Earlier this year I wrote an article saying how much sunshine Northern Ireland got.
As someone who has always found grey Ulster days depressing, and who used to long to live in a sunnier country, I was not being entirely serious. But I was being partly so.
Belfast gets around 1,400 hours of sunshine a year, which is an average of about four hours a day. However, it is a mathematical certainty that all of the many, many days in which the sun appears for less than an hour, or perhaps not at all, have to be balanced by other days in which the sun appears for six, or eight, or perhaps even 10 hours a day.
And then, very occasionally, we will have a run of days, such as the one we have had this past week, in which the sun appears for 15+ hours (the glorious combination of the 17 or so long hours of daylight that Northern Ireland gets each day at this point in the calendar, and the high percentage of sunny such hours).
My point earlier this year was that as you get older and time seems to pass more quickly (also my point above), these sunny days seem to come round with more frequency than they once did.
And this week has shown us another thing: the potential for solar power even in mostly grey Northern Ireland.
I have long been concerned about the capacity of western countries to wean themselves off fossil fuel-sourced energy. Nuclear does this, but some of the opposition to it is hysterical and almost superstitious, such as the hyping of the risk from Sellafield and of the long-term impact of the Chernobyl disaster (which is not to deny that it was a disaster).
But there are legitimate concerns about nuclear waste and in particular how we will be able to identify its location and hazards to post-apocalyptic communities thousands of years hence.
Thus I have long wondered about the potential of solar. It doesn’t take much scientific knowledge to sense its potential – you only need to stand outside directly under its rays in NI (let alone in the sweltering Sahara, as I have done).
Since travelling around that desert a decade ago, I have had a heightened interest in the potential of solar to power communities, particularly in impoverished Africa.
Now there is a large-scale solar farm even in NI (launched this week) near to Aldergrove that will provide the airport with a remarkable 27% of all its energy needs.
The rise of solar is one of the most exciting technological advances in the world.
Ben Lowry (@BenLowry2) is News Letter deputy editor