful on several levels. Firstly, on an individual level, it optimises self-consumption by enabling you to use your generated electricity at a later time. The battery may also help to smooth out consumption peaks, which can lead to extra costs due to higher grid tariffs. Finally, if I choose a dynamic electricity pricing tariff, it helps me optimise my electricity use based on hourly market prices. These uses also have a positive impact on the electricity market and help to reduce the overall load on the power grid.
Optimising solar energy self-consumption
Batteries help optimise the self-consumption of electricity produced by my solar installation. By storing electricity when production exceeds consumption, they make it available at a later point when production is no longer sufficient to meet my needs, such as in the evening during peak usage times. Using surplus electricity generated during the day helps reduce the amount I draw from the grid and increases my level of energy self-sufficiency.
Partage d’électricité avec une batterie domestique
Batteries can also be used within an electricity sharing group, bringing greater flexibility to members of a collective self-consumption group or an energy community. They support better collective electricity management, strengthen the energy autonomy of participants, and help reduce costs associated with electricity consumption from the grid.
Learn more about electricity sharing
Backup power supply
Although power outages are rare and usually very brief in Luxembourg, a home battery can act as a backup power supply, ensuring uninterrupted access to electricity. This feature typically requires an additional investment, but it increases energy resilience and reduces the risk of supply interruptions.
Dynamic electricity pricing
Opt for an electricity contract with dynamic pricing! Use your battery to store excess electricity generated by your solar system when feed-in tariffs are low, and discharge it by injecting the unused surplus when market prices are high. Even without solar production, this strategy can be a smart way to make your battery more cost-effective.
Dynamic tariffs for both consumption and feed-in are based on the hourly price on the wholesale electricity market. To benefit from this setup, you'll need a battery equipped with an advanced Home Energy Management System (HEMS) to manage charging and discharging based on price fluctuations.
Lowering peak consumption
With the new low-voltage grid tariffs introduced in January 2025, it’s more important than ever to avoid exceeding your reference power level to prevent higher network charges. Batteries help manage the amount of power drawn from the grid, thereby lowering consumption peaks. Excess electricity produced during the day by your photovoltaic system can be stored in the battery and used in the evening during high-demand periods. This practice, known as peak shaving, helps lower your bill and reduce the strain on the electricity distribution grid. This application also requires the installation of a HEMS.
Efficiently manage your electricity with an intelligent control system
Want to optimise your electricity use? Thanks to a Home Energy Management System (HEMS), you can monitor and manage the energy flows of your solar installation, home battery, and major appliances such as an EV charging station and/or heat pump. The HEMS coordinates these devices to ensure energy is consumed and stored as efficiently as possible, drawing from or feeding into the grid in the most cost-effective way. This can significantly increase the profitability of your energy system.
The profitability of a home battery for your solar installation
Manufacturing a battery requires significant resources and represents a considerable investment—even with Klimabonus subsidies. That’s why it’s important to consider several factors to determine whether such an installation is economically viable in your case. For example, if you have a guaranteed feed-in tariff for your solar electricity, investing in a battery is generally not an economically sound option.
Profitability increases when the following conditions are met:
Indeed, if electricity prices are high and the storage of your solar power allows you to use your production later, it helps reduce your grid electricity bill. However, it’s important to ensure that your evening and nighttime consumption is high enough to significantly discharge the battery daily. This highlights the importance of adequately sizing your installation.
A low feed-in tariff is another factor that encourages storing locally produced energy for self-consumption. However, if you have an electricity contract with dynamic tariffs, it’s possible to further optimise battery usage through an energy management system. This approach helps to maximise the return on investment from your home battery.
| ⚡Klimabonus subsidy: check your eligibility criteria for acquiring a home battery. |
The sizing of the battery is a decisive factor in determining its profitability. It depends on several factors, such as your self-consumption potential during the day and at night, or whether you plan to share surplus electricity with others. It’s important to avoid oversizing your battery and to ensure it can be discharged daily.
To support you in this process, you can consult an independent energy advisor, a qualified electrician, or use the Solarisator simulation tool to assess the adequate sizing of your solar installation and home battery. In addition to Solarisator, Klima-Agence will launch its own national tool in 2025 for optimising photovoltaic self-consumption, specifically adapted to the Luxembourgish context.
Start your simulation on Solarisator
Before investing in a solar battery, it’s important to assess whether one is truly necessary and to explore alternative ways to manage your electricity production and consumption effectively. In fact, these alternatives can be less costly and just as effective—for example, by monitoring and managing your energy use, or sharing electricity when your photovoltaic panels generate more than you need during the day.
Keep in mind that conscious and responsible energy use can also lead to savings by adopting smart energy habits. Depending on your energy profile, investing in a home battery may not necessarily be the most suitable option.
Practical aspects to consider before installing a home battery
Choosing the right inverter
If you don’t yet have a photovoltaic (PV) installation, choose a hybrid inverter, which allows you to connect a home battery directly and easily. The inverter is the device that converts electricity between your solar panels and your home’s electrical system.
If you already have a PV system but are unsure about your inverter type (hybrid, standard, or micro-inverters), ask your installer for advice. There are home battery solutions compatible with all inverter types.
If you want your home battery to function as a backup power supply, choose a hybrid inverter that supports islanding mode—a feature that allows the system to disconnect from the grid when needed.
💡 | The “islanding mode” or “off-grid” function: the inverter must be capable of disconnecting from the grid and operating as a stand-alone system, supplying electricity solely to the house. |
Finally, choose an inverter model that ensures maximum compatibility with other energy devices, such as an energy management system.
General recommendations for home batteries
Home batteries are typically lithium iron phosphate (LFP) batteries, known for their stability and durability. Unlike the batteries used in electric vehicles, stationary battery applications are less demanding, which helps extend their lifespan. It is also important to note that these batteries have an extremely low risk of catching fire.
Make sure your installation is carried out by a certified installer approved in Luxembourg, and that the battery has CE conformity (European compliance certification).
In addition, both the solar installation and the home battery represent significant assets that should be reported to your insurance provider.
Finally, choose a dry, shaded location with a stable temperature, such as a basement, for the installation.
💡 | To extend the lifespan of your battery, avoid discharging it below 10% and charging it above 90% of its capacity. This setting is usually configurable within the inverter’s app. |