These days the talk is all about storing solar energy: How can we best store the energy from solar panels temporarily until we need it? Should we already be connecting solar panels to battery systems?
Solar energy is produced the moment the sun shines, obviously. But that isn't necessarily the same time as when there's a need for energy. So far, the difference in supply and demand can still easily be compensated by large power plants on the grid. However, as more and more solar panel systems are installed, it's becoming more important to find solutions for temporary energy storage, such as batteries.
With batteries, you can achieve a greater degree of self-sufficiency. If you're not home during the day, but you are in the evening after sunset, you can ensure that the energy generated during the day is stored in batteries, to become available for your consumer appliances in the evening.
What do you need to store solar energy?
First of all, you would need batteries. The more batteries you have, the more energy you can store. However, the energy stored in the batteries must become available again in the grid when you want it. This requires an inverter, which converts the direct current from the batteries (DC current) into alternating current on the grid (AC).
Batteries are expensive, and their life is highly dependent on how they are charged and discharged. The more “cycles” (of charging and discharging) they undergo, the faster they lose capacity. Therefore, it's important to use the batteries in a smart way: only start charging when it makes sense (a lot of sun in the near future and little consumption in the short term) and only supply back to the grid at the best moments (a lot of consumption is expected and the sun's gone for the time being). This requires a system with smart control that takes into account the weather forecast, for example.
What does storing solar energy cost?
The cost of such systems depends greatly on the desired capacity. Batteries are the most expensive component, and the more batteries you install, the more expensive it becomes. Furthermore, battery inverters are also quite expensive: for a hybrid SMA inverter, you easily pay about 33% more than what you pay for a solar inverter of the same capacity. The products for smart control of the system are a lot cheaper, but still amount to several hundred euros. And finally, there are installation costs involved..
Most manufacturers today offer “hybrid” inverters; these are devices that connect to both solar panels and batteries on the DC side. This is a smart solution because it allows you to connect only solar panels to the inverter initially and decide to add batteries at a later date. You would not need an additional device for the batteries and your system is already ready for the future.
Is it worth the investment?
Until January 1st 2027, the Netherlands has the net-metering system, which means that the public grid basically acts as a buffer for people with solar panels. Excess energy from solar panels flows into the grid, and is deducted from the energy consumed on your annual bill. In principle, therefore, batteries would be of little added value, were it not for the fact that by now all energy suppliers charge some form of feed-in fee to people with solar panels. If you have a dynamic energy contract you don't pay feed-in costs, but on the other hand you get less compensation for your feed-in power because the prices are low when everyone feeds in at the same time.
There is currently a lot of investment in new battery technology worldwide, a.o. because of all the electric cars that are now driving around everywhere. The cost of lithium-ion batteries has dropped dramatically as a result. The latest battery systems are also being made to trade based on dynamic power rates; when the power price on the market is low, they charge up, and when, a few hours later, the power price is high, they sell that power back to the grid, at a profit. Thus, the investment in batteries soon becomes worthwhile.
One plus for the many owners of SMA hybrid inverters is that these devices are compatible with battery solutions. For example, the Sunny Tripower Smart Energy and the Sunny Boy Smart Energy in combination with the Sunny Home Manager are specifically made to work together with high-voltage Lithium-ion batteries such as the SMA Home Storage batteries. SolarEdge system owners also know they are in the right place, since SolarEdge has released the StorEdge. Of course, we keep a close eye on developments so that we can always give you the best advice.
By the way, batteries can of course also come in handy as an emergency power supply during power outages; even if the whole street is in the dark, you still have power thanks to your own stored electricity.
In short: with the introduction of feed-in tariffs and dynamic energy contracts, installing batteries has become an interesting option that can also help you guard against grid failures. Reason enough to contact us so that we can provide you with appropriate advice.
