The objective of these tasks it to develop the basic sets of requirements and test methods for emerging application areas of solar thermal energy. Quality assurance measures for these already widely spread applications are not covered by any standards so far, this is in particular the case with large solar thermal systems. Or the mode of using solar thermal energy is new on the market and therefore no quality assurance measures ever existed, which is the case for combinations of solar thermal technology with heat pumps and solar cooling systems.

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Performance references and test methods for Heat Pump + ST combi-systems

ESTIF is seeing a clear trend towards more renewable energy and more energy efficiency in Europe’s heating systems. Already today, many solar thermal systems are backed-up by condensing gas boilers or wood pellet burners. And a growing number of companies are successfully offering very efficient systems combined from solar thermal systems and ground source heat pumps. In several EC countries applications using solar thermal energy in combination with heat pumps have become increasingly common in recent years. In this respect, big multinational players in the heat pump business are now taking solar thermal into account and thus acting as a new important marketing channel for this technology. Therefore it is be important to study the rapidly growing number and configurations of such systems.  

As manufactures originate either from the solar energy field or from the heat pumps, there are different approaches for the combination of solar thermal energy and heat pumps available on the market. The common combinations are following:  

• The main purpose of the heat pump is understood as a method to increase the energy gain of the solar collector system. The heat pump allows to use solar energy even the temperature of the gained heat has a temperature level below the required temperature of the demand side.
• Overall system concepts are developed in which solar energy and heat pump either work in parallel or interact in e sense that solar heat is used as a heat source of the heat pump either directly or indirectly. 

There are however also those that are not and where drawbacks of increased system complexity greatly outweighs the additional energy gains. What is lacking is a good overview of the market and of the test standards available in order to be able to, in the short term and in a longer perspective, define the different concepts and evaluate them.  After all only high quality of offered systems will ensure a sustainable development of the markets for this type of combinations of solar thermal energy and heat pumps. Part of this task is in other words aimed at identifying those combinations that are mature and those that are not.

Function and Yield Controlling of Large Systems

So far, most of the solar thermal market in Europe was focussed on 1- und 2-family houses. In the more developed markets we now see a big push – partly helped by support policies – for larger, collective systems (e.g. for multi-family houses, hotels, office buildings and process heat). While a detailed accounting of the energy yields would be too complex and expensive for small systems, larger systems have for long times been equipped with much more elaborate monitoring devices. Here, their costs are small compared to the total system costs. With the strong growth in larger systems, the need to study more closely also these F&YC devices and concepts becomes more and more important.

Solar Cooling Systems - Quality requirements 

Several factors are driving the market for solar cooling solutions. On the one hand the exploding demand for cooling and consequently the demand also for electricity to drive the conventional cooling machines is becoming not only very expensive but also endanger the stability of whole electricity grids. In several European countries, the peak electricity demand has already shifted from winter to summer and the demand for more comfort and cooling is rapidly increasing also in more moderate climates. Furthermore, the trend to larger solar thermal systems and higher solar fractions, which we see in several countries, lead to more available solar heat output being available in summer than what is actually needed. These two factors make solar thermal cooling a more and more attractive option. The number of installed systems has increased tremendously in the past few years and several new thermally driven cooling machines – especially designed for smaller capacities and lower driving temperatures – have entered the market. As this is a very new market, there are hardly any (quality) standards so far. To ensure a good quality and to avoid any backlashes from low- or no-performing systems, quality requirements need to be developed soon.

As solar cooling technology is developing very fast and high expectations are put in it. Solar cooling systems require always huge investments and therefore any kind of guarantees on life expectancy, performance or durability are welcome to convince or reassure customers and investors.  

The objective of this task is to develop a basis of requirements and test methods with a focus on the solar thermal part of a solar cooling system.

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• Technical report on combined solar & heat pump systems with system overview and quality enquiries
• Information material for installers and planners on F&YC of large solar thermal systems 
• Technical report on the requirements for durability and performance testing of solar cooling systems 
• Quality enquiries on combined solar & heat pump systems
• Harmonised technical approach for function and yield controlling of large solar thermal systems (quasi-standard)
• Catalogue of requirements for durability and performance of solar cooling systems

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