What is the principle of the evacuated collection system

Describe the structure and principle of operation of flat plate and evacuated tube solar collectors (both water heating and air heating) Determine key performance parameters for a flat plate collector from collector test results C Describe the structure and principle of operation of the key storage elements of low temperature solar thermal systems -namely hot water storage tanks and rock beds C o Define and use the various angles used to specify solar position and the angle of incidence of direct sunlight on an arbitrary surface Describe the characteristics of solar radiation at the earth's surface in terms of magnitude, clearness index and spectral characteristics o Describe how solar radiation is measured and the advantages and disadvantages of the different types of pyranometers o Set up a pyranometer to measure solar radiation o Describe the process by which, given the solar radiation on a horizontal surface, the solar radiation on a tilted surface can be calculated, o Use a spreadsheet to calculate the monthly average daily solar radiation on a tilted surface given the monthly average daily solar radiation on the horizontal surface Explain the concept of utilisability and why it can be a useful solar radiation statistic o Characterise the solar radiation resource for a particular location, given certain key data O
Describe the structure and principle of operation of close-coupled thermosyphon solar hot water systems Describe the components of, and the operation of, an active solar hot water heating system Use software to predict the performance of a thermosyphon solar hot water system Use software such as f-Chart and RETScreen to estimate the performance of solar thermal systems Describe the issues in the design of large solar thermal systems relating to