Browsing by Subject "energy efficiency"

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  • Isoaho, Karoliina Laila Hannele; Moilanen, Fanni Sofia; Toikka, Arho Ilmari (2019)
    The Energy Union, a major energy sector reform project launched by the European Commission in 2015, has substantial clean energy and climate aims. However, scholarly caution has been raised about their feasibility, especially with regards to accommodating climate objectives with other closely related yet often competing policy goals. We therefore investigate the policy priorities of the Energy Union by performing a topic modelling analysis of over 5,000 policy documents. A big data analysis confirms that decarbonisation and energy efficiency dimensions are major building blocks in the Energy Union's agenda. Furthermore, there are signals of policy convergence in terms of climate security and climate affordability policies. However, our analysis also suggests that the Commission is not actively prescribing trajectories for renewable energy development or paying close attention to declining incumbent energy generation technologies. Overall, we find that the Energy Union is not a 'floating signifier' but rather has a clear and incrementally evolving decarbonisation agenda. Whether it further develops into an active driver of decarbonisation will largely be determined by the implementation phase of the project.
  • Jokiniemi, Tapani; Mikkola, Hannu; Hakojärvi, Mikko; Alakukku, Laura (2021)
    Fuel consumption of various forage harvesting methods was assessed with a theoretical calculation model, which was validated with field measurements. The examined harvesting methods were tractor-powered forage harvester (TPFH), self-propelled forage harvester (SPFH), self-loading forage wagon (SLFW), and combined baling and wrapping (CBW). The results from the field measurements indicated that the model was working either well or satisfactorily with the examined methods, apart from the CBW method, which would require re-defining the model coefficients. Model sensitivity analysis indicated that variables such as yield level, working width and transportation distance have a significant effect on the fuel consumption. When the working width was increased from 3 m to 9 m, the fuel consumption of the examined methods decreased ca. 54-61%. Increasing the working width by windrowing was found recommended for all examined methods. In all, the most energy efficient method was SLFW, but it was also most sensitive to transportation distance. With the transportation distance of 10 km, the fuel consumption of the SLFW method was already 9-11 % higher compared to that of TPFH and SPFH methods. The strong effect of these variables may cause a wide variation in the fuel consumption of the examined methods, but the model can be used to standardize this effect. The results from this study can thus be used for approximate estimations of average fuel consumption of the examined forage harvesting methods.
  • Hernesniemi, Anu (Helsingfors universitet, 2010)
    In Finland energy requirement is high because of the cold climate and long distances. Energy is needed to ensure the welfare and an industrial life’s needs. Energy taxation, emissions trading and subventions are well known political instruments for decreasing energy consumption. Energy efficiency has become a famous policy for reducing energy consumption without lowering the quality of energy services. There have always been critics for the energy efficiency and its consequences among the researchers. It is possible to have improving energy efficiency, while still seeing rises in energy consumption. This phenomenon is known as a rebound effect. If energy consumption rises above the level it would have been without efficiency improvements the phenomena is called backfire effect. The objective of this thesis was to find out how to investigate the rebound-effect, what are the critical factors of it and present the results of the resent empirical studies. Attention has been also in finding out what energy efficiency is, how it appears in economical models and why it is an important research area. The effects of energy efficiency are difficult to allocate between different economic factors. Hence it seems that a computable general equilibrium framework is obvious tool to investigate the rebound effect in the national economy level though it’s quite complicated. The production function and the elasticity of substitution seem to be crucial for the size of the rebound effect in a computable general equilibrium framework. It was observed that when the elasticity of substitution was high, the rebound effect was also high. For this reason the form of production function is crucial, it should be one where the elasticity of substitution is not a constant. Empirical studies have established evidence of the rebound effect but its size varies with different areas, with a different elasticity of substitution and in different time periods. In some scenarios even backfire was observed. None of the cases reach total utility of the efficiency improvements.
  • Poteri, Juho (Helsingin yliopisto, 2020)
    The Internet of Things (IoT) paradigm is seeing rapid adoption across multiple domains—industry, enterprise, agriculture, smart cities, households, only to name a few. IoT applications often require wireless autonomy, thereby placing challenging requirements on communication techniques and power supply methods. Wireless networking using devices with constrained energy, as often is the case in wireless sensor networks (WSN), provokes explicit considerations around the conservation of the supplied power on the one hand and the efficiency of the power drawn and energy used on the other. As radio communications characteristically consume the bulk of all energy in wireless IoT systems, this constrained energy budget combined with aspirations for terminal device lifetime sets requirements for the communications protocols and techniques used. This thesis examines two open architecture low-power wide-area network (LPWAN) standards with mesh networking support, along with their energy consumption profile in the context of power-constrained wireless sensor networks. The introductory section is followed by an overview of IoT and WSN foundations and technologies. The following section describes the IEEE 802.15.4 standard and ecosystem, followed by the Bluetooth LE and Bluetooth Mesh standards. A discussion on these standards' characteristics, behavior, and applicability to power-constrained sensor networks is presented.
  • Hossein Motlagh, Naser; Mohammadrezaei, Mahsa; Hunt, Julian; Zakeri, Behnam (2020)
    Integration of renewable energy and optimization of energy use are key enablers of sustainable energy transitions and mitigating climate change. Modern technologies such the Internet of Things (IoT) offer a wide number of applications in the energy sector, i.e, in energy supply, transmission and distribution, and demand. IoT can be employed for improving energy efficiency, increasing the share of renewable energy, and reducing environmental impacts of the energy use. This paper reviews the existing literature on the application of IoT in in energy systems, in general, and in the context of smart grids particularly. Furthermore, we discuss enabling technologies of IoT, including cloud computing and different platforms for data analysis. Furthermore, we review challenges of deploying IoT in the energy sector, including privacy and security, with some solutions to these challenges such as blockchain technology. This survey provides energy policy-makers, energy economists, and managers with an overview of the role of IoT in optimization of energy systems.
  • Kauste, Krista (Helsingfors universitet, 2012)
    The aim of this study was to compare warm white LED and High Pressure Sodium (HPS) -lamps in the greenhouse cultivation of lettuce. Two experiments were carried out in which lettuce growth and external quality was observed, the effect of lamps on leaf temperature was measured and the electricity consumption of LED- and HPS-lamps was compared. First experiment carried out with iceberg lettuce (´Frillice`) and second experiment with red oakleaf lettuce (´Rouxai´). In the second experiment, the effect of light treatment on the color of leaves was also investigated. The presence of tipburn was another measurement of external quality in both experiments. LED-lamp with DLC-sensor (Dynamic Light Control), which was designed to optimize the illumination according to the existing natural light, was also included in the experiments. Light quality or observed differences in temperatures or relative humidity did not significantly affect the fresh weight or external quality of ice berg lettuce. Oakleaf lettuces grown under LED-light were much smaller and they had more tipburn symptoms compared to HPS-treatment. No significant differences were found in the anthocyaninlevels of oakleaf lettuce grown under different lightning treatments. LED -lighting consumed about 22% less electricity than HPS-lamp in both experiments. However, energy efficiency of HPS- and LED-lamps cannot be directly compared, since HPS-lamps illuminated larger area than the LED- luminaires. DLCsensor was able to adjust illumination according to natural light and to reduce energy consumption, but it did not increase fresh weight accumulation in relation to power consumption compared to LED-luminaire without DLC.
  • Dristig, Amica (Helsingin yliopisto, 2020)
    The reduction of greenhouse gas emissions is one of the EU's top priorities for climate goals as it is for Helsinki. Emissions from heating alone stand for over half of the total emissions in Helsinki, presenting smart heating as an excellent opportunity to reduce both energy consumption and greenhouse gas emissions. Smart heating has gained attention as a means for reducing energy consumption due to its increased energy efficiency and automatic function. Previous studies confirm users having a more significant impact on residential heating consumption than previously considered. However, there is less understanding of what factors influences the user while using smart heating and how smart heating impacts the user. This study aims to contribute to better understand the different influencing factors by focusing on heating behavior and user experience with smart heating thermostats in a residential apartment building in Lauttasaari, Helsinki. A modified version of the Unified Theory of Acceptance of Technology (UTAUT) is used as a base. The model uses the original categories along with two added categories. Instead of using the traditional questionnaire as a method, this research uses semi-structured interviews to get a deeper perspective on the experiences in the post-implementation stage. The results indicate the most evident user experience influences to be information, trust, and the use of itself. Each user's life situation has an impact on the indoor temperature and the heating schedule. The smart thermostat increases control over indoor temperatures and individual heating possibilities due to more setting options. By gaining more control, the smart thermostat enabled the user to disregard the heating by letting the smart thermostat work in the background. Even with an increase of control, some of the participants experienced difficulties using the mobile application. Since this study is limited due to short follow-up time and small sample size, more comprehensive and in-depth research is required for the results to apply to a general population. This study shows a new point of view for influences towards the use of smart thermostats and brings up the potential benefits it can have for the city of Helsinki.
  • Viita, Tapani (Helsingfors universitet, 2013)
    In Finland grain has to handle that seeds will stay in good condition in storage. The most common method of preservation is drying. 11 % of energy consumption in a grain growing chain is used in drying. EU has set the aim to achieve 9 % energy saving by year 2016 compared to average energy consumption in years 2001-2005. Ministry of agriculture and forestry has started energy program in agriculture, which aims to energy saving in agriculture. The aim of this study was to find out by computer simulation how to get the best energy efficiency in grain drying in different conditions. In the study was made a series of simulations to find out is different adjustments needed in different conditions. By sensitivity analysis was found out, which variable (condition or adjustment) affects most to the drying process. To find out reliability of the simulator energy consumption and drying time results was compared between simulation and real dryings in Viikki’s research farm. The best energy efficiency was achieved when high drying air temperature, fast grain circulation and small amount of air were used. The grain drying process is very sensitive to drying air temperature, moisture of grain and amount of air. The process is quite sensitive to density of grain and outside temperature. The simulator givesreliable results for energy consumption when grain moisture is more than 17% (w.b.) and for drying time when grain moisture is lower than 17 %. By adjusting grain drying process it is possible to save remarkable amount of energy. It is important to harvest and dry grain as good conditions as possible. Also isimportant to use isolation in dryer and maintain the burner.