Solar energy: the past, present and future

Annual long-term average for global horizontal irradiance (in kWh per m2 per year). Source: Gerlach et al. (2011).

What is your train of thought when looking at the map above? If the question was: "Is solar energy globally feasible?", which of the following would be your response?

"No: some areas of the world receive barely any sunlight."

or,

"Yes: everywhere receives some sunlight."

I hark back to my first post on the blog. The Achilles' heel of solar energy for so long was the lack of sunlight hours for some populations, as well as the variability of energy generation from day to day. Energy storage was required to eliminate the uncertainty of receiving sufficient solar energy from day to day. Widespread home energy storage was first made more feasible with the release of Tesla's Powerwall in 2015. After this, perceptions changed.

History of the development of solar power

The solar movement was sparked by the observation of the photovoltaic effect by Alexandre Becquerel in 1839: the ability of a light source to induce an electric current in a material (Recherches sur les effetsde la radiation chimique de la lumière solaire, au moyen des courants électriques). About 50 years later, a patent for the first solar cell was gained by Edward Weston in 1888 and developments have been made ever since. In the 1950s, solar cells were adapted by Bell Labs for space activities which in turn fuelled the boom in space exploration, and the first commercial company for solar cells was founded in 1955. 

1985 was a breakthrough year for solar energy: technological developments led to a doubling in the efficiency of solar cells from 10% to 20%. To date, the recognised record for efficiency is 34.5%, although this is reported to have been exceeded unofficially in 2008. In the future, cell efficiency is likely to increase with investment. Investment is inevitable because the solar industry has proved that profitability is increasing. This is very good news for a world striving towards a net zero-emissions future. However, despite progress, there have been setbacks along the way, and some predict more setbacks to come… 

Progress in state investment: The good and the bad 

Some nations have made outstanding investment towards the cause for solar energy generation for example, China (Reuters, 2016), Germany (Fraunhofer, 2016) and Japan (Reuters, 2015). Greece has also installed significant photovoltaic capacity by offering feed-in tariffs to secure long-term contracts, leading to a solar boom in 2009. This meant that Greece currently ranks as 5th in the world for PV capacity per capita (IEA, 2015). However, the combination of the financial crash and over-saturation of the market led to a collapse. Many proposals and constructions have been halted, and all installed photovoltaic power stations must pay a tax to operate. 

The example of China tells a similar tale. I have already referred to China and their state-led incentives for mass production in a previous post. This has helped to make solar energy significantly more affordable and desirable. However, high Chinese output is keeping prices low, which is stunting the growth and foundation of solar companies elsewhere. Many European and American companies are relying upon a reduction in Chinese output in order to become more profitable (The Guardian, 2016). As a result, the competition in the market is not as healthy or as innovative as it could be. Innovation then rests more significantly on state investment.

Over in the US, a pioneering solar future is looking uncertain under a Trump administration. The Guardian’s Arthur Neslen paints a picture of a wary solar industry, speculating what the outcome of this election means for them. Under Obama, the solar industry is soaring thanks to investment tax credits of 30% tax rebate. This has helped initiate a record 4.1GW of solar power installation in the third quarter of 2016 in the US. Solar companies disagree as to what happens next under Trump. Some (including CEO of SolarPower Europe, James Watson) are certain that these state initiatives for solar and wind development will be scrapped under the new administration. Not unlikely with the appointment of Rex Tillerson (ExxonMobil CEO) for Secretary of State, alongside other oil industry executives and climate change deniers. However, the Republican-led congress under Obama has shown significant support towards renewables industries by voting to extend the tax credit scheme to 2022. Furthermore, solar energy has become one of the cheapest sources of electricity. Surely, as a businessman, Trump will recognise the profitable power of the industry? 

What about progress in the private sector? 

If you’ve learned anything about me over the course of this blog, it’s probably that I’m a huge Tesla and SolarCity fan. These companies have really captured by interest in mainstream renewable technology development. Old news, perhaps, but in August 2016, Tesla and SolarCity formally announced their deal to merge. Praised by some, criticised by others. Under this acquisition, Tesla made clear to the public its hopes of diversifying beyond electric vehicles into renewable energy generation and storage. 

Despite financial reservations beyond my remit from economic experts, I thought that this made sense. Surely merging the number one provider of residential and commercial solar energy in the US with the second largest manufacturer of plug-in vehicles worldwide was a progressive move? As a consumer, the concept of buying into a renewable lifestyle under one brand is appealing. Apple have achieved this concept. It's clear that Tesla wants in on this too. Beyond Tesla and the US, private sector growth is looking strong thanks to the state. In 2014, 6 out of 10 of the top solar companies by output were Chinese, including Trina Solar and Yingli Green Energy (Forbes, 2014).

At present, private investment depends heavily on state incentives, restricting development in some countries depending on their budget. Furthermore, the nature of the global economics means that there is a framework of quarterly reviews, meaning that many companies opt for short-term gains as opposed to long-term ambitions to build a positive presence. This is paralleled with the short-term nature of democratic elections. Both of these could act to slow progress towards a solar and fully renewable future.

Overall, with solar energy storage now part of global picture, the future of solar looks promising. But a balance must be achieved to make it a profitable industry for all, the environment included. With the recognition of the profitability of the industry, independent private sector progress is ready to flex its muscles, but the state must recognise their role in regulating this progress to promote optimal and sustainable development of the industry.