The Power of Solar
The SHC Programme is demonstrating the value of solar’s contribution in residential buildings. This work is important because space heating and hot water heating account for over 75% of the energy used in single and multi-family homes. Solar energy can meet up to 100% of this demand.
An innovative solar technology is the solar combisystem as it provides both heat and hot water. These systems can meet up to 100% of a building’s heating demand, depending on the collector size, the storage capacity, the heat load, and the region’s climate.
In Austria, after the successful installation of pilot systems on new multi-family houses, several developers decided to make solar combisystems a standard technology in all their new buildings. As a result around 1,000 systems with a capacity of 50 MWth (70,000 m2) are now in operation.
A combination of reliable, low-cost technologies and effective marketing strategies is required to push sustainable, low-energy solar houses further into the conventional housing market. With the technical performance of this type of house proven, how these houses are marketed is critical.
In the Netherlands, the Dutch branch of the World Wildlife Fund (WWF) started a campaign to stimulate the construction of sustainable housing. This effort soon evolved into a collaborative project with the WWF, five major property developers and energy experts. Working together, this group developed the WWF-label for housing. Over 10,000 homes have been built meeting the label requirement of 50% greater energy efficiency in heating than the current Dutch building standard plus the installation of either a solar water heater or photovoltaic (PV) panels for electricity. The main reason for the success of the WWF housing project was the creation of win-win alliances for all the parties involved—WWF, project developers, local government, and home buyers. As a result of the WWF initiative, a Dutch National Certificate for Solar Housing was developed.
AT THE OFFICE
The SHC Programme, working with building designers, owners, and operators, is optimizing systems and demonstrating the economic and environmental benefits of applications in commercial buildings. This work is important because office building energy bills are the highest of any commercial building type. The combination of heating, ventilation, air conditioning and lighting account for approximately 70% of a building’s energy use.
Solar assisted air-conditioning of commercial buildings is a promising concept. The advantage of solar is that the demand for cooling coincides with the availability of high solar radiation. To bring this technology into the market, the SHC Programme monitored 11 systems to understand how they perform and identify ways to improve their performance. The system monitored at the Chamber of Trade and Commerce in Freiburg, Germany is a solar-assisted desiccant cooling system operated by a solar air collector. It is used to cool the top floor seminar room and cafeteria, which had been very uncomfortable during the summer.
This system saves approximately 30% of the primary energy used compared to a conventional system. The extra cost for the solar collector field was about 10% of the overall installation. In operation for over three years, the users continue to be very satisfied with their decision to install this environmentally-sound technology.
Linking research to implementation accelerates the development, application, and market acceptance of solar technologies. The New York Times Building in New York City is an excellent example of this approach at work. This project, building upon the SHC Programme’s daylighting work, used extensive field performance data to stimulate changes in manufacturers' product offerings and ultimately promote broader market acceptance of daylighting systems.
Through demonstration, this project shows that integrating automated shades and daylighting controls saves money and improves occupant comfort. By simply including the ability to dim lights, the energy savings range from 50% to 70% for the south and west facing windows.
AT THE FACTORY & ON THE FARM
The energy needed by commercial and industrial companies in their production processes and to heat their factories can be met using solar thermal collectors. The lower temperature levels, less than 80°C, can be reached using solar thermal collectors that are already on the market, while the continued development of high-performance collectors and system components will improve the cost-effectiveness of higher temperature applications. This work is important because solar’s potential contribution is significant. For example, by installing a 360 kW solar thermal collector at Contank, a Spanish plant that cleans rail transport containers, the estimated annual savings are €13,050 with a 10-year payback period.
One of the most promising agricultural applications for active solar heating is the drying of agricultural products. Wood and conventional fossil fuels are used extensively, and in many countries more expensive diesel and propane fuels are replacing wood. The use of solar crop drying systems results in significant energy savings, reduced use of fossil fuels and lower GHG emissions. The solar-assisted drying system installed at a Costa Rican coffee cooperative uses 850 square meters of solar collectors on the roof to warm air that intake fans use to dry the coffee beans. This system has lowered operating costs, replaced wood heat with solar, and reduced CO2 emissions.
IN THE LAB & IN THE FIELD
Collaborative research and testing foster the production of quality products and the development of certification methods for products and software. The SHC Programme is working in both areas.
In laboratory test facilities, international teams of SHC Programme experts have tested many new technologies and components. Manufacturers from seven countries tested well-established and promising prototype solar air collectors at a facility in Austria. The tests resulted in a common testing procedure and technical improvements in specific systems.
The results of design tool evaluations by the SHC Programme are used in building energy code compliance by national and international standards organizations. In the United States, IEA BESTEST (Building Energy Simulation Test) results were used to develop a standard test method for evaluating building energy analysis programs and for home energy rating software certification. Other countries, such as the Netherlands, Australia and New Zealand, are using BESTEST as a standard method of testing building energy analysis tools for their national energy codes and home energy rating software. In addition, many of the test methods for solar technologies in the ISO and CEN standards are based on test methods developed in the SHC Programme.