The home battery is increasingly making the news. More and more new models are coming onto the market, technology is improving, prices are falling and there is even an interesting subsidy for Flanders. But is now the time to invest in a home battery? We figured it out for you.
What is a home battery?
A home battery is your store of solar energy that you produce too much. After all, according to UGent figures, we only use 30% of our products directly, 70% we put on the public electricity grid. We pay a levy for this in Flanders and Wallonia: the prosumer rate. This compensation is because you use the electricity network to set up and purchase energy. Check electricity nz.
A home battery, therefore, saves the excess power from your solar panels. As soon as your panels produce more than your consumption, the home battery starts to charge. You use that power at times when the sun does not provide energy. The most common systems can store between 3 kWh and 8 kWh. On average, a family consumes around 10 kWh per day. That means that a home battery can not fully insure your power needs, but still a good deal. Unless you take a larger (and therefore more expensive) battery.
There are three advantages to a home battery
The first is, of course, that you use more self-produced energy and therefore have to draw less power from the grid - and thus save.
The second advantage is that you no longer pay a prosumer rate because with a home battery you don't need a counter that turns back. We will explain how this works later.
The third advantage is that you have your own power supply and therefore switch to your home battery in the event of a power failure. There is even a fourth advantage for Flanders: subsidy. You get back up to 35% of your investment costs, up to € 3200. This automatically brings us to the biggest stumbling block: the price.
What does a home battery cost?
New technology is usually expensive and so is the home battery. In addition, the higher the storage capacity, the higher the price. For a 3 kWh battery, you have to count on € 4,000. For an 8 kWh model, this increases to € 8,000 and for a power of 14 kWh, this is about € 10,000. For Flanders, you may deduct the subsidy of € 250 per kWh, with a maximum of € 3,200 or 35%. A number of conditions are attached to the subsidies. You can find electric vehicles nz
Of course, you not only look at the costs but also at the return. Three things play a role there.
The quality of the battery can make a big difference. A top-quality lithium-ion battery provides 95% efficiency while a lower quality, the cheaper battery can be 70% effective
The number of charging cycles or the number of times your battery can store and return power. Top models achieve up to 10,000 cycles, most basic models around 5,000.
The peak consumption of your electricity. You have to plan your consumption smartly so that production, consumption, and capacity are well balanced. Then you need to get as little energy as possible from the public grid and save.
There is also a fourth factor: the prosumer rate. You pay this levy (not in Brussels) if you have a reversing counter. How much you pay depends on the power of your inverter. So not from your actual production. If you no longer have a revolving meter, the prosumer rate will lapse and you will immediately save. The reversing counter is less interesting with a home battery anyway. After all, you first charge your battery, and only then does the rest go to the public network.
If you keep your rev counter, you can have a converter with a lower power installed. As a result, your prosumer rate decreases, without jeopardizing your production.
Just as technical
A home battery may need an additional inverter to do its job. The inverter for your solar panels converts direct current into alternating current. For direct use, to put on the public network or for your home battery. The system works in one direction, but your home battery must also be able to return the stored power. And for that, you need the extra converter that converts the alternating current back into direct current. On some models, the two-way interface (direct current <-> alternating current) is already provided thanks to the built-in inverter.
Low efficiency in the winter
About 70% of solar panel production is in late spring, summer, and early fall. The days are longer and the sun shines more often. But in the dark and rainy months, your solar panels have no overproduction. Your home battery will not be able to store excess energy and will therefore not be profitable. You can also only store a limited amount of energy, so your home battery will have to be unemployed during this period.
A calculation
Paying back your home battery: that is not feasible today. We have made a calculation of what you invest and what it yields.
An average family uses about 3600 kWh annually. If it has solar panels with a power of 4 kW, it can generate about 70% of its electricity itself. This means that it must take 1080 kWh from the electricity grid. That comes with the current prices at € 270. There is the advantage that the prosumer rate is eliminated because the family no longer has a 'reversing' counter.
The purchase price of a home battery is around € 5,000. As a result, it takes more than 50 years for the investment to become profitable. However, the life of a home battery is up to 20 years.
