All the hype, investment, policies and incentives may be finally paying off. Power generation and transmission in America in the next 10 years will look nothing like it did in the previous decade, to say nothing of the years before that.

Alternative sources of power will soon represent a larger proportion of the nation’s composite generation of electricity, a composite that will be far more diverse than it has ever been before.

According to the North American Electric Reliability Corp. (NERC), “an unprecedented, continuing change” in the way power is generated in this country will take place over the next 10 years. This will include an expanding contribution from new gas-fired, wind, solar and nuclear generation.

According to NERC’s 2010 Long-Term Reliability Assessment, released in October, generating capacity increased by 11,200 megawatts (MW) or 1.1 percent in the last year. It is expected to increase by 131,000 MW in the next decade. The big story is so-called “variable resources,” most of which is wind and solar. About 53,000 MW of planned wind and solar-generating capacity is expected to come online by 2019.

The NERC study also gives much of the credit for the changing face of American power to so-called demand management, including conservation and energy efficiency. While the economic recession has contributed to a reduction in energy demand over the last two years, the NERC study projects demand-management programs to diminish peak demand growth by 40,000 MW, or roughly four years of growth, by the year 2019.

Luckily, the nation’s transmission system is also up to the task. The report concludes that existing systems, along with planned additions, will be able to meet the increasing contributions from variable sources of power. However, risks are still present due to delays caused by siting and permitting for new projects. NERC encourages planners and policy-makers to minimize these obstacles to ensure reliable delivery of the growing supply of variable power.