Solar Energy: The future of energy is bright Of all the renewables, solar power is the biggest hope for a future seismic shift in energy. We are seeing large solar farms feeding grids, household solar panel installations are trending and solar frequently makes the news for breakthrough milestones. Solar power is growing in market share and being adopted around the world. Whilst many consumers choose solar energy for environmental reasons, it is the practical efficiency and lower costs that can drive wider uptake and that’s where the power of research and innovation will come into play. By Richard Forsyth
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he sun is a fusion reactor that fuses 620 million metric tons of hydrogen every second in its core and unlike oil, it has a lifespan of around 5 billion years before it runs out. The days of finite carbon fuels are numbered. The concept of finite resources and increasing consumption is the talking point and chief concern of the era. Meanwhile, there is enough solar energy calculated to be available daily to power the Earth for 27 years. It’s our best hope to replace carbon-based fuels.
Costing the sun It was in 1876 that William Grylls Adams and Richard Day discovered when selenium was exposed to light it produced electricity, which was the first seed of science for solar power. It was only relatively recently, in the late 50s that solar power became commercially available. Solar panels can absorb photons – particles of light – and transform them into electrical power, by taking electrons from atoms. The solar industries have witnessed exceptional growth and have the potential to shift the balance of our entire global power supply in the future.
As with any technology shift on a global scale, in the end it boils down to economics, if it’s affordable and efficient as a daily solution. The price of a solar panel in the 1970’s was well over 200 times higher than it is today. We are at a stage where choosing solar can be seen as a practical option for home owners and also for governments, but efficiency and performance is key. This journey of improving conversion efficiency is on-going. The success of energy as a commodity will always depend on the economics of its daily viability and solar power is improving consistently. This is why innovation has been and will continue to be, the key for its wider adoption. Photovoltaic (PV) technology is evolving and there have been recent breakthroughs.
PV Innovations that make the difference Much of the innovation that is powering the solar industry’s success can be seen in materials research. For example, there is great potential with perovskites, a class of material that has superconductivity, magnetoresistance and it is easily synthesised - considered ideal for low cost and effective photovoltaics.
Whilst rooftop PV is growing, most of the growth is down to ground-based PV. Solar farms between 1 and 100 acres are increasingly visible in the rural areas of many countries.
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Perovskite’s structural compositions can be fine tuned to create material which can absorb any frequency of light. Silicon in comparison only absorbs light in a limited range of frequencies. Perovskite thin film solar cells are lightweight and flexible. They can even be printed directly on materials like glass or metal. This gives rise to exciting possibilities in the construction of buildings in the future. One idea is to fit all buildings with facades that are functioning as solar collectors. This is making buildings into mini power stations, that store and release energy from walls and exteriors. Such buildings could be self-reliant in providing heat and light for the whole year around. What’s exciting about this idea is that the higher the performance that localised solar power can achieve, the more self-reliant and off grid the applications can become. For rural areas this is particularly useful but this could be applied to city urban areas too. Take for example, the street lights in San Diego, where they are powered by the sun in the daytime to power light emitting diodes (LED) during the night to keep the streets lit. Combined with smart sensors it’s been proposed these streetlights will be able to direct drivers to parking spaces. A project in Finland by VTT Technical Research Centre is creating prototypes of solar powered trees, with a view to future solar forests or perhaps trees for your back yard. They have 3D printed trunks made of biomaterials whilst the leaves are basic solar cell power converters. Another innovation does away with panels altogether and instead uses paint – which comprises of polymers dissolved into a solvent which can be applied to any surface. Every aspect of a building that faces the sun is being scrutinised for possibilities for absorbing solar energy. Adapting windows to harvest light is a focus of research. In the US, The National Renewable Energy Laboratory (NREL) has created window technology where a household window transforms from clear to tinted in sunlight, creating electricity during the process. They used advanced materials including the aforementioned perovskites,
and single-walled carbon nanotubes. These kinds of innovation give us a glimpse of possibilities for solar harvesting in new and exciting ways. A point here worth including, is that beyond the technical innovation around improving efficiency, aesthetics plays a part in consumer adoption. The fact is, that large solar panels, resembling great mirrors on rooftops, is not everyone’s idea of homely or blending into the neighbourhood. A recent innovation focus is in making solar power an invisible energy collection device, so your house will not look out of place in a street. This is about blending in. A well-publicised example of this kind of innovation can be seen in a technology devised by the company, Tesla. Tesla is rolling out solar tiles that look like conventional roof tiles – called building-integrated photovoltaics (BIPV). Human factors such as this are an important consideration for technology adoption.
The National Renewable Energy Laboratory (NREL) has created window technology where a household window transforms from clear to tinted in sunlight, creating electricity during the process.
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EU’s total achievement. However, it’s been suggested renewables could provide a third of Europe’s electricity in 2018. As the European Power Sector in 2017 report by Agora Energiewende points out, this is all in a time when we are seeing additional power demand in many sectors due to the digital revolution – for instance, video streaming, electric vehicles (800,000 vehicles by end of 2017) and Bitcoin mining. This, combined with increasing population expansion and subsequent electricity reliance. As our commitment for renewable energy bolsters, the demand for electricity will continue to rise.
Local schemes leading to national transformations
The power from harvesting sunshine At present solar PV does not produce the same amount of equivalent electricity over a year as coal-fired power and we still use about 100 times more energy in the form of oil and 90 times as much in the form of coal. Despite this, solar power is tipped by many as the renewable that could surpass coal and rival oil in just a few decades. To demonstrate the growth trend, according to Data Bridge market research, the global photovoltaic glass market is projected to grow at a CAGT of 33.5% during the forecast period of 2017 to 2024, from USD 4.39 billion in 2016. The year 2017 was an historic year for solar power. More solar PV capacities were installed globally than any other power generation technology according to Global Market Outlook report 2018-2022. The report goes on to say that ‘Solar alone saw more new capacity deployed than fossil fuel and nuclear combined. Solar added almost
twice as much capacity as its renewable peer, wind power...with a total global solar power capacity of over 400GW in 2017 after solar exceeded the 300GW mark in 2016 and the 200GW level in 2015.’ Whilst rooftop PV is growing, most of the growth is down to groundbased PV. Solar farms between 1 and 100 acres are increasingly visible in the rural areas of many countries. In Europe this is linked in part to the EU’s targets for renewable energy. The latest political agreement was put forward by the Commission, the Parliament and the Council on 14 June 2018, to include a binding renewable energy target for the EU for 2030 of 32%, with a clause for an upwards revision by 2023. Many EU countries have already not only hit the EU’s 2020 renewable consumption target but also surpassed ambitious country targets, such as Sweden which has a renewable consumption closing on 50% of total energy consumption. The other end of the scale has countries such as Latvia struggling to commit to very low country targets, offsetting the
Whilst public adoption is key, it also takes a concerted effort from governing authorities to champion renewables like solar. In the UK there is a movement called UK:100 where a network of local authorities have committed to a transition to 100% renewable energy by 2050. This network connects local government to national government and consumers with the sole aim to transform the UKs energy resource to renewable. Around the world, similarly, around 400 cities are committed to ditching fossil fuel by 2050. It will be initiatives like this that can provide a platform to connect together local action for change in a way that drives national transformations. Another example seen in the UK, is a campaign to encourage schools to use solar energy. This was proposed by the Friends of the Earth organisation in their Run to the Sun campaign. The chief message from the campaign was that cash strapped schools can benefit from savings of £8,000 a year by generating their own independent source of electricity. The school gets paid for every unit of electricity the solar panels produce, for either the school, or if it is sent to the national grid (the Feed in Tariff). Such a scheme has the knock-on educational effect in schools of influencing the next generations about the advantages of using solar power. It’s true that the original sums for installation of solar panels can seem daunting, in the tens of thousands, yet with fundraising, help from local education authorities and councils it seems more achievable. Of course, it’s important that governments keep supporting solar, rather than imposing new taxes on it, because without that support it can halt this game-changing solution in its tracks.
Is the sun always shining? It goes without saying, having sunny weather and heatwaves really helps solar perform. Europe’s recent summer heatwave in Britain, France, Germany and northwest Europe has shown how effective solar is in good conditions. In Britain and Germany, it helped break solar power generation records. Ironically, in locations where climate change maybe developing this kind of extreme weather, the more suitable solar will be for high performance. Ultimately, solar power is a renewable with great promise and one that will be increasingly relevant to solving our energy issues as we intend to move away from carbon fuels. Innovation for greater performance, greater economic viability and greater general appeal will make solar a power to contend with.
Perovskite’s structural compositions can be fine tuned to create material which can absorb any frequency of light.
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