When would I see this?
You notice that on a sunny day, your solar system isn't producing as much energy as you'd expect — even though the sun is shining and your panels should be performing well. When you check the app, you see production is being capped or limited during certain hours. This article explains why that happens and why it's actually working in your favor.
Why does this happen?
On certain days — usually very sunny ones — so much solar energy is being produced across the grid that supply outpaces demand. When that happens, wholesale energy prices can drop below zero. These are called negative electricity prices.
When prices are negative, you have to pay for the solar energy you export to the grid. In other words, it can cost you money for your own production. Helios fixes this problem by limiting how much solar your system produces during these hours.
In theory, negative prices also mean you'd get paid for consuming energy from the grid. In practice, you still pay grid fees and taxes on that energy, so any benefit is usually canceled out.
How your system protects you
To prevent this, Helios automatically applies curtailment during these negative-price hours.
When curtailment is active, the EMS tells your inverter to:
Limit solar production to only what your home needs (self-consumption)
Use any extra solar production to charge your battery, if you have one
Stop sending any energy to the grid (zero export)
In short: your system deliberately produces less energy during these specific hours, so you don't end up paying to export power you'd otherwise be charged for.
Is this a problem?
No — this is expected, automatic behavior, not a fault with your system. It only happens during negative-price hours, and it's designed to protect you from the extra costs that come with exporting energy at those times. Once prices return to normal, your system will resume producing and exporting energy as usual.