Upgrade your solar panel system

Zonnefabriek has been around for over 15 years now, which means that the first solar power systems we installed are also starting to reach middle age. In itself, 15 years is not that old for a solid Zonnefabriek system: SMA inverters are designed for a lifespan of at least 20 years and the panels can easily generate electricity for 25 years or more.

However, an upgrade of your system may still be worth considering. With a limited investment in new panels, you can often generate much more electricity on the same roof surface. Also, a newer type of inverter can not only improve the yield, but also prepare your system for the future. We will go through the various options.

Solar panels: make a big step in efficiency

The solar panels of 15 years ago often had an efficiency of around 15%. This means that 15% of the incoming sunlight is converted into electricity. The panels from that time have an annual degradation of around 0.65%. As a result, the panels that had an efficiency of 15% fifteen years ago, now only have an efficiency of around 13.6%. The latest SunPower solar panels, on the other hand, have an efficiency of 22.7%. This means that if you were to replace the old panels with brand new ones, you could get at least 67% more solar power from exactly the same roof surface area!

Fifteen years ago, solar panels were a lot more expensive than they are today. That is why at the time only the most favourable piece of roof, perfectly oriented towards the south, was used for solar panels. It's a bit of a shame if that perfect piece of roof is now occupied by solar panels that yield much less than what is possible today. That is why you could consider moving the existing panels to a slightly less favourable location (for example a roof facing north?) and use the freed up space for modern, highly efficient panels.

At this site the older panels from 2011 (photo 1) were replaced by much more powerful SunPower panels (photo 2). There were already 5 panels at the back of the house (photo 3) and the 6 older panels from the front were added to them (photo 4)

Inverters: more yield, more possibilities

Inverters, the other important component of a solar power system, have also improved considerably in recent years. For example, inverters from 12 years ago often did not have shade management. This means that if one or more of the solar panels were partially or completely shaded, the production of an entire string of solar panels was reduced. The shade management software ShadeFix (formerly called OptiTrac Global Peak) solves this problem by bypassing the shaded (parts of) panels. This software was only introduced by SMA later on and has become a standard feature on SMA inverters for years now. However, if you still have an old inverter without this software, and if your solar panels are now sometimes shaded by trees or by recent construction, a new inverter can give your production a considerable lift.

Old SMA inverter, one without shadow management software

Furthermore, online monitoring of the production didn't use to be possible on old inverters: they had no internet connection, only a small screen on which limited data were displayed. All modern inverters, on the other hand, are connected to the internet; this makes it possible, for example, to use an app on your smartphone to keep track of exactly how much power is being generated and whether that generation meets expectations. Errors in the system are detected more quickly, which prevents any loss of production. An inverter with an internet connection can also communicate better with other devices in the home. For example, electric vehicle chargers and heat pumps can be supplied with as much power as possible from the roof, and the feed-in to the grid can be halted if electricity prices are negative.

Replacing an inverter? Then go for hybrid

Since the announcement that the net metering mechanism will disappear on 1 January 2027, there has been a clear trend when it comes to types of inverters: hybrid is hot. A hybrid inverter is one which, in addition to solar panels, you can also connect batteries to. By replacing an existing inverter with a hybrid model, you are making your solar power system ready for the future. That doesn't mean you have to add batteries right away; you can do that in two years' time, if you like. But your system will already be ready for it.

What we often see when people replace old inverters with new ones, is that, for example, a 2.1 kW Sunny Boy 2100TL inverter is replaced by a 3.6 kW hybrid Sunny Boy Smart Energy 3.6 inverter. The new inverter is a lot larger in terms of power and has 3 separate MPP trackers, so that both the existing panels and one or two sets of new panels can be connected to this device. An emergency power socket can also be installed with the SBSE3.6, which supplies power if the public grid fails.

This customer replaced their old SMA SB1300 inverter by an SBSE3.6 (right) with a 3.2 kWh battery (middle) and an emergency power outlet (left)

Zonnefabriek disposes of the old stuff responsibly

It may feel a bit strange to throw away older solar panels that still work fine. If you have no other place on your house or shed roof to place the old panels, Zonnefabriek will take them back to Amsterdam after the job. We ensure responsible disposal via the 'Open' foundation, which is responsible for recycling solar panels in the Netherlands. We'll check to see if there are parts of the old inverters that can still be used, and we'll take the rest to the recycling center.

An upgrade of an older installation naturally requires a certain investment, but it often pays for itself quickly, especially in the future after the net metering mechanism no longer exists. Curious about how much you can benefit? Our advisors are happy to help.