Floater or fixed price: Which electricity tariff suits the heat pump?

With a heat pump, you buy significantly more electricity than before, and most of it falls in the heating season. This raises a question: Do I choose a tariff whose price changes every month, or do I commit to a fixed price? There is no one-size-fits-all answer. It depends on how much fluctuation you can and want to afford. However, with a few clear criteria, the decision is easy to make.

How the models differ

With a floater, the energy price is linked to an index via a formula, for example the Österreichischer Strompreisindex ÖSPI (Austrian Electricity Price Index). According to E-Control, it is automatically reset at fixed intervals, such as monthly or quarterly. If the wholesale price falls, you pay less; if it rises, you pay more. You cannot object to such an adjustment. In return, the provider is not allowed to tie you to a minimum contract term with a floater. Some floaters have a cap, i.e. an upper limit above which the price cannot rise.

Spot tariffs go one step further. There, the stock exchange price is passed on daily or hourly; a smart meter is a prerequisite.

With a fixed price with a price guarantee, the energy price remains the same for an agreed period, for example 12 months. However, you will not benefit from falling market prices during this time either. A price guarantee is not the same as a contract tie-in. According to E-Control, a tie-in period may last a maximum of one year, and the notice period a maximum of two weeks.

Why the heat pump shifts the bill

Electricity tends to be more expensive wholesale in winter than in summer. An indication of this are the forward market prices, which E-Control evaluates every quarter: On 28 September 2026, the baseload future for the first quarter of 2027 was 187,48 Euro per MWh, and for the second quarter of 2027 it was 111,49 Euro per MWh. These are wholesale prices, not end-customer prices, and not a forecast that is guaranteed to happen. But the pattern is clear. A floater that looks cheap in May can cost significantly more in January, and January is when your heat pump runs the most.

A second point is often overlooked. The index only moves the energy component. According to the Österreichische Energieagentur (Austrian Energy Agency), this makes up around 45 % of the total price for the end customer; the rest is grid fees, taxes and duties. Fluctuations on the market therefore appear weakened on the bill, both upwards and downwards. Regarding the current direction: The ÖSPI for October 2026 is 3,8 % above the previous month and 10,7 % above October 2025.

PV system and new grid fees

With photovoltaics, you cover part of your own demand in summer, but only a little in winter. The electricity you buy is therefore even more concentrated in the expensive months. For you, the annual average of a floater is less important than what it costs between November and February.

Regardless of the supply tariff, the grid fees are changing. Since 1 April 2026, the energy charge in the grid fee for households has been reduced by 20 % from April to September between 10 am and 4 pm; this is called SNAP. For the period from 1 January 2027, E-Control has presented a draft for new grid fees; statements could be submitted until 24 July 2026. Among other things, the draft provides for a cheaper winter low-energy charge, valid from 1 October to 31 March between 10 pm and 4 am. A heat pump with a buffer cylinder could benefit from this.

Anyone who already has their own interruptible metering point for the heat pump should know the following: According to E-Control, this tariff form was used for heat pumps, among other things. According to the draft, such connections are to switch to the regular grid fee from 1 January 2030; a model for flexible withdrawal is planned as a successor. This has not yet been decided, so do not rebuild anything for the time being.

Which type are you?

A floater might suit you if

• you can easily cope financially with months of noticeably higher costs,
• you follow the index development and are ready to switch quickly,
• your house is well insulated and the heat pump needs comparatively little electricity,
• the tariff has a cap that limits the upward risk.

A fixed price is more suitable if

• you want predictable instalments and a large additional payment would hit you hard,
• your consumption is high, for example in an older, poorly refurbished house,
• you do not want to deal with electricity prices every month.

The Arbeiterkammer Oberösterreich (Upper Austrian Chamber of Labour) explicitly names float and spot tariffs as a possible cause of high annual additional payments. In March 2026, it advised a price tie-in for anyone who wants to rule out rising prices over the winter. This is a question of risk appetite, not a question of right or wrong.

What you can do specifically

1. Check your last annual bill to see how much electricity you consume, and if possible in your grid operator's portal, how it is distributed over the months.
2. Compare fixed-price and floater quotes with your real consumption in the E-Control tariff calculator. Pay attention to the duration of the price guarantee, tie-in period, cap and new customer discounts that drop away after the first year.
3. Note down when the price guarantee and discount end, and compare again shortly beforehand.
4. With a floater: Have the instalments set so that the winter months are covered, then the additional payment remains small.
5. If you are just planning: A cleanly designed system with a low flow temperature reduces consumption more than any tariff choice. With the cost comparison, you can see what this means in Euros.

If you are planning a heat pump, you can get quotes from up to three checked installers via meine-waermepumpe.at, free of charge and without obligation.