How to Use the Grid Connected Solar Calculator
This calculator estimates how much energy a solar panel system may generate during a simplified 24-hour day and compares it with a typical household demand profile.
Inputs
Location profile: Select the region closest to your installation. The calculator uses a simplified solar irradiation profile for that region.
Solar panel area: Total panel area in square meters. Larger area usually gives more energy generation.
Installed cost per square meter: A simplified cost input. Real installed cost also includes inverter, mounting, wiring, permits, labor, roof work, maintenance, and taxes.
Buying price: The electricity price paid when importing power from the grid.
Selling price: The price received for exported solar electricity.
Core Solar Formula
The simplified hourly solar generation is estimated as:
The calculator compares each hour of generated solar energy with household demand:
The financial estimate is then:
Built-In Location Assumptions
| Location profile | Panel efficiency used | Use case |
|---|---|---|
| EU South | 15% | Sunny southern European profile |
| EU Central and North | 14% | Moderate northern European profile |
| USA North | 14% | Moderate northern USA profile |
| USA South | 15% | Sunny southern USA profile |
| Canada | 13% | Lower-sunlight simplified profile |
Is It Profitable to Install Solar Panels?
The simple payback estimate shows how many years it may take for annual savings to recover the simplified system cost. A shorter payback period usually means a more attractive investment, but the result should be checked with real quotes and local energy rules.
Frequently Asked Questions
Can this calculator predict my exact solar savings?
No. It gives a simplified estimate. Exact results require real solar resource data, roof geometry, shading analysis, equipment specifications, inverter losses, tariffs, and local regulations.
Why can daily cost with solar be negative?
A negative daily cost means the value of exported solar electricity is larger than the remaining grid import cost in this simplified model.
Does this include batteries?
No. This version assumes a grid-connected system without battery storage. Excess generation is exported, and deficits are imported from the grid.
Why does the payback period change so much?
Payback depends strongly on system cost, sunlight profile, electricity buying price, export price, and panel area.