Not using grid power for six whole months
Being almost completely independent of the power grid: that's already quite feasible during the summer months. With a combination of solar panels and home batteries, you can be virtually self-sufficient for at least half the year. Here are a few examples.Now that the summer months are well and truly over, it's nice to look back at the performance of Zonnefabriek systems over the past six months. We've noticed that many of our customers, thanks to a combination of solar panels and home batteries, have needed almost no power from the grid!
To run entirely on solar power for such a long time, a home battery is, of course, essential. You can try your best to run all your power consumers during the day, but there's always a need for power during the dark hours as well.
However, it's not even necessary to purchase an overly large system. The customer in the picture below, for example, has a fairly standard 9.8 kWh battery combined with approximately 7 kWp of solar panels (with the current panels, that amounts to about 16 panels).
During the summer months from April to September, they consumed approximately 200-300 kWh of electricity per month, and almost all of this power came from their own roof!
This customer with solar panels and batteries needed almost no power from the grid ( in red) from March/April!
In the figure, the green portion represents "direct consumption," i.e., the energy consumed simultaneously with the panels' generation. Without batteries, everything outside the green portion would have had to come from the grid—the red portion represents grid power. But thanks to the batteries (orange), the solar surplus of the day is stored for the evening and night, which means grid supply has been virtually zero since March/April!
Exactly how many batteries you need to achieve this at home depends on several factors: how much electricity you use in the summer, how many solar panels you have, and how much of your consumption occurs during the day versus the evening and night. However, we find that for most people with an annual consumption of up to around 6,000 kWh, a battery of around 10 kWh is sufficient.
With a 9.8 kWh battery like the one in this photo (the 3 modules on the right), you might not need to rely on the grid at all during the summer months
A minimum reserve isn't necessary
Incidentally, you don't necessarily need to set a minimum reserve capacity with Zonnefabriek batteries. Some customers worry that discharging them completely to 0% wouldn't be good for their health. However, it's important to realize that 0% doesn't actually mean there's nothing left in the battery: the percentage you see is only the usable capacity. The battery still has some capacity left that you can't use, but that's there to prevent excessive discharge. Our batteries with a capacity of 9.8 kWh, for example, can therefore truly make their full 9.8 kWh available for charging and discharging, unlike some other batteries on the market. It's also good to know that batteries connected to the grid maintain their health, even if they haven't been charged for a long time. If the battery charge drops too low, the system will draw a small amount of power from the grid to recharge itself.
Also interesting for larger power consumers
Larger consumers such as sports clubs or businesses can also become largely self-sufficient with batteries. The image below comes from a sports club in Rotterdam, with 18 kWp of solar panels and a 16.4 kWh battery installed in the summer. Monthly consumption is high at 1000-1500 kWh, partly due to the floodlights illuminating the sports fields in the evenings. Thanks to the use of the batteries, monthly power consumption has decreased significantly: in addition to the 500-1000 kWh of direct consumption, the batteries have reduced grid consumption by another 500 kWh per month: that's a significant gain!
Power consumption of a sports club: from July onwards, more than 80% of the power comes from the club's own roof, thanks in part to the 16.4 kWh batteries
On the path to energy independence
Having your own batteries means you don't need to draw any grid power for such long periods, which is a great feeling. This gives you more control over your energy costs, while still keeping the support of the public grid during periods of limited sunshine. The next step could be to live completely off the grid, even during short-term power outages. Systems like the new BackUp Box 1P from SMA can help with this. This way, you can gradually increase your self-reliance and reduce your dependence on energy suppliers or other external parties!