Variable energy sources: a global overview

Torna al sommario Alessandro Clerici| CESI corporate advisor and chair of WEC Study Group
Daniele Daminelli | CESI assistant to CEO and WEC Member of The Study Management team

In 2014 World Energy Council (WEC) together with CESI, the Italian testing and engineering company that provides services throughout the energy value chain, launched a study group to increase awareness of the technical, economic and market issues related to integrating variable energy sources (VRES) such as wind and photovoltaic (PV) into electricity systems.

The WEC and CESI Report entitled Variable Renewables Integration in Electricity Systems – How to get it right has been launched on September 20, after 2 years of activity of the relevant study group.
Renewable Energy Sources (RES) offer many benefits, such as CO2 emissions mitigation, fossil fuels import reduction and new jobs creation, just to name a few.

At the same time, the recent expansion of VRES such as wind and photovoltaic (PV) also poses for their variability certain challenges, both technical and economic when assuming an appreciable share in the electricity production mix.[...]
The global installed RES capacity has more than doubled over the past ten years, from 814 GW in 2004 to 1,712 GW by the end of 2014. This growth was mainly driven by wind and solar power which increased from 48 GW and 3 GW in 2004 to 370 GW and 181 GW respectively in 2014. Hydro is still the largest RES accounting for 73 percent of global RES output.
The relatively low share of wind and solar in the global electricity production - 4 percent of total in 2014 - can be explained by their still small installed capacity and a lower number of equivalent operating hours per year (world averages are 2,000 hours for wind and 1,200 hours for PV).
In developed countries, the 2015 investments reached USD 49 billion in Europe (21 percent less compared to 2014), USD 44 billion in US and USD 36 billion in Japan. The staggering investments especially in Europe underline the business case for VRES, which have grown at a tremendous rate, mostly due to the supportive policies and measures.[...]