The value of the global market for renewable energy was nearly $225 billion in 2010, but is expected to increase to $331 billion in 2015, for a five-year compound annual growth rate (CAGR) of 8.1%. The largest segment of the market, wind energy, is projected to increase at a CAGR of 6% to $87 billion in 2015, after being valued at an estimated $65 billion in 2010. The second-largest segment, hydroelectric energy, is estimated at $62 billion in 2010, but is expected to increase at a CAGR of 3.5% to reach nearly $74 billion in 2015.

The solar energy segment will have the highest rate of growth in the next five years, with a CAGR of 17.1%, rising from an estimated $44 billion in value in 2010 to $97 billion in 2015. The biofuels segment will increase in value from $45 billion in 2010 to $60 billion in 2015, for a CAGR of 6%

The geothermal energy segment will experience a CAGR of 8%, increasing from $6 billion in 2010 to $8.8 billion in 2015. The smallest segment, energy derived from the ocean by way of tides, waves or wind, will rise from $2.4 billion in 2010 to $4.4 billion in 2015, at a CAGR of 12%.

Market studies have become increasingly “stove-piped” regarding green technology in general and renewable energy sources specifically. This is natural. Each of the sources of renewable energy employs differing technologies, has differing constraints, and offers different possibilities to differing classes of users.

However, bringing renewable energy sources together allows an assessment of the combined contribution they can make in reducing CO2 emissions, helping countries achieve energy independence, conserving natural resources, and bettering the environment in various ways. Looking at renewables in a single report also allows an assessment of policy-relevant issues in terms of gauging where support is warranted, how close some energy sources are in terms of providing significant contributions to the portfolio of available resources, and what metrics might be useful in deciding what energy sources are best-equipped to satisfy the needs of individual countries and regions.
 
The scope of this report is intentionally wide. We cover the major sources of renewable energy as primary fuels—hydroelectric, wind, solar, liquid biofuels for transportation, geothermal, and oceanic sources (wave, tidal and thermal). There is no shortage of reports on each of these in the marketplace. What is lacking, and what this report is intended to provide, is a global perspective that places each of these sources in a relevant context for decision makers in both the public and private sectors.
 
This report is intended for professionals at several levels working in the energy and/or environmental field. Although the report is structured around specific technologies, it is largely nontechnical in nature. That is, it is concerned less with theory and jargon than with what works, how much of the latter the market is likely to purchase, and at what price.
 
As such, the report’s main audience is executive management, marketing professionals, and financial analysts. It is not written specifically for scientists and technologists, although its findings concern the market for their work, including the availability of government and corporate research funding for different technologies and applications, so it should interest them as well.
 
Others who should find the report informative include government agencies and environmental and public policy interest groups concerned with energy, sustainable development, and the environment.