The incandescent light bulb, rated at about 60 W, is one we all know and which endeared for about 130 years.

Along the way had been invented various other types of light: gas-discharge lamps (such as streetlights) fluorescent lamps, metal halide lamps, and so on. But, for a very long time, basic domestic lighting has been, or was, by means of incandescent lamps.

In any middle-class house, about 20% of the total energy consumption was the lighting. You will note the past tense, ‘was’. With the green movement came an insistence on getting rid of the ‘old-technology, inefficient’ incandescent light bulb and replacing it with compact fluorescent light bulbs. When one went into a person’s home, one could easily tell if they were republican right or greener than the bottom of a swamp by whether or not you saw white colour ugly compact fluorescent light bulbs or the glow of a shaded incandescent bulb.

The greens thought nothing of filling the landfill with mercury-tainted waste compact fluorescent light bulbs all to sacrifice incandescent light bulbs to the god of infinite greenness.

But now things have moved along. Light-emitting diodes (LEDs) are starting to become the lamp of choice. Initially, like the model T Ford, only available in one colour, they are now available in any number of soft glows. The consumption of the LEDs is way down, compared with the incandescent bulb, and its lifetime is almost infinite. The number of styles available is astonishing. I have, next to my bed, a bedside light that has an LED light in it, which is everything you want: glowing filaments, warm colour and very cheap to operate.

One difficulty, however, is that they are not very cheap to buy. And here is one of the great failures of the modern world. There are many, many people living in the bush in Africa and elsewhere who would like some light at night. For them, the incandescent bulb and the cost of operating it come to something like 12c/h. Thus, they would spend roughly 50c a day, or R15 a month, on light. If they are lucky enough to have an electricity supply, they will certainly be charged some sort of connection fee, generally about R150 a month. They definitely would not afford this and, thus, they fall back on paraffin lamps and candles, which cost about R35 a month.

There is certainly no chance that they will be able to afford an LED light. Thus, the new technology will hardly benefit the hundreds of thousands of people who live in the bush. What does benefit them (following a five-year trial by myself and the inhabitants of Mabova village, in Zambia, with the assistance of social worker Fanwel Sibenda, are the solar jar lights supplied in this country by Consul Glass. We have distributed over 500 of these lights over the last five years and effectively have rendered a portion of the community in Mabova free from the costs of pushing back the night.

The developments now on the cards are laser diode lights. These promise to be even less power hungry than LED lights. They also promise to be infinitely flexible, allowing homes to be lit up with light panels or waveguides – the possibilities are endless. But costly. The tragedy of this all is that the light requirements of bush people are not at all at the forefront of technological research. From the time of the invention of the incandescent light 150 years ago, absolutely nothing has been done to help them have light at night. We all know that Africa is slow. We all know that the average African politician hardly does a single thing that is effective. They see their people without light and they care not. The US and United Nations (UN) donors donate solar panels that are installed and then stolen and sold to US and UN donors.

The solar jar lights are an invention which could change the whole of Africa. Which could eliminate more greenhouse gases than anything else possible. Somebody has to do it.