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Version: 2026.7

FAQ

How are savings calculated?​

Power Insight separates three financial concepts:

  • Cost savings — money saved by replacing grid imports with your own generation, minus the device's operating costs: 
    cost_savings = avoided_import_cost − operating_costs
  • Export compensation — feed-in revenue for power exported to the grid (its own dedicated sensors).
  • Financial return — the combined picture: 
    financial_return = cost_savings + export_compensation

For PV systems the operating cost is mainly standby consumption at night; for batteries it's the cost of the energy used to charge them, adjusted for round-trip losses. See How savings and financial return are calculated.

Why does my battery have negative cost savings?​

Any device can show negative cost savings if it doesn't earn enough to cover its costs — and a battery always shows negative cost savings while charging, because Power Insight tracks the cost of the energy going into it. That cost turns into positive savings when the battery later discharges and offsets a grid import. See the concepts page.

Does Power Insight work with dynamic electricity prices?​

Yes — this is a core design goal. Every calculation uses the current value of your grid price entity, so a live/dynamic tariff sensor works out of the box. No energy meters or daily averaging are involved.

Do I need energy (kWh) meters?​

No. Power Insight is driven by instantaneous power sensors (W / kW / MW), not energy meters. Each device and the grid connection must expose a power sensor.

Can I track two grid connections?​

Not within one config entry — a config entry models a single grid connection / energy mix. Add a second config entry for a second grid connection.

I enabled a cost/levelized sensor but it didn't appear. Why?​

Those sensors need extra data. Cost sensors need an electricity price entity on the grid; levelized sensors need lifetime production and cost on the device. The options flow will name any device that's missing data and ask you to Reconfigure it. See Sensors, presets & options.

Are there CO₂ sensors?​

Not yet. CO₂ tracking is scaffolded — the config flow may ask for a CO₂ intensity entity or footprint — but no CO₂ sensors are created in this release.

If I turn a sensor off, do I lose its history?​

No. Disabled sensors are hidden and stop updating, but their history is kept and they return the moment you re-enable the option.

How do I carry over historical totals?​

Use the power_insight.set_value service to seed an accumulated total sensor with a starting value.