Frequently asked questions about solar panels

Sunlight consists essentially of small packets of energy called photons. Photons contain different amounts of energy depending on the wavelength of the solar spectrum. For example, blue light or ultraviolet light has more energy than red or infrared light. 

When photons strike a photovoltaic cell, some are reflected, some pass through it, and others are absorbed by the photovoltaic cell. These last photons are the ones that produce electric current. These photons cause the electrons in the photovoltaic cell to move to another position and, as we know, electricity is nothing more than the movement of electrons. 

This simple principle of physics is the basis for one of the most advanced electricity-generation technologies of our time.

Photovoltaic systems, which convert solar radiation into electricity, are considered ideal energy conversion systems because they use the planet’s most readily available energy source (the sun) to generate electricity, the most useful form of energy. Solar energy is clean, inexhaustible, gentle and renewable. 

Solar radiation is not controlled by anyone and is an inexhaustible domestic energy resource that provides independence, predictability and security in energy supply. Photovoltaic systems give consumers complete control and immediate access to information about the energy produced. This makes them more mindful of how they consume energy and thus helps promote its rational use and conservation. 

Since solar electricity is produced and consumed locally, significant losses in electricity transmission and distribution are avoided, resulting in energy savings of 10% compared with conventional electricity supplied through the grid. 

Solar photovoltaic systems operate quietly, are reliable and have a long lifespan. They can be expanded to meet changing needs, and the energy they produce can be stored (in the grid or in batteries). They require minimal maintenance. 

When sizing a photovoltaic system, it is recommended to take into account the annual consumption of the property to which it will be connected. Since energy netting is carried out over a three-year period and any surplus energy remaining after the three-year netting period is not compensated, the photovoltaic system’s annual energy output should not exceed the total annual consumption. 

For informational purposes, typical output from fixed-mount photovoltaic systems ranges from 1.300-1.650 kWh/kWp/year (kilowatt-hours per kilowatt peak per year), depending on the installation’s geographic coordinates, tilt and orientation, with a weighted average of approximately 1.350-1.550 kWh/kWp/year. Therefore, the system’s power should be selected based on annual energy needs, subject to the restrictions set by law. 

Please note that for existing single-phase low-voltage supplies, the photovoltaic system’s power cannot exceed 5 kWp. A higher-powered photovoltaic system requires the supply to be upgraded in advance by converting it to three-phase. 

Everything you can power with electricity from ΔΕΗ. There is absolutely no difference. 

Most buildings are suitable. They simply need to meet the following requirements: 1. There must be enough available, unshaded space. As a rough rule of thumb, allow about 0,5 square meter for every 100 Watt (if you use standard commercially available solar panels). Approximately 4-5 sq.m/kWp is needed for a tiled roof and 10-12 sq.m/kWp for a flat roof or plot, because on flat surfaces the solar panels are installed in rows spaced apart to prevent them from shading one another. Make sure the area is as close as possible to 100% unshaded throughout the day. Otherwise, your system will operate less efficiently. 

A rough rule to make sure your system does not produce less due to shading is that the distance from any obstacle (building, tree, etc.) should be twice the height of the obstacle. 2. Solar panels perform best when facing south. Deviations from south are acceptable, but they reduce output. 3. The solar panels must be tilted correctly relative to the horizontal plane. 

A tilt is usually chosen to provide the best results throughout the year. In Greece, the optimal tilt is around 25 -30 degrees. Don’t worry, though. Our installation team will determine the correct tilt. 

Changes to the type and/or manufacturer of the panels and inverters are accepted following written notification to the competent unit managing the request, accompanied by the relevant technical manuals and certificates. This must be done no later than when the application to activate the connection is submitted. No amendment to the Connection Agreements and Simultaneous Netting Agreements is required, provided that the new equipment sizing does not change the station’s total installed capacity (kWp).

Applications to increase the capacity of stations for which an initial application has been submitted, but no connection offer has been issued in the meantime, are treated as new applications and examined in the order in which the capacity increase application was submitted. 

Applications to increase the capacity of stations for which a connection offer has been issued and remains in force are treated as new applications; that is, they are examined in the order in which the capacity increase application was submitted, and a new connection offer is issued for the new total capacity, provided that electrical capacity is available. The original offer is cancelled; otherwise, it remains in force. 

Applications to increase the capacity of generation stations after connection activation will be possible at the same voltage level, following the submission of a new application, the issuance of a new Connection Offer, and payment of the relevant cost. In these cases, the Connection Agreements and Simultaneous Netting Agreements will be amended to reflect the capacity of the generation station. 

Collective Self-Consumption is a way of producing and consuming energy from photovoltaic systems, where two or more people share the energy generated by a shared power plant. This model is particularly suitable for residents of apartment buildings or small communities who want to reduce their energy bills and benefit from green energy production.

With Solar Home, you can easily get started and benefit from all the advantages of collective self-consumption, helping to reduce costs and use energy sustainably.

1. It applies to all categories of consumers (residential, commercial, farmers, Local Authorities, Energy Communities). 

2. Under net-billing, the offsetting of the energy produced against the energy consumed takes place in real time. Any surplus energy is injected into the grid and compensated for twenty years based on the wholesale market price during the hours when it is injected. 

3. A special “Residential Photovoltaics” program has been established for the installation of photovoltaic stations with an installed capacity of up to 10,8 kW, using simultaneous or virtual simultaneous offsetting exclusively for residential consumers (households). 

4. Residential self-consumers are not considered business operators and are not subject to tax obligations for the disposal of the energy they produce and inject under the offsetting arrangement. 

5. Specifically for the Non-Interconnected Islands (NII), because there is no organized market, surplus energy is paid to the self-consumer at a price (€/MWh) equal to the Special Market Price (SMP) for RES & CHP technologies, as published by DAPEEP. It is settled by the NII Operator (HEDNO S.A.) in each NII electricity system, in accordance with the provisions of the NII Code. 

6. Collective self-consumption at building level is provided for, using virtual net-billing. At least two (2) self-consumers located in the same building may jointly participate in activities and agree among themselves on how to allocate the energy produced by their stations, subject to applicable network charges and other related charges, fees, contributions and taxes. Under virtual net-billing within a collective self-consumption scheme, common-area consumption in buildings may also be included. 

7. For simultaneous net-billing and zero feed-in, the capacity of each generating station installed may be up to one hundred percent (100%) of the agreed consumption capacity (in kVA). For virtual net-billing, the capacity of each generating station installed may be up to one hundred percent (100%) of the installed capacity of all the consumption being offset. 

8. The self-consumer’s station may be owned by the self-consumer or a third party, or its installation and operation—including metering and maintenance—may be managed by a third party, provided that the third party remains under the self-consumer’s direction. In this case, the third party is not considered a self-consumer. If the self-consumer’s station is installed by a third party rather than by the self-consumer, any financial benefit from surplus energy under simultaneous or virtual simultaneous net-billing, if compensated, accrues exclusively to the self-consumer. 

9. The self-consumer or the third party that owns the station may enter into bilateral power purchase agreements (PPAs) for surplus energy in cases of simultaneous net-billing where the energy is paid for by the market. Similarly, the Supplier or the Aggregator may guarantee a fixed sale price for surplus energy. 

This is the netting of the electricity produced by the generation station and the electricity consumed at the prosumer’s consumption supply, over a time window equal to the Imbalance Settlement Period (15 minutes of an hour), based on certified metering data from the competent Operator. 

If energy is injected from the generation station into the Grid or the System, the prosumer may be compensated for the Injected Energy, provided that this activity is not their main commercial or professional activity (for commercial—non-residential—prosumers, the relevant KAD for the production and sale of electricity must be in place). The consumption supply is located on the same or an adjacent premises as the generation station, or on another premises but is electrically connected via a dedicated interconnection line. 

The generation station is connected to the Grid or the System through the supply of the consumption installation. 

The offsetting of the electricity generated by the generating station against the electricity withdrawn at the consumption supply for offsetting by the self-consumer, which is carried out over a time window equal to the Imbalance Settlement Period (15 minutes of the hour), based on certified metering data from the competent Operator, while the self-consumer may be compensated for surplus energy, provided that this activity does not constitute their primary commercial or professional activity. 

The consumption installations for offsetting are not electrically connected to the internal electrical installation of the generating station, even if they are located on the same or an adjacent site. Generating stations may be installed in any Region of the country, regardless of the location of the consumption installations for offsetting, provided that both the station and the consumption installations are located within the same electrical system, that is, the Interconnected System or, for the Non-Interconnected Islands, the corresponding electrical system. 

Virtual net billing from plants owned by Local Government Organizations (O.T.A.) of the first and second tier, with the energy absorbed by facilities of public-benefit enterprises and Municipal Water Supply and Sewerage Enterprises under Article 107 of Law 3852/2010 (A’ 87), municipal children’s, infant and infant-toddler daycare centers, primary and secondary schools, health centers and hospitals, municipal and public sports centers, street lighting facilities and networks, water supply and sewerage facilities, as well as any other building, infrastructure or facility that either belongs to or serves the needs of the O.T.A. 

For the implementation of virtual net billing by Local Government Organizations (O.T.A.) of the first and second tier, the supply connections of the generating stations, as well as the corresponding consumption connections to be offset, do not need to be in the name of the same legal entity. 

At least two (2) self-consumers located in the same building may jointly participate in the installation of generation stations and agree among themselves on the allocation of the energy they produce, subject to the network charges in force and other related charges, fees, contributions and taxes. The collective self-consumption scheme may also include consumption in the common areas of buildings. Virtual Net Billing applies to renewable energy self-consumers acting jointly. 

The netting of the energy produced by the generating station against the electrical energy drawn at the final consumer’s consumption supply, without energy being injected from the generating station into the Network or the System. 

Photovoltaic systems are installed on buildings (on the roof or rooftop of a building), on veranda/balcony canopies, on pergolas (on the roof or in an uncovered area of the plot), on façades and shading structures, as defined in Articles 16 and 19 of Law 4067/2012, as in force, as well as in ancillary areas of the building, such as storage rooms and parking areas, as defined in paragraph 96 of Article 2 of the same law) or on the ground, as well as on solar tracking systems installed on the ground. 

a. In the case of simultaneous netting or virtual simultaneous netting, individuals (whether or not they are self-employed) or legal entities governed by public or private law are entitled to participate, provided that they either own the site where the generation station is installed or have lawful use of it (e.g. through a lease, a grant of use free of charge, etc.) and have obtained the site owner's written consent. 

b. In the case of virtual simultaneous netting by Energy Communities, the right to participate may be exercised by natural and/or legal persons who are members of the Energy Community, as well as by vulnerable consumers or citizens living below the poverty line (under the legislation in force at any given time), whether or not they are members of the Energy Community. 

In all cases, one or more generation stations may be installed in a shared area of a property, provided that all co-owners of the building give their consent in a written agreement in accordance with the provisions of the Civil Code. In cases of bare ownership, the consent of the usufructuary is sufficient. In the case of a lease or grant of use, the tenant/user is also entitled to participate, provided that the owner gives written consent. 

In the case of simultaneous netting, each generation station is matched with the self-consumer's electricity supply point. The same station may be matched with one or more electricity supply points that are not necessarily located on the same or an adjacent site, provided that they belong to the same self-consumer. In this case, virtual simultaneous netting applies to those electricity supply points. 

In the case of virtual simultaneous netting, each generation station is matched with one or more electricity supply points that are not necessarily located on the same or an adjacent site. 

In the case of simultaneous or virtual simultaneous netting, where the generation station is installed by a third party rather than by the self-consumer, the Energy Community, or a first- or second-tier local authority (OTA), the generation station may be matched with one or more electricity supply points that do not belong to the same self-consumer, provided that those electricity supply points are located on a site owned by the same third party that installs the generation station. In this case, the third party is not considered a self-consumer, and any surplus energy benefits the end consumer/self-consumer. 

An electricity supply point may participate in or be included in more than one system, provided that all systems apply simultaneous netting or virtual simultaneous netting. 

In the case of simultaneous net billing, as well as zero injection, the capacity of each generating station (in kWp) may be up to one hundred percent (100%) of the agreed consumption capacity (in kVA). 

In the case of virtual simultaneous net billing, the capacity of each generating station (in kWp) may be up to one hundred percent (100%) of the installed capacity of all the consumption facilities included in the net billing arrangement (in kVA). 

Specifically, for the installation of stations with or without an integrated electricity storage system for self-consumption with simultaneous net billing and without the possibility of injecting energy into the grid, the capacity of the stations may be up to one hundred percent (100%) of the agreed capacity of the consumption connection. 

For systems with an installed capacity of up to 10,8 kWp and a maximum generation capacity of up to 10 kW, applications are submitted online through the HEDNO platform: https://deddie.gr/el/themata-stathmon-ape-sithia/ilektroniki-platforma-ypovolis-aitiseon- ape-sithya/fv-stathmo-10-8kw-10kw-netmet/ 

For larger systems, applications are submitted through a different platform: 

https://ape.deddie.gr/apewebportal-ws/ 

As the two platforms may be consolidated soon, check the HEDNO website for relevant guidance. 

The Network Operator has available power absorption capacity of ten megawatts (10 MW) per Substation, in addition to the existing capacity, exclusively for the installation of RES and CHP stations by self-consumers, for self-consumers applying energy netting, and for the application of virtual energy netting. 

The above additional capacity is made available at all substations of the Network, including areas with saturated networks and excluding only the network of the Non-Interconnected Islands (NII), without being subject to restrictions related to the System’s absorption capacity, and is allocated as follows: 

If the capacity allocated to any of cases a), b), or c) is exhausted, the Operator may reallocate the capacity, while ensuring a minimum available power hosting capacity of one (1) MW for cases a) and b). 

A joint decision of the Ministers of Environment and Energy and of National Defence shall determine the priority issuance of Final Connection Offers and allocation of the 10 MW of power absorption capacity for the installation by the Ministry of National Defence, for reasons of national security, of RES stations with a capacity of up to three megawatts (3 MW) each, using simultaneous energy netting or virtual simultaneous energy netting. 

If the power absorption capacity of ten megawatts (10 MW) per Substation referred to in the first paragraph is exhausted, the Operator shall assess whether it is technically feasible and may extend the above capacity per high-voltage/medium-voltage transformer (HV/MV). 

The available power hosting capacity for RES and CHP stations at each substation (S/S) or high-voltage/medium-voltage transformer (HV/MV), excluding from this calculation the capacity of ten megawatts (10 MW), is allocated for the connection of RES and CHP stations as follows: 

a) Twenty percent (20%) for the installation of RES and CHP stations by self-consumers, including stations under the special photovoltaic systems development program;
 b) eighty percent (80%) for the installation of other RES and CHP stations. 

In this case, the Network Operator accepts new applications for total capacity of up to ten percent (10%) above the available capacity of each substation (S/S) or HV/MV transformer. 

At least twenty percent (20%) of the available capacity for developing photovoltaic stations, per NII system, is allocated to photovoltaic stations installed by self-consumers, subject to a maximum installed capacity of: a) ten point eight kilowatts (10,8 kW) per consumption supply, for residential use (households), including stations under the special photovoltaic systems development program; and b) fifty kilowatts (50 kW) per consumption supply, for the primary sector, as well as the secondary and tertiary sectors (other uses), Renewable Energy Communities, and Energy Communities of Citizens. 

In the case of simultaneous net billing with the option to inject the generated energy into the Grid or System, a Simultaneous Net Billing Agreement (S.T.S.) is entered into by the self-consumer, the electricity supplier and the Aggregation Representative with whom the self-consumer has contracted, respectively for the supply of electricity to the consumption connection and for representing the RES plant in the electricity market, for twenty (20) years, commencing on the date the generating station’s connection is activated. 

A Connection Agreement for the generating station must have been entered into with the competent Operator before an S.T.S. can be concluded. An active consumption connection at the site where the system is installed is required for the generating station to be activated and the energy to be netted. 

In the case of virtual simultaneous net billing, a Virtual Simultaneous Net Billing Agreement (S.E.T.S.) is entered into by the self-consumer, the electricity supplier and the Aggregation Representative with whom the self-consumer has contracted, respectively for the supply of electricity to the consumption connection and for representing the RES plant in the electricity market, for twenty (20) years, commencing on the date the generating station’s connection is activated. A Connection Agreement for the generating station must have been entered into with the competent Operator before an S.E.T.S. can be concluded. One or more active consumption connections at the consumption installations to be included in the netting arrangement are required for the generating station to be activated. If any details change (including, for example, the consumer’s name or business name at a connection, the consumer’s tax identification number, etc.) or the number of consumption connections included in the netting arrangement changes (including, for example, the agreed capacity or the percentage (%) allocation of injected energy, etc.), the S.E.T.S. must be amended to reflect those details and notified to the competent Operator. 

In the case of simultaneous net billing, the lawful user of the connection at any given time automatically assumes the rights and obligations arising from the S.T.S., provided that they continuously meet the conditions on the basis of which the S.T.S. was concluded. If the lawful user of the connection changes, the S.T.S. must be amended to include the details of the new self-consumer. 

In the case of virtual simultaneous net billing, if ownership of the site where the generating station is installed is transferred, the S.E.T.S. is automatically terminated, unless the new owner of the site, or a person who acquires the lawful use of the site following a written agreement between that person and the new owner (e.g. by lease, free-of-charge grant of use, etc.), is entitled to participate under the provisions governing virtual simultaneous net billing. In that case, the S.E.T.S. must be amended to include the details of the new self-consumer and the connection, and the new owner or the person who acquires the lawful use of the site automatically assumes the rights and obligations under the S.E.T.S. of the transferor or the new owner granting the use. 

In the case of simultaneous net billing without the option to inject the generated energy into the Grid or System, the self-consumer does not enter into a Simultaneous Net Billing Agreement (S.T.S.). 

The following are required to activate the connection of the photovoltaic self-consumption system: 

The photovoltaic plant is connected to the Grid as follows: 

The diagram 2 shows the two meters, as well as the boundaries of ownership and responsibility between the Grid and the self-consumer for installations connected at the LV and MV levels of the Grid. Specifically: 

To ensure that the energy generated is used exclusively by the self-consumer’s loads and that the plant does not feed energy into the Grid (“zero feed-in”), the following arrangement may be implemented: a “directional sensor” (“energy flow direction sensor” or “smart energy meter”) is installed at the installation’s incoming supply. It may be single-phase or three-phase, with or without measuring transformers, as applicable. 

The installation and proper operation of the sensor (S) are the self-consumer’s responsibility. When increased generation and/or a reduced load results in surplus energy that is about to flow from the electrical installation into the Grid, the plant receives a signal from the sensor to reduce or stop its generation so that no energy is fed into the Grid (Figure 3). Equivalent solutions may be accepted, provided they demonstrate and ensure that the installation does not feed energy into the Grid. 

The “zero feed-in” arrangement makes it possible to connect a generating plant to a saturated network, provided the saturation is due to the rated power of the Grid components being exceeded or the desired voltage limits at Grid nodes being exceeded. 

If the Grid has been designated as saturated because the short-circuit level at the MV busbar of the upstream HV/MV transformer has been exceeded, implementing the “zero feed-in” arrangement does not make it possible to connect the generating plant. 

The self-consumer intending to implement the above scheme is required, in addition to the other documents and supporting documentation, to submit to HEDNO a Technical Description demonstrating compliance with the non-export obligation, accompanied by an electrical diagram and the manufacturer’s technical manuals for the generating station and the “directional sensor”. 

The Connection Offer and the Connection Agreement include a special clause requiring that no energy be exported to the Grid. In addition, the self-consumer undertakes, by means of a Solemn Declaration of N.1599/86, that the settings of the generating station’s management system will not be modified throughout the installation’s operation. 

When the generating station is commissioned, HEDNO may carry out appropriate tests to check compliance with the non-export requirement. During operation, it monitors the supply’s metering data in order to identify any breach of the requirement. If it is found that the above requirement has been breached, HEDNO may disconnect the self-consumer from the Grid. 

The electricity generated by the photovoltaic system, as well as the electricity imported from and exported to the Grid, is metered simultaneously by DEDDIE, according to the existing metering cycle governing the prosumer’s consumption installation. 

Regulated charges (ETMEAR, System Usage Charge, Network Usage Charge, YKO and other regulated charges) are calculated on each consumption bill based on the energy drawn from the Grid. 

For all the above cases, charges for the Special Consumption Tax, the Special Fee 5‰ of Law 2093/1992 and VAT are calculated as provided for by the applicable legislation in force at the time. 

In the case of simultaneous net billing, energy injected into the Grid is compensated on the basis of the Day-Ahead Market Clearing Price. To sell the energy, the self-producer, as the owner of RES or CHP plants commissioned in the Interconnected Grid, participates directly in the electricity market. 

The Operators to whose networks the consumption connections and the self-consumer’s RES or CHP plant are connected provide the Supplier, the self-producer and the Aggregation Representative of the RES or CHP Plant, with whom the Simultaneous Net Billing Agreement has been signed, with certified metering data as follows: 

Based on the metering data received from the Operator, the Aggregation Representative calculates, for each Imbalance Settlement Period, the monetary value of the Surplus energy from the plant, based on the revenue from market participation. Final settlement is carried out monthly. 

Specifically:
A. On a monthly basis, the Aggregation Representative pays the self-consumer the monetary value of the total Surplus energy, aggregated at the monthly level. 

B. The Supplier issues electricity consumption bills to the self-consumer for the connection subject to net billing. The bill for this connection separately details the total energy withdrawn, which is charged in accordance with the applicable provisions governing energy supply and the Supplier’s tariff in effect for the connection subject to net billing. 

Specifically, for household self-consumers with a self-consumption system of up to 10,8 kW, the Aggregation Representative is DAPEEP. If the bill shows a credit balance, the difference is credited to the self-consumer. Household self-consumers have no tax obligations for the disposal of the energy generated and injected under the net billing scheme. 

There is no limit. 

If the electricity supply is in the usufructuary’s name, the usufructuary can do so without the bare owner’s consent. If it is in the bare owner’s name, the bare owner can do so with the usufructuary’s consent. In cases of co-ownership, the owner in whose name the electricity supply is registered can do so with the written agreement of the co-owners. 

The above Declaration of Responsibility may cover the entire installation, that is, both the existing consumption installation and the generation installation incorporated into the consumer’s internal electrical installation. Alternatively, it may cover only the generation installation, if the Declaration of Responsibility for the existing consumption installation is still valid, meaning that the time for its next regular inspection has not yet elapsed. 

This Declaration of Responsibility, together with the relevant supporting documentation (plans, technical report, description of the method used to prevent islanding, protection settings, etc.), is signed by an Electrical Engineer, an Engineer in a related field with the corresponding professional rights (e.g. a Mechanical Engineer) and, specifically for installations up to 10 kW, by an electrical installer, in accordance with the provisions of Presidential Decree 108/2013. 

Self-consumers must ensure compliance with the provisions of applicable town planning and environmental legislation when installing the generating station, and arrange for all permits, approvals or other relevant administrative acts required in each case to be issued, and must keep them. 

Before the generating station is activated, DEDDIE will receive a solemn declaration from N.1599/1986 (the relevant template is available on its website) from the self-consumer and their responsible engineer, in which they will certify compliance with all relevant provisions and assume responsibility for it. 

According to paragraph 13 of Article 8 of Law No. 3468/2006, as in force, photovoltaic stations installed on buildings or other structures, or within organized industrial activity zones, are exempt from the requirement to obtain a decision approving environmental terms (E.P.O.) and from being subject to Standard Environmental Commitments (P.P.D.). No certificate is required for exemption from E.P.O. and P.P.D. 

A building permit or approval for small-scale construction works is not required to install photovoltaic stations on buildings with a capacity of up to 100 kW. For photovoltaic stations with a capacity greater than 100 kW, approval for small-scale construction works and a structural adequacy study of the building on which the installation will be carried out are required. The study must be signed by a qualified civil engineer. 

Photovoltaic stations with a capacity less than or equal to 1 MWp that are installed on plots of land are exempt from environmental permitting, provided they are not located in a Natura 2000 network area or in a coastal location less than 100m from the shoreline boundary, excluding rocky islets. 

Otherwise, the stations are classified as Category B under Ministerial Decision No. ΥΠΕΝ/ΔΙΠΑ/53510/3616 (Government Gazette 3327 B/19.5.2023) and are subject to Standard Environmental Commitments (Π.Π.Δ.). In all cases, approval for small-scale construction works is required to install photovoltaic stations on plots of land. 

For a three-phase supply, the plant connection must be configured as three-phase; that is, it must be connected using a three-phase inverter and a three-phase production metering device (Meter 1), even when installing a plant with a capacity of ≤5 kW. 

As an exception, for three-phase supplies serving a group of consumers in close proximity, such as supplies belonging to the same apartment building, single-phase configurations of production plants may also be accepted, provided that the group’s total capacity is distributed symmetrically across the three phases of the Grid. 

At self-consumer installations using simultaneous netting, installation of a stationary or mobile (i.e. electric vehicle) battery system for storing electrical energy (hereinafter, the storage system) is permitted following an application to the competent network operator. The storage system forms part of the self-consumer’s Internal Electrical Installation, and its installation must comply with the corresponding national and international standards and rules. 

The maximum current of the overall installation may not exceed the maximum charging capacity of the self-consumer’s electricity supply. 

When changing Supplier, the relevant contract is amended and the new supplier takes over. 

The process from submitting an application through to the connection and operation of a photovoltaic station with a capacity greater than 100 kW is summarized in the following steps: 

Step 1: Submit a connection application to the Network Operator. 

Step 2: If the application file is complete and its details are correct, the Operator examines the request and issues a connection offer to the applicant, or notifies them that connection is not possible. The offer describes the connection works and their cost, and is initially valid for a period of two (2) months from the date it is issued. The applicant must submit written acceptance within this period. If the two-month period expires without action, the connection offer automatically expires. 

Under Ministerial Decision ΥΠΕΝ/ ΓΔΕ/84014/7123 (Government Gazette B’ 4333/12.8.2022), applications for photovoltaic stations installed on buildings or other structures, or operated under the responsibility of General Land Reclamation Organizations (G.O.E.B.), Local Land Reclamation Organizations (T.O.E.B.) or the Organization for the Development of Crete S.A. (O.A.K. S.A.), or owned by non-profit Energy Communities, or involving low-voltage self-consumption, are classified in Group C, while other self-consumption photovoltaic stations are classified in Group E. If connection is not possible, the Operator keeps the application pending, provided it receives a relevant request from the applicant. 

Step 3: Accept the connection offer and submit a request for the Connection Agreement to be drawn up. If the Final Connection Offer is accepted, its validity period for photovoltaic stations with a maximum production capacity of up to and including one megawatt (1 MW) for self-consumption with simultaneous and virtual simultaneous netting is set at: 

a) Eighteen (18) months from its issue for stations connected to the Distribution Network or the System, provided that no work is required at HV/MV substations,
 b) Thirty (30) months from its issue for stations connected to the Distribution Network, if construction of a new HV/MV substation or expansion of an HV/MV substation is required. 

For stations with an installed capacity greater than 1 MW, the Final Connection Offer is valid for thirty-six (36) months. 

Step 4: Sign the Connection Agreement and pay the relevant charge at the same time. The Operator then proceeds with construction of the connection works. The responsible Operator completes the connection works within one (1) month of signing the Connection Agreement, provided that no new works are required. Otherwise, the connection works are completed within four (4) months for stations connected to low voltage; within eight (8) months for stations connected to medium or high voltage, provided that no work is required at HV/MV substations; or within eighteen (18) months if construction of a new HV/MV substation or expansion of an HV/MV substation is required. If a third party (representative) submitted the application for the Final Connection Offer, that same third party accepts the Final Connection Offer, signs the Connection Agreement and pays the relevant charge. 

Step 5: Submit an application to enter into a Simultaneous Netting Agreement to the Supplier representing the supply to be used for netting, and to the Aggregator. 

Step 6: Sign the Simultaneous Netting Agreement. 

Step 7: Submit an application to activate the connection. Once construction of the generation station is complete, the applicant declares that it is ready and requests the Operator to activate the station’s connection. 

Step 8: Activate the connection within the validity period of the connection offer. When the connection is activated, the Simultaneous Netting Agreement, which has a term of twenty (20) years, enters into force. 

For smaller stations (“notified” stations, i.e. those with a capacity of up to and including 100 kW), the process is simpler, as DEDDIE does not need to issue a connection terms offer. 

To connect these stations, the applicant informs the Network Operator of their intention to install the station in question by submitting the required supporting documents. 

Within fifteen (15) days of being notified of the applicant’s interest, the Network Operator informs the applicant whether the requested connection has been accepted or rejected. 

Next:
 A. In In the event of acceptance, the Network Operator sends the applicant the Connection Agreement, which specifies the connection cost, the required connection works, the time required to complete them, as well as any other information required to substantiate the need to carry out the specific connection works and their cost. 

The applicant must sign the Connection Agreement within sixty (60) days and pay the corresponding fee for the agreement to take effect. 

The Network Operator completes construction of the connection works:
 a) Within one (1) month of signing the Connection Agreement, provided that no new distribution network works are required, or
 b) Within four (4) months for stations connected to the low-voltage network,
 c) Within eight (8) months for stations connected to the Medium Voltage network, provided that no work is required at HV/MV substations, or
 d) Within eighteen (18) months, if construction of a new HV/MV substation or expansion of an HV/MV substation is required.
 B. In the event of rejection, the responsible Network Operator informs the applicant of the reasons for the rejection. 

Since surplus energy is sold at the wholesale electricity market price during the hours when it is fed into the grid, a reasonable question arises: how can this price be calculated? 

Clearly, this price varies from quarter to quarter, from day to day, and from year to year. The chart below shows two recent examples: a Friday with high energy consumption in the country, and the following Saturday, when lower consumption led to much lower net-billing sale prices. It also shows an estimate of the average sale price over a 20-year period, based on simulations of how wholesale markets in Greece will evolve over the next two decades. 

As of 1.1.2024, an important measure is in effect to support small residential self-consumption systems, with or without a battery. If you are not participating in a subsidy program, you may benefit from tax deductions (tax deductions do not apply if you are already receiving a subsidy through a program). 

According to Law No. 5073/2023, Government Gazette 204A/11.12.2023, expenses incurred to purchase goods and receive services related to the energy, functional, and aesthetic upgrades of buildings that have not already been included in, and will not be included in, a building upgrade program reduce the personal income tax of individuals in equal installments over a period of five (5) years, up to the amount of tax due for each tax year, with a total maximum expenditure limit of sixteen thousand (16.000) euros. The amount of expenditure on the purchase of goods taken into account for the tax reduction may not exceed one third (1/3) of the expenditure on services taken into account for the tax reduction. 

The measure covers photovoltaic self-consumption systems with or without storage. 

The “I Upgrade My Home” Program was created to provide co-financed housing loans to individuals through participating Credit Institutions, with the aim of improving the energy efficiency of their existing homes, in accordance with the Joint Ministerial Decision “Eligibility criteria for the housing loan program for natural persons ‘I Upgrade My Home’, using resources from the Recovery and Resilience Facility, and determination of the procedure for allocating funds to the Hellenic Development Bank S.A. and Credit Institutions” (Government Gazette 6896 B, 16-12-2024).

Benefits: 

The “I Upgrade” program offers you the following benefits:

Interest-free loan
For 75% of the loan amount funded by RRF resources.

100% interest rate subsidy
From the Greek State (the interest rate is not subject to the levy under Law 128/75)

No application fees
You will not incur any application fees.

Get a detailed offer now and Upgrade Your Home