Electric Light from Sunlight
For considerable time scientists have been desirous of using the sun for power, and by some strong processes to use it for light at night. Now at last “The Technical World” announces in the June number that Mr. G. S. Cove has invented a mechanism to catch the light of the sun, bottle it up, so to speak, and have it on tap to be turned on at will in dark places. Not only can he store the sun’s rays to be transformed into light, but they can be used for energy as well. For ages inventors have worked from time to time on schemes for economizing the heat of the sun’s rays as a source of power, but all these devices have come to naught. This new mechanism, as described by the author of the article just mentioned, Mr. Winthrop Packard, consists of what might be called the primary cell of the solar electric generator and is a three-inch-long rod or plug of metal composed of several common metals, on one end of which the sun shines in a glass-enclosed space, the other end being in the shadow, in cool, free air. This rod is part of a circuit wired as is customary to a good storage battery. The sun shining upon one end of this rod produces a difference in temperature between it and the other end; and differences in other conditions are also caused, not yet fully understood. These differences set up an electrical action which is passed along to the storage battery, and there held in reserve power to be turned on as light, heat, or power, whenever desired. Of course the amount of energy trapped and thus stored by one rod in a day is small, but it is a simple matter to arrange any number of these rods in batteries and thus make their individual work cumulative. In the space of an ordinary window sash five feet square, a thousand rods may be placed side by side, and the electric force thus generated is a thing to be reckoned with. The electrical energy seems to be generated in equal quantity under slanting rays as under those which fall perpendicular. Even in its present somewhat crude and experimental state, given two days’ sunshine, it will store sufficient electrical energy to light an ordinary house for a week. The inventor has proved this now for months in his own establishment, so that in portions of the country where even one day in three is sunny, a single machine five feet square and holding less than a thousand plugs is sufficient for the ordinary lighting of a house. As the author says: “The possibilities of the amount of power which might be obtained in the future by batteries of these simple devices working without expense and with a minimum of attention are simply staggering.” The present cost of such a machine need not be much over a hundred dollars, and it is as indestructible as a kitchen range. The current being handled automatically, when it is once properly secured and wired upon the roof or any other spot where it gets the day’s sun unimpeded, it needs no further attention. Thus knowledge which has been sought for ages along this particular line seems now realized.