The Solar Revolution?

Of all the renewable technologies, solar has grown the fastest in recent years, with current capacity 48x higher than in 2004. 2014 saw a record 40GW global growth, with the biggest markets being Japan, China and the US. Ontop of this, solar is reducing dramatically in price and this year, it became the cheapest form of electricity in Chile.

Are we about to see a solar revolution?

Many experts claim we are reaching a 'tipping point' where advances in solar technology, such as the Tesla lithium battery that allows solar energy to be stored, will result in rapid and widespread distribution of solar power. A study published earlier this year by Pinner & Rogers (2015), stated that this is the 'age of solar power' and they attribute this to four factors:

1. Regulatory support by governments, including subsidies and feed-in-tariffs

2. Decreasing costs, with prices reducing by up to 8-12% a year

3. Industrialisation; growing demand has led to production process improvements and increased competition which has resulted in cost reductions

4. Improved technology including increased efficiency (currently at about 20%) and developments in storage of solar energy

A UK Solar Farm
Source: The Green Organisation

So, how do photovoltaic panels work?

A photovoltaic panel is made up of a number of cells. These cells are created using two semi-conducting layers (usually silicon). An electric field must be established to enable this to work, which is done by making one layer positive, typically by adding boron, and the other layer negative, by adding phosphorus which adds additional electrons to the silicon.

As a result of this electric field, when a photon from sunlight knocks an electron from an atom, the electron then moves towards the bottom of the cell and is collected on metal conductive plates. From here the electrons are transferred through wires where they flow as an electrical current that can be used as a power source.

Layers of a Photovoltaic Cell
Source: pbs.org

Solar power is hugely flexible, able to power a device as small as a calculator but with the potential to power an entire city. There are continuous advances in this technology and a recent study by Jin et al. (2015), demonstrated progress in increasing efficiency of solar cells by introducing a new oxygen-based coating which enhances the amount of charge carriers, leading to a greater conversion of sunlight into electricity.

With increasing innovation in this area we are seeing rapid advances in solar technology. As well as becoming more efficient, the ability to store solar energy is now an option; as these technologies develop and reduce in price, solar power will become increasingly attractive, gaining more investment and increasing in distribution. I really do hope that the experts are right and we are about to witness this 'tipping point' into widespread installation of solar technology.