Investments in Croatian RES Plants and Energy Efficient Building Retrofits: Substitutes or Complements?

Croatian energy strategy defines ambitious goals aimed at achieving energy transition toward a sustainable low-carbon society. Achieving those goals requires significant investments in the renewable energy sources and improved energy efficiency of buildings. The purpose of this paper is to estimate and compare the economic effects of the energy transition on the renewable energy supply and demand side. The estimation of the energy transition effects in Croatia in the period 2020–2050 is based on the input-output model, which identifies direct, indirect and induced effects of investments in renewable energy sources and energy efficient buildings renovation. Results of the study reveal relatively higher gross value added and employment effects induced by investments in building retrofits, but the effects of investments in renewable energy are also significant. Investments in sustainable, efficient and environmentally effective energy system could significantly contribute to Croatian GDP. While GVA effects range from 0.4% to 0.6% of annual GDP, the share of full-time equivalent jobs induced by energy transition could reach 0.5% to 1% of total employment in Croatia. Investments in RES plants and energy efficient building reconstruction are not substitutes but complements which ensure a smooth energy transition if undertaken together.

Selection of Energy Upgrades for Canadian Single-Detached Residential Households Based on Occupancy Profile

The use of energy efficient building systems can play a key role in reducing energy consumption and the adverse impacts of greenhouse gas (GHG) emission. The occupancy profile of residential dwellings has a notable influence on the effectiveness of selecting appropriate energy upgrade retrofits. Building simulation models can be integrated to determine the impact of independent occupancy profile in realizing a building’s carbon mitigation target. In this paper, the most desirable energy upgrade retrofits are suggested for three different occupancy profiles by considering important economic parameters, such as the initial investment, payback period and environmental parameter such as GHG emissions. The three occupancy profiles considered were a single adult, couple without children and couple with children. For this purpose, a calibrated energy model was developed for a single-detached family household in British Columbia, Canada, which was equipped with power sensors for monitoring the real time energy data. From the calibrated energy model, three different energy upgrade retrofits (solar, window, and wall/roof insulation) were modelled for the occupancy profiles chosen and the most suitable energy upgrades were suggested. The results show that solar panels contributed the most in energy cost reduction and upgraded windows had the least GHG emission. With suitable financial initiative, the combination of all the three energy upgrades can be the best option in terms of environment and economy.

A method of shaping an energy-efficient building envelope based on natural patterns in order to achieve save of energy

This article aims to present an innovative way of designing objects called A method of shaping an energy-efficient building envelope based on natural patterns. The method uses currently available technologies in an unusual way. Digital photogrammetry data are inserted into a process of designing envelope structure of future objects. In the process of construction, this method counts on the use of all the advantages of 3D printing technology. This combination of the use of relatively innovative technologies in the process of design and construction of buildings opens up new possibilities for the design of the building envelope. Consequently, new building envelope shaping options create space for more efficient use of the energy savings associated with the building envelope shape as a building shape factor. The final design solution of the proposed building takes inspiration directly from the environment in which it is to be situated. Final design takes inspiration of its shape from the environment in which it will be built as a future object. As a result, the building works harmoniously and in accordance with the environment in which it was designed. This creates a pleasant ecological environment for its inhabitants and the surrounding area.

Energy-Efficient Building Design for a Tropical Climate: A Field Study on the Caribbean Island Curaçao

Based on an extensive literature review on passive building designs for tropical climates, seven energy-efficient building design principles for tropical climate areas were deduced. These are: 1. To orientate a building design in such a direction that it protects from excessive solar radiation; 2. To accommodate for indoor natural ventilation; 3. That it makes maximal use of indirect instead of direct natural light; 4, That it reduces the amount of heat transmission through the roof as much as possible by natural ventilation between roof and ceiling and by lowering the roof surface temperature; 5. By preventing the use of high thermal mass materials; 6. By reducing through the exterior walls as much as possible heat transmission by e.g., preventing direct sunlight on the external walls and applying reflective paints on the external walls and; 7. By creating outdoor and transition spaces such as balconies, terraces atriums and corridors. The insights from the literature review were used as input to conduct a field study to evaluate the practice of applying passive building design principles. To this end, for 626 buildings on the Caribbean island Curaçao, it was investigated to what extent the recommended passive design principles for tropical climates were actually applied. Based on the results of the field study, several recommendations are made to improve the practice of applying passive building principles.

The Effect of Density on the Delicate Balance between Structural Requirements and Environmental Issues for AAC Blocks: An Experimental Investigation

Among other construction materials, Autoclaved Aerated Concrete (AAC) offers several advantages to face the pressing need to build more sustainable and energy-efficient buildings. From the building side, the low thermal conductivity of AAC allows the realization of energy-efficient building envelopes, with interesting savings in terms of heating and cooling processes. The equilibrium between structural performances (related to safety issues) and energy efficiency requirements is, however, very delicate since it is strictly related to the search for an “optimum” material density. Within this context, this work discusses the results of wide experimental research, showing the dependency of the most important mechanical properties (compressive strength, elastic modulus, flexural strength and fracture energy) from density, as well as the corresponding variation in thermal conductivity. In order to identify the better compromise solution, a sort of eco-mechanical index is also defined. The big challenge for future researches will be the improvement of this eco-mechanical index by working on pore structure and pore distribution within the material without significantly reducing the density and/or by improving the strength of the skeleton material.