Why We are Entering the Solar Age

With concerns about rising oil prices and climate change spawning political momentum for renewable energy, solar electricity is poised to take a prominent position in the global energy economy. However, claiming that we are ready to enter the solar age, when the global consumption of oil is steadily on the rise may sound as a green-minded false prophecy. All predictions of an oil peak made in the 1960s were wrong : We never experienced lack of oil as was doomed inevitable after the 1973 oil shock, and the exhaustion of world oil reserves is a hotly debated topic. For example, an oil industry geologist tackling the mathematics of Hubbert’s method suggests that the oil peak occurred at the end of 2005.

Predicted scenario by 2040. Out of a total electricity consumption of 36.346TWh (from 15.578TWh in 2001, IEA) renewable energy sources will cover 29.808 TWh, with solar energy becoming largely predominant. (Source: EREC).

On the other hand, the price of oil has multiplied by a factor of 10 in the last few years, whereas in the US, for example, domestic petroleum now returns as little as 15 joules for every joule invested compared to the 1930s when the energy return on energy invested (EROI) ratio was 100.

The demand for oil has boomed in concomitance with globalization and rising demand from China and India. In China and India, governments are managing the entrance to the industry job market of some 700 million farmers, that is about twice the overall amount of workers in the European Union. Global energy demand will more than double by 2050 and will triple by the end of the century. At the same time, an estimated 1.64 billion people, mostly in developing countries, are not yet connected to an electric grid.

Finally, the world’s population is rapidly learning that climate change due to human activities is not an opinion: it is a reality that in the US has already hit entire cities (New Orleans, 2005), and in southern Europe hurt people and the whole ecosystem with temperatures close to 50°C in mid-June 2007. Overall, these economic, environmental and societal critical factors require us to curb CO2 emissions soon, and switch to a massive scale use of renewable materials and renewable energy (RE) until the day when cheap and abundant solar energy becomes a reality.

Access to affordable solar energy on a large scale, admittedly, is an enormous challenge given that presently only 0.2% of global energy is of solar origin. The low price of oil in the 1990s ($10–$20 a barrel) put a dampener on scientific ingenuity for the whole decade, since many developments were put on the shelf until a day in the future when their use would become “economically viable.” All is rapidly changing with booming oil prices. Solar electricity generation is now the fastest-growing electricity source, doubling its output every two years. The solar energy market has grown at a rate of about 50% for two years, growing to 3800MW in 2007 from 2521MW in 2006.

PV Technology evolution. (Source: EPIA, 2004).