General Frequently Asked Questions

Does WATT+VOLT supply electricity all over Greece?

WATT + VOLT supplies electricity to households and businesses at the following locations:

Greek Interconnected Grid

  • Mainland Greece
  • Islands: Agistri, Aegina, Alonissos, Ammouliani, Andros, Antipaxos, Antiparos, Delos, Dokos, Elafonisos, Ereikoussa, Evia, Zakynthos, Irakleia, Thassos, Ithaca, Ios, Kalamos, Kastos, Kea, Corfu, Kefalonia, Koufonisi, Kythira, Lefkada, Mathraki, Meganisi, Mykonos, Naxos, Othoni, Paxi, Paros, Poros, Rhenia, Salamis, Samothrace, Sikinos, Skiathos, Skopelos, Skorpios, Spetses, Spetsopoula, Stamphani, Syros, Schoinousa, Tinos, Hydra, Folegandros.

Athens International Airport Grid

Independent Electrical Systems
Gyali, Thimena, Kalymnos, Kasos, Karpathos, Kimolos, Crete, Chios, Kos, Lipsi, Lemnos, Leros, Lesvos, Megalonisi, Milos, Nisyros, Oinousses, Rhodes, Telendos, Thira, Thirasia, Tilos, Halki, Psara, Pserimos, Samos, Skyros, Symi, Fournoi.

What is RAE?

The Regulatory Authority for Energy (RAE), which was set up in July 2000, is an independent administrative authority assigned with the task of monitoring the energy market, as it develops – so univocally in the Greek market – and its operation and development compared to foreign energy markets, and in particular the ones with which it is interconnected. RAE was established by L. 2773/1999, in the framework of harmonization with the directives 2003/54/EC and 2003/55/EC for electricity and natural gas. By the above law, its internal regulation (P.D. 139/01), and mainly by the amendments of L. 2773/1999 that followed, RAE has acquired the competency of monitoring and controlling all sectors of the energy market, namely, electricity generation from conventional fuels, renewable energy sources and natural gas. Furthermore, RAE has specific responsibilities regarding the oil products market. (Source: RAE website).

What is the role of HOEM?

HOEM (Lagie) is the Hellenic Operator of Energy Market. WATT + VOLT purchases wholesale energy from the energy pool in order to subsequently provide it to its customers. HOEM charges are calculated based on the System Marginal Price.
HOEM is a limited company, 100% state-owned.

What is the role of IPTO?

IPTO (ADMIE) is the Independent Power Transmission Operator. IPTO performs the duties of System operation maintenance and development so as to ensure Greece’s electricity supply in a safe, efficient and reliable manner. IPTO also undertakes the clearing of divergences in the wholesale market.
IPTO is a limited company 100% owned by PPC.

When was the retail electricity market liberated in Greece?

In accordance with the European Legislation, the liberization og the Greek Electricity Market was legislated on December 22nd 1999. By 2001, the first private companies had already entered the market and began their operations enabling the Greek consumers for the first time to choose freely between a number of electricity providers.

How can I be informed about topics concerning HEDNO (metering, Social Residential Tariff etc.)?

You can contact the Customer Information Call Center of HEDNO at 11500. Calls are at local rates (daily from 07:00 p.m. to 19:00 a.m.).

HEDNO’s Customer Information Call Center will give you information about all topics that fall within the responsibilities of HEDNO (Hellenic Electricity Distribution Network Operator), such as electricity connections to the Network, changes in existing supply connections, metering, Social Residential Tariff, initial electricity supply, increase or decrease of power and other technical issues.

In addition, you can find information about the procedure and the necessary documents for executing your various requests to the local services of HEDNO.

You can alternatively visit the website at to find any information you might require.

What is the Solemn Declaration by the Installation Electrician (SDIE) and when is it required?

The Solemn Declaration by the Installation Electrician (SDIE) aims at the observation of the regulations and the legislation concerning electrical installations, in order for such installations to be manufactured and maintained in a truly safe and functional condition for their owners or users, and to prevent accidents (electrocution, fires due to electrical causes) that occur due to electricity.

The Solemn Declaration by the Installation Electrician has recently been changed and modified according to Resolution no. F.50/503/163 (Official Gazette of the Hellenic Republic 884 B 15.05.2011), and the full application of the new Solemn Declaration has been effective since 01.11.2011. This Declaration is required by law, and without it there can be no supply of electricity to either a new or an old installation whose electrical supply has been cut off because it needs to be re-inspected.

This Declaration is drafted by the electrician, who declares the following:

  • The installation described in the contents is constructed pursuant to the legislation in force regarding electrical installations.
  • The installation has been inspected by the electrician signing the declaration, also according to the legislation in force, in order to confirm that it is safe.
  • An existing installation has been re-inspected; also, the declaration confirms that it is safe.
  • The installation is delivered by the electrician to its owner or user and provides him or her with the statutory safety against electrocution, fire and malfunction.

This Declaration is necessary because:

– It helps in distinguishing among owners, users and electricians who fail to observe the law regarding electrical installations, and it also forces them to take responsibility.

– It helps in assigning responsibilities in the event of accidents (electrocutions or fires due to electrical causes).

Is there a requirement for the Solemn Declaration by the Installation Electrician to be renewed?

There is a legal obligation concerning its renewal. According to Ministerial Resolution no.F.7.5/1816/88 on 27/02/2004, published in FEK no. 470 on 05/03/2004, this Solemn Declaration is mandatory for purposes of initial inspection and re-inspection.

The initial inspection must be performed prior to the initial supply of electricity to an installation, or after any extensive modifications. Re-inspections must be performed in intervals, which differ according to the type of installation, and these intervals are:

  • For residences and similar spaces, at least every 14 years.
  • For indoor occupational spaces not containing flammable materials, at least every 7 years.
  • For indoor occupational spaces containing flammable materials, at least every 2 years.
  • For entertainment venues and public gathering places, at least once a year.
  • For outdoor occupational installations (swimming pools, marinas, camping spaces) at least once every year, and in cases of interruption of electricity supply, prior to reconnection.
  • For all the above categories, re-inspection is mandatory in cases of change in use of the installation.
  • For all the above categories, re-inspection is mandatory if the installation has been damaged due to natural disasters (floods, earthquakes).
  • After serious accidents or events (fire, electrocution).

Click here to download the new form of Solemn Declaration of Installation Electrician (SDIE).