Final report on Contracting Models for Solar Thermally Driven Cooling and Heating SystemsTask 48 - C6 activity final report
September 2014 - PDF 1.99MB
Editor: Daniel Mugnier
The IEA Task 48 focuses on projects which make solar thermally driven heating and cooling systems at the same time more efficient, reliable and cost competitive. Within the four subtasks, quality procedures on component levels, quality procedures on system levels, market support measures and dissemination and policy advices were elaborated.
This Subtask C6 report´s activity will emphasize contracting models for solar cooling systems. For that purpose, a narrow collaboration was established with ongoing IEA SHC Task 45 on large systems for district heating and cooling systems.
This analysis focuses on details, such as investment models, contracts and other relevant issues with regard to which information on ESCos is limited and dispersed in the EU and worldwide. The work will also deepen our understanding of hurdles which ESCos are faced with and will provide information on ways of overcoming such hurdles in practice.
Solar thermal technology is defined as a technology used to harness energy from the sun for use in a thermal process. There are a wide variety of applications for this technology, including, but not limited to, water/process heating, radiant heating and air conditioning. In each application, solar energy is obtained through a solar collector and transferred to a thermal process. Given the proper conditions and system design, solar thermal technology can provide a reliable and cost-effective energy source in residential, commercial, and industrial applications.
In the field of solar air conditioning, an exponential increase of activities occurred during the last years. Some solar cooling systems are available at small scale, starting at approx. 15 kW. Below this figure a lot of research was done to achieve satisfactory results in regard of the systems´ thermal efficiency. Most solar cooling installations were realized in the scale between 15 kW and 500 kW, being perfectly suitable for all buildings that have a continuous and regular load profile (e.g. public buildings, offices, hospitals…). Since 2011, there are also solar thermal cooling systems with cooling powers beyond 1 Megawatt in operation, like in Singapore and the USA. These systems were the first solar cooling systems based on ESCo financing models.
Solar collectors for air conditioning of buildings are generally also used for other applications, such as space heating and domestic hot water preparation. Latter usually contributes to a reduced payback time of the investment. The technologies of concentrating solar cooling applications as well as the technology of solar flat plate cooling applications have their specific advantages or disadvantages in each case, depending on location and application characteristics. Components have to be carefully selected and developed through an integrated design approach to become a functional system.
ESCos for solar thermal air conditioning are in many cases a competitive energy service concept to execute energy efficiency projects in buildings or production facilities. Further work will be done in the IEA SHC Task 48 and other projects to make this financial service more competitive and superior to other products