What are the requirements for home batteries?

There is currently no standard for installing home batteries. The following sentence (712.11) has been in the NEN1010 (the Netherlands rulebook for low-voltage installations) for years: ‘Requirements for PV systems with batteries or energy storage methods are being prepared.’ As long as these requirements are not in place, installers such as Zonnefabriek have little to go on when it comes to what is and is not allowed.

A document that is often discussed when it comes to energy storage systems is the ‘Publicatiereeks Gevaarlijke Stoffen' (Publication Series Hazardous Substances), or PGS for short. This is a series of guidelines on the safe storage of hazardous substances and associated activities in the Netherlands. It deals with substances such as LPG, ammonia and propane, but also with ‘lithium-containing energy carriers’ such as batteries. PGS number 37 has been drawn up for this last category.

PGS-37-1 provides guidelines for the installation of battery systems larger than 20 kWh

Do the PGS-37 guidelines also apply to home batteries?

The PGS-37 guidelines apply to lithium-containing ESSs (energy storage systems) with a capacity greater than 20 kWh (kilowatt-hours). Furthermore, PGS-37 explicitly states that the guidelines do not apply to systems in private households, but with the added remark that 'for an ESS with an energy storage capacity greater than 20 kWh, it is recommended to apply the measures from this PGS'.

There is currently no real obligation to follow the PGS-37 guidelines; they are mere 'recommendations'. However, many insurance companies will only want to insure a building containing an ESS if these guidelines are adhered to. Since the PGS-37 guidelines are quite expensive and involved (more on this later), Zonnefabriek has decided not to install batteries greater than 20 kWh in homes: instead, we offer batteries of e.g. 10, 12 or 16 kWh, which is more than sufficient for most households.

Large indoor battery storage system: here, the PGS-37 guidelines do apply (source: PGS)

Other guidelines for installing home batteries

Despite the lack of mandatory standards for home batteries smaller than 20 kWh, there are some common sense measures that we want the installation to comply with. Here are a few:

• Do not install the home battery in an escape route. Although home batteries are extremely safe and will not catch fire by themselves, they can contain a lot of energy. If a fire breaks out in a home, the solid metal casing will make it hard for the home battery to catch fire. But in the event it does catch fire, the energy stored inside can make the existing fire even worse. That is why we do not want the device to block an escape route. So: we don't put them in the hallway, near a staircase or near an exit.
• Home batteries are heavy: a complete system can easily weigh several hundred kilos. A condition for installation is that the surface or wall can bear the weight, and that the floor surface is flat.
• If the battery is placed in a basement, we must be sure that there is no risk of flooding: batteries do not tolerate water well and we want to avoid the risk of short circuits.
• Although the battery cells are firmly packed in a metal casing, we still want to prevent them from being exposed to impact hazard. For example, if the battery is placed in a garage, the location must be chosen in such a way that a car cannot accidentally drive into the battery.
• Batteries last longer if the ambient temperature is relatively constant and not too hot. Some batteries (but certainly not all) can be placed outside, but they must be under a roof and not in direct sunlight.
• To ensure that batteries always have the latest firmware and to quickly detect any abnormalities in the batteries before a problem can arise, it is important to always have a stable internet connection to the home battery.

The battery must be placed on a firm, flat surface with sufficient ventilation space to dissipate heat

Guidelines for larger battery systems

As mentioned, we follow the PGS-37 guidelines for systems larger than 20 kWh. This is a whole list of measures for the space in which the batteries are located. Here we list a few:

• Fire resistance 60 minutes. This means that the space in which the batteries are installed must be closed off with a fire-resistant door that can withstand fire for at least 60 minutes. If the battery is located at a height of more than 12 meters from the ground, the fire resistance must be 120 minutes
• Since toxic fumes can be released in the event of fire, there must be a (separate) ventilation system in the room
• There must also be a measurement of CO (carbon monoxide) and H₂ (hydrogen) in the room
• There must be a fire management system
• There must be an emergency shut down button
• Escape routes must be at least 3 meters away from access to the ESS room
• Any pipes for rainwater, sewage water, drinking water may not run through the room where the ESS is located
• There must be an emergency plan and a registration system with, among other things, a logbook on the (annual) inspections

Cover page of an emergency plan for battery systems according to PGS-37 (source: PGS)

As you can see, there is quite a lot involved with battery systems larger than 20 kWh. To make it easier, larger battery systems are often placed in a separate container at a certain distance from the building. This is usually not possible for residential systems. The need to implement all these measures means that larger battery systems only become worthwhile from 100 kWh or more.

Zonnefabriek has been installing battery systems since 2020. On our product page you will find the most common batteries that we install today, but if you have wishes for a device that is not listed, you can always contact us: we will be happy to find out what the possibilities are for you.