On 2 September 2022 the Confederation signed a contract for a power station that arrives in shipping containers. It was eight General Electric TM2500 mobile gas-turbine units, 250 MW in total, set up in Birr in Canton Aargau, owned by GE and operated by Axpo Solutions AG. As nau.ch put it, that is about a quarter of the Leibstadt nuclear plant’s output. Europe was heading into a winter of uncertain gas supply, and Bern bought insurance.

You judge insurance by its premium, not by whether the house burned down. Read that way, Birr was clean public procurement. The capacity was defined, and so were the owner, the operator and a tariff anyone could look up. Consumers paid for it through a reserve surcharge that averaged 0.34 Rp/kWh across 2022–2026.

A building nobody planned to keep

A temporary power station is still a building, and it still has neighbours. According to Canton Aargau, the turbines and the grid connection were ready in early 2023, behind a 20-metre noise barrier wall. Some people rarely get named in this story: the GE and Axpo crews, the grid engineers and the cantonal permitting staff. They turned a September contract into a working plant in about half a year, and that is why the insurance existed at all.

On 25 June 2025 UVEK announced the end: the plant must be dismantled by the end of 2026. The department said an extension would only be possible if a power shortage were imminent. Canton Aargau judged that even a modified project would not meet all cantonal requirements: nicht bewilligungsfähig. That is federalism doing its job. An emergency instrument stays an emergency instrument because a canton holds the line on what “temporary” means.

The reserve role itself continues. From February 2027, Ansaldo Energia’s gas-turbine test stand in Birr steps in as an interim 250 MW reserve until five planned reserve facilities come online. It needs a CHF 275 million supplementary credit. For 2027 to 2044 the reserve tariff is set to average 0.26 Rp/kWh.

←TODAY: Swiss PV grew from 4,729.5 MW at end 2022 to 9,498.6 MW at end 2025.
→3012: Reserve capacity is drawn into the city plan as public infrastructure, not parked in a container yard during a crisis.
Fulcrum: The 2022 premium reads differently only because the 2025 roofs are now visible.

Then versus now

Swissolar’s statistics show the shift. At the end of 2022, Switzerland had 4,729.5 MW of installed photovoltaics. By the end of 2025 it had 9,498.6 MW across 338,270 systems, roughly double, and solar covered 13.71 % of domestic consumption. Batteries moved faster still. Home and commercial storage installed in 2025 reached 1.38 GWh, up from 0.884 GWh the year before, and sales rose 70 %.

In March 2026, Swissolar director Matthias Egli told swissinfo why the batteries matter beyond the meter: “This has a very positive effect on grid load. We can connect more installations to the same grid without having to expand it expensively.” PAZ has covered the other side of that sentence before. In Two Clocks, grid connection is the slowest clock on any project.

Now the honest middle. Swiss solar output is concentrated in summer. A kilowatt-hour harvested on a July roof does not light a February evening, and doubling capacity does not insure the winter on its own. The Federal Council’s report of 2 September 2026 on synthetic energy carriers and seasonal storage, its answer to Postulate 23.3023, is about exactly that winter question, which is still open. That is why the reserve continues in a new form.

From where I write, in the late 2070s, the lesson to pack is a small one. The winters were survived by offices that kept updating their assumptions, not by those that froze them at the moment of fear.

Atelier: Many Swiss offices still carry 2022 energy assumptions in their design basis: peak-tariff scenarios, worst-case grid-supply clauses, and PV sized as a gesture. Those numbers were sensible when written, but today they are dated inputs. Monday move: open the energy concept of your live project, find every figure from 2022, and add a column with today’s value and its source.

Hack: Put the then-vs-now solar ratio and your building’s reserve premium side by side in one check. The script uses the Swissolar capacity figures and the 0.34 Rp/kWh reserve tariff reported by nau.ch. Replace the consumption value with your building’s metered annual kWh. Dividing Rappen by 100 gives francs.

pv_2022, pv_2025 = 4729.5, 9498.6        # MW installed, Swissolar
print(f"PV growth: x{pv_2025 / pv_2022:.2f}")
kwh_year = 180_000                        # your building, metered
print(f"Reserve premium: CHF {kwh_year * 0.34 / 100:,.0f}/yr")

Paste both results into the design-basis sheet, next to the 2022 numbers they replace.

Pick one worst-case number from a 2022 project and rewrite it with today’s figure, with the source written beside it.