According to a 2011 International Energy Agency (IEA) report, enough sunlight strikes the earth in 90 minutes to fuel the planet’s entire yearly energy consumption. Even if solar energy’s contribution to the world energy mix remains negligible (less than 1%), its tremendous potential makes it one of the possible leaders of a future “green” energy mix.
Countries have supported the development of solar energy by making it more affordable. The impact of governmental support was proven in the UK, for example, where solar capacity dramatically increased with the introduction of generous feed-in tariffs. The Department of Energy and a Climate Change’s 2015 report acknowledges that “The popularity of domestic PV installations is the result of […] generous tariffs for installations smaller than 4kW”.
“Cumulative installed FIT eligible solar PV capacity”
At COP21, Indian prime minister Narendra Modi launched an International Solar Alliance, comprising 120 member states. The launch was a high profile event attended by French president and host of the summit François Hollande as well as by UN Secretary-General Ban Ki-Moon who praised the alliance’s “vision of a solar-powered path to prosperity”. Modi, whose country was widely criticized for pledging to unambitious climate measures and targets during the meeting, nevertheless expressed great enthusiasm for solar energy stating that with it, “the dream of universal access to clean energy is becoming more real. This will be the foundation of the new economy of the new century.” He then expressed his hopes that the alliance would bring clean energy to “villages and homes still in darkness, for mornings and evening filled with a clear view of the glory of the sun”. Beyond the laudatory words, India will be providing an initial $30m to the alliance, and expects to raise a further $400m from members. The alliance can already boast partners such as government-owned energy multinational Areva, or leading energy provider Enel, showing a serious interest in both the public and private sector.
From the ecological perspective, Photovoltaic (PV), the most developed method used to harness solar energy, is one of the cleanest energies currently available. It is carbon-free, and the energy “spent” in a classic solar panel’s production (or “grey energy”) is compensated within the first 3 years of use on average, on a lifetime usually longer than 20 years.
PV energy has benefited from an exponential market growth over the past years: its global capacity got 2,000 times bigger between 1992 and 2013. If Europe represents the biggest part of this cumulative mix (half of it in 2014), the US and Asia (especially China) are rapidly increasing their capacity, with ambitious targets for the future.
From the financial perspective, the cost of PV electricity production can change greatly from one country to another, mostly because of different governmental incentives. If the average price is still higher than other common electricity production methods, it is constantly dropping. There are two main reasons for this: the dropping prices of silicon (main component that makes most of the price) and the rising efficiency of the solar cells. The energy efficiency is the amount of energy produced (the output, electricity) compared to the amount received (the input, the sunlight). The first “solar cells” converted sunlight into electricity with efficiency lower than 1% (receiving more than a hundred times energy from the sun more than they are producing electricity); nowadays, efficiency is around 15-16% and rising (a 30-40% efficiency is reached in labs), making PV efficient enough compared to other means. In comparison, the efficiency of a car’s combustion engine (from fuel to locomotive power) is, depending on the vehicle, between 10 and 50%.
PV is also an excellent means of decentralizing energy production: solar panels can be set up on any flat surface and don’t need supervising, providing an alternative to huge power plants, which take over lots of land.
Solar energy, however, is not without flaws and several issues need to be dealt with.
First, a 2008 report from the Washington Post pointed to the problem of chemical pollution: the refining process used to produce polysilicon needed for solar cells has a toxic by-product called silicon tetrachloride. And even if that by-product can be recycled into more polysilicon, the equipment required to do so is extremely expensive. Hence some manufacturers in China (the biggest solar cell producer) dumped it in rivers or empty fields, leading to public health problems. However, in 2011, China set up laws to force companies to recycle this tetrachloride. The bigger problem is that China’s environmental standards are lower than Europe’s, leading to a carbon output about twice as big for the production of solar panels.
The recycling of solar panels must also be considered. Nowadays, up to 85% of the mass of a classic solar panel can be recycled. However, the recycling process requires specific equipment and is expensive, and thus raises the question of the recycling responsibility. Most manufacturers take responsibility for either recycling the panels themselves or hiring a third party to take care of it. However, appropriate policies and regulations are needed in order to ensure a proper systematic and safe recycling process, as only large-scale recycling programs can be cost-effective.
The main drawback of solar energy is contained in its name: it needs sunlight. In the UK, demand for electricity peaks in winter, whereas solar electricity’s highest production is met in summer. Solar electricity production is dependent on the weather, and is weak or non-existent at night. As we still lack means to properly store energy a balanced mix of energy has thus to be set up to ensure a stable basis of electricity production at all times. In Germany, this continuous production is assured mostly by coal power plants, thus raising many complaints from environmental activists. Having this mix composed only of renewable energies will be a tough challenge. On the solar side, the use of Concentrated Solar Power (CSP) plants, that allow heat conservation, is an option to consider. However, by lack of investment, and even if some large plants are currently being built (like the Ouarzazate solar plant), this method is currently lagging and failing to reach its full potential.
Technical issues are not the only factors holding solar back. While still at its early stages, the solar industry heavily relies on public investment and support, which in turn attracts private investments. Public policy regarding solar can, however, be fluctuating and create instability in the solar industry.
The UK provided a striking example when it decided to cut financial aid for the installation of rooftop solar panels by 65%, just after COP21, provoking outrage in the climate industry and among climate activists. Green MP Caroline Lucas reacted to the cuts, accusing the British Government of “happily take credit for being climate champions on an international stage while flagrantly undermining the renewable industry here at home.” She added that ”To cut support at this stage not only dashes hopes of Britain leading the way in meeting the 1.5 degree target set in Paris last week, but also risks putting thousands of people off of work.” The cuts have already had concrete effects, with the announcement early this year that Ikea would stop selling solar panels.
Despite its huge potential and the worldwide enthusiasm it has recently generated, what solar really needs to fully develop is commitment from policy makers and a long-term approach that will guarantee stability within the industry and in turn attract private investments. Only then can we hope for a solar future.