What is the self consumption or net billing using photovoltaics/solar pv panels with or without battery pack in Greece?

Net billing or self consumption is the new energy support program for households and all businesses in order to reduce electricity bills and replaces the old net metering one. Net billing is the offset of the energy produced by a photovoltaic/solar pv panel system with the energy consumed at the same time by the electrical loads of the installation (e.g. lighting, air conditioning, domestic hot water, motors, devices, electric car charging, etc). The photovoltaic/solar pv panel system is matched and connected with a single power supply line which is located in the same or adjacent space with the solar panels. The photovoltaic/solar pv panel system can be expanded with special type of battery pack. Part of the energy produced by the solar pv panels can be stored and used during the night in order to reduce the energy absorbed by the grid. The self consumer can take advantage of the energy produced and consumed simultaneously and receive an extra income from any excess/surplus energy that is fed into the grid. The self consumer remains connected to the power grid and receives energy from it mainly during the night and after the battery is fully discharged. This leads to significant saving on electricity bills for at least 20 years.

What is the virtual net billing with photovoltaics/solar pv panels in Greece?

Virtual net billing has exactly the same characteristics as the net billing but the photovoltaic/solar pv panel power station is matched with one or more power supply lines (different houses and/or businesses) that are not necessarily located in the same or adjacent area. This means that the houses and/or businesses may be located in the same or in a different region inside the territory of Greece, but must belong to the same electrical system/grid (interconnected, non-interconnected/island grid, etc.). For example, a virtual self consumer may produce energy from a photovoltaic/solar pv panel system on a house in Crete and offset with energy consumed by this house and by two other houses, one in Athens and one in Thessaloniki.

What happens in net billing or virtual net billing when the energy produced from the photovoltaic/solar pv panel system is more or less than needed?

The excess/surplus energy is fed into the electricity grid and recorded by a special meter for specific time frame. The self consumer can be paid for this energy with a variable market price (approximately 0.06-0.07 euros/kWh) depending on the wholesale prices and the moment this energy is supplied to the grid. This amount of money is credited to the self consumer’s next electricity bill as a refund bonus.

If the energy produced by the photovoltaic/solar pv panel system is less than the energy required for the electrical devices operating at that moment, either due to night operation or low battery capacity or weather conditions etc, then an amount of energy will be absorbed by the electricity grid. This amount of energy will be charged according to the user’s typical contract with the electricity provider (eg day/night, fixed or variable tarif).

What are the components of a self consumption/net billing photovoltaic/solar pv panel system?

• Photovoltaic/solar pv panels which are semiconductor devices that convert solar energy into electricity (DC voltage & current).
• The DC panel which provides lightning protection to avoid overvoltages and contains special circuit breakers to protect against DC overcurrent or short circuit.
• The inverter (on/off grid & backup inverter) which offers the maximum conversion efficiency from direct current (DC) to alternating current (AC 230V/50Hz) and is compatible with all the electrical devices and the electricity grid requirements. The inverter may have the capability to operate either on grid or off grid mode to supply energy as a standalone/backup power system utilizing the energy from the solar pv panels and the battery pack.
• The battery pack which stores part of the excess/surplus energy produced during the day in order to be used at a later time of high power demand and low power production from solar panels (e.g during the night). The battery pack guarantees the off grid/stand alone/backup operation of the solar system during an event of power cut at the electric/power grid.
• The AC panel which protects against electrical surges/overvoltages created by lightning strikes or manipulations in the grid, as well as against overloads and short circuits.
• The smart meter that communicates with the inverter for the need of the building to absorb or feed energy by/to the grid. This is to perform optimal operations and also the transition between the on grid and off grid/standalone/backup mode.

How is the billing carried out regarding the charges/fees and energy offset for a net billing/self consumption photovoltaic/solar panel pv system in Greece?

The billing is carried out based on several indications received from two special energy meters as shown in the image above:

• The photovoltaic/pv solar energy meter continuously records the total energy produced during the day which is either consumed on site for powering electrical devices and the charging of the battery, or fed into the grid when in excess (surplus energy).

• The incoming & outgoing energy meter records: 1) the electrical energy absorbed by the grid when the photovoltaic/solar pv panel system and/or the battery cannot fully power the existing electrical loads (e.g. during the night or a cloudy day) and 2) the excess/surplus energy fed to the grid when the pv solar power system produces more energy than consumed at that moment when the battery is fully charged.

The energy that will be charged at the next electricity bill is equal to the energy absorbed by the grid when the photovoltaic/solar pv system with the battery pack cannot meet 100% the power demand of the electricity devices in operation.

The excess/surplus energy fed to the distribution grid will be credited with a variable tarif per kWh at the next electricity bill as mentioned before.

Is it necessary for a self consumer to add a battery pack on a photovoltaic/solar panel pv net billing system?

The battery contributes to the partial or total power supply during night hours by storing part of the energy produced from the photovoltaic/solar pv array during the day. Thus, the energy absorbed by the power grid is minimized and so are the transmition, distribution charges and fees. If the user is able to consume most of the energy during the day when solar production is maximized, the need to integrate a battery pack into the system is reduced. An extra advantage of the battery is that it can be used for standalone operation of the whole system (backup/off grid mode) to power critical loads for several hours during power failures.

What are the advantages of self consumption/net billing systems with photovoltaics/solar panels in Greece?

• Reduced payback time of the investment which is estimated at 5-7 years based on the significant energy savings at electricity bills and also the five-year income tax deduction due to energy investments in buildings in accordance with law N.5073/2023, FEK 204A 11/12/2023. The amount of savings is different for each self consumer and depends on the annual income and the energy consumption profile. After the payback period you take advantage of permanent savings of energy and money.
• Protection against electricity tarif increase due to stock market changes in energy prices or due to variance at transmition, distribution charges and fees. These charges can be further reduced by adding a battery pack.
• Τransmission and distribution power losses are significantly reduced due to the self consumption of the energy produced at the same time. This leads to increased energy efficiency, reduced air pollution and less metal mining needed for the cable extension of the national electric grid.
• Significant increase in the competitiveness of businesses operating during the day or summer time (e.g hotels, industries, shops, offices, etc.)
• Motivation for free electric mobility, air conditioning (heating, cooling, ventilation) and lighting utilizing solar pv energy.
• The energy is produced far away from big power plants (decentralized and distributed power generation).
• The environment is protected and the economy is supported by the exploitation of clean, renewable/sustainable solar energy which is consumed or stored on site.
• All materials are recyclable.
• Reduced maintenance needs for the operation of the whole system.
• Remote monitoring and supervision of the important parameters of the solar panel pv system through internet telemetry.

Who has the right to install self consumption/net billing or virtual net billing solar systems in Greece?

All individuals, freelancers, businesses/companies, and legal persons of public and private law, who either own the space/area at which the photovoltaic/solar system will be installed, or have the legal use of it (e.g. renting or free concession) with the owner’s written approval.

Where can net billing/self consumption systems be installed?

Photovoltaic/solar pv systems can be placed on roofs (tiled or flat), shelters, facades, pergolas, sunshades, parking areas, warehouses, industrial roofs (panel type) but also on the ground as long as the urban planning and environmental legislation is not violated.

Self consumption/Net billing photovoltaic/solar pv systems for electric vehicle charging.

Electric vehicles are increasingly entering the car market in order to replace the old  ones that use fossil fuels (gasoline, diesel, LPG, natural gas, etc.). This leads to the significant increase of power demand for charging electric cars by individuals or businesses. The use of solar net billing/self consumption pv systems is very important for charging electric cars with clean and renewable free energy from the sun, which reduces up to 100% the exhaust air emissions and the cost of moblility/ transportation. Photovoltaics/Solar panels for electric mobility is a modern and environmental friendly way to drive using unlimited solar energy and  become permanently energy self sufficient. An extra advantage is that the battery of electric cars, when updated with appropriate manufacturer’s software, can be used as a backup energy source to supply houses or businesses with electrical power allowing the bidirectional flow of energy (actively or passively).

 

Photovoltaic self consumption (net billing) solar pv systems for heating, cooling, air conditioning and domestic hot water use.

The use of heat pumps for heating, cooling, air conditioning is nowadays a common practice for any type of building (residential, commercial, industrial, accommodation and business). This is mainly due to the very high thermal and cooling efficiency ratio (COP and EER) of heat pumps compared with the typical heating/cooling technologies. Also, the unstable international prices of fossil fuels and the insecurity of energy supply chains increase the demand for heatpumps. This trend leads to a big increase in electric power consumption and can be compensated with a photovoltaic/solar pv power system which produces a significant part of the energy required for the heat pump. In this way you enjoy heating, air conditioning and hot water utilizing free energy from the sun.

What is the procedure of having a self consumption/net billing or virtual net billing solar power system?

• Contact our office to confirm if the basic criteria are met for issuing the necessary licenses of the photovoltaic/solar pv system, but also to guide you through the available alternatives based on your energy consumption profile.
• Digital representation of the project area and data collection for designing an appropriate system which will be licensed and installed accordingly.
• Submission of the initial connection claim to DEDDIE (Electricity Grid Manager in Greece) digital platform. The application will include all the necessary documents, technical studies, self declarations, plans/blueprints, etc.
• Positive feedback by DEDDIE authorities.
• Signing of the necessary contracts with DΕDDIE and energy provider.
• Order placement for the required materials of the project.
• Installation, assembly and adjustment of solar system equipment.
• Application to DEDDIE authorities for the evaluation and activation of the photovoltaic/solar system. After carrying out the required tests, the connection to the grid is finalized and the whole solar power system is set in operational mode.
• Quality assessment of the photovoltaic/solar pv power system using modern digital measurement tools. As long as the conditions for optimum operation are met, the project is delivered to the owner.