Optimal use of solar collectors for residential buildings

Abstract

SUMMARYSolar radiation is an abundant free resource which may be used in the form of solar heated water. This is achieved in solar collectors which, unfortunately, are expensive devices and, further, the warm water must be stored in accumulators*items which also cost money. This paper shows how we have optimized the situation for a block-of-#ats in Sweden. In order to "nd this point we have used the minimum life-cycle cost (LCC) concept as a criterion. The best solution is therefore found when that cost "nds its lowest value. It is also examined under which conditions solar collectors are part of the optimal solution and further it is calculated what happens if this optimal point is abandoned, i.e. how much will the LCC increase if other than optimal solutions are chosen. LCC optimization for multi-family buildings almost always results in a heating system with low operating costs such as district heating or dual-fuel systems where a heat pump takes care of the base load and an oil boiler the peak. The installation cost must, however, be kept to a reasonable level. Expensive solar panel systems are therefore normally avoided if the lowest LCC shall be reached, at least for Swedish conditions. This is so even if the solar system has a very low operating cost. For buildings where the only alternative energy source is electricity, solar collectors seem to be on the rim of pro"tability, i.e. for an energy price of about 0.6 SEK kWh\.

Predicting Spare Parts Inventory of Hydropower Stations and Substations Based on Combined Model

“…For electric power enterprises, the problem of predicting inventory of equipment without monitoring devices has a high practical value, and subsequent research efforts can add more influencing factors, such as product batches, idle time, and extreme weather conditions, but data on these influencing factors are currently unavailable. Under the many factors, we can reconstruct the prediction model and choose the remaining useful life (RUL) [31,32] of the equipment as the main influence variable while considering the life-cycle costing (LCC) [23,33] of the equipment to achieve a more accurate prediction of the equipment inventory, which is more conducive to the operation and maintenance of relay protection equipment, as well as reducing inventory expenditures.…”

“…At present, power enterprises like DH Hydropower Station and JC Power Supply Company stockpile spare parts using the agreed inventory procurement [22]. is form of procurement relies on experience to speculate on the approximate demand rather than some theoretical model, such as the minimum life-cycle cost (LCC) [23] for spare parts for the next year. It has the disadvantage of insufficient spare parts inventory caused by both internal and external factors, which often leads to insufficient spare parts inventory and the need for temporary procurement.…”

Synthesis of Cobalt Diselenide Nanoparticles for the Integrated All-Solid-State Supercapacitors

“…Today, it is particularly important to investigate energy storage systems due to the increasing energy consumption and environmental challenges. New energy sources, such as hydrogen energy and solar energy, have become one of the hot topics because of their advantages. − Although they can alleviate the energy crisis and environmental problems, they are limited by shortcomings such as inefficient utilization and poor continuity of energy supply, and the shortcomings can be well solved by energy storage devices. Therefore, stable and efficient devices for energy storage have been strongly supported and explored by many researchers.…”

Design of Intelligent Customer Service Questioning and Answering a System for Power Business Scenario Based on AI Technology

“…Based on the aforementioned justification, this paper proposes to build an intelligent customer service questioning and answering a system for power business scenarios based on AI technology. AI technology has been widely used in the area of prediction [12], state estimation [13,14], control [15][16][17], and optimization [18] and has made considerable contribution.…”