North and South America

United States of America

In the US, three primary incentives have enabled the growth of STE:


  • Federal Investment Tax Credit. The Energy Policy Act of 2005 created a 30% ITC for commercial and residential solar energy systems that applies to STE.52 The ITC provides credits equal to 30% of the eligible property that is placed in service by the end of 2016. After this date, the commercial credit will drop to 10% unless Congress acts to extend the credit.
  • State renewable portfolio standards. Most US states have now established an RPS, which re- quires the increased production of electricity from renewable energy sources, such as wind and solar. These include the southwest states that have the best solar resources in the US.
  • US DOE Loan Guarantees. DOE is authorized to provide loan guarantees for projects that “avoid, reduce or sequester air pollutants or greenhouse gases; employ new or significantly improved technologies and provide a reasonable prospect of repayment.”[1]


The combination of these three incentives has led to the construction of five STE projects totalling over 1,300 MW. Each of the five projects were awarded loan guarantees that totalled US$ 5.84 billion.


Present Status of Market


By 2014, the primary incentives for STE projects were no longer available. Several states had just about reached their RPS goals, the loan guarantee programme was no longer funding utility-scale STE projects, and the long-lead time required to build solar thermal power plants made the ITC unavailable because the projects would have to be placed in service by the end of 2016. As a result, no projects started construction after the five that received loan guarantees. Those five became operational between 2013 and 2015.


Of the five projects, three were PT and two were CR. One of the troughs and one of the towers included thermal storage. Utilities, state energy regulators, and the financial community are evaluating the projects to determine if they operate as planned and produce the amount of power predicted. This is especially true for the solar tower projects, which are the first commercial towers operating in the US, and the two projects with storage, which are the first commercial STE projects in the US to using molten salt storage.

Future Prospects of Market


Several things are on the horizon that could impact the US market for STE:


  • EPA’s Clean Power Plan. This Plan would require a 30% reduction in CO2 emissions from the electricity sector by 2030.  Renewable energy is emphasized in the Plan as one way to achieve this reduction.  The final rule for the Plan was issued in 2015.
  • Increasing RPS targets. US states have announced or are currently considering increases to their renewable energy mandates.  Hawaii, for example, has committed to 100% renewable electricity by 2040.  In California, the Governor has proposed to raise the state’s RPS to 50%.
  • Extension of the ITC.

[1] See, Energy Policy Act 2005.


Chile is one of the new emerging markets for STE, and Chile is one of the countries with the highest solar radiation in the world.  At the moment, however, Chile’s electricity sector relies heavily on coal, diesel and gas.[1] Concerns related to economics, energy security and climate change have prompted the government to draw up a new energy policy, the “Estrategia Nacional de Energía” (ENE) 2012 -2030. The main goals of this policy are to generate 20% of the energy from clean energy source and to interconnect the SIC[2] and SING.[3] These aims could increase the capacity installed in the Chilean market and it could be an opportunity for supplying local mines with energy produced by STE technologies.


Due to Chile’s great solar conditions, STE is already competitive with conventional sources. Currently, the first solar thermal power plant in Chile is being developed within the Atacama-1 complex in Cerro Dominador. The project is a 110 MW solar thermal electric tower with 18 hours of thermal storage system in molten salts, allowing the plant to provide electricity 24 hours a day


[2] Central Interconnected System (SIC) is comprised by 5 electric subsystems in the central area of Chile: from Quellón to the island of Chiloé

[3] Northern interconnected System (SING) supplies the north area of Chile, from Arica to Coloso. Mainly, its generation is based on gas and local mines.

The first solar thermal power plant in Chile is being developed with the Atacama-1 complex in Cerro Dominador. Photo: Abengoa