Net billing, zero feed-in and virtual net billing

Since September 2024 (Law 5106/2024), new self-generation systems are connected under net billing with simultaneous matching. Here we explain simply what that means, which connection method suits you and how the benefit is worked out.

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The basic idea

What “simultaneous matching” means

Generation is compared with consumption at the same moment, not at the end of the year.

In the past, with net metering, the energy you sent to the grid at midday was offset against energy you took in the evening or in winter, kilowatt-hour for kilowatt-hour. It was like using the grid as a free battery.

Today, with net billing, what counts is what happens at each moment. Energy you use while it's being generated costs you nothing. Any surplus goes to the grid and is paid for in euros, at a lower price than you pay when you buy.

That's why the right system size, a battery and appliances that run during the day (heat pump, water heater, car charging) now make the big difference.

Solar generationUsed immediatelyHome consumption

A typical summer day in a house. Illustrative only.

The three methods

In detail, with a diagram for each

1 · Net billing

Net billing with simultaneous matching

The standard choice for homes and most businesses. The solar system powers the property first. Any surplus goes to the grid and is credited in euros on your bill. Households can use a special scheme for systems up to 10.8 kW.

The biggest benefit comes when you use power during the day.
With a battery you keep the surplus for the evening.
It works perfectly with a heat pump and EV charging.

2 · Zero feed-in

No export to the grid

The inverter constantly measures consumption and limits generation so that no energy goes to the grid. You aren't paid for surplus, because there isn't any. It's the answer when the local grid won't accept new export, or when a business steadily uses all of its output.

Ideal for businesses with a steady daytime load: cold rooms, machinery, offices.
With a battery, output that would otherwise be “curtailed” isn't lost.
It needs a proper study so that no output goes to waste.

3 · Virtual net billing

Virtual net billing with simultaneous matching

The solar system is installed somewhere other than the supply that uses the power, e.g. on a plot of land, a warehouse or another of the business's buildings. The output is offset with simultaneous matching against one or more supplies, provided the conditions are met.

When there is no space at the property that uses the power.
For businesses with several shops, or farmers with several supplies.
We check the conditions and connection terms before making any proposal.

Which one to choose

A simple decision guide

A simple guide. The final choice is made in the study, once we've seen your bill and the local connection terms.

Note: the three methods are mutually exclusive. An installation connects in one way only. For example, the same system can't be both zero feed-in and net billing. And an off-grid system isn't connected to the grid at all, so it has no net billing.

Example

How the benefit works out with net billing

A 6 kWp solar system, 9,000 kWh output, no battery.

Calculation

Used immediately (35%)	3,150 kWh × 0.16 € = 504 €
Goes to the grid (65%)	5,850 kWh × 0.06 € = 351 €
Total benefit	855 € / year
If self-consumption rises to 60%	1,080 € / year

Every kWh you move from “goes to the grid” to “used immediately” is worth about 0.10 € more.

Assumptions used in the examples: electricity price 0.16 €/kWh, surplus payment 0.06 €/kWh, heating oil 1.15 €/litre, Athens. Figures are indicative. Our study works out your own numbers.

The same solar system, different self-consumption.

Comparison

The three methods at a glance

	Net billing	Zero feed-in	Virtual net billing
Where the system is	On the same property	On the same property	Somewhere other than the supply
Export to the grid	Yes, the surplus	No, limited to zero	Yes
How you benefit	Self-consumption + credit in € for the surplus	Self-consumption only	Offset with simultaneous matching on another supply
Role of a battery	Very important	Very important	Depends on the project
Suits	Households, businesses	Businesses with a daytime load, saturated grids	Businesses, farmers, landowners
Can it be combined with the other two?	Not in the same installation	Not in the same installation	Not in the same installation

Already on net metering? Your contract carries on as normal under its own terms. Before we add a battery or expand the system, we check whether it's affected.

Glossary

Terms you'll hear

Self-consumption: The share of output you use on site, at the moment it's generated.
Surplus: Energy that is generated but not used at that moment, so it goes to the grid.
Export (feed-in): Energy sent from the solar system into the grid.
Supply: A property's electricity meter, with the number you see on your bill.
HEDNO: The distribution network operator, to whom we submit the connection application.
kWp: The rated power of the panels. In Athens, 1 kWp produces about 1,400–1,600 kWh a year.

FAQ

What people ask us most

I already have net metering. Does anything change?

No. Existing net metering contracts continue under their own terms.

Which one should I choose?

It depends on when you use power, whether the grid accepts export and where you have space. We decide together during the study.

What do I gain with zero feed-in?

All the output is used or stored on site. It's the answer when export isn't possible, or when a business uses power steadily during the day.

Who handles the permits?

We do, step by step: paperwork, the HEDNO application and follow-up until activation.

One study for power, heating and cooling

Tell us about your property and your consumption. One of our engineers will call you to arrange a site survey and a price, with no obligation.

Get a quote 211 103 8038