The electricity sector in Switzerland relies mainly on hydroelectricity, since the Alps cover almost two-thirds of the country's land mass, providing many large mountain lakes and artificial reservoirs suited for hydro power. In addition, the water masses drained from the Swiss Alps are intensively used by run-of-the-river hydroelectricity (ROR). With 9,052 kWh per person in 2008, the country's electricity consumption is relatively high and was 22% above the European Union's average.
In 2013, net generated electricity amounted to 66.2 terawatt-hours (TWh). About 60% of Switzerland's electricity generation comes from renewable sources, most of it from hydro (56.6%), while non-hydro renewables supplied a small contribution of 3.4%. Nuclear contributed 37.6% to the countries electricity production and only about 2.5% were generated by fossil fuel based thermal power stations.
According to IEA the electricity use (gross production + imports – exports – transmission/distribution losses) in Switzerland was in 2004 60.6 TWh, (2007) 61.6 TWh and (2008) 63.5 TWh. In 2008 Switzerland consumed electricity per inhabitant 122% compared to the European Union 15 average (9,052 / EU15: 7,409 electricity use per inhabitant 2008, kWh/person) and 133% compared to the United Kingdom (2008: UK 372.19 TWh per 59.9milj. person and Switzerland 63,53 TWh per 7,71 milj.person).
Hydroelectricity is by far the country's most important source of energy, and contributing more than half to its electricity generation. Hydro power is generally divided into conventional hydroelectricity (using a dam) and run-of-the-river hydroelectricity. In addition, pumped-storage hydroelectricity (PHS) plays an important role in Switzerland, being used in combination with base load power plants and to green-washing nuclear power from France.
The KEV remuneration (see below) also applies to small-scale hydro power plants with nameplate capacities up to 10 megawatts.
There are four nuclear power plants, with a total of five operational reactors. In 2013, they produced 24.8 terawatt-hours (TWh) of electricity. Nuclear power accounted for 36.4% of the nation's gross electricity generation of 68.3 TWh In addition, there are a number of research reactors in Switzerland, one of them at the EPFL.
In 2011, the federal authorities decided to gradually phase out nuclear power in Switzerland as a consequence of the Fukushima accident in Japan. In late 2013 the operator BKW decided to cease all electrical generation in 2019 in the Mühleberg plant
As of December 8, 2014, the National Council has voted to limit the operational life-time of the Beznau Nuclear Power Plant—which houses the oldest commercial reactor of the world—to 60 years, forcing decommissioning upon its two reactors by 2029 and 2031, respectively.
The federal government adopted feed-in tariffs to offer a cost-based compensation to renewable energy producers. The feed-in remuneration at cost (KEV, German: Kostendeckende Einspeisevergütung, French: Rétribution à prix coûtant du courant injecté, Italian: Rimunerazione a copertura dei costi per l'immissione in rete di energia elettrica) is the primary instrument for promoting the deployment of power systems using renewable energy sources.
It covers the difference between the production and the market price, and guarantees producers of electricity from renewable sources a price that corresponds to their production costs. The following renewable energy sources are supported by the KEV remuneration: distributed small hydro (with capacities up to 10 MW), solar photovoltaics, wind power, geothermal energy, biomass and biogas (from agriculture, waste and water treatment).
The KEV remuneration is financed by collecting a surcharge on the consumed kilowatt-hour of electricity. As in other countries, industries with a large electricity consumption are exempt from the surcharge, which has gradually been increased and stands at 1.5 cents per kWh as of 2014.
The remuneration tariffs for renewables have been specified based on reference power plants for each individual technology. Feed-in tariffs are applicable for 20 to 25 years, depending on the technology. In view of the anticipated technological progress and the increasing degree of market maturity of renewables energy technologies (especially for solar PV), the feed-in tariffs are subjected to a gradual reduction once or twice a year. These reductions only apply to new production facilities that are put into operation.
Planned installations of renewable power facilities have to be registered with Swissgrid, the national network operator. As of the end of 2014, a growing waiting list for solar photovoltaic systems has accumulated as demand excess the capped capacities given by the currently available funds of the KEV remuneration.
Swiss wind power accounted for only 89 GWh or 0.1% of net-electricity production in 2013.
For many years, Switzerland's pace of deploying solar PV had been lagging significantly behind its neighboring Germany and Italy. However, installed capacity of solar PV increased by 300 MW or 69% to 737 MW in 2013 and is likely to continue its strong growth due to the recently ramped up KEV funds. In 2014, another installed 320 MW brought the country beyond the gigawatt mark and the IEA-PVPS estimates the now installed capacity sufficient to supply close to 2% of the domestic electricity demands.
An induced seismicity in Basel led the city to suspend a geothermal energy project and conduct a seismic hazard evaluation, which resulted in its cancellation in December 2009.
Emissions of carbon dioxide in total, per capita in 2007 were 5.6 tons CO2 compared to EU 27 average 7.9 tons CO2.
A study published in 2009 showed that the emissions of carbon dioxide (CO2) due to the electricity consumed in Switzerland (total: 5.7 millions of tonnes) are seven times higher than the emissions of carbon dioxide due to the electricity produced in Switzerland (total: 0.8 millions of tonnes).
The study also show that the production in Switzerland (64.6 TWh) is similar to the amount of electricity consumed in the country (63.7 TWh). Overall, Switzerland exports 7.6 TWh and imports 6.8 TWh; but, in terms of emissions of carbon dioxide, Switzerland exports "clean" electricity causing emissions of 0.1 millions of tonnes of CO2 and imports "dirty" electricity causing emissions of 5 millions of tonnes of CO2.
The electricity produced in Switzerland generated 14 grammes of CO2 per kilowatt hour. The electricity consumed in Switzerland generated 100 grammes of CO2 per kilowatt hour.
In Switzerland, there also exists a single-phase AC grid operated with 16.7 Hz for power supply of railway lines, see List of installations for 15 kV AC railway electrification in Germany, Austria and Switzerland.