While the world's energy need grows like avalanche, studies are continuing on new and sustainable resources to meet the supply. The International Energy Agency (IEA) estimates that by 2040 the world population will be 1.7 billion more than today; energy demand will increase by 25 percent compared to today by the rise in urbanization and per capita income. But demand for electricity, which accounts for 20 percent of total energy consumption today, will be many times greater than demand for fossil resources. The IEA estimates that electricity demand in 2040 will be close to twice that of today (90%).