Chapter 1 — France after the Oil Crises: an Energy Emergency

Context: a dependence brutally exposed

Yves Lenoir’s article was written in a very particular context.

The two oil crises of 1973 and 1979 upended French energy policy entirely. Within a few years, the price of oil multiplied several times over, brutally exposing the country’s dependence on imports. The energy bill spiralled out of control, and the government was forced to fundamentally rethink its strategy.

France’s response rested on three pillars:

• a civilian nuclear programme, launched by the Messmer Plan in 1974;
• energy conservation;
• the electrification of heating.

EDF was therefore looking for new outlets for the electricity its future nuclear plants would produce. Heat pumps appeared to be the ideal solution: they could replace some of the heating oil with electricity, while achieving an apparent COP¹ of 2 to 3 — meaning two to three times more thermal energy returned than electrical energy consumed.

The PERCHE programme: a good idea launched too quickly

The concept adopted by EDF was elegant. The PERCHE programme — an acronym for Pompe à chaleur En Relève de CHaudière Existante (Heat Pump Replacing an Existing Boiler) — did not seek to replace existing heating systems, but to graft onto them:

• the existing oil-fired boiler was kept in place;
• the heat pump handled heating as long as outdoor temperatures remained moderate;
• when the cold became severe, the boiler automatically took over.

This approach had several advantages: it avoided replacing the existing installation entirely, significantly reduced oil consumption, and retained the boiler as a backup. EDF launched a major promotional campaign, and the market took off rapidly: annual sales rose from around 1,000 heat pumps to 40,000–50,000 units at peak, in the early 1980s.

But growth was too fast to be controlled. Manufacturers improvised insufficiently tested models, many installers had no refrigeration training, machines were often poorly sized — and some became noisy, corroded quickly, or consumed far more than expected.

In 1982, EDF relaunched the programme with a stated target of 100,000 units per year by 1985. In 1984, the Ministry of Industry was still responding to a parliamentary question on the subject in an optimistic tone. The government acknowledged no failure.

Yet this was precisely the gap that Yves Lenoir was pointing to: while official communications remained triumphant, difficulties in the field were becoming obvious. The oil counter-shock of 1986 would finish off a market already weakened by its own poor reputation. According to a Ministry of Ecology study on the heat pump sector, sales reached 40,000 to 50,000 units at their peak, “then collapsed following the oil counter-shock but also due to the poor quality of certain equipment and installations.” It would take the heat pump nearly fifteen years to recover.

Historical note. EDF had produced technical training films entitled Perche C and Perche T, intended for installers — proof of the strategic importance attached to the programme. These documents remain difficult to find in publicly accessible archives today.

A discredited technology, yet with sound principles

The failure of the PERCHE programme does not mean that the heat pump was a bad idea. The thermodynamic principles on which it is based are indisputable. What was lacking was implementation: immature equipment, shoddy installations, approximate sizing.

It was against this backdrop of disillusionment that Yves Lenoir, science journalist at Science & Vie, travelled to Finland. There he discovered a radically different approach — and it is this encounter, with Professor Risto Suominen of the University of Jyväskylä, that forms the subject of the next chapter.