Frequently Asked Questions

An index is generally a key figure that reflects the prices on a market or market segment with an average value. Derived from the Latin word "index", meaning "mark, index finger, directory", the function of a price index is clear: to characterise market developments through a single value without having to consider the individual values included in it.

Energy products such as gas and electricity are traded on wholesale markets, so the Austrian Electricity Price Index (ÖSPI) and the Austrian Gas Price Index (ÖGPI) represent the respective price development of goods sold by wholesalers. The calculation is based on wholesale sales prices excluding VAT. These are the prices that wholesalers realise when reselling goods to non-consumers, such as energy supply companies.

The Austrian Energy Agency calculates the monthly indices as an independent service. With the indices, the Austrian Energy Agency aims to contribute to the transparency of energy prices.

The Austrian Energy Agency calculates the index on the basis of existing prices on the exchange; it does not set any prices itself. The index reflects realised prices on the exchange, it does not set prices itself. The method is standardised and documented, so the Energy Agency has no degrees of freedom in calculating the indices.

Any adjustments to the indices are based on exogenous factors. For example, the ÖSPI was changed as part of the price zone separation in 2018, as the products on which the ÖSPI is based were no longer available on the exchange due to the separation of the German and Austrian bidding zones. All such changes are announced on the AEA website.

Electricity and gas are traded on the energy exchanges. The prices for electricity and gas are formed according to the principle of supply and demand. This leads to price fluctuations that cannot be passed on to end customers on a daily basis.* The price indices are a way of averaging these fluctuations over a certain period of time and can therefore be used as a basis for charging end customers.

In addition to the price mean (average), another feature of the indices is what is known as smoothing: this means that price increases and price reductions are cushioned. Smoothing is achieved by calculating the mean value over a previously defined period, the trading results of which are included in the calculation. In the case of the ÖSPI, this trading period is nine months in the past. For the ÖGPI, the trading period is three months in the past.

This leads to two effects: A) The index is smoothed. Fluctuations within the calculation period are equalised and rates of change between the individual index values are reduced. The index thus becomes more stable. B) The index is delayed. By averaging, trading results that lie in the past but still within the calculation horizon are still used to calculate the mean value. Accordingly, trading results from the past have an effect on the index and changes in the price level are only gradually reflected in the index. When market prices fall, the index falls more slowly than the market price. If prices rise, the index also rises more slowly than the market price. The index therefore has a retroactive effect. This has the advantage for end customers that price developments become more predictable and this creates room for manoeuvre for medium-term measures, for example by comparing offers from energy supply companies or taking efficiency measures.

* In the case of contracts that are directly linked to the exchange price, price fluctuations are passed on to end customers on a daily basis.

In principle, the calculation method works the same for both indices. What is relevant in each case is an observation period for the trading results and the selection of the corresponding products for which trading prices are used. Once the trading results for the corresponding products have been selected from the trading period, the mean value is calculated (simplified). The methods of the indices differ on the one hand in the selection of the products analysed and on the other hand in the selected observation period. In addition, there are certain special features of the calculation that arise from the requirements of the ongoing publication process.

A detailed description of the methodology can be found here for the ÖSPI and here for the ÖGPI.

Both indices (ÖSPI and ÖGPI) are published ex ante, i.e. in advance. The indices therefore "look" one month into the future. This ensures that both suppliers and customers know the prices at which they will purchase or supply electricity or gas in the coming month. However, the different calculation methods result in different publication dates. The ÖSPI is usually published at the beginning of the previous month. The ÖGPI is published on the 27th of the previous month at the latest.

The ÖSPI has been published by the Austrian Energy Agency since 2006. The calculation method chosen back then is still valid today. The new edition of the ÖGPI has been published since 2019. The calculation method of the ÖGPI is based on an analysis of possible adequate methods.

The existing gas price indices currently include the ÖGPI (calculated using the 2018 methodology) and, since December 2023, the ÖGPIx (ÖGPI_Year, ÖGPI_Season, ÖGPI_Quarter and ÖGPI_Month)_.

The ÖSPI and ÖGPI have different calculation periods: for the ÖSPI, the trading period is nine months in the past, for the ÖGPI it is three months. The OSPI therefore requires nine months for a price development ("price event") to fall out of the index. The ÖGPI only takes three months. Energy suppliers often use the "ÖGPI 12 MA" for price adjustments, i.e. the average value of the ÖGPI over the last 12 months. This means that it takes 15 months for a price event to disappear completely from the index.

Volatility is an indicator of the rates of change. Indices that look at a long trading period smooth out the development more and are therefore less volatile. Indices based on a short trading period are more volatile.

The ÖGPI 12-month MA represents the average value of the ÖGPI over the last 12 months. (MA stands for moving average). Some energy suppliers refer to the average value of the ÖGPI over the last twelve months instead of the monthly ÖGPI. The ÖGPI 12 MA therefore also helps customers whose contract is indexed to this value to obtain the index values from an independent source without having to make their own calculations.

The Austrian Electricity Price Index (ÖSPI) shows purchase prices for electricity on the exchange, in the coming month compared to the base period (= starting point), compared to the previous month and compared to the previous year. The Austrian Energy Agency calculates the index on the basis of existing prices on the exchange; it does not set any prices itself. The index therefore reflects the prices on the exchange, it does not set prices itself.

Many energy supply companies purchase their products such as electricity and gas on the wholesale market, often several months or even years in advance. This means that the price valid at the time of purchase often only reaches the end consumer with some delay - this applies to both price increases and price reductions. However, contractual factors are also important when passing on prices: For customers with fixed-price tariffs, price changes usually arrive with a time lag, while for customers with floater tariffs, price changes are usually noticeable immediately.

The ÖSPI only reflects the pure energy component. The total price of electricity for the end consumer is divided into the energy component (just under 55%) and grid fees, taxes and levies (45%). A rise or fall in the OSPI can therefore only be expected to result in a correspondingly smaller increase or decrease in the total electricity price. Other factors that influence the electricity price - such as the procurement strategies of energy suppliers - are not taken into account in the OSPI. The OSPI cannot be used to determine how energy suppliers actually set their prices for end customers.

Contracts that are concluded for a longer period of time often contain price adjustment clauses. The price adjustment is usually made by agreeing or specifying a reference value in the contract or in the provider's General Terms and Conditions (GTC). This reference value is a point of reference that makes it possible to determine how the agreed price behaves in relation to market developments. Parties can agree different values as a reference or point of reference.

There are products, contracts and general terms and conditions of delivery that use or have used the OSPI, as well as other indices, as the basis for these adjustment clauses.

There are currently a number of court cases concerning price increases in the electricity sector.

Whether and in what form indices are used is the decision of the respective supplier. In addition, many suppliers also offer different products, such as those with or without a price guarantee, or more dynamic products such as so-called "floaters". With these products, the price changes - usually on a monthly basis - depending on an index. This can be the ÖSPI or ÖGPI, for example.

If you have any questions about your specific contract or product, please contact your energy supplier or the E-Control hotline.

Whether and in what form indices are applied is the decision of the respective supplier. There are currently a number of proceedings on the subject of price increases in the electricity sector.

For all questions relating to your electricity and energy bill, please contact your energy supplier or E-Control as the competent authority:

The E-Control website

The experts at the Austrian Energy Agency carry out price and market analyses for business customers and provide advice to administrations, companies, organisations and interest groups such as employees and consumers.

For copyright reasons, the data used to calculate the ÖSPI is not published. The ÖSPI is calculated on the basis of quotations on the EEX (European Energy Exchange) in Leipzig. Specifically, the Austrian Energy Agency uses the fee-based EEX Group DataSource product "EEX Power Futures (all Market Areas)" and has acquired the corresponding limited licence rights.

The methodology of the calculations and explanations of the ÖSPI can be found here.

For copyright reasons, the data used to calculate the ÖGPI is not published. The ÖGPI is calculated on the basis of quotations on the EEX (European Energy Exchange) in Leipzig. Specifically, the Austrian Energy Agency uses the fee-based EEX Group DataSource product "EEX Power Futures (all Market Areas)" and has acquired the corresponding limited licence rights.

The methodology of the calculations and explanations of the ÖGPI can be found here.

While the ÖGPI and ÖSPI reflect prices on the stock exchange, the Energy Price Index (EPI) shows the prices of energy sources for households in Austria. The EPI is a weighted index, which means that the price development of each energy source is taken into account to varying degrees according to its importance for the average household. In contrast to the ÖSPI and ÖGPI, the EPI is published retrospectively and is primarily used for information purposes.

The weighting of the EPI indicates the share of each individual energy source in the overall index. In the current 2024 weighting key, diesel (27.7%) and electricity (22.8%) have the largest share of the EPI, followed by premium petrol (19.2%), gas (10.7%), heating oil (7.7%), district heating (6.6%) and solid fuels biomass (5.3%). It should be noted that the average household does not use all energy sources equally. Accordingly, the development of energy expenditure varies from case to case. A considerable 65.4% of the PPI is directly attributable to fossil fuels such as natural gas and petroleum products, which have to be imported almost in their entirety. In addition, substantial shares of electricity and district heating are also provided from these energy sources. The majority of household energy expenditure is therefore dependent on the price movements of fossil fuels. The weightings are adjusted once a year in January.

For copyright reasons, the data from which the PPI is calculated is not published. The EPI is calculated on the basis of data from Statistics Austria (basket of goods for private households). Specifically, the Austrian Energy Agency obtains the fee-based basket of goods for private households and has acquired the corresponding limited licence rights.

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In the wake of the energy crisis, the Austrian Energy Agency has realised that a single electricity or gas price index cannot adequately reflect the new dynamics on the electricity and gas market and also does not do justice to the range of electricity and gas supply contracts. In order to do justice to this development, the Austrian Energy Agency has expanded the two existing indices to include a series of new indices.

The basic concept of the Indices 2.0 is based on providing a fair and tradable reference value for the Austrian electricity and gas market. Since December 2023, the Austrian Energy Agency has published twelve electricity and four gas price index variants (ÖSPIx and ÖGPIx respectively) with different characteristics in order to cater to the different risk preferences of end customers.

Yes, ÖSPI and ÖGPI calculated according to 2018/2019 methodology remain unchanged. The current value will be published monthly as usual. The new indices are a supplement to the existing indices and do not replace them.

Indices 2.0 will be published from December 2023 onwards. Historical values will be published back to January 2020. The indices will be published on the 23rd of each month (or on the next possible working day after the 22nd of the month) before the indices come into effect.

The fundamental concept of Indices 2.0 is based on providing a fair and tradable reference value for the Austrian electricity and gas market. Since December 2023, the Austrian Energy Agency has been publishing twelve electricity and four gas price index variants (ÖSPIx and ÖGPIx respectively) with different characteristics in order to meet the different risk preferences of end customers.

The range of indices allows the range of electricity and gas supply contracts to be better reflected. This applies in particular to the frequency of price adjustments, which is stipulated in the contracts.

The indices 2.0 are calculated on the basis of a standardised, documented and published calculation method (METHODOLOGY) and are available to all. Included data can be obtained from the European Energy Exchange (EEX).

Whether and in what form indices are used is the decision of the respective supplier. With a greater variety of electricity and gas price indices, the Austrian Energy Agency offers the opportunity to better fulfil different risk preferences. This applies in particular to the frequency of price adjustments, which is stipulated in the contracts. In this way, the Austrian Energy Agency aims to contribute to greater transparency.

ÖSPI and ÖGPI will continue to operate as usual. Current contracts can therefore still refer to ÖSPI and ÖGPI.

Yes. Whether and which indices are used in new contracts is the decision of the respective supplier.

You can find detailed information on the calculation methodology for the electricity price indices 2.0 and the gas price indices 2.0 here.

AEA is not currently planning to publish any further indices.

As a transparent information service, the Indices 2.0 are available to the general public free of charge.

Commercial use of the Indices 2.0 (the new indices) will be subject to a fee from 2024. If you are interested in commercial use, please send a message to preise@energyagency.at

The existing electricity price indices currently include the ÖSPI (calculated using the 2008 methodology) and, since December 2023, the ÖSPIx (ÖSPI_Year, ÖSPI_Quarter and ÖSPI_Month)_.

ÖSPIx stands for "Austrian electricity price indices from the Indices 2.0 group".

In order to do justice to the different risk preferences, the Austrian Energy Agency produces three index types with different time horizons: monthly, quarterly and annual (ÖSPI_Year, ÖSPI_Quarter and ÖSPI_Month). These index types are further subdivided into total, base, peak and off-peak indices.

This means that a total of twelve new electricity price indices are now available. The different time horizons and sub-variants reflect the energy suppliers' different procurement strategies. This pluralisation of the indices allows the dynamics on the energy markets to be presented better and more transparently.

The existing gas price indices currently include the ÖGPI (calculated using the 2019 methodology) and, since December 2023, the ÖGPIx (ÖGPI_Year, ÖGPI_Season, ÖGPI_Quarter and ÖGPI_Month)_.

ÖGPIx stands for "Austrian gas price indices from the Indices 2.0 group".

In order to cater for different risk preferences, the Austrian Energy Agency is creating four index types with different time horizons: monthly, quarterly, seasonal and annual (ÖGPI_Year, ÖGPI_Quarter, ÖGPI_Season and ÖGPI_Month).

This means that a total of four new gas price indices are now available. The different time horizons reflect the energy suppliers' different procurement strategies. This pluralisation of the indices allows the dynamics on the energy markets to be presented better and more transparently.

The ÖSPI_Month represents the short-term index within the electricity price indices. It is based on the future products for the coming month (product designations: Austria Base Month/ATBM and Austria Peak Month/ATPM). The ÖSPI_Month indices are suitable for contracts with monthly price adjustments (floaters). The ÖSPI_Month indices react quickly to price changes on the wholesale markets. They are more volatile than indices with longer observation periods.

The ÖSPI_Quarter represents the medium-term index in the group of electricity price indices. It is based on the future products for the coming quarter (product designations: Austria Base Quarter/ATBQ and Austria Peak Quarter/ATPQ). The ÖSPI_Quarter is suitable for contracts with a quarterly price adjustment. The OSPI_Quarteris more stable than the OSPI_Month. It reacts more slowly and with a slight delay to price changes on the wholesale markets.

The ÖSPI­_Year represents the long-term index within the electricity price indices. It is based on the future products for the next four quarters (product designations:Austria Base Quarter/ATBQ: first to fourth front quarter; Austria Peak Quarter/ATPQ: first to fourth front quarter). The ÖSPI_Year is suitable for contracts with an annual price adjustment clause. The OSPI_Year reacts to price changes on the wholesale markets in a very muted and delayed manner.

The ÖGPI_Month represents the short-term index within the gas price indices. It is based on the futures products for the coming month (product name: G8BM/ Gas Marktgebiet Ost Base Monat). The ÖGPI_Month index is suitable for contracts with monthly price adjustments (floaters). The ÖGPI_Month index reacts quickly to price changes on the wholesale markets. It is more volatile than indices with longer observation periods.

The ÖGPI_Quarter is one of the medium-term indices in the group of gas price indices. It is based on the futures products for the coming quarter (product name: G8BQ/ Gas Marktgebiet Ost Base Quartal). The ÖGPI_Quarterly is suitable for contracts with a quarterly price adjustment. The ÖGPI_Quarterly is more stable than the ÖGPI_Monthly. It reacts more slowly and with a slight delay to price changes on the wholesale markets.

The ÖGPI_Season is one of the medium-term indices in the group of gas price indices. For the winter and heating season, it is based on the future products for the six months from 1 October to 31 March inclusive. For the summer season, the ÖGPI_Saison is based on the futures products for the six months from 1 April to 30 September inclusive (product name: G8BS/ Gas Marktgebiet Ost Base Saison).

The OGPI_Saison is suitable for contracts with a half-yearly price adjustment. The OGPI_Saison reacts to price changes on the wholesale markets in a muted and delayed manner.

The ÖGPI­_Year represents the long-term index within the gas price indices. It is based on the futures products for the next four quarters (product name: G8BQ / Gas Marktgebiet Ost Base Quartal; first to fourth front quarter, i.e. the next twelve months). The OGPI_Year is suitable for contracts with an annual price adjustment clause. The PUCI_Year reacts to price changes on the wholesale markets in a very muted and delayed manner.

The electricity price indices 2.0 are further subdivided into total, base, peak and off-peak indices. Base refers to a continuous supply (24 hours) with constant output (base load). In contrast, peak refers to delivery with constant power at peak times (peak load), i.e. from Monday to Friday from 8:00 am to 8:00 pm. Off-peak is the counterpart to peak and refers to the consumption that occurs between 8 p.m. and 8 a.m. (Monday to Friday) and all day at the weekend. This means that a total of twelve new electricity price indices are now available.