What Net Billing is
The Net Billing — or energy offsetting in value – is the self-consumption scheme under which new solar systems are installed in Greece today. Its philosophy is simple: you install solar on the roof, the terrace or open ground on your property, and the energy produced supplies your own consumption as first priority.
Whatever you do not consume at the moment it is produced is not lost: it is exported to the grid and credited to your bill in monetary value. Conversely, at times when the solar system is not enough – at night or in cloudy weather – you draw energy from the grid and are charged as normal. At the end of the settlement period the two flows are offset and you pay the difference.
The critical difference from the earlier Net Metering is the unit of offsetting. Under Net Metering, offsetting was energy-based: one kilowatt-hour you gave to the grid was equivalent to one kilowatt-hour you took back. Under Net Billing, offsetting is value-based: the energy you export is valued in euros at a reference price, while the energy you import is charged at your supplier tariff. Because the two prices are not the same, the financial outcome depends directly on how large a share of production you consume on site.
This is the most important conclusion for any prospective investor: under Net Billing it is not whoever installs the largest solar system who wins, but whoever installs the correctly sized solar system – the one that matches its real consumption profile. That is why every Fotergeia project starts from an energy study and not from an equipment catalogue.
At a glance
How a Net Billing system works
Technically, a Net Billing system is a grid-connected solar installation: the panels produce direct current, the inverter converts it to alternating current and feeds it into the property electrical panel. From there, the energy follows a strict order of priority.
Direct self-consumption
Production first supplies the loads running at that moment: air conditioning, refrigeration, machinery, heat pump, lighting.
Battery charging
If a storage system is present, the surplus charges the batteries for use in the evening or at peak hours.
Export to the grid
Whatever is left over is exported to the grid, measured by the meter and credited in value to your bill.
Import from the grid
When production and the battery are not enough, the shortfall is covered by the grid at your normal tariff.
Energy & money flow diagram
Two parallel flows: the energy (green) and the financial valuation (white).
Metering is performed by a bi-directional meter, which records separately the energy exported and the energy imported. Your supplier then applies the offsetting contract and issues a bill showing both quantities, together with the regulated charges that follow the energy actually drawn from the grid.
In practice this means a properly designed Net Billing system can dramatically reduce energy costs, but the bill never falls to zero: fixed and regulated charges remain. The aim of the study is to maximise the self-consumption rate, because every kilowatt-hour you use yourself is worth more than one you export.
Legislation & current self-consumption framework
The Greek framework for self-generation has evolved considerably over the past decade. It began with virtual and physical energy netting (Net Metering) and, through successive legislative interventions and ministerial decisions which transposed the European directives on active consumers, and culminated in the scheme of energy offsetting in value (Net Billing). Net Billing is today the principal self-consumption scheme for new installations, while older Net Metering contracts remain in force until they expire.
Broadly, the framework regulates four things: who are entitled to become self-consumers, how much capacity can install in relation to the agreed capacity of their supply, how exported energy is valued and how permitting and grid connection are handled through the operator.
What the framework regulates – the key points
- ▸Offsetting contract: is signed with the electricity supplier and runs for several years. It defines how exported energy is valued and how settlement is carried out.
- ▸Matching to the supply: the solar system is connected to a specific consumption supply and its capacity relates to the agreed capacity of that supply.
- ▸Connection terms: the network operator examines the available margin in the area and grants connection terms. On saturated grids Net Billing may not be feasible – there we consider Zero Feed-In.
- ▸Storage: the framework provides for combining the solar system with a battery system, with growing institutional encouragement of storage.
- ▸Subsidies: funding programmes for households and farmers are activated periodically, with rates and deadlines that change with each call.
Note: the regulatory framework and subsidy programmes are updated regularly. The information on this page is indicative and describes the general logic of the scheme. For what applies at the moment you plan your project – capacity limits, valuation method, active subsidies – contact our technical team for current, documented guidance.
Who can install a Net Billing solar system
Net Billing is available to a very wide range of consumers. The basic requirement is that there is an active electricity supply in the applicant name and suitable installation space – roof, terrace, canopy or open ground on the property.
The process step by step
Fotergeia handles all seven stages. You sign and stay informed – all the technical and administrative work is done by us.
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01
Energy study
We collect bills and consumption profiles, analyse demand by hour and season, estimate production from geographic location, orientation and tilt, and propose the optimal capacity and the right storage size.
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02
Equipment selection
We select panels, inverters, mounting systems and – where needed – batteries, on criteria of performance, warranties, compatibility and spare-parts availability. We work with Tier-1 manufacturers and certified materials.
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03
Application submission
We prepare the technical file and submit the connection application to the network operator, with the required proof of ownership, single-line diagrams and equipment datasheets.
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04
Connection terms
The operator examines the available margin and issues the connection terms. We check whether any constraints affect the design and, where required, adjust the solution – for example with export limitation or the addition of storage.
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05
Installation
Mounting of frames and panels, DC/AC electrical wiring, installation of the inverter and protection panels, earthing and lightning protection, cable routing and monitoring. For residential projects, typically 1-3 days.
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06
Testing
Insulation and continuity measurements, polarity and protection checks, inverter operation tests, preparation of the Installer Declaration and the technical handover file.
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07
Activation
Meter replacement, signature of the offsetting contract with the supplier and activation of the connection. The system begins to produce and record; you follow performance from the monitoring app.
Advantages of Net Billing
Drastic bill reduction
A correctly sized system can cover most of your annual consumption, cutting your electricity bill to a fraction of what it is today.
Protection from price rises
Every kilowatt-hour you produce yourself is a kilowatt-hour you do not buy at the current market price. The higher the price of electricity climbs, the greater the benefit.
No surplus wasted
Unlike a zero-export system without a battery, under Net Billing the energy you do not consume is not thrown away – it is valued and credited.
Higher property value
A property with an active solar system and documented energy performance is more attractive on the market, both for sale and for rental.
Environmental footprint
For businesses, reduced indirect energy consumption is a measurable indicator in sustainability reporting and a criterion in supply chains.
Expandability
A Net Billing system can be designed to accept a battery, an EV charger or a heat pump later, without being rebuilt from scratch.
Return on investment & payback
The performance of a Net Billing system does not depend on capacity alone. It is determined by the combined effect of five factors, which we quantify in the study before giving you any quotation.
Self-consumption rate
The single most important factor. Businesses operating during the day reach very high rates; homes without a battery, clearly lower.
Electricity tariff
The more expensive the kilowatt-hour you replace, the faster the investment pays back.
Solar potential
In Attica each kWp yields around 1,400-1,500 kWh per year, with correct orientation and tilt.
Equipment cost & quality
The cheapest equipment is rarely the most economical over a 25-year horizon. Performance warranties matter.
Subsidies
When an active support programme for households or farmers exists, the payback period shortens significantly.
The figures above are indicative and do not constitute a financial commitment. The actual payback period follows from the energy study of the specific property and its specific consumption profile.
Net Billing, Net Metering or Zero Feed-In?
The three concepts are often confused. The table clarifies the substantive differences.
| Criterion | Net Billing | Net Metering | Zero Feed-In |
|---|---|---|---|
| Unit of offsetting | Value (EUR) | Energy (kWh) | No offsetting |
| Availability for new projects | Current scheme | Older contracts still in force | Available |
| Contract with supplier | Yes, offsetting contract | Yes | Not required |
| On a saturated grid | Often impossible | — | Usually feasible |
| Role of the battery | Significantly improves performance | Less critical | Practically essential |
Frequently asked questions about Net Billing
What is the difference between Net Billing and Net Metering?
Under Net Metering, offsetting was done in energy: one kilowatt-hour exported was equivalent to one kilowatt-hour imported. Under Net Billing, offsetting is done in value: exported energy is valued at a reference price, while imported energy is charged at your supplier tariff. This is why, under Net Billing, self-consumption and storage carry far greater financial weight.
Does the electricity bill go to zero?
Not entirely. Even with very high coverage, fixed and regulated charges remain, linked to the supply point and to the energy actually drawn from the grid. In practice, a well-designed system reduces the bill to a small fraction of what you pay today.
What if the grid in my area is saturated?
On saturated grids the operator may not grant connection terms for export. In most such cases there is a solution with a zero export (Zero Feed-In), usually combined with a battery so that surplus production is not wasted.
How much capacity can I install?
Capacity is linked to the agreed capacity of the consumption supply and to the available grid margin, while in practice it is also limited by the space available. Because these limits are updated, we confirm the exact cap for your case in the study.
Is there a subsidy for solar with Net Billing?
Support programmes for households and farmers are activated periodically, often at a higher rate when a storage system is included. Rates, ceilings and deadlines change with each call – contact us for what is active at the moment you plan your project.
What happens during a power cut?
A conventional grid-connected system shuts down automatically for safety reasons. If you want power during an outage you need a hybrid inverter with backup functionality and a battery – a solution we design to supply selected critical loads.
Want to know how your own Net Billing system would perform?
Send us your electricity bills and some details about your site. You will receive a free technical study with a production estimate, coverage percentage and a detailed quotation.
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