Worldwide growth of Photovoltaic and Wind installed power, by Emilio Martines. Data from IEA Photovoltaic Power Systems Programme, European Wind Energy Association and Earth Policy Institute.

For a change, here is a non-Cassandric post. Look at the data in the figure above, kindly provided by Emilio Martines, member of ASPO-Italy. The growth of photovoltaic and wind energy has been impressively fast during the past 2-3 decades. The log scale evidences the exponential growth of both technologies. There are no signs of slowdown, so far, despite recessions and the bad state of the economy. According to the graph, wind power grows of a factor 10 in less than 10 years, PV power takes little more than 5 years. At these rates, both wind and PC could reach the goal of one installed terawatt (TW) each around 2020.

Of course, the capacity factor of wind and PV is smaller than that of conventional sources, so that one TW of renewable power can produce considerably less energy than one TW of - say - a coal fired plant. Then, there is the question of storage and other issues. Nevertheless, the data are impressive, considering that the total electric power installed in the world today is around 2 TW. It is exactly the value of renewable peak power that we could reach by the end of the current decade. Are we seeing a glimpse of light at the end of the tunnel?

Obviously, nothing can grow exponentially forever. But we have nevertheless generated an energy revolution: renewable power has a market and it grows. It is a revolution that can't be stopped any more. It gives us a chance to replace fossil fuels before it is too late. It is a fighting chance, but we have it.