 about whether all the investment needed will actually be forthcoming with respect to both capacity and the quality and reliability of electricity supply. The last section considers the implications of trends in electricity markets, investment needs for the structure of the electricity supply industry, and how new investments could be financed. 2. Past trends in global electricity supply and investment Market Trends World electricity supply - gross output from generating plants - totalled 742 TWh in 2003. The OECD accounts for most of the electricity produced and consumed worldwide. The United States alone accounts for a quarter of world electricity output and other OECD countries for just over one-third (Table 3.1). However, the share of the OECD area in world consumption has fallen significantly in the last three decades, from almost three-quarters in 1971 to 59% in 2003. Demand for electricity services has grown rapidly in recent decades. Worldwide, demand expanded at an average rate of 3.6% between 1971 and 2003. OECD countries saw average demand growth of 3.2%, while non-OECD countries experienced growth of 4.8%. Electricity use has grown fastest in developing Asian countries - notably China, where growth averaged 8.4%. The share of electricity in world final energy use almost doubled, from 9% in 1971 to 16% in 2003. Investment patterns and trends Comprehensive data on total electricity industry investment are not available, but a number of indicators suggest that global electricity investment has picked up strongly in the last decade or SO following a period of stagnation in the late 1970s and 80s. Investment has tended to follow a cyclical pattern around a steadily rising trend, in response to growing end-user demand for electricity. Orders for generating plant, for example, peaked between the late 1960s and early 70s at about 150 GW a year, and then plummeted in the mid-1980s (Figure 3.1). They recently increased again, reaching a new high at the start of the current decade, mainly because of a substantia