One of the challenges of this project was to identify suitable areas on the roof to install the solar heating systems, in accordance with the Malta Environment and Planning Authority Guidelines [5] , while leaving sufficient space for drying clothes and for a photovoltaic system for the showroom. The task was further complicated by the existence of two lift rooms, which caused shading on large parts. In conclusion, it was deemed necessary to place 6 out of the 10 solar heaters on 1-metre elevated metal structures, to avoid shading by the perimeter walls, as shown in the background of Figure 2.
The solar heating systems were chosen to be of a 150-litre capacity each, as this would be sufficient for the washing needs of a family of four. Evacuated-tube systems were chosen due to the limited space, as they would occupy less area than an equivalent flat-plate solar system. Moreover, these systems were equipped with an electronic controller and display unit, which managed the volume of the feed-in cold water supply and the time at which replenishment is made. Also, it controlled the back-up electric booster element, in terms of thermostatic control and scheduling. The display showed the temperature and volume of water in the solar tank and also allowed for the control of the whole system from the comfort of one’s home. These features allowed a better control of hot water usage and gave a complete picture of the system’s conditions at one glance.
The project started by the preparation of detailed technical specifications for inclusion in the tender document. Adjudication was then made and the tender was awarded to the successful bidder. Close inspection during the installation stage was necessary to ensure full compliance to tender
[2] Be inherently safe and easy to fit for both professionals and those installing DIY domestic
solar panels for home use
• Be simple and tamper-proof, for example by having no interface buttons on the front of the
unit meaning that it cannot be programmed or deprogrammed without first unscrewing the unit.
• Have minimal need for component replacement by eliminating both batteries and mechanical
[3] D J. Naron, H Visser, (2002). Direct Characterisation Test Procedure for Solar Combisystems, Technical report, IEA Solar Heating & Cooling programme Task 26, http://www. iea-shc. org/task26
[4] P Vogelsanger, (2002). The Concise Cycle Test – An Indoor Test Method using a 12-day Test Cycle, Technical report, IEA Solar Heating & Cooling programme Task 26, http://www. iea-shc. org/task26
[5] H Druck, S Bachmann (2002). Performance testing of Solar Combisystems – Comparison of the CTSS with the ACDC procedure, Technical report, IEA Solar Heating & Cooling programme Task 26, http://www. iea-shc. org/task26
[6] M. Haller, R. Heimrath (2007). The reference heating system, the template solar system, Technical report, IEA Solar Heating & Cooling programme Task 32, http://www. iea-shc. org/task32
[7] S. A. Klein (2004). Manual of TRNSYS 16, a TRaNsient SYstem Simulation program, University of Wisconsin-Madison, USA
[8] Matlab Tutorial (2005), The Language of Technical Computing, The Math Works, Inc
[9] Intelligent Energy Europe
[10] Avis Technique 14+5/04-887, 2.00 Ecosol Collector by ESE.
[11] Night hot water storage is frequently used in France due to the lower electricity price (0.064 €/kWh) usually between 22h and 6h.
[12] The tank temperature is recorded at 10 levels equidistant along its height. Obvious, the temperature at the top of the tank is the highest on this graphic and the bottom temperature is the lowest.
[13] Introduction
The expected solar thermal market boom in Portugal, due to the implementation of the new building code, will pose new challenges to contractors, building owners and users, and some conflict situations will certainly arise from the novelty of adoption of these systems in very large scale over a short period of time. The lessons to take from these first times will be of paramount importance to all sectors and agents involved in the process.
EPUL, Lisbon public building promoter, has acted as a pioneer in the Portuguese real estate market for some years, asking INETI to make technical-economic feasibility studies for the installation of domestic solar hot water systems in new multi-owned buildings under their responsibility.
These studies consistently showed the feasibility and profitability of such investment, even at a time when the current escalade of oil prices was not foreseeable, and previously to the introduction of the new building code (RCCTE) as a result of the implementation of EPBD (Energy Performance of Building European Directive).
It is the case of TELHEIRAS XXI, an apartment building in Lisbon, whose study was done in October 2003. After project approval and construction, the building was concluded, and ready for occupation in early 2007, just after the enforcement of the new building code making the use of solar energy compulsory in all new buildings.
