vacuum tube collectors

This technical report is a deliverable of Task 38, Subtask C within the framework of the International Energy Agency’s Solar Heating and Cooling Programme. It describes both existing and developing simulation tools and models used for solar cooling applications.

As part of its plan to reduce the dependence on fossil fuels, the Kent County Regional Wastewater Treatment Facility in Milford (Delaware), USA, has been using solar energy from a vacuum tube collector field with 317 m2 of gross area for its biosolid drying process since August 2011. The collector field with 66 panels of type SPP-30A was delivered by US-American company Solar Panels Plus. The panels supply the energy for a radiant floor system, which heats the concrete floor of three greenhouses measuring 240 by 80 feet.
Photo: Jim Newton / Kent Country Regional Wastewater Treatment Facility

This is the report of a study done by the Architecture Department of the Uruguayan Republican University. The goal of the research was to find out whether it was technologically and economically feasible to integrate solar thermal system for underfloor heating into the already existing systems.

Chinese company Hejia Solar Energy presented a new collector type at the All-Energy Australia 2011 trade fair in Melbourne in October 2011. The collector’s automated coverage prevents the system from overheating during daily operation. The participation in the fair was organised jointly by the Chinese manufacturer of the new collector type, Heijia Solar, represented by Chief Engineer Pan Kexue, as well as CEO and owner of Hejia Solar, Wu Guosheng, and the Australian Sales Office OZ Hejia Solar, represented by Director Frank Witowski (middle).
Photo: Oz Hejia Solar

The Turkish Ministry of Economy has introduced a new calculation method for import taxes and the VAT on imported vacuum tubes. The ’Protection and Inspection Tax’ (Korunma ve Gözetim Vergisi) was made official in the ‘Public Gazette’ and has been in place since 6 July 2011. The new regulation assumes the price of a vacuum tube to be at 6 USD/kg, even if the real price is much lower. The import tax of 1.9 % and 18 % VAT are both calculated based on this assumed price. With an estimated weight of 1.6 kg per tube, import tax and VAT add up to USD 1.9 per tube. That means that the new regulation significantly increases the price of a vacuum tube, which is said to cost between two and three US dollars.

The extra-thick double-glass vacuum tubes by German company Soltark have survived a test with 40 mm hailstones at the Swiss test institute SPF Solartechnik in Rapperswil. A systematic investigation of vacuum tubes at SPF Rapperswil two years ago showed that most of the 26 tested vacuum tube collectors were damaged after several hits with 35mm hailstones. In large parts of Switzerland, however, hail with a thickness of 30 mm must be expected at least once in 50 years (red-coloured areas in the above map). More and more Swiss building insurers are adopting rules for the hail resistance of solar collectors, which the owners hope to incorporate into already existing insurance contracts.

Source: www.hagelregister.ch

Taiwan remains a country strongly dominated by flat plate collectors. Solarthermalworld.org spoke with local solar thermal manufacturers and planners about the advantages of the technology in comparison to vacuum tubes. The photo shows an installation at the elementary school in the municipality of Jin-Yue - planned and installed by Taiwanese company Wang Aun.
Photo: Wang Aun

German heating systems manufacturer Viessmann operates a solar process heat system at its factory in Faulquemont, France. 260 m² of the new heat pipe vacuum tube collector Vitosol 200-T have been installed on the roof and at the facade of the building. The system is used for heating up an alkaline cleaning bath to up to 60°C, in order to degrease hot water storage units before enamelling.
Photo: Viessmann

According to a press release by German manufacturer Consolar, the solar thermal system at the Antarctic polar station "Princess Elisabeth" is going to be expanded during the current research season 2010/2011. The station of the International Polar Foundation (IPF) started its work in February 2009 and is the first polar research base operating entirely on renewable energies (see http://www.solarthermalworld.org/node/605). Thomas Gillon (photo) from the Belgium office of Consolar put the two systems through their paces and could confirm their flawless operation even under extreme weather conditions.
Photo: International Polar Foundation

162 vacuum tube collector panels supplying the Oxford Gardens Retirement Village with domestic hot water, a warm water pool, space heating in winter and cooling in summer: According to project leader Suni Ball of Canadian solar system provider Proterra Solar, the system is the largest solar cooling installation in the country. Over 80 guests came to its inauguration in November 2010.
Photo: Oxford Gardens