My parents were both in essential industry, so they weren't immediately affected by the three day week. We were lucky. A 40% pay cut following huge fuel hikes must have been a real kicking and bleak Christmas for many. I was 11 at the time, and I remember the price of my oil based Airfix kits and paints went up rapidly! It wasn't easy making model planes by candlelight, either.

Anyway, just did some digging on Wikipedia on the oil crisis and 3 day week -
"The (European) Community finally issued a statement on 6 November, after the embargo and price rises had begun; widely seen as pro-Arab, this statement supported the Franco-British line on the war and OPEC duly lifted its embargo from all members of the EEC. The price rises had a much greater impact in Europe than the embargo, particularly in the UK (where they combined with industrial action by coal miners to cause an energy crisis over the winter of 1973-74, a major factor in the breakdown of the post-war consensus and ultimately the rise of Thatcherism.
The global effect of the 1973 oil crisis also drove up the price of coal. The Heath government entered into negotiations with the NUM, to no avail. To reduce electricity consumption, and thus conserve coal stocks, a series of measures were announced on 1973-12-13 by Heath, including the "Three-Day Work Order", more commonly known as the Three-Day Week, which was to come into force at midnight on 31 December. Commercial consumption of electricity would be limited to three consecutive days each week.[1] Heath's objective was business continuity - survival. Rather than risk a total shutdown, working time was reduced with the intent of prolonging the life of available fuel stocks."