Solar collectors good for the pocket and the environment
Researchers supported by the EU-funded ASTEP project have developed leading-edge solar collectors for industrial processes. The SunDial, as the technology is called, promises to lower production costs and carbon emissions for different industries. The SunDial is based on a rotary platform with a number of mirrors mounted on top. The platform rotates, tracking the Sun so that it is fixed in a given relative position. As described in the study published in the journal ‘Thermal Science and Engineering Progress’, this technology has two versions: one for low latitudes and one for high latitudes.
What makes the SunDial different
The one-axis-tracking SunDial design for low latitudes focuses on cost reduction. In this case, the collector is mounted on a rotary platform, while the mirrors remain fixed. The platform rotates, keeping the Sun within the longitudinal plane, eliminating the need for mirrors to track the Sun and consequently lowering costs. The two-axes-tracking SunDial focuses on high efficiency at high latitudes, where Sun altitude is low for most of the year. In this design, the platform rotates to keep the Sun in the field’s cross-section, and each individual mirror tracks the Sun’s elevation. Here, the Sun is positioned within the cross-section plane to minimise cosine losses. “These improvements enable the SunDial to achieve the same energy production of 27.8 MW h at a latitude of 47.1 °N as it does at 37.9 °N,” state the study authors. The two prototypes of the SunDial technology are being tested in two sites located at different latitudes. The first, low-latitude location (37.9 °N) is Mandrekas, a dairy company in Corinth, Greece, that needs to generate steam at 175 °C for milk pasteurisation and keep yoghurt chilled at 5 °C. The second is ArcelorMittal, a steel company located at a high latitude (47.1 °N) in Iasi, Romania, with a heating demand above 220 °C for tube preheating in a coating process. As reported in an ‘Envirotec’ news item, Prof. Antonio Rovira from ASTEP project coordinator National University of Distance Education, Spain, believes that the technology can help reduce both energy consumption and maintain productivity. Referring to the dairy’s requirement of both steam generation and cooling, the researcher comments: “The ASTEP project proposes a viable concept to demonstrate the viability of using solar thermal energy for heating and cooling, that is both cost effective and environmentally responsible.” ASTEP (Application of Solar Thermal Energy to Processes) is a key initiative in project partner Crowdhelix’s Solar Energy Helix. “Our Solar Energy Helix has become a thriving community of nearly 500 experts and stakeholders who are positioned at key junctions throughout the solar industry’s burgeoning value chains. It is only by bringing together all the stakeholders across key strategic areas that you can build the solutions that will generate a significant impact,” notes Crowdhelix CEO Michael Browne. “ASTEP’s SunDial demonstrates what can be achieved when researchers and innovative businesses collaborate to construct a solution that can lower production costs and carbon emissions simultaneously.” For more information, please see: ASTEP project website
Keywords
ASTEP, SunDial, solar collector, energy, heating, cooling, latitude