Megawatt park is located next to the E18 between Vasteras and Enkoping. Photo: Jörgen Appelgren
The sun stands today for a fraction of the world’s total electricity generation – more than one percent. But the expansion is fast, and the potential is large enough to replace the nuclear power and fossil fuels, claims a Swedish professor.
– There are only two technologies that can enable a world where 10 million people use as much energy as we in Sweden: solar energy and advanced nuclear power, says Bjorn Sanden, newly appointed Professor of Innovation and Sustainability at Chalmers Department of Energy and the environment.
Nuclear power, he believes, is the wrong way to go, because of the risk of accidents and proliferation. What remains is the solar energy. And it is more than enough to replace both existing nuclear power and fossil fuels, according to the professor.
– The amount of solar energy reaching the Earth’s surface every hour is equal to the total world energy consumption for a whole year. The potential is enormous, he says.
In recent years, solar power has grown rapidly. Last year installed 40 gigawatts of new solar power in the world, according to the international energy organization IEA PVPS PV applications.
– In terms of power growing solar energy is already faster than nuclear power increased when it was built like most of the 1980s. Installations on commercial basis is done throughout the world by a lot of different reasons, says Bjorn Sanden.
He gives several examples of driving forces: China To reduce air pollution from coal power, Japan will need to replace nuclear power and reduce its dependence on imports of oil and natural gas. In the US, more people want to cut the power cord to the power companies, German and Italian homeowners want to lower their elnota. On the African and Indian countryside gives the solar cells electricity where the grid is missing.
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Bjorn Sanden is convinced that the high rate of expansion will continue, not least because photovoltaic industry has invested in factories that now syringe from the 50 gigawatts of new solar power per year. It is nine times more than the total installed wind power in Sweden at the turn of the year.
– If demand were to decrease slightly as prices drop and then demand increases again. So the development will continue for a good while, he said.
But rapid growth is from a modest level. The world’s installed PV power at year end amounted to 177 gigawatts, according to the IEA PVPS estimate. This is equivalent to just over one percent of the total electricity production.
Although it considers Bengt Stridh, which is solar scientist at ABB Corporate Research and Adjunct Lecturer at Mälardalen University, that solar energy can play an important role in replacing fossil fuels and reducing greenhouse gas emissions.
– Absolutely. Not solar energy alone, but together with wind energy, hydropower and biomass and other renewable energy. The potential for solar energy is incredibly high, by far the largest of all renewable power sources. Even here in Sweden is potential, he said.
late autumn low sunlight warms wonderfully when new technology hits Bengt Stridh of Sweden’s largest solar park, Megawatt Park between Enköping and Västerås. It turns 92 trackers slowly from dawn to dusk to catch the light. The park has been in operation since February 2014 and Bengt Stridh will soon release a report that states that Sweden does not pay to invest in solar trackers to maximize electricity production. Photovoltaic modules have become so cheap that you might as well get some extra modules instead.
The collapse in solar modules is an important explanation for the the expansion has gained momentum. In recent years, prices have leveled off, but between 2008 and 2012, the price fell by 80 percent in many countries.
– In the past, the economy a major obstacle. Even optimistic industry associations could predict that module prices will fall as soon and that the installation rate would rise so fast, says Bengt Stridh.
Meanwhile, increased efficiency of silicon solar cells, the technology that dominates large market. When ABB Corporate Research, bought its first solar modules in 2005 so they could convert 11.9 percent of incident solar energy into electricity. Megawatt Park’s solar modules, which was bought for around two years ago, has an efficiency of 15.5 percent. Since then, the technology has been improved still further, and cut the solar cells sold in the market today is around 16 percent.
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But technology development must continue if the solar energy to become a major source of power to be reckoned with, consider Bengt Stridh. Here are some examples:
The efficiency must increase. A technology leap that dramatically increases efficiency at a reasonable cost, Bengt Stridh difficult to see the next 5-10 years. Therefore, the current trend in the improvement of a few tenths of a percentage point per year continue.
Production costs must fall even more. One way could be to continue to thin silicon layer, in which electrons are knocked off by the sun’s rays. Another possibility is to reduce the amount of silver in the conductor that transports electrons.
The cost of other components and the installation also need to fall further .
The life span can increase. The economic calculation becomes easier to obtain return for each year that day warranty period of 25 years could be extended.
One problem with solar cells is the they do not produce any electricity when the sun shines by its absence. If the solar energy to be embraced in large-scale energy must either be distributed through the grid over large distances or stored, perhaps in reservoirs, batteries or hot water.
Technically, it is possible to solve, according to both Bengt Stridh and Bjorn Sanden. But there are other challenges. Bjorn Sanden emphasizes that large energy companies try to slow down the transition because they lose financially if today’s centralized power is replaced by many small producers of solar electricity. If solar energy is to be built on massive front so also requires political decisions as well as major investment.
– But in the long run should become a very profitable economically speaking. In particular, compared with a climate crisis would cost the society. I actually think that solar energy is vital to our civilization’s survival and development, says Bjorn Sanden.
