1. 1 Historical Background and Relationship to the lEA One of the objectives of the energy research, development and demonstra tion program of the International Energy Agency (lEA) is to promote the development and application of new and improved energy technologies which could potentially help cover our energy needs. Early in 1976, a working party for Small Solar Power Systems (SSPS) was created with the approval and encouragement of the Committee for Research and Develop ment of the International Energy Agency (lEA) [1]. At that time the following countries showed interest in attending the formative meeting: Austria, Belgium, Canada, Great Britain, Greece, The Federal Republic of Germany, Italy, Japan, Spain, Sweden, Switzerland and the United States of America. In its first meetings the SSPS Working Party explored the technological possibilities of the exploitation of solar power at small levels (photovoltaics, wind, waves and thermal power conversion) and also reviewed what was being done at that time in the domain of solar power in each of the participating countries. At a meeting in mid 1976 in Vienna, a study performed by MBB was presented. It stated that as distributed systems (systems using a large number of parabolic trough collectors "DCS", see chapter 4) grow linearly in terms of power, the associated costs grow as a function of the size of the intended system. By comparison, the cost per unit output of the central receiver systems ("CRS" , see section 5.

The Project's origin As a consequence of the so-called "first oil crisis," the interest in solar electricity generation rose sharply after 1973. The solar ther mal way of solving the problem was attractive because the main task was simply to replace the fossil fuel by a "solar fuel" in an other power plant -that was at least what many wise conventional thermal thought at that time. Thus more than half a dozen of solar thermal plant projects were created in the mid-seventies. One of them is the Small Solar Power Systems (SSPS) Project of the International Energy Agency (lEA). It consists of the design, development, construction, operation, test and evaluation of two dissimilar small solar thermal electric power systems each at a nominal power of 500 kW . e ITET and TOAB In order to assist the Operating Agent (DFVLR - Deutsche Forschungs und Versuchsanstalt fUr Luft- und Raumfahrt e. V. ) in managing the project, the Executive Committee (EC) created two bodies called the "International Test and Evaluation Team" (ITET) and the "Test and Operation Advisory Board" (TOAB). The latter consisted of a group of experts from the different participating countries, meeting three to four times a year to articulate i. a. the technical interests and expectations of the different parties in the project. It was the TOAB that formulated e. g."

The Project's origin As a consequence of the so-called "first oil crisis," the interest in solar electricity generation rose sharply after 1973. The solar ther mal way of solving the problem was attractive because the main task was simply to replace the fossil fuel by a "solar fuel" in an other wise conventional thermal power plant -that was at least what many thought at that time. Thus more than half a dozen of solar thermal plant projects were created in the mid-seventies. One of them is the Small Solar Power Systems (SSPS) Project of the International Energy Agency (lEA). It consists of the design, development, construction, operation, test and evaluation of two dissimilar small solar thermal electric power systems each at a nominal power of 500 kW . e ITET and TOAB In order to assist the Operating Agent (DFVLR - Deutsche Forschungs und Versuchsanstalt fUr Luft- und Raumfahrt e. V. ) in managing the project, the Executive Committee (EC) created two bodies called the "International Test and Evaluation Team" (ITET) and the "Test and Operation Advisory Board" (TOAB). The latter consisted of a group of experts from the different participating countries, meeting three to four times a year to articulate i. a. the technical interests and expectations of the different parties in the project. It was the TOAB that formulated e. g."

The Project's origin As a consequence of the so-called "first oil crisis", the interest in solar electricity generation rose sharply after 1973. The solar ther mal way of solving the problem was attractive because the main task was simply to replace the fossil fuel by a "solar fuel" in an other wise conventional thermal power plant -that was at least what many thought at that time. Thus more than half a dozen of solar thermal plant projects were created in the mid-seventies. One of them is the Small Solar Power Systems (SSPS) Project of the International Energy Agency (lEA). It consists of the design, development, construction, operation, test and evaluation of two dissimilar small solar thermal electric power systems each ~t a nominal power of 500 kW . e ITET and TOAB In order to assist the Operating Agent (DFVLR - Deutsche Forschungs und Versuchsansta1t fUr Luft- und Raumfahrt e. V. ) in managing the project, the Executive Committee (EC) created two bodies called the "International Test and Evaluation Team" (ITET) and the "Test and Operation Advisory Board" (TOAB). The latter consisted of a group of experts from the different participating countries, meeting three to four times a year to articulate i. a. the technical interests and expectations of the different parties in the project. It was the TOAB that formulated e. g.