Net metering offsets the energy your plant generates against the energy your site consumes. The critical point is this: the matching is done hour by hour, not on annual totals. If you generate at midday and consume in the evening, the two never meet in the same hour, and your surplus goes to the grid at a different price.
The share of generation consumed on site at the moment it is produced. This is the most valuable part: the energy you do not draw from the grid is saved at the retail price.
Generation you could not consume in that hour. It is usually valued below the retail price, which is why surplus generation does not always mean extra profit.
Energy imported in the hours when generation falls short. Night-time consumption falls here, and the plant does not reduce it directly.
Your hourly consumption curve. Two sites with the same annual consumption get different net-metering results if their profiles differ.
The common mistake is to compare annual generation with annual consumption and conclude that “if they are equal, the bill goes to zero”. Because the energy is not stored, that does not hold: energy generated at midday does not by itself cover consumption in the evening.
In a real calculation each hour is handled separately. If generation in that hour exceeds consumption, the difference goes to the grid; if it falls short, the shortfall is imported. The year-end picture is the sum of those 8,760 comparisons.
Choosing module tilt and orientation to suit your consumption hours is the most direct route. An east-west layout lowers total generation slightly but spreads it across the day, which can raise self-consumption.
Sizing the installed capacity to the consumption also matters. An oversized plant exports its surplus at a low rate and can lengthen the payback period.
The calculation is an hour-by-hour match between the yield simulation and the consumption profile.
It means offsetting the energy you generate against the energy you consume. Where generation exceeds consumption the difference is exported; where it falls short, energy is imported. A bi-directional meter records each direction separately.
No. Because the matching is hourly, energy generated at midday does not cover evening consumption. How far the bill falls is decided by the self-consumption ratio, not by the annual total.
It is usually high for commercial sites operating during daylight and markedly lower for homes that consume in the evening. The ratio changes the result you get from the same plant, which is why the profile is asked for.
Exported energy is valued according to the applicable regulations, and the rate paid is usually below the retail price. Rules differ by country and change over time — check current terms with your network operator.
Let generation and consumption match hour by hour so payback comes out on real figures. Runs in the browser.