Why Next-Gen Solar Panels Could Revolutionise Energy Generation
This article is contributed by Robert Puto, Global Head of Photovoltaics at TÜV SÜD. He reveals why the next generation of solar panels have the potential to revolutionise global energy generation.
It is widely accepted that the future of energy is renewable. An endless supply of energy, after all, is a rather enticing prospect in the face of diminishing commodities. It is also clean; safe; generally requires less maintenance than traditional generators; and produces little or no harmful waste products. And when it comes to the renewable energy sector – as far as potential is concerned – solar energy stands out among its peers. Each year, for example, the sun lavishes 3.85 million exajoules  of energy on the earth’s atmosphere – approximately 7,900 times  the amount consumed by mankind. To put that into perspective, capturing just 10%  of the sun’s energy would – in one fell swoop – provide enough power to replace all of the world’s fossil fuel sources. As if that wasn’t enough, solar energy is also noise free and can generate energy from far-flung places like satellites orbiting the earth, baron deserts and mountains.
Today, however, solar panels (photovoltaic systems) produce just 0.1 per cent  of the electricity used in the world. Why? Principally, because photovoltaic (PV) technologies are still expensive compared to fossil fuels, ineffective on cloudy days and require a large area to generate a substantial amount of electricity. Currently, for example, one of the largest solar power stations in the world covers more than 10 square miles (16.9 km squared) and creates enough energy to power 200,000 homes . This is in many ways impressive. However, some experts suggest that to provide power for the entire United States – with current technology in place – an area approximately 100 miles (160.9 km) squared would be required .
The good news is that engineers, researchers and academics continue work round the clock to find solutions and grid parity (the point at which PV-generated electricity becomes competitive with the retail rate of grid power) is starting to become a reality in some countries. Continued advancement toward grid parity will inherently make PV technology a more commercially viable option for large and small-scale projects – a critical element of success.
As the Global Head of Photovoltaics at TÜV SÜD, which provides end-to-end testing, inspection, auditing and certification services to some of the world’s largest renewable energy projects, I have the enviable position of overseeing, aiding and enabling such advancements. For example, my team and I not only work with manufacturers to test and certify solar panels, but also with operators (contractors, installers and importers) to audit their suppliers or OEM factories, including pre-shipment inspections of the goods ready to be shipped to the installation location. Moreover, we support the PV industry with testing and validation starting from the R&D phase, including extended test programs which provide higher levels of confidence than existing standards in terms of reliability in the field, enhancing the “bankability” of the new products.
The following outlines two revolutionary concepts currently in development that – along with the advent of smart grids (digitally enabled electrical grids that gather, distribute, and act on information about the behaviour of multiple energy sources in order to improve their holistic efficiency) – could finally see solar panels fulfil their potential and, in doing so, account for 5 per cent of the world’s energy needs in less than 20 years (a 4,900 per cent increase on today) – in line with the expectations of the International Energy Agency (IEA) .
1. Third-Generation PV Cells
After years in development, third-generation PV cells (which include a wide range of materials engineered with semi-conducting properties at the molecular level) are starting to become a reality. Their benefits are threefold. Firstly, they have the potential to double or maybe even treble the efficiency achieved by first-generation (crystalline silicon) and second-generation (thin-film PV) cells. This means the 10 square mile solar power station mentioned earlier could in years to come generate enough energy to power 600,000 homes, rather than 200,000 (or be a third of the size).
Third-generation PV cells also have the potential to cost significantly less than their predecessors as they use inexpensive high-throughput printing and coating techniques that require less energy during manufacture and lower capital investment in equipment. The clean room environments required for first-generation and second-generation manufacturing, for example, are not required for third-generation PV fabrication.
The third and final benefit of third-generation PV cells is flexibility. For example, as their high light-absorption properties can be made nanometres thick with high-transparency levels, they can be screen-printed onto windows. This provides them with the potential to be built into the very fabric of our built environment. In the future, everything from buildings to bridges could act as giant plants – effortlessly harnessing the suns energy to fulfil our escalating needs.
2. 3D Solar Panels
The second innovation we’re seeing come to the fore is based around form rather than function: 3D solar panels. Unlike their 2D cousins, 3D solar panels – according to initial prototype testing – capture almost all the sunlight striking them. A core inefficiency of flat panels, for example, is that they induce the reflection of sunlight. According to historical records, the first 3D solar panel was designed in 2007 by Georgia Tech Research Institute . However, a multitude of universities and companies now have designs in development.
An example of such solar panels is the (March 2012) 3D design from MIT Engineering Professor, Jeffrey Grossman, and his team. The vertical accordion-like tower structure can produce up to 20 times more energy per square foot than traditional flat arrays and almost as much energy on cloudy days (the Achilles’ heel of 2D solar panels) as sunny days. The form was selected by a bespoke software analysis tool that tested countless solar configurations to establish which could generate the most energy. They then assessed the highest performing structures for ease of manufacture, transportation and cost.
According to the MIT team, in general, 3D shapes could have a big advantage over flat panels in locations where space is limited, such as flat-rooftop installations or in urban environments. Such shapes could also be used in larger-scale applications, such as solar farms, once shading effects between towers are carefully minimised – a challenge the team is tackling now. Due to their ability to be transported flat and unfolded when required Grossman also believes his 3D solar towers might end up acting as charging stations for electric cars, an interesting and potentially powerful theory.
For 3D solar panels to be successful, however, they do still need to overcome a variety of hurdles underpinned by commercial viability. The tower structures, for example, require more panels to cover the same footprint as an ordinary 2D configuration, which makes them more expensive to manufacture. Having said that, some believe3D arrangements can counteract this cost by reducing the need for a mechanical sun-tracking system (as they can capture sunlight at optimal angles throughout the day). Ultimately, new technologies have to be rigorously tested for feasibility and reliability, and production techniques need to be optimised before they are ready for mass production.
The Sky’s the Limit
The sun’s energy is a phenomenal resource. It already powers me and you – providing us with life and sustenance – and in years to come will increasingly power our homes, cars and goods. In the PV sector, third-generation PV cells and 3D solar panels, possibly in tandem, have the potential to lead the charge (along with innovations in the solar-thermal technology sector and smart grids). These innovations genuinely harbour the potential to provide us all with a brighter future (both economically and environmentally) – one my colleagues and I hope to play a small but important role in enabling.
About Robert Puto
Robert Puto holds the position of Global PV Director in TÜV SÜD. He is in charge of the Photovoltaics business in TÜV SÜD globally, with operations in Mainland China, Hong Kong and Taiwan, Japan, India, Germany, Italy, USA, Eastern Europe, etc.
He began his career with TÜV SÜD in 2006 in Shanghai, as Electrical Safety Department manager in product testing and certification. In 2007 he started developing PV services for TÜV SÜD from China and expanded it globally to a multi million Euro business today.
He will continue to lead the development of Photovoltaics and other Renewable Energies for TÜV SÜD globally and in particular in the AP region, through identifying strategic growth opportunities and implementing the Group’s corporate objectives.