How Much Does Solar Save Per Year?
Annual savings usually come from two buckets: onsite energy that avoids retail electricity purchases, and exported energy that earns a lower tariff or credit.
Simple formula
Annual solar savings = self-consumed energy x retail tariff + exported energy x export tariff - annual O&M.
That is why two systems with the same generation can produce very different financial results. The missing variable is not just sun. It is how much of that energy is actually valuable to the owner.
Inputs that matter most
- Annual production after losses and degradation.
- Self-consumption ratio.
- Retail electricity tariff.
- Export tariff or net metering credit.
- Maintenance cost.
Why self-consumption matters so much
If exported electricity earns only a small credit, every extra unit used onsite is more valuable than an exported unit. That is why homes with daytime air conditioning, EV charging, water heating, or commercial daytime loads often save much more than similar roofs with weak daytime demand.
Typical mistake
Many quotes show total generation and then assume that all kilowatt-hours are worth the full retail tariff. That overstates savings whenever export compensation is lower than retail electricity price.
How to improve the estimate
- Use the real utility tariff, not a national average.
- Estimate daytime load honestly.
- Adjust shading and orientation losses.
- Check whether inverter clipping or future degradation will reduce usable output.
For many users, “how much does solar save?” is better question than “how much does solar make?” Savings usually drive the value.