Frequently Asked Questions (FAQ)

• General Information
• Information for Producers and Suppliers
• Working with the XMtrade®/ZPE System
• Information about Guarantees of Origin Auctions
• Explanation of Abbreviations

General Information

General Information Expand allCollapse all

What are Guarantees of Origin (GOs)?

A Guarantee of Origin is a certificate proving that the corresponding energy was produced from renewable energy sources (RES), nuclear sources or by high-efficiency combined heat and power generation (HEC) and was either consumed on-site at the place of generation, injected to the electricity system or heat/cooling distribution networks.

The Guarantee of Origin entitles the energy supplier to declare the respective amount of energy delivered to the final consumer as electricity produced from renewable sources, nuclear sources, or HEC.

What is the purpose of Guarantees of Origin?

The purpose of Guarantees of Origin is to provide proof to the final consumer that a certain amount of energy was produced from RES, nuclear sources, or HEC. At the same time, they serve as a basis for calculating the electricity energy mix.

Who is eligible to apply for the issuance of Guarantees of Origin?

In Slovakia, market participants in the role of energy producers who do not receive support in the form of a Feed-In Tariff (FIT), Feed-In Premium (FIP) or investment support may apply for the issuance of Guarantees of Origin.

Who can request access to the information system for Guarantees of Origin?

Producers and suppliers of electricity or heating/cooling.

What is the life cycle of a GO?

A Guarantee of Origin is issued for an amount of energy corresponding to 1 MWh and is valid for 12 months from the production date of the corresponding energy. Within this period, it can be handled according to Act No. 251/2021 Coll., i.e. it can be traded, transferred between account holders, and cancelled for the end consumers.

What does the application of a GO mean?

According to Act No. 251/2012 Coll., the application of a Guarantee of Origin means it is a cancellation of the GO to prove the share of energy in the total amount of energy delivered to the end consumer.

What form do GOs have?

Guarantees of Origin are issued exclusively in electronic form and are recorded in OKTE’s information systems or on the international AIB HUB platform.

Why is OKTE a member of AIB?

OKTE, a.s. became a member of the Association of Issuing Bodies (AIB) on 27th September 2019 at the AIB General Assembly in Reykjavik. AIB brings together entities authorized to issue and manage Guarantees of Origin and enables international transfers of energy certificates through AIB HUB platform. AIB members include energy regulatory authorities, transmission system operators, and market operators designated by governments to issue Guarantees of Origin under EU directives on RES (2009/28/EC) and cogeneration (2012/27/EU).

What are the EECS Rules?

The harmonized rules of the European Energy Certificate System (EECS) define the standard for the issuance, registration, transfer, and use of EECS certificates, as well as related processes. EECS rules require members to implement these standards into their national schemes as a condition of participation in the EECS. Currently, EECS enables trading between certification schemes in 30 European countries.

Information for Producers and Suppliers

Information for Producers and Suppliers Expand allCollapse all

What is required to obtain GOs?

• Conclude a Data Provision Agreement
• Conclude an Agreement on Activities Related to the Issuance and Use of Guarantees of Origin
• Submit valid documents from regulatory authority [ÚRSO] (Supplier – License for electricity business; Producer – Confirmation of electricity origin, Confirmation of production in a local source, or Confirmation of fulfilment of the notification obligation)
• Submit a single-line diagram of the production device (applies only to the Producer)
• Pay the annual fixed fee for maintaining the account in the system
• Submit an application to create an account in the XMtrade®/ZPE system

What are the fees associated with the GO scheme?

OKTE, a.s. charges a tariff of €0.008/MWh for the issuance or the transfer of Guarantees of Origin. The price list can be found here.

Which information systems are used in the GO scheme?

The ISZPE system is used to record Guarantees of Origin. It handles issuance, transfers between account holders, and cancellation to final consumers. Necessary data regarding individual production devices and the corresponding measured values are automatically transferred from the ISOM system (Information System for the Measurements ).

What types of Guarantees of Origin does OKTE, a.s. issue?

OKTE, a.s. issues Guarantees of Origin for electricity (ZPEe) and for heating or cooling (ZPEt). GOs can be obtained separately for electricity delivered to the grid (Supply), for delivered heat/cooling in the CHS (Central Heating Supply) system, or for electricity consumed on-site at the production device (Onsite consumption).

For what quantity of energy can GOs be issued?

In accordance with EECS rules, GOs are issued only for whole megawatt-hours produced during the given period. Residual amounts are currently not considered.

Can different types of GOs be requested simultaneously?

No, since these are separate products that differ in several aspects, each type of Guarantee of Origin must be applied for separately.

When can an issuance of GOs be requested?

GOs must always be requested in the month following the month of the respective energy production. The quantities available for GO issuance depend on receiving the necessary data from energy producers and distribution system operators, as well as for evaluating the support in the form of Feed-in tariff and Feed-in premium. Typically, we start issuing GOs between the 13th and 17th calendar day of the month, always for the production of the previous month.

For what period can GOs be obtained?

OKTE, a.s. is bound by EECS certificate rules (Rule C3.4.4, paragraph a) which state that GOs can only be issued for periods during which the relevant production device was registered in the issuer’s information system (ISZPE).

What can be done with Guarantees of Origin?

GOs issued for energy delivered to the grid can be traded, i.e. transferred to other account holders, or cancelled for the end consumers. In the case of GOs issued for energy consumed on-site at the production device, they are automatically cancelled up on issuing.

Is the electric energy covered by cancelled GOs exempt from excise tax?

OKTE, a.s. is not the competent authority to interpret Act No. 609/2007 Coll. on excise duty on electricity, coal, and natural gas. For proving the cancellation of GOs, OKTE, a.s. issues a Cancellation statement, which can be generated in OKTE’s information systems in PDF format in case of cancelled GOs.

Working with the XMtrade®/ZPE System

Working with the XMtrade®/ZPE System Expand allCollapse all

Where can I find details on how to use the system?

The user guide for the XMtrade®/ZPE system can be found at this link, or by clicking on the “i” symbol within the system.

How does the login process for the XMtrade®/ZPE system work?

The access to the information systems of OKTE, a.s. is based on the Single Sign-On principle. Login credentials are valid across platforms (excluding EDC) and you can smoothly switch between them using the nine-square icon in the top-left corner of the system menu.

What do I need to log into the system?

A login name (typically created in the format “entity_surname”) and a password (automatically generated by the system). Authentication can be done via SMS or a digital security certificate (mandatory for the producers that operate photovoltaic sources with installed capacity above 100 kW and for other types of production sources above 1 MW). The suppliers get access to the ISZPE via the digital security certificate.

Do production devices require registration in the system?

Yes, producers are required to register each production device within the XMtrade®/ZPE system. All the necessary data is automatically uploaded from the ISOM system, so registration takes only a few minutes. The registration is valid for 5 years.

What date should I enter in the “Registration from” field?

This date does not refer to the commissioning of the production device or the issuance of related documents by RONI (ÚRSO); it is only the date of registration within the GO scheme in the ISZPE. You should enter the current month. Production devices are usually registered as of the 1st day of the month so that producers can request GOs for the entire month within their first registration.

What needs to be filled out when requesting GO issuance?

During the issuance process, measured data is automatically transferred from the ISOM system. You must select the commodity (Electricity  or Heat), then the specific production device, whether it is a “Source” or “Technology” (technology applies to HEC), and the production month (the previous month is filled in automatically). You must also choose whether the GOs are for electricity injected to the grid (Supply) or consumed onsite (Own consumption). The producer must enter the amount of GOs being requested. It is standard to request the maximum available amount.

Does ISPZPE offer the possibility of automating the process of issuing GOs?

Yes, within ISPZPE (menu Business records / Plants overview and setting) the producer can set the option of automatically submitting requests for issuing guarantees of origin of energy individually for registered production facilities. After starting the issuance of guarantees for the previous month, the system automatically creates requests for issuing guarantees for the maximum available amount of energy according to the measured data from the ISOM system.

Where can I find issued GOs?

GOs issued for “Own consumption” are automatically applied and therefore marked as “Cancelled,” meaning they cannot be traded or otherwise handled. GOs issued for “Supply” remain “Active.” Individual GOs can be found in their relevant menus under the Guarantees of Origin section.

How does the transfer of GOs work?

In the “Active Guarantees of Origin” tab, select the GOs you wish to transfer, then click the narrow arrow in the “Operations” column labelled “Transfer certificate,” fill in the account holder – recipient – and the amount selected for that specific transfer. GOs can be split into individual megawatt-hours.

What steps are required to apply GOs?

In the “Active certificates account” tab and “Operations” column, click on the round icon with an arrow labelled “Cancel certificate” and choose whether the consumer is existing or new. For an existing consumer, you can select them from the list or upload them via an .xlsx file containing the appropriate EIC codes (used mainly for groups of consumers). For a new consumer, you must enter the consumer type (Individual, Legal Entity, Group of Consumers, Production device) along with identification details. You also need to specify the period to which the given GOs are being cancelled.

Where can I find the confirmation of cancelled GOs?

The confirmation must first be generated in the “Business records” section under the “Consumers” menu. After selecting a specific consumer, click “View record” in the “Operations” column, navigate to the “Cancelled certificates” tab, and select the specific GOs (symbols ! or ✓ indicate whether a Cancellation statement has already been generated). After selecting the GOs, the “Generate cancellation statement” button will be activated. The confirmation will then be saved under the “Cancellation statements” tab, where it can be downloaded in a bilingual (Slovak/English) PDF format.

What should I do if the system shows zero values when requesting for issuance?

First, check the date when the request was submitted. Since the issuance of GOs is tied to the evaluation of support, data typically becomes available in the second half of the month after data has been transferred between systems. It is also important to verify the accuracy of measured data and the date it was entered into the ISOM system. If the entry occurred later than the deadlines specified in the Market Rules, the data may not have been transferred. The registration date of the production device in the GO system is also critical. According to the EECS rules (Rule C3.4.4, paragraph a), OKTE, a.s. can only issue Guarantees of Origin for the period during which the production device was registered in the issuer’s database. If none of these reasons apply to the zero values, please contact us at zpe@okte.sk.

Information about Guarantees of Origin Auctions

Information about Guarantees of Origin Auctions Expand allCollapse all

How do auctions of energy guarantees of origin work?

OKTE, a.s., as the organizer of the short-term electricity market, conducts auctions of guarantees of origin (GO) for electricity from renewable energy sources and guarantees of origin for electricity produced by high-efficiency cogeneration. These are issued in accordance with Act No. 309/2009 Coll. for production devices supported by investment aid and devices receiving operational support in the form of a Feed-In Tariff or Feed-In Premium. Producers and suppliers of energy may also offer guarantees of origin in auctions, with OKTE, a.s. acting as an intermediary within the trading mechanism.

At what intervals are GO auctions organized?

Auctions of guarantees of origin are typically organized at least once every three months; if necessary, they may be held monthly.

Who can participate in a guarantees of origin auction?

Any Account Holder in the GO information system may participate in the auction. Access to the information system requires the conclusion of an Agreement on activities related to the issuance and use of guarantees of origin and submission of an Application for account creation/change.

Does OKTE charge fees for participation in GO auctions?

No, participation in auctions is free of charge. Auction participants only pay the standard fee for the transfer of guarantees of origin (0,008 €/MWh) that they successfully acquire based on matched orders. This fee is invoiced after the end of the month.

What information is published when an auction is announced?

The auction announcement includes the auction date, opening and closing time for order submission (typically 13:00), auction evaluation time (typically 15:00), and information on national guarantees of origin divided by source type and remaining validity, including the starting price. It also includes information on all categories of guarantees of origin traded in the auction.

Which products can be traded in GO auctions?

OKTE, a.s. specifies for each auction which guarantees of origin will be tradable. In total, 13 source-type categories and 4 validity categories are supported.

Supported source categories:

• RES – Solar
• RES – Hydro and marine
• RES – Biomass
• RES – Wind
• RES – Geothermal
• RES – Unspecified and other
• Nuclear – Nuclear fuel
• Fossil – Hard coal
• Fossil – Lignite
• Fossil – Peat
• Fossil – Oil
• Fossil – Natural gas
• Fossil – Unspecified and other

Supported validity categories:

• 0 – 3 months
• 3 – 6 months
• 6 – 9 months
• 9 – 12 months

What types of orders can be submitted?

Orders are divided by direction into Sell and Buy, and by type into Simple and Variable. Sell orders can only be of the Simple type and contain guarantees of origin from one source type and one validity category. In addition to the allocated quantity, the participant specifies the offered price.

For Buy orders, the Variable type can also be used. It may include two or more combinations of source type and validity, each with its own offered price. The participant can manually set the priority of settlement for individual combinations or allow the system to automatically sort them based on the offered prices.

How many guarantees of origin can be included in an order?

The quantity of guarantees of origin within a single order is not limited. In the case of selling, the limit is the number of guarantees available that the Account Holder can allocate for sale in the auction.

How is the price entered in orders?

For each category, the participant enters the offered price per megawatt-hour (MWh), with a supported range from 0,01 to 999,99 EUR/MWh. For categories containing national guarantees of origin, the starting price is also the minimum price.

Is VAT considered when creating orders?

The offered price in an order is entered excluding VAT. The dynamically displayed financial deposit is calculated based on the total value of each submitted order, with VAT added accordingly.

When can orders be submitted to an auction?

Order submission opens on the day the auction is announced and continues until the closing time on the auction day (typically 13:00).

Can submitted orders be modified?

Yes. Orders can be modified after submission until the order submission deadline on the auction day. The order direction (Buy/Sell) and type (Simple/Variable) cannot be changed, but the offered guarantees and price can be adjusted. The system records the version of each order.

How many buy and sell orders can be submitted?

The number of orders is not limited. For selling, the limit is the number of available guarantees allocated for sale. For buying, the limit is the amount of the financial deposit (FD). The system dynamically evaluates the remaining FD, checking it with each submitted order.

When must the deposit for an upcoming auction be paid?

Deposit submission opens on the day the auction is announced. The deposit must be paid to a designated account no later than 2 working days before the auction.

What happens to a deposit paid after the deadline?

A deposit paid after the deadline will not be considered in the auction and will be returned to the participant’s bank account.

How are unused deposits settled?

Any unused portion of the deposit will be returned to the participant’s bank account after the auction evaluation. If the participant was not successful, the full deposit is returned.

How are prices formed in auctions?

Guarantees of origin auctions operate on a “pay-as-clear” principle with a single marginal price for each category. The algorithm aims to maximize social welfare for each category. The resulting marginal price is determined by the lowest price of a partially or fully matched buy order.

When are acquired guarantees of origin credited to the account?

Guarantees acquired in the auction are credited to the account after the auction is closed and evaluated, typically after 15:00 on the auction day.

Is it possible to automatically offer guarantees of origin in auctions?

Yes. Slovak energy producers can set their production devices so that guarantees of origin issued for their production are automatically placed for sale in the next auction. They define their minimum price.

Explanation of Abbreviations

Explanation of Abbreviations