Solar

Most countries are trying to increase the percentage of their electricity supply that comes from renewable sources. But because capital costs for renewable generation still, in most cases, are higher per kilowatt-hour than for fossil-fueled power, governments are looking at all options for encouraging the development of greater renewable capacity. Feed-in tariffs (FITs) are one policy tool that has been used, most notably in Europe. Now North America is testing FITs as well.

A defining challenge for the U.S. electricity industry is to economically integrate renewable energy facilities into grid operations without sacrificing reliability. Bulk energy storage options are commercially proven technologies that enable that integration most expediently. Existing and emerging national and state policy frameworks are supporting their application in projects under development throughout the country.

Feed-in-tariffs (FITs)—above-retail rates paid for renewable power that producers "feed" into the grid—are gaining momentum all over the world as a means of driving project growth. Here are some of those established and proposed FITs.

As U.S. utilities increase the percentage of renewable energy in their generation portfolio, they must deal with a number of key issues related to selecting specific technologies. Additionally, they must figure out what it will take to make renewables emerge as a mainstream generating option in the future.

Abengoa Solar in early May began commercial operation of Solnova 1, the company’s first 50-MW parabolic trough plant. Covering 980,000 square feet with mirrors requiring an area totaling 280 acres (Figure 2), it is one of five planned concentrating solar power (CSP) plants to be built at the Solúcar Platform in Spain. All will use a technology developed by Abengoa with experience gained from a trough pilot built in 2007. Solnova 1 will also be equipped to burn natural gas if sunlight is weak.

It’s no surprise that China leads the world in recent power capacity additions. What may surprise you is the precise mix of options this vast country is relying upon to meet its ever-growing demand for electricity. As a result, this ancient civilization is fast becoming the test bed and factory for the newest generation and transmission technologies.

Mexico has already developed substantial large hydro and geothermal resources. However, without policy changes and government-sponsored financial incentives, unconventional renewable sources are taking the equivalent of baby steps.

Shrinking water supplies will unquestionably constrain the development of future power plants. A hybrid system consisting of concentrated solar thermal power and desalination to produce water for a plant, integrated with a combined cycle or conventional steam plant, may be the simple solution.

In late January, a 1.5-MW concentrating solar power (CSP) plant began providing power to Salt River Project customers in Greater Phoenix, Ariz. Though small, the plant, developed by Tessera Solar and Stirling Energy Systems (SES), is seen as a prelude to 1,500-MW projects that are due to break ground in California and Texas later this year.

The U.S. isn’t the only country evaluating and implementing elements of smart grid technology. In fact, it could be argued that other nations are much farther along the path to a comprehensive, technically advanced system for integrating renewables, managing load, and creating a more flexible power grid.