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Solar Sunrise

Increasing national government focus on energy security and climate change drives the uptake of large-scale solar as the leading renewable supply

The combined pressures of rising global energy demand, increasing concern about climate change, greater focus on the advance of ‘peak oil’ and heightened awareness of the challenges around energy security are driving many countries to look for alternative energy sources. While long term prospects rest on technological breakthroughs and the wider adoption of nuclear energy that decrease the use of fossil fuels, as highlighted in section 1, the next decade is still very much where oil, gas and coal are the major sources of energy. With India and China growing fast, and so requiring greater energy to fuel this growth, with the US still very much “addicted to oil” and with governments yet to agree a global way forward, the energy world in 2020 will, according to International Energy Agency projections, still be over 70% fossil fuel based.

However, by implication, over the next decade there will be a significant shift in the adoption of renewable, alternative energy supplies. Wind, wave, solar, nuclear, bio, hydro and geothermal are all pushing ahead, some with clear momentum and others with inertia yet to be overcome. As different countries are advocating different options, it is clear that there isn’t a single global answer. Coastal locations favour wind turbines, mountainous districts like hydroelectricity, Iceland is a fan of geothermal, sunny places are great for solar and, while some countries want access to nuclear, many others do not.

That said, talking through the problem in workshops it is evident that globally the next decade is one where overall solar energy is expected to make the most headway.  To achieve change in the first place however many experts drew attention to two key issues:

Firstly, we are using the wrong business models – we are trying to look at the potential future solutions through the lens of today’s business models: “The current economic models we use are not suitable for managing our future energy needs where the payback periods will be longer than the usual norms. We need to provide a framework to appropriate change in the energy mix and support the huge investment needed. The speed of transition that we need to address the energy challenge is out of sync with the established views on returns on investment.”

Secondly “it is not just about the technology; policy and markets are just as important.” This view is becoming increasingly clear as green stimulus packages start to take effect alongside the existing incentives already in place: Germany’s feed in tariff provides a long term guaranteed price for renewable energy that has made it a leader in solar energy development while the U.S. government’s subsidies for bio-fuels have kick-started the ethanol and bio-diesel market across the Americas. Add in the failure of Copenhagen to agree any meaningful global ambition, growing concerns of the environmental impacts of the Canadian tar sands and U.S. government reaction to the Deepwater Horizon disaster in the Gulf of Mexico and one can see a raft of new nationally focused policies on the horizon. As countries scramble to protect their supplies to gain individual energy security and veer away from what Shell sees as the ‘blueprint’ scenario of greater global cooperation, governments will seek to support the alternatives that are within reach from both a technological and economic point of view. Experience has shown that successful approaches work at many levels so this combination of technology and economics also has to align with social acceptance and political will.

Together these will mean that we are likely to see increased investment in nuclear energy for those that have access to the technology. As such by 2020, in support of the traditional centralized view of supply, there will be more nuclear power stations coming on stream than ever but, given the overall dynamics of the sector, there is unlikely to have been a tangible shift in the percentage of supply that nuclear provides. We are also likely to see increased investment in proof of concept schemes for wave power, but again this will not have achieved scale. Geothermal and hydro will continue to be limited to certain geographies and many scenarios increasingly expect that the fuel vs. food debate around biofuels will have been exasperated by more spikes in food prices and government U-turns on subsidies.

The fastest growing area of renewable energy supply at the moment is wind. Quoting Xi Lu of Harvard suggested that “wind power in the US could potentially generate 16 times the nation’s current electricity production” – even when limiting locations to rural, non-forested sites (both on land and offshore) with high wind speed. Moreover “worldwide, wind energy under the same constraints could supply at least 40 times the current electricity consumption.” What was not mentioned however is the speed at which this capacity can be rolled out, at what cost and by who and so what the impact will be by 2020?

A pivotal issue in any assumptions about wind is that of material availability: Given that most existing wind turbines use significant amounts of copper, a material which is already on the watch list of limited resources, there could be major supply limitations. “In a world where telephone lines are routinely dug up so that people can resell the copper, using millions of tonnes of it in wind turbines seems unlikely.” Alternative materials such as high temperature superconductors are now in trial applications, but the ability to scale these up sufficiently within ten years is low and so, despite the optimism by some, others see that “current growth in wind turbines will not be sustained.”

So this brings us to solar energy – a virtual, limitless clean resource. In its most common form photovoltaic (PV) panels convert sunlight into electricity. Typical current panels have an efficiency of around 10%, with more expensive ones achieving 20%. In the next few years experts see that this “may rise to around 40%.” In 2009 PV installations grew by 20% to over 7GW of new installations globally. While Europe, led by Germany, currently accounts for nearly 80% of global demand, over the next few years many expect that more large scale solar power systems will be installed across the world from the US and China to Africa and India. As German subsidies decline in line with cheaper and more efficient technology, a tipping point of commercial viability will occur. According to the US Department of Energy’s Solar America Initiative, PV solar energy will be competitive without subsidy by 2015. Just as with other technologies, increasing capacity will result in a steady cost decline and “across the supply chain, manufacturers are increasing cell efficiency, using thinner silicon wafers and increasing power in low light levels.”

In the short term, the 2009 US Stimulus Bill which included $60bn in loan guarantees for companies building wind and solar plants is kick starting the US market. As Carol Sue Tombari, of the US Department of Energy’s National Renewable Lab points out in her recent book “Wal-Mart is aiming to meet 100% of its power needs from renewable energy” and, as part of this, is already installing solar power on its supermarket roofs in California and Hawaii for example. In addition Google, a huge energy user, has announced a partnership with Sharp for PV roof systems. Elsewhere China has also announced a subsidy for solar energy installations and, in 2009, the Qinghai province gave the go ahead for the world’s first 1GW solar farm. More significantly, in January 2010 the Indian Government launched its National Solar Mission which aims to make India a global leader in solar energy and envisages an installed solar generation capacity of 20GW by 2020 and 2000GW by 2050.

While some countries, such as those in Northern Europe, could get around half their electricity needs from PV and solar farms within their national boundaries, if they can access solar power from other countries, solar could provide nearly all electricity. According to calculations by experts including Professor David MacKay of Cambridge, “a 100km by 100km square area of concentrated solar power (CSP) systems in the Sahara could provide enough power to meet Europe’s current demand.”  Going forward organisations such as DESERTEC are promoting the adoption of the use of CSP in Mediterranean countries and high voltage DC transmissions lines as a credible way to provide Europe with secure, clean energy. The same arguments clearly apply elsewhere in the world, and given the economic constraints in Europe, some expect that they are likely to occur first in either India or China.

As was pointed out in the most recent Technology Futures programme hosted by Shell; “Global energy consumption is around 470EJ per year. The sun delivers to the earth almost 4m EJ of energy. So theoretically the sun could provide at least eight thousand times the energy we need.” There is little argument that “in the long term all energy can be solar” and it looks like the next decade will be when the shift to solar really starts gaining momentum.

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One Response to “Solar Sunrise”
  1. American institute of physics demonstrates us more effective Selenium pv cells

    Did you know that many scientists would like to find light-catching elements in order to convert more of the sun’s energy into carbon-free electricity?

    A new study announced in the magazine Applied Physics Letters in August this year (released by the American Institute of Physics), explains how solar power could potentially be collected by using oxide elements that have the element selenium. A team at the Lawrence Berkeley National Laboratory in Berkeley, California, inserted selenium in zinc oxide, a relatively economical component that could make more effective use of the sun’s power.

    The team observed that even a relatively small quantity of selenium, just 9 % of the mostly zinc-oxide base, drastically improved the material’s performance in absorbing light.

    The most important author of this study, Marie Mayer (a 4th-year University of California, Berkeley doctoral student) states that photo-electrochemical water splitting, that signifies employing energy from the sun to cleave water into hydrogen and oxygen gases, could possibly be the most fascinating future application for her work. Harnessing this reaction is key to the eventual generation of zero-emission hydrogen powered vehicles, which hypothetically will run only on water and sunlight.

    Journal Research: Marie A. Mayer et all. Applied Physics Letters, 2010 [link: http://link.aip.org/link/APPLAB/v97/i2/p022104/s1

    The conversion productivity of a PV cell is the proportion of sunlight energy that the solar cell converts to electrical energy. This is very important when discussing Pv units, because enhancing this efficiency is vital to making Photovoltaic electricity competitive with more standard sources of energy (e.g., non-renewable fuels).

    For comparison, the earliest Photovoltaic products converted about 1%-2% of sunlight power into electrical energy. Today’s Photovoltaic devices convert 7%-17% of light energy into electrical power. Of course, the other side of the equation is the money it costs to manufacture the PV devices. This has been enhanced over the years as well. In fact, today’s PV systems produce electricity at a fraction of the cost of first PV systems.

    In the 1990s, when silicon cells were 2 times as thick, efficiencies were much lower than nowadays and lifetimes were reduced, it may well have cost more energy to make a cell than it could generate in a lifetime. In the meantime, the technology has developed substantially, and the energy payback time (defined as the recovery time needed for generating the energy spent to produce the respective technical energy systems) of a modern photovoltaic module is normally from 1 to 4 years depending on the module type and location.

    Typically, thin-film technologies – despite having relatively low conversion efficiencies – reach substantially shorter energy payback times than standard systems (often < 1 year). With a typical lifetime of 20 to 30 years, this means that modern photo voltaic cells are net energy producers, i.e. they generate significantly more energy over their lifetime than the energy expended in producing them.

    About the writer – Rosalind Sanders publishes articles for the pool solar covers review blog, her personal hobby weblog focused on suggestions to help home owners to save energy with solar power.

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