This is the title of a recently re-discovered book http://www.amazon.co.uk/Look-And-Learn-Book-1966/dp/B001HUTU1C from my childhood, published in 1966, in which there is an article entitled "The World's Great Powerhouse", which refers to the putative prospects for solar energy, as envisaged almost 50 years ago, and makes fascinating reading now. As it states, "In one year the sun gives out more energy than will ever be obtained from all the world's coal and oil. How can it be harnessed? How can it be used to prevent land becoming desert?" As time has unfolded them over the past half-century, these matters are now at a critical stage in regard to the intrinsic availability of fossil fuels, our use of them, and the non-maintainable rate at which we are eroding the world's soils. Indeed, 2015 has been proclaimed as "International Year of Soil", http://www.fao.org/soils-2015/en/such is the call to arms to protect this fragile, living skin of the earth http://www.resilience.org/stories/2014-05-30/for-our-children-s-earth-rebuilding-the-soil-sustaining-the-future.
The article refers to the power of the sun, and how it may be accidentally harnessed by a carelessly discarded bottle which starts a fire, laying waste to "millions of acres" of forest, and the familiar childhood experiment with a magnifying glass that sets fire to piece of paper held in the focus of its lense. It is noted that coal and oil are non-renewable resources and that "It takes millions of years to create coal and oil, but man is using them up at a fantastic rate." And indeed, he continues to do so, consuming almost one thousand barrels of crude oil every second. The statistic is given that "The amount of sunshine falling on the whole world creates an amount of heat which would equal 400,000,000,000,000,000,000,000 tonnes of coal being burned." The amount of energy hitting the top of the Earth's atmosphere is reckoned to be 174 Peta-Watts https://en.wikipedia.org/wiki/Solar_energy, and so over a year, that equals 5.49 x 10^24 J. Assuming that the coal is anthracite, we have an energy content of 32.5 GJ/tonne http://hypertextbook.com/facts/2003/JuliyaFisher.shtml meaning that the above mentioned 4 x 10^23 tonnes of it would release 1.3 x 10^34 J, so the "Look and Learn" estimate of the annual solar energy equivalent in terms of coal appears to be overestimated, which should be nearer 169,000,000,000,000 tones of coal.
For the most part, the article addresses the thermal power of sunlight, and how difficult, yet tantalising, is the prospect of "trapping at least some of it", and is prescient in terms of the development of solar thermal power stations, giving mention to "use reflectors, either glass mirrors or sheets of polished metal" to concentrate the sun's rays on a "big scale". Such power plants have subsequently been developed, e.g. the 354 MW SEGS solar complex in northern San Bernardino County, California https://en.wikipedia.org/wiki/Concentrated_solar_power Smaller. Smaller scale devices are alluded to, e.g. the "hot umbrella" solar cooker, and passing mention is made of "silicon cells" which had not so long been developed, but were by then the main source of energy for Earth-orbiting satellites and space-probes, and remain so to this day https://en.wikipedia.org/wiki/Solar_cell#Space_Applications. It is salient however that even now, little more than 1% of global electricity demand is met from solar energy http://cleantechnica.com/2015/06/12/solar-power-passes-1-global-threshold/.
The prospects for extracting useful elements from the oceans are visited later on in the book under the heading "Amazing Treasure House of the Sea." Although there are indeed vast quantities of various elements contained in seawater (e.g. 100 tonnes of silver and 600 tonnes of copper in each cubic mile of it), the problem of obtaining them is similar to that implicit in harvesting solar energy, namely that being present in fairly diffuse abundance, it is necessary to concentrate them into useful amounts, which poses a considerable challenge. Research continues, in an effort to find materials that might serve as "filters" for the extraction of substances such as uranium from seawater, which it is said would make nuclear power an effectively limitless technology in terms of its fuel supply http://www.technologyreview.com/news/514751/novel-material-shows-promise-for-extracting-uranium-from-seawater/
The final section of the book is called simply "Oil!", the exclamation mark being given to emphasise the importance of this remarkable substance to most human activities. As is stated, "In 1859 oil came from the world's first well to light the lamps of America. From these modest beginnings, rose a vast industry which today supplies the nations of the world with the life-blood of civilization." It is indeed the life-blood of the global human mechanism, and it is significant to note that in 1964, 1,405 million tonnes of oil were produced throughout the world, which is equal to around 10 billion barrels. We may note that current oil production is 84.9 million barrels a day https://en.wikipedia.org/wiki/List_of_countries_by_oil_production or 31 billion barrels in a year, and so although the global population has a little more than doubled in the past half century, our use of oil has trebled. The article observes that, "Drills bore down nearly five miles into the earth to obtain it; floating derricks probe the sea bed in the everlasting search for more supplies. So vital is the possession and safety of oil pipelines that they have become a major concern of many governments." Thus the increasing difficulty of maintaining the global oil production was noted even then, long before it became necessary to drill in ever deeper fathoms of water, to process "oil" from bitumen in tar sands, and to frack hydrocarbons out of shale, as is done now to prop up the global oil supply.
The book itself was a Christmas present to me, I think from my Great Grandmother (on my
mother's side of the family), as it is signed "Nan", which we all called
her. She was Welsh (as indeed am I, having been born in Cardiff), and a resilient lady, being the widow of a slate miner, killed in a roof-fall
underground. Left with two very young sons to
bring up, and needing a man's wage in the house, out of expediency she made an arrangement with her lodger "Griffith" (who had himself been injured in the mine, and walked with a stick and a dragging leg), to become his
wife. She was 10 years older than him, and lived to be 93. They seemed very content, as I recall.
The coalmines of Wales are now largely abandoned, although there is the odd mention that they might be reopened, so long as clean burn technology (CCS) is introduced to any power stations they may fuel http://www.telegraph.co.uk/news/politics/labour/11791434/Jeremy-Corbyn-Labour-could-reopen-coal-mines-and-nationalise-gas-and-electricity-sector.html. In all probability the fossil fuels will be with us for some time, but ideally in the service of sustaining us as we Transition to a less global and more local way of doing things. Probably there is no simple substitute for oil, and limitations on the number of electric vehicles we may have in the future, hence our salvation might be looked for in more resilient, and more sustainable communities. However, I do not deceive myself that this transformation will be easy and painless. In a new order of lower energy and more locally based lifestyles we may need to learn more of the kind of practical skills that the likes of and Nan and Griffith knew.