Enel’s geothermal activities in the United States

A recent news piece in Automation World, describes the activities of Enel Green Power, a company of the Italian Enel Group in the United States and the role of the stimulus legislation for its activities in the country.

The article talks about the complete renewable energy activities of the group, but also looks into the geothermal activities. For the company, so the article, “Enel’s Toni Volpe has been responsible for the introduction of geothermal activities into the company’s U.S. portfolio, as well as the expansion of wind and hydropower projects.

Enel Green Power operates two binary geothermal power plants in Churchill County, Nevada. The Stillwater and Salt Wells geothermal plants have a total gross installed capacity of 65 MW, which will generate over 400 million kWh of electricity a year, enough to meet the needs of some 40,000 U.S. households and avoid the emission of more than 300,000 tons of carbon dioxide.

In this field, the use of the binary cycle makes thermal sources usable at lower temperatures. The company is also working on experiments with dry rocks, which allows thermal sources without steam to be used.

The entry of Stillwater and Salt Wells into service quadrupled the amount of electricity generated from geothermal resources by EGP in the United States, and it makes a significant contribution to achieving the state of Nevada’s goal of generating 20 percent of its electricity from renewables by the year 2015.

The plants have been awarded more than $60 million in funds through the American Recovery and Reinvestment Act’s 1603 Program, aimed at creating jobs and helping expand the development of clean, renewable domestic energy.

The facilities are medium-enthalpy plants, meaning that they operate at temperatures between 130-150 degrees C (266-302 degrees F), using binary-cycle technology that employs two fluids: hot water is extracted from the ground and brought into contact with a working fluid (in this case, isobutane) contained in a closed circuit. The working fluid, rapidly heated to very high temperature and pressure, drives turbines to generate electricity. The geothermal water is returned below ground and the secondary liquid remains in the closed circuit, ensuring no emission of greenhouse gases or other negative impact on local resources.

Stillwater and Salt Wells, on which construction began in 2007, employ more than 300 people and contribute to Churchill County in terms of energy generation from renewables, as well as in economic terms. According to the Economic Development Authority of Western Nevada, the two plants will have a positive impact of more than 4 million U.S. dollars on the area and will create 25 permanent jobs for the next 30 years.

With its century-old experience in Italy, Enel Green Power is a driver of geothermal power in the U.S., with a pipeline of advanced-stage projects providing capacity of 150 MW in Nevada, as well as California and Utah.

Volpe observes: “The support of the Obama Administration and the Congress for renewable energy is having a positive influence on the sector. Developing renewable energy can have significant up-front costs. In geothermal, for, example, site exploration and drilling requires a significant investment for the developer, and support from government to assist with those costs is very helpful, especially in the current economic environment where lenders are understandably skeptical about financing these somewhat risky endeavors.”

Source: Automation World