A proposal is made in the sanitary hot water system in a hotel installation consisting in the change of the black steel pipe system by high density polypropylene pipes in the primary circuit of the system. A field of vacuum tube solar collectors is sized to work in replacement of the heat recovery system of the water chiller. An economic and environmental analysis of the proposal is made. With the installation of the solar collectors, the hotel will deduct 27,545 liters (15,425 kg) of liquid gas propane (LPG) from its annual consumption, equivalent to 51,728 USD, avoiding the emission of 104,583 kg of CO₂eq into the environment. The simple recovery time of the investment will be 5.88 years. The results obtained demonstrate the feasibility of using solar thermal energy in the heating of sanitary water due to the decrease in the consumption of liquefied petroleum gas and, therefore, the environmental damage is reduced when greenhouse gases are no longer emitted.

At present, intelligent buildings have formed a relatively mature and complete industrial chain and industrial scale in China, but there are still some technical and application problems to be solved urgently, mainly including the lack of linkage between different demand-side energy demand scenarios, the inability to guarantee information security, and serious building energy consumption. In view of the above problems, scholars at home and abroad have launched relevant research, but they have not comprehensively considered the relevance of the above problems. Therefore, this article sorts out the research status of source-load joint forecast method of intelligent building clusters, and analyzes the related development trends, including three major directions: source-load joint forecast method of intelligent building clusters, key technologies of energy supply and demand data security of intelligent building clusters, and distributed energy transaction strategy of intelligent building clusters. Through combing and analysis, this article has formed a number of valuable research directions, which can provide directional reference and knowledge for the accurate response of electric-thermal load and energy transaction strategy of intelligent building clusters and P2P method theory in other scenarios.

The invention of chemically flexible solar cells, known as dye-sensitive solar cells (DSSC), has led to cheaper, more ecologically friendly, yet inefficient solar cells. The poor link between the semiconductor and the substrate, which impacts the DSSC electrons' mobility, is the root reason of the low efficiency. TiCl₄ pre-coatings have been used in many studies on semiconductor engineering to boost electron mobility. In order to lower the internal resistance in the DSSC, it is known that using TiCl₄ pre-coating affects the mechanical strength between the semiconductor and the substrate. TiCl₄ pre-coating can be done by immersing FTO glass, where semiconductors have deposited, in the TiCl4 solution. This study examines how the TiCl₄ pre-coating time in the production of TiO₂ semiconductors affects DSSC performance. To reveal the effects on alterations in the semiconductor morphology of TiO₂, immersion times in the TiCl4 treatment were set to 10, 20, 30, 40, 50, and 60mins. The results show that TiO₂ nanoparticles with a 60min TiCl₄ treatment had better connectivity between individual particles than those with shorter treatments. The performance metrics like open circuit photovoltage (Voc), short-circuit photocurrent density (Jsc), and fill factor (FF), and efficiency (η) were 0.569 V, 7,616 mA/cm2, 43.3%, and 2.208%, respectively.

In This research article represents the study of optical, and electrical properties of Methylammonium lead (MAPbBr_3-nI_n; n=0, 1, 2 and 3) (CH₃NH₃PbI₃, CH₃NH₃PbI₂Br, CH₃NH₃PbIBr₂, and CH₃NH₃PbBr₃) based Perovskite solar cell. An FTO/TiO₂/ MAPbBr_3-nI_n/Spiro-OMeTAD/Al based structure with TiO₂ as electron transport layer and Spiro-OMeTAD hole transport layer has been used for this study. The opto-electrical properties such as resonance time period, indirect and direct band gap have been studied. The results shows that the resonance time period, indirect band gap, and direct band gap for each of the Perovskite layer CH₃NH₃PbI₃ is 9.09 µs, 1.4 eV and 2.6 eV, for CH₃NH₃PbI₂Br is 6.25 µs, 1.5 eV and 2.7 eV, for CH₃NH₃PbIBr₂ is 6.25 µs, 1.7 eV, and 2.8 eV and for CH₃NH₃PbBr₃ is 5.55 µs, 2.1 eV and 2.9 eV respectively.