scholarly journals Cost-Optimal Plus Energy Building in a Cold Climate

Energies ◽  
2019 ◽  
Vol 12 (20) ◽  
pp. 3841 ◽  
Author(s):  
Szymon Firląg

The main objective of this article is to propose possible requirements for cost-optimal plus energy building in a cold, heating dominated climate. The open question is what is more cost-effective: reduction of energy demand or increase of production from renewable energy sources. The target of the research was to check which solution has the lowest investment and maintenance costs. The analysis was made for a single-family house located in central Poland, including three different energy standards: WT2021 with energy need for heating ≤100 kWh/(m² year), NF40 with energy need for heating ≤40 kWh/(m² year) and NF15 with energy need for heating ≤15 kWh/(m² year)). Air and ground source heat pumps were used as a heat source and a photovoltaic system for the production of the electrical energy. For each case the investment and running costs were calculated very precisely, taking into account heating, ventilation, domestic hot water and auxiliary systems. Global cost for a 30-year period showed that house variants with air source heat pumps are more cost effective. The investment, replacement and maintenance cost related with energy systems have the biggest share in the global cost. Reaching the plus energy standard was possible only in the case of low-energy standard NF40 and NF15. Based on this research the proposed requirements for plus energy single-family residential buildings in central Poland are the following: the final (delivered) electrical energy demand (including heating, ventilation, domestic hot water and auxiliary systems) <45 kWh/(m² year) and the on-site electrical energy production >45 kWh/(m² year).

Energies ◽  
2019 ◽  
Vol 12 (18) ◽  
pp. 3492 ◽  
Author(s):  
Crainz ◽  
Curto ◽  
Franzitta ◽  
Longo ◽  
Montana ◽  
...  

The design of multi-carrier energy systems (MESs) has become increasingly important in the last decades, due to the need to move towards more efficient, flexible, and reliable power systems. In a MES, electricity, heating, cooling, water, and other resources interact at various levels, in order to get optimized operation. The aim of this study is to identify the optimal combination of components, their optimal sizes, and operating schedule allowing minimizing the annual cost for meeting the energy demand of Pantelleria, a Mediterranean island. Starting from the existing energy system (comprising diesel generators, desalination plant, freshwater storage, heat pumps, and domestic hot water storages) the installation of solar resources (photovoltaic and solar thermal) and electrical storage were considered. In this way, the optimal scheduling of storage units injections, water desalination operation, and domestic hot water production was deduced. An energy hub model was implemented using MATLAB to represent the problem. All equations in the model are linear functions, and variables are real or integer. Thus, a mixed integer linear programming algorithm was used for the solution of the optimization problem. Results prove that the method allows a strong reduction of operating costs of diesel generators also in the existing configuration.


Energies ◽  
2019 ◽  
Vol 12 (12) ◽  
pp. 2436 ◽  
Author(s):  
Julià Coma ◽  
José Miguel Maldonado ◽  
Alvaro de Gracia ◽  
Toni Gimbernat ◽  
Teresa Botargues ◽  
...  

The building sector accounts for one third of the global energy consumption and it is expected to grow in the next decades. This evidence leads researchers, engineers and architects to develop innovative technologies based on renewable energies and to enhance the thermal performance of building envelopes. In this context, the potential applicability and further energy performance analysis of these technologies when implemented into different building typologies and climate conditions are not easily comparable. Although massive information is available in data sources, the lack of standardized methods for data gathering and the non-public availability makes the comparative analyses more difficult. These facts limit the benchmarking of different building energy demand parameters such as space heating, cooling, air conditioning, domestic hot water, lighting and electric appliances. Therefore, the first objective of this study consists in providing a review about the common typologies of residential buildings in Europe from the main data sources. This study contains specific details on their architecture, building envelope, floor space and insulation properties. The second objective consists in performing a cross-country comparison in terms of energy demand for the applications with higher energy requirements in the residential building sector (heating and domestic hot water), as well as their related CO2 emissions. The approach of this comparative analysis is based on the residential building typology developed in TABULA/EPISCOPE projects. This comparative study provides a reference scenario in terms of energy demand and CO2 emissions for residential buildings and allows to evaluate the potential implementation of new supply energy technologies in hot, temperate and cold climate regions. From this study it was also concluded that there is a necessity of a free access database which could gather and classify reliable energy data in buildings.


2018 ◽  
Vol 44 ◽  
pp. 00162 ◽  
Author(s):  
Kamil Skoneczny

In the article it was discussed how the energy efficiency of the air-to-water heat pump can change depending on the different ways of the building usage. The author shows that the following factors influence this efficiency: the DHW demand and the demand of the energy for the heating of the building. The article shows that it is very important to take into account the cooperation of both systems, the DHW and the heating. Two models of the SCOP calculations were discussed: in monthly and hourly steps of the calculation. For each model the following assumptions were considered: the different profiles of the domestic hot water demand and the different profiles of the demand for the heating of building.


Energies ◽  
2019 ◽  
Vol 12 (22) ◽  
pp. 4331 ◽  
Author(s):  
Rokas Valancius ◽  
Rao Martand Singh ◽  
Andrius Jurelionis ◽  
Juozas Vaiciunas

Similar to other cold climate countries, space heating and domestic hot water (DHW) accounts form the largest share of household energy demand in Lithuania. Heat pump technology is considered to be one of the environmentally friendly solutions to increase energy efficiency and reduce the carbon footprint of buildings. Heat pumps have been finding their way into the Lithuanian market since 2002, and currently there are many good practice examples present in the country, especially in the residential and public sectors. Heat pump use is economically advantageous in the Baltic Region, and the market share of these systems is growing. Studies have reported seasonal performance factor (SPF) ranges within 1.8 and 5.6. The lower SPF values are typically attributable to air source heat pumps, whereas the higher efficiency is achieved by ground or water source heat pump applications. While the traditional heat pump techniques are well established in the region, there is a slow uptake of new technologies, such as solar-assisted heat pumps, absorption heat pumps and heat pumps integrated into foundations, tunnels or diaphragm walls. This paper provides a critical review of different heat pump technologies, using Lithuania as a cold climate case study to overview the market trends within the European context. Potential trends for the heat pump technology development in terms of application areas, cost-benefit predictions, as well as environmental aspects, are discussed.


2019 ◽  
Vol 111 ◽  
pp. 06075
Author(s):  
Calin Sebarchievici

A ground-coupled heat pump system (GCHP) and an air source heat pump (ASHP) driven by photovoltaic panels are used to provide domestic hot preparation for a NZEB house. The experimental measurements are used to test both the heat pump models in the same conditions of water temperature and volume of domestic hot water. A comparative analysis of the two heat pumps for domestic hot water preparation is performed. In addition, using the software TRNSYS (Transient Systems Simulation), two numerical simulation models of thermal and electrical energy consumption in DHW mode are developed. Finally, the simulations obtained using TRNSYS software are analysed and compared to the experimental data.


Energies ◽  
2019 ◽  
Vol 12 (14) ◽  
pp. 2788 ◽  
Author(s):  
Francesco Mancini ◽  
Benedetto Nastasi

Electrification of the built environment is foreseen as a main driver for energy transition for more effective, electric renewable capacity firming. Direct and on-time use of electricity is the best way to integrate them, but the current energy demand of residential building stock is often mainly fuel-based. Switching from fuel to electric-driven heating systems could play a key role. Yet, it implies modifications in the building stock due to the change in the temperature of the supplied heat by new heat pumps compared to existing boilers and in power demand to the electricity meter. Conventional energy retrofitting scenarios are usually evaluated in terms of cost-effective energy saving, while the effects on the electrification and flexibility are neglected. In this paper, the improvement of the building envelope and the installations of electric-driven space heating and domestic hot water production systems is analyzed for 419 dwellings. The dwellings database was built by means of a survey among the students attending the Faculty of Architecture at Sapienza University of Rome. A set of key performance indicators were selected for energy and environmental performance. The changes in the energy flexibility led to the viable participation of all the dwellings to a demand response programme.


2019 ◽  
Vol 116 ◽  
pp. 00084
Author(s):  
Krystian Szczerbak

The climate in Poland is slightly disparate in each region. The differences in temperature not always come along with the intensity of solar radiation in 5 climate zones. South of the country is colder, but well irradiated by the Sun and northern regions have milder climate, but are less irradiated. This fact alone makes people consider the suitability and safety of using renewable energy sources such as air-to-water heat pumps, solar collectors and photovoltaics instead of more traditional, fossil fuel powered sources. This paper presents a comparison analysis of energy demand and the cost for heating in a group of single-family buildings by 4 variants (gas boiler, gas boiler and solar collectors, air-to-water heat pump, air-to-water heat pump and photovoltaics) in 5 chosen cities in each polish climate zone. Calculations were done for space heating and domestic hot water energy demand, CO2 emissions and cumulative costs for all variants and locations. The results confirm the inconsistency of polish climate and have shown profitability and utility of renewable energy sources.


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