Where does Swedish electricity come from? Counted in TWh for 2024

Your electricity bill shows a number in kilowatt hours. That is what you used. The question of where it came from rarely gets an answer, because the answer is rarely simple: electricity from different power stations is mixed in the same grid, and what comes out of your socket has no label.

But for the country as a whole there is an exact answer, one year at a time. Every year the Swedish Energy Agency (Energimyndigheten) publishes the final statistics for electricity and district heating, produced by Statistics Sweden (Statistiska centralbyrån, SCB) from a survey of nearly all companies that produce electricity in Sweden. This article goes through what it says for 2024: how much electricity was produced, from what, where it went and how reliable the figures are. No forecasts, no scenarios, only what happened.

What a terawatt hour is

The statistics are counted in terawatt hours, TWh. One terawatt hour is a billion kilowatt hours, so a billion of the unit on your bill. Swedish households used a combined 33.0 TWh of electricity in 2024.² The figure 169.3 TWh, the country's entire production, is therefore about five times what all homes used together.

What one kilowatt hour is enough for in everyday life, and why the same unit is used for both batteries and electricity bills, is something we cover in a coming newsletter. Here it is enough to keep the order of magnitude in mind: one TWh is a billion kWh.

169.3 TWh: this much electricity was produced, and from what

In 2024 Sweden's electricity production came to 169.3 TWh, a rise of 6.2 TWh on the year before.^{1, 2} This is how it was split between the types of power.

Hydropower gave 64.2 TWh, a fall of 2%. Nuclear power gave 48.7 TWh, a rise of 4%. Wind power gave 40.4 TWh, a rise of 19%. Conventional thermal power, meaning power stations that burn fuel and make electricity from the heat, gave 11.8 TWh, a fall of 13%. Solar power gave 4.1 TWh, a rise of 34%.³

If you add up the three largest, hydro, nuclear and wind, you get 153.3 TWh, or 90.5% of all electricity produced, worked out as 153.3 divided by 169.3. Solar power grew fastest in percentage terms, but from a small base: 4.1 TWh is 2% of production.

Wind overtook hydro on one measure, but not on the one that counts on the bill

The statistics for 2024 note something that has not happened before: for the first time the installed capacity in wind power was higher than in hydropower. At the same time, production from hydropower was still much larger, 64.2 TWh against 40.4.^{6, 9}

How does that add up? Through the difference between power and energy, and that difference is worth learning once and for all.

Power is how much a power station can deliver at a given moment. It is measured in watts, and for large plants in megawatts or gigawatts. Installed capacity is the sum of what all power stations of one type can give at the same time, if they all run at full output.

Energy is how much was delivered over a period, for example a year. It is measured in watt hours, and it is what appears on the bill. Energy is power multiplied by time.

A wind turbine only delivers when the wind blows, and rarely at full output.⁹ A hydropower station with a reservoir can be run when the electricity is needed. Two types of power with the same installed capacity can therefore give very different amounts of energy over a year, and 2024 was the first year in which Sweden had more wind capacity than hydro capacity but still got much more energy from the water. Anyone reading a headline saying "wind has overtaken water" needs to ask: on which measure?

A worked example of power and energy

Take a power station with a capacity of one megawatt, that is a million watts. If it runs at full output every hour of a normal year, it delivers one megawatt multiplied by 8,760 hours, that is 8,760 megawatt hours, or 8.76 gigawatt hours. That is the most a power station with that capacity can give in a year.

No power station gets there. Hydropower stations stand still for maintenance and when the reservoirs need to be saved. Nuclear power stations stop to change fuel. Wind turbines stand still when there is no wind and run at half speed when the wind is moderate. Solar panels give nothing at night. The share of the theoretical maximum that a power station delivers in practice therefore differs a lot between the types of power, and that is the whole explanation for why wind can have more installed capacity than hydro and still give less energy.

When you read about new electricity production, the most important question is therefore always which measure is given. Power in megawatts tells you what has been built. Energy in gigawatt hours or terawatt hours tells you what has been delivered. The statistics in this article are about the second, because that is what the bill and the grid are about.

Where the electricity went

Electricity use in Sweden, counted without losses in the grids, was 125.3 TWh in 2024, a rise of 1.2%.⁴ Industry used 45.3 TWh, a rise of 0.6%. Households, permanent homes and holiday homes together, used 33.0 TWh, a rise of 1.8%.²

The difference between production and use counted without grid losses was split between net exports and grid losses. The flow of electricity from Sweden to other countries was 39.1 TWh, 3.3 TWh more than the year before. The flow into Sweden was 5.7 TWh, a fall of 1.6 TWh.² So on balance 33.4 TWh left the country, worked out as 39.1 minus 5.7.

Production, 169.3 TWh, is larger than use for two reasons: the net flow out of the country, and the losses on the way from power station to socket, which are not included in the figure for use. Comparing production and use directly, without counting those two items, gives the wrong picture of how much electricity was "left over".

The fuel behind the electricity

Water, wind and sun are not fuels; they drive the power stations directly. Nuclear power releases heat through nuclear fission, and conventional thermal power by burning fuel, and the statistics count that too.

Nuclear fuel was the dominant fuel at 143.9 TWh, a rise of 8.3 TWh.⁵ The figure is larger than nuclear power's electricity production, 48.7 TWh, and that is no contradiction. About a third of the energy in nuclear fuel becomes electricity, worked out as 48.7 divided by 143.9. The rest becomes heat. In nuclear power stations it is cooled away. In combined heat and power plants some of it is put to use as district heating. What all power stations that make electricity from heat have in common is that only part of the fuel's energy becomes electricity, and that is why the amount of fuel is always larger than the amount of electricity.

Leaving out nuclear fuel, wood fuels accounted for 49.5% and waste for 28.7% of the fuel used for electricity and heat. Fossil fuels, meaning heating oils, natural gas and hard coal, made up 3.4%, a rise of 0.4 percentage points on the year before.¹ The rise was in heating oils, while natural gas and hard coal fell. In total, fuels equal to 66.4 TWh were used on top of nuclear fuel, a fall of 4.6 TWh.

The same fuels also heat houses. Deliveries of district heating to end users were 50.4 TWh in 2024, a fall of 3.3%.¹ That is why the statistics are called "electricity and district heating": the two are linked in the same boilers.

Two more items in the same statistics

The first is about where the rise in electricity use went. Besides industry and households, use also rose in information and communication activities, which include telecoms and IT services.⁴

The second is about district heating. The number of subscriptions rose in 2024, while the amount of heat delivered fell. Total heat production, including electric boilers, heat pumps and flue gas condensation, was 53.0 TWh, a fall of 3.8%, and fuel-based production was 41.3 TWh, a fall of 4.3%. Within the fuel mix, the share of wood fuels fell by 1.7 percentage points while the share of waste rose by 1.9 percentage points. Of the 4.6 TWh by which total fuel use fell, wood fuels accounted for 3.5 TWh.

The batteries counted for the first time

The statistics for 2024 contain a new item: the power and storage capacity of batteries connected to the grid. It is the first time they have been reported.¹ The agency itself writes that the values are still uncertain and probably under-reported, and that is why no figure for them appears in this article. An item that the agency itself calls uncertain should not become a headline.

The agency describes grid-connected batteries as a fast-growing area, and from the statistical year 2024 they are counted in the official statistics. Batteries and storage are a theme of their own in this area and get their own articles.

How reliable are the figures?

The statistics are produced by Statistics Sweden on behalf of the Swedish Energy Agency. They are based on a full survey of about 600 companies, meaning all companies in the population and not a sample, with a response rate of about 93%.^{7, 8} The agency itself judges the statistics to be reliable.⁷

That is an unusually good basis. The figures in this article are not estimates from an industry body or scenarios from an international report. They are the sum of what the companies that produce electricity in Sweden have reported about the past year, with a known method and a stated response rate. That is also why the article sticks to the outcome year 2024 and not to the years ahead: what has happened can be counted, what will happen can only be guessed.

What to take away

Sweden produced 169.3 TWh of electricity in 2024, of which 90.5% came from hydro, nuclear and wind, while use without grid losses was 125.3 TWh and the net flow out of the country 33.4 TWh.^{1, 2, 3, 4} What lasts is the difference between power and energy: the installed capacity of wind power overtook that of hydropower in 2024, while water gave 64.2 TWh against 40.4 for wind.^{6, 9} So one type of power can lead on one measure and not on the other. The figures are based on a full survey with a response rate of about 93%.^{7, 8} Follow the Swedish Energy Agency's final statistics for electricity and district heating, produced by Statistics Sweden, the table of installed capacity by type of power, and the power balance report from the national grid operator Svenska kraftnät.^{1, 6, 9}

The next episode is S4:E2 Batteries & Storage, about how a battery works and why storage is hard.

Education, not advice.