Limit solar power injection (curtailment)

The media are full of it: negative injection rates are inevitable. To keep you up to date within the developments of the FlexiO EMS, we have prepared this article.

We discuss how curtailment works and what exceptions you should take into account.

1. How does it work? Curtailment example:

On 09/03/2025, for the FlexiO user below, the price was negative between 11am to 3pm. Follow us along for the day.

1. FlexiO knows electricity prices and weather forecasts a day in advance. A lot of sunshine is expected for the coming day, and FlexiO calculates that the battery will be fully charged anyway. As long as the prices are positive, excess solar power is injected into the grid (green = injection) , because the user receives compensation for it.

2. At some point, prices drop below zero. From then on, injection would become a cost instead of a revenue. FlexiO switches immediately: the battery charges and nothing more is injected into the grid

3. Around 13:00, the battery is fully charged, but prices are still negative. At that time, FlexiO automatically reduces the production of the solar panels (curtailment) to prevent further injection. At 13:30, the owner comes home and connects the EV to the charging station. FlexiO detects this additional consumer and re-enables the solar production so that the generated energy is optimally used to charge the EV and power the house.

2. Compatible Inverters

We’re working hard behind the scenes to get every inverter compatible with curtailment. Here you can find our up-to-date list with inverters and their compatibilities:

https://n.lifepowr.io/user-devices

3. Activation of curtailment

New and existing installations are automatically activated for users with a dynamic tariff and a compatible inverter. The owner gets notified by email, also we ask to fill in a form when the installation has greencertificates. (see next chapter for more information).

It is critical that users read the emails from FlexiO & Lifepowr to ensure the best EMS steering possible!

4. Exception: Green Certificates

As described above, this is done by means of a mailing we send out to ask the end user to fill in a Google Form.

If the customer has green certificates, they are asked to fill in the value per MWh and the end date of their certificates. This way, FlexiO will only start curtailing if the negative value per kWh is higher than the value of the certificate per kWh.

In this way, FlexiO again provides added value tailored to the customer!

5. Exception: Retrofit Systems

Retrofit system that are installed parallel next to a FlexiO controlled system, it is important that the customer knows that we cannot curtail this inverter!

However, FlexiO can take this into account by turning off the FlexiO controlled inverter to minimize the amount of energy injected into the grid. The energy produced by the retrofit installation will be used to cover the home's consumption and charge the battery. If there is still surplus at that time, this energy will be injected into the grid.