About five years ago, the organisation Greenpeace released a report on Concentrating Solar Power, which starts off by declaring that “CSP (Concentrating Solar Power) systems produce heat or electricity using hundreds of mirrors to concentrate the sun’s rays to a temperature typically between 400 and 1000ºC. There are a variety of mirror shapes, sun-tracking methods and ways to provide useful energy, but they all work under the same principle. Individual CSP plants are now typically between 50 and 280MW in size, but could be larger still. CSP systems can be specifically integrated with storage or in hybrid operation with fossil fuels, offering firm capacity and dispatchable power on demand. It is suitable for peak loads and base-loads, and power is typically fed into the electricity grid”, and in suitable alarmist fashion the report continues that the “planet is on the brink of runaway climate change. If annual average temperatures rise by more than 2ºC, the entire world will face more natural disasters, hotter and longer droughts, failure of agricultural areas and massive loss of species. Because climate change is caused by burning fossil fuels, we urgently need an energy revolution, changing the world’s energy mix to a majority of non-polluting sources. To avoid dangerous climate change, global emissions must peak in 2015 and start declining thereafter, reaching as close to zero as possible by mid-century. CSP is a large-scale, commercially viable way to make electricity. It is best suited to those areas of the world with the most sun; Southern Europe, Northern Africa and the Middle East, parts of India, China, Southern USA and Australia, where many are suffering from peak electricity problems, blackouts and rising electricity costs. CSP does not contribute to climate change and the source will never run out. The technology is mature enough to grow exponentially in the world’s ‘sun-belt’ . . . In the last five years [2004-09], the industry has expanded rapidly from a newly-introduced technology to become a massproduced and mainstream energy generation solution. CSP installations were providing just 436 MW of the world’s electricity generation at the end of 2008. Projects under construction at the time of writing, mostly in Spain, will add at least another 1,000 MW by around 2011. In the USA, projects adding up to further 7,000 MW are under planning and development plus 10,000 GW in Spain, which could all come online by 2017. According to the Global CSP Outlook 2009, under an advanced industry development scenario, with high levels of energy efficiency, CSP could meet up to 7% of the world’s projected power needs in 2030 and a full quarter by 2050. Even with a set of moderate assumptions for future market development, the world would have a combined solar power capacity of over 830 GW by 2050, with annual deployments of 41 GW. This would represent 3.0 to 3.6% of global demand in 2030 and 8.5 to 11.8% in 2050”.
And now, as reported by Computerworld‘s Lucas Mearian, “IBM, working with other researchers, has announced an ‘affordable photovoltaic system that can concentrate solar radiation 2,000 times’. A byproduct of the system is that it also produces a massive amount of heat. That heat can be harvested to perform other functions, such as desalinating water and creating cool air in sunny, remote locations where they are often in short supply, the IBM researchers said. The High Concentration PhotoVoltaic Thermal (HCPVT) system can convert 80% of the incoming solar radiation into useful energy”.
Mearian continues that the “HCPVT system uses a big mirror that looks like a satellite dish to concentrate sunlight onto a small semiconductor chip, which then converts that light into energy. Because of the high concentration, along with energy, heat is also concentrated and must be dissipated so it doesn’t melt the system. That heat can be used for other processes, such as desalination (evaporating saltwater to make potable water), according to Bruno Michel, a lead scientist with IBM Research, Zurich”. The above-quoted Greepeace report, in turn, adds that “We have known the principles of concentrating solar radiation to create high temperatures and convert it to electricity for more than a century but have only been exploiting it commercially since the mid 1980s. The first large-scale CSP stations were built in California’s Mojave Desert. In a very short time, the technology has demonstrated huge technological and economic promise. It has one major advantage – a massive renewable resource, the sun – and very few downsides. For regions with similar sun regimes to California, concentrated solar power offers the same opportunity as the large offshore wind farms in Europe. Concentrating solar power to generate bulk electricity is one of the technologies best-suited to mitigating climate change in an affordable way, as well as reducing the consumption of fossil fuels. CSP can operate either by storing heat or by combination with fossil fuel generation (gas or coal), making power available at times when the sun isn’t shining”.
The Zurich-based IBM researcher Bruno Michel stated that the “Sun is the
most abundant energy we have. We get 85,000 terawatts of energy [from the Sun] on the face of the globe, and we only need 15 terawatts. So we only need a fraction of .3 or .4% of the surface of the earth in order to provide all our energy. So we could build a solar power station in unused land in the Sahara, for example, to provide enough energy in the long term to replace all of the fossil and nuclear energy”. The Sahara as the world’s one and only power-station . . . Michel’s words sound good, but in order for such a project to come to fruition a lot of obstacles will have to be removed first: territorial, political, social and the opposition of the fossil fuel lobby of course . . .
In fact, the SSB or Sahara Solar Breeder project has been underway for a while now . . . the former television meteorologist and climate activist Anthony Watts informs us that the “Sahara Solar Breeder Project is a joint initiative by universities in Japan and Algeria that aims to build enough solar power stations by 2050 to supply 50 per cent of the energy used by humanity. The idea is to begin by building a small number of silicon manufacturing plants in the Sahara, each turning the desert sand into the high-quality silicon needed to build solar panels. Once those panels are operating, some of the energy they generate will be used to build more silicon plants, each churning out more solar panels and generating more energy that can be used to build even more plants, and so on. Hideomi Koinuma at the University of Tokyo leads the Japanese end of the project. He admits that making silicon panels from the rough sands of the Sahara or other deserts has not been attempted before, but says it is a logical choice . . . Koinuma wants to use “high-temperature” superconductors to distribute the power as direct current – more efficient than a conventional alternating current. Despite their name, high-temperature superconductors typically operate at around -240 °C, and the long power lines will require a formidable cooling system”.