Voltage regulators reduce the risk of outages of domestic photovoltaic installations
Voltage regulation, which is the action to stabilise and control the voltage on electricity grids, can indeed have an impact on the shutdown of photovoltaic (PV) installations in homes. Problems with home PV installations shutting down are most often due to the voltage on the local electricity grid being too high. Here's how it works:
How the system works:
- Home photovoltaics and inverters: The PV installation produces direct current (DC), which is then converted to alternating current (AC) by an inverter so that it can be used on the home grid or sent back to the public grid.
- Network voltage regulation: Electricity network operators (DSOs - distribution system operators) are responsible for keeping the network voltage stable. Standards specify acceptable voltage ranges, which are typically between 207 and 253 volts for low-voltage networks (for a standard voltage of 230 volts).
- Inverter shutdown: If the mains voltage exceeds a certain level (e.g. 253 V), the inverter of the home PV system automatically switches off to protect the equipment on the grid and the user himself. This action also protects the electricity grid from destabilisation.
Why is the grid voltage increasing?
Rising grid voltage can be caused by a number of factors:
- Excessive energy production: On sunny days, when many houses in the area produce more energy than they consume, the local grid can become 'overloaded' with photovoltaic energy.
- Inadequate infrastructure: In some areas, the power infrastructure, especially at the low-voltage level, may be unsuited to accepting large amounts of energy from distributed sources like photovoltaics.
- No energy storage: An increase in the use of batteries for energy storage could alleviate problems with surplus production.
What are the solutions?
- Modernisation of infrastructure: Grid operators can invest in infrastructure upgrades to better cope with the increasing amount of energy coming from RES (renewable energy sources), including photovoltaics.
- Power management: Introducing what is known as dynamic power management, where inverters are regulated to adjust energy production according to current grid conditions. This would ensure that the inverters would not switch off completely, but would reduce production.
- Energy storage: Installing home energy storage (batteries) can help minimise problems with overproduction of energy during peak production hours.
- Local voltage regulation: The installation of voltage stabilisation devices or load-controlled transformers at the local level could help to reduce high voltage problems on the grid.
Summary:
Voltage regulation can indeed limit the operation of domestic PV systems, but this is a problem due to the current technical limitations of electricity grids. Grid modernisation, dynamic power management, installation of energy storage and better voltage regulation can minimise the shutdown of PV inverters, which is an important step towards a stable and efficient renewable energy system.
