When it comes to transporting heat from boilers to heating surfaces or supplying cooling energy to cooling ceilings, water has proved to be an excellent heat transfer medium. However, in some application areas it is now facing competition: various research groups are working on heat transfer fluids that have at least double the energy density. Phase change materials such as paraffin, which are finely distributed in water, store heat when they melt and release it again when they solidify.  more...

Instead of screwing various module and collector types for solar power and solar heat on the roof, an obvious idea would be to use a hybrid collector that can do both and which creates a uniform appearance. In addition to generating photovoltaic electricity, which only utilises 15-20 % of the incident solar radiation, a so-called PVT collector can use the remaining radiation energy for generating heat. Researchers are working on optimising the output and production of these systems.  more...

The economic and ecological success of many CHP plants, district heating networks and large-scale solar power systems very much depends on the utilisation of heat outside of the heating periods. An increasingly interesting market for low-temperature heat is cooling and air-conditioning buildings as well as generating process cooling energy with thermally driven chillers. Scientists from Berlin and Bavaria have developed a new generation of particularly compact, efficient absorption chillers with small capacities for cooling and heating operations.  more...

Researchers from the Technical University of Dresden have succeeded in significantly improving the efficiency of chillers that use carbon dioxide as a refrigerant. One possible application of their system is in refrigeration for supermarkets, where cooling is required for equipment ranging from refrigerated display cases right through to large cold storage rooms. The researchers expect average annual energy savings of 10% compared to conventional refrigeration systems, with savings of up to 25% on warm days. The researchers are cooperating with an industrial partner to obtain initial operating experience with these systems.  more...

Copper cables only conduct electricity under resistance, meaning the cable heats up and energy is lost. In contrast, superconductors conduct electricity without loss. Their use in cable and generator projects thus increases the efficiency of the electricity supply infrastructure. With this in mind, the German Federal Ministry of Economics and Technology is promoting the cost-effective production of superconductive band conductors at the manufacturer Zenergy Power with funding of 3.5 million euros.  more...

The Absorber Box by Watergy, a company from Berlin, Germany, uses humid air as a source of energy. The air conditioning system can heat or cool air, thus controlling the humidity and temperature using a saline solution for intermediate storage, which saves energy. The project, supported by funding from the German Federal Ministry of Economics and Technology, is now in the market for beta-testers.  more...

Researchers at Zeo-Tech GmbH in Unterschleissheim, Germany, have developed freezer boxes and mini refrigerators for mobile and stationary use that are designed to operate more efficiently in their respective application areas than current technology allows. As it is powered by heat, the adsorption-based cooling process can utilise a range of different energy sources. Mobile freezer boxes are already being tested in practice. Once they are charged via a normal power socket, they can be stored loss-free until used, when the cooling process is started at the touch of a button. After a short cooling time they reach deep freeze temperatures which are maintained over 24 hours.  more...

The Internet offers rapid and convenient access to information - including for energy research. However, when it comes to obtaining reliable, complete and quotable information for research purposes, there is no real alternative to using specialist databases. This is the conclusion of scientists from the ETDE (Energy Technology Data Exchange). In a study they compared the search results provided by their ETDEWEB database with those from Google and Google Scholar, whereby they used search terms from different areas concerned with energy transformation and utilisation. The main thematic focus was on renewable energies, but energy efficient technologies such as recycling waste heat or utilising daylight in office buildings were also looked at.  more...

Solar energy is already used for air conditioning buildings, and now researchers want to use it to refrigerate fruit and other easily perishable food. Scientists from the Fraunhofer-Institute for Solar Energy Systems ISE in Freiburg are demonstrating its feasibility in the Mediterranean region using the example of a winery in Tunisia and a dairy in Morocco.  more...

By combining solar thermal energy and adsorption technology, heat can be turned into cold to cool buildings. The German Federal Ministry for the Environment is currently funding a large-scale practical test for solar air conditioning systems. The partners involved, Solvis, SorTech, Fraunhofer ISE and Offenburg University, are seeking interested participants for this project.  more...