To the surprise of many, solar power has been used much more, and been more effective, over the past two decades than was anticipated.
Different types of 'solar systems'
Now in the 21st century, we have become familiar with many ways that the power of the sun is being used in our everyday living: from the tiny to the huge; from the commonplace to the weird.
My household, and many others I know, have had solar hot-water systems for 30 years or more; although today's versions are cheaper, more efficient and more robust.
The vast numbers of photovoltaic (PV) panels on roofs feeding electricity into the grid for payment, here and in other countries, have become commonplace. There are now over 1 million in Australia. One church at Caloundra, Queensland has them in the shape of a cross; and others around the world are employing a range of ways to incorporate panels into ancient Church structures. (www.businessspectator.com.au/news/2014/1/9/renewable-energy/aust-hits-2-million-solar?; www.businessspectator.com.au/article/2013/6/19/science-environment/religious-climate-change-response)
In small devices, we have all seen solar-powered torches, watches, computers, even a pepper-grinder. Most of these have a battery back-up that is charged by the sun.
Farmers make use of the sun to power devices in their isolated paddocks, such as electric fences and automatic farm gates. We have seen how councils have employed solar panels for temporary traffic lights used by road maintenance gangs and school speed-limit signs that only need to flash at certain times. These things are only required during the day, and are in places where electrical cabling would be awkward and dangerous so this technology is a perfect fit for purpose.
On the larger scale, solar energy is being used in industrial situations such as desalination plants to extract fresh water from salt water. A wonderful example of this is an innovative farming system called Sundrop, where solar power is used to desalinate water, which is used in irrigation and an integrated system also cools the glasshouses where various vegetables are grown. (www.abc.net.au)
On the even larger scale, there are trials of 'solar thermal' plants that would be just like any other electricity-generating plant, but using concentrated sunbeams to heat the water to make the steam to drive the turbines (instead of coal or gas or nuclear energy). (www.csiro.au)
Then there is the weird. Well, we may now think these oddball ideas and competitions are weird now but in the future they may be commonplace. One is the biennial World Solar Challenge in which students design solar cars and run them in a race between Darwin and Adelaide. (en.wikipedia.org; www.worldsolarchallenge.org)
Brief history of solar-energy technology
(www.aglsolarenergy.com.au; exploringgreentechnology.com; en.wikipedia.org/wiki/Solar_cell)
Of course the direct heat and light from the sun has been used by humans for various uses over many centuries. However, the first documented use of a 'solar oven' was in 1767. The first demonstration of the 'photovoltaic' effect was noted by Bequerel in 1839. The term 'photovoltaic' or PV means an electrical current (measured in volts) that is caused by the energy from photons (pulses of light energy).
Between the 1800s and 1940 there were various advances in constructing solar cells where the energy from the light can be coaxed to create an electrical current along a wire and therefore be used to do something useful. However, these were inefficient and made from materials that were difficult to manufacture, or rare, so they were expensive.
Albert Einstein worked out the theory of the photoelectric effect in 1905; work which won him the Nobel Prize for Physics. This was the beginning of quantum theory. It was not until 1916 that Millikan showed that it worked experimentally.
After World War II, solar-powered equipment became more available to the general public for private use, particularly in the USA. The first commercial use of solar energy was in technology for satellites and space stations, beginning in 1958.
The next major milestone was in the design of more efficient solar panels that were cheaper to manufacture, by Exxon Corporation, in 1970. It was then that they started to pave the way for the burgeoning use we see today.
In Australia at that time, the CSIRO and various Universities also sponsored some really useful research into solar-energy systems. For example, multi-award winning Professor Martin Green has been researching improved solar cells since the mid 1980s. His technology has been sold overseas, but he is now back at the University of New South Wales (UNSW) continuing to improve this technology. (en.wikipedia.org/wiki/Martin_Green)
The future looks brighter than expected (excuse the pun).
Psalms 74 verse 16 (KJV): "The day is thine, the night also is thine: thou hast prepared the light and the sun."
Because the sun doesn't shine at night, people expected that electricity generated by solar power would only ever be supplementary to 'base-load' power that could be delivered at any time; unless the electricity could be stored in something like a battery. Research into better batteries is ongoing, and is not the subject of this article.
The idea is to try to find some sort of synthetic photosynthesis system. In nature, leaves and some bacteria harvest the light energy, and by a complex and beautifully finely co-ordinated set of chemical reactions, use it to make sugars as a storage for future use for the living organism.
Humans haven't managed to find such an efficient system yet. We need to keep watching this space; for example, research by groups in the USA and Australia: (www.rsc.org/chemistryworld/2013/07/artificial-leaf-synthetic-photosynthesis;
www.rsc.org/chemistryworld/2013/05/hydrogen-harvest-chlorine-seawater-sunlight)
But, encouraged by various political and financial incentives around the world, individual consumers have taken up solar technology at a much faster rate than anticipated. For example, solar power from individual's homes helped to allay any shortfall in electricity in the recent heat waves in Victoria and South Australia.
Despite some technical problems in the conventional grid system, there were no blackouts, partly because solar power from peoples' homes was contributing electricity exactly in the heat of the day when it was most needed for cooling. (www.businessspectator.com.au)
It is always nice to end with reports of awards. Professor Stuart Wenham of UNSW has recently won a prestigious engineering award, for his work on improving the technology of manufacture of solar cells so that their efficiency will increase and their price decrease even further in future.
The Australia Solar Council spokesman stated: "The research has shown the search for greater efficiencies and cost savings in solar photovoltaic, that has dropped prices by over 80 per cent in the last three years, is certainly not over." (www.businessspectator.com.au)
Missions and Churches as cited above, including our own Well-Being Australia mission (with the courtesy help of Green Initiative) have solar panels. This reduces the electricity bills by putting power back into the grid and we get paid for that.
Dr Mark Tronson is a Baptist minister (retired) who served as the Australian cricket team chaplain for 17 years (2000 ret) and established Life After Cricket in 2001. He was recognised by the Olympic Ministry Medal in 2009 presented by Carl Lewis Olympian of the Century. He mentors young writers and has written 24 books, and enjoys writing. He is married to Delma, with four adult children and grand-children.
Mark Tronson's archive of articles can be viewed at www.pressserviceinternational.org/mark-tronson.html