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Abstract Increasing electrification of final uses can be a viable solution towards low-carbon energy systems, when coupled with local renewable power generation. Mountain areas can already benefit from high shares of hydro-power generation, but, at the same time, rely on oil products for transport and for the heating sector in remote areas where natural gas infrastructures are not available. This research work evaluates potential scenarios for the electrification of transport and heating sectors, by coupling the simulation tool EnergyPLAN with a multi-objective optimization algorithm to analyse economic and environmental aspects. Results show that the largest benefits are expected from the electrification of the heating sector. Indeed, a CO2 emissions reduction up to 30% can be reached by acting on the transport sector alone, while up to 65% combining it with measures on heating, industry and agriculture sectors and additional electricity generation from photovoltaic systems. Moreover, the use of heat pumps can lead to significant CO2 emissions decrease with only to a slight increase in the overall annual costs thanks to lower variable costs that partly compensate the higher required initial investment and electricity storage deployment. The optimization analyses also highlight the effect of progressive penetration of electric vehicles in the private cars fleet and hydrogen trucks in the light-duty vehicles one.

This paper deals with developing and implementing a bidirectional galvanically isolated on-board charger of a high-power density. The power density of the new charger was 4 kW/kg and 2.46 kW/dm3, and the maximum efficiency was 96.4% at 3.4 kW. Due to the requirement to achieve a high-power density, a single-stage inverter topology was used. Regarding switching losses, due to the topology of the circuit with so-called hard switching, the switching frequency was set to 150 kHz. A laboratory prototype was built to verify the properties and operating principles of the described charger topology. The on-board charger has been tested in a microgrid test platform. Due to the parasitic properties of the transformer and other electronic components, overvoltage with subsequent oscillations occurred on the primary side of the transformer and damped resonance on its secondary side. These parasitic properties caused interference and especially voltage stress on the semiconductor elements. These undesirable phenomena have been eliminated by adding an active element to the charger topology and a new transistor control strategy. This new switching control strategy of transistors has been patented.

Mobile Global Navigation Satellite System (GNSS) measurements carried out on the railway consist of using satellite navigation systems to determine the track geometry of a moving railway vehicle on a given route. Their purposes include diagnostics, stocktaking, and design work in railways. The greatest advantage of this method is the ability to perform measurements in a unified and coherent spatial reference system, which effectively enables the combining of design and construction works, as well as their implementation by engineering teams of diverse specialties. In the article, we attempted to assess the impact of using three types of work mode for a GNSS geodetic network [Global Positioning System (GPS), GPS/Global Navigation Satellite System (GLONASS) and GPS/GLONASS/Galileo] on positioning availability at three accuracy levels: 1 cm, 3 cm and 10 cm. This paper presents a mathematical model that enables the calculation of positioning availability at these levels. This model was also applied to the results of the measurement campaign performed by five GNSS geodetic receivers, made by a leading company in the field. Measurements with simultaneous position recording and accuracy assessment were taken separately on the same route for three types of receiver settings: GPS, GPS/GLONASS and GPS/GLONASS/Galileo in an urban area typical of a medium-sized city. The study has shown that applying a two-system solution (GPS/GLONASS) considerably increases the availability of high-precision coordinates compared to a single-system solution (GPS), whereas the measurements with three systems (GPS/GLONASS/Galileo) negligibly increase the availability compared to a two-system solution (GPS/GLONASS).

The focal point is to present the areas where the technology in buildings can be supported by proper motivation and take substantial advantage measurable in technical units. The need to understand the integration between ecology, society, economy and technology is crucial when global improvements are the targets. These targets should consider urban environments as natural human settlement, in this understanding that accepts human psychological needs for wide and deep education, acquiring highly professional satisfaction without resigning from family style of life and leisure as natural. There is the necessity to accept human production also in its advanced levels as a natural human activity and to make it integrate with the other mentioned components of integration. The attention has been directed to clean energy certification in newly constructed objects and refurbished buildings, to formation of owner’s responsibility for possessed goods and their best use in sustainable development. The particular attention has been put to the increase of the use of resources only if it is justified by proportionally very high advantages to the society. This has been presented with the examples of energy savings in low energy and passive building. Moreover the examples show the ways of sustainable development which are the use of renewable energy, using coal only in collective industrial systems very restricted in protection against pollution and uncontrolled use of energy, and similarly, of other conventional fuels, water and land.

The basis for developing logistics solutions in cities is to know the requirements and expectations of current and potential transport users and for decision makers to strive to meet them. In building an urban logistics strategy, it is therefore necessary to take into account different stakeholder groups. Building stakeholder relations should be aimed at involving them in the development of a sustainable transport policy for the city. It should be noted, however, that the importance of stakeholders in transport policy is diverse. This assumption was made in the paper, which aimed to identify the role of the various groups of urban logistics stakeholders in the sustainable movement of people. This challenge is subordinated to the methodology proposed in the paper, which combines the analysis of urban logistics stakeholders and the assignment of roles to them in the pursuit of sustainable flows of people in the city with the identification of tasks in which stakeholders characterized by a particular role should be involved. Achieving the stated goal required collaboration with experts. Research on the roles of stakeholders, as well as the tasks in which they should be involved, was conducted in Polish cities. Infrastructure managers, small mobility organisers, public safety organisations and public transport organisations turned out to be the development leaders who, as a result, were recommended to be included in most tasks by local government units of Polish cities. What deserves special attention in the results obtained, on the other hand, is the role of the unpredictable main player, which is other cities.

Reducing energy consumption, increasing energy efficiency technologies and solutions, decreasing emissions are very effective tools towards EU environmental policy. The constant demand for domestic hot water (DHW) throughout the year creates great benefits for drain water heat recovery (DWHR) systems in hotels, which is the most promising and significant feature of energy saving potential for the hotel sector in Poland. This paper determines the feasibility of heat recovery in a typical hotel in Poland. The energy analysis was carried out for the installed DWHR system (from washbasins and showers) at the hotel building. To evaluate the energy saving potentiality, daily, monthly and yearly calculation results were performed for an exemplary hotel in Poland. Two types of heat exchangers were adopted for further calculations: vertical (System 1) and horizontal (System 2), this intention aimed to find the most efficient type and relevant solution of energy saving and reduction of CO2 emissions in the analysed hotel. The analysis and calculations were repeated to enhance the saving potentiality of the proposed DWHR systems for various parameters like constant and variable temperature of supply cold water, daily hot water consumption profiles, the efficiency of heat recovery, reduction of annual carbon dioxide emission (CDE), facility standard of operating procedure, the impact of hotel size, etc. The obtained results of the conducted calculations ensure a significant potential of energy savings by implementing the proposed DWHR systems in analysed hotel, which allow to save energy demand and to reduce CO2 emission by 27.3% and improve the efficiency of the DHW preparation system.

When designing a year-round home heating system that uses only solar radiation energy, the cooperation of an architect and an HVAC (heating, ventilation, and air conditioning) designer is necessary. These systems occupy a large area in relation to a building’s floor surface, especially when they are located in a climate like Central Europe or colder. The aim of the article was to create a balanced integration process by implementing the subsequent steps that are necessary to integrate a solar heating system within a building. In the first stage, a solar collector and a heat accumulator were selected. The innovation of the system involves the use of a solar concentrating collector as an air heater. Assessment criteria were then proposed in order to show the influence of the location of the solar heating system on the building’s architecture, functionality, and energy balance, while at the same time assuming its passive standard. System integrations concerning both an existing and new building were analyzed. The system’s basic components were selected for the three chosen solutions, taking into account the possibility of using heat losses resulting from the location of the installation.

In this article, an investigation of a free-piston Stirling engine-based micro-cogeneration (μCHP) unit is presented. This work is a step towards making the system calculations more reliable, based on a data-driven model, which enables the time-domain simulation of the μCHP behavior. A laboratory setup was developed that allowed for the measurement of a micro-cogeneration unit during long-term operation with a variable thermal load. The maximum efficiency of electricity generation was equal to 13.2% and the highest overall efficiency was equal to 95.7%. A model of the analyzed μCHP system was developed and validated. The simulation model was based on the device’s characteristics that were obtained from the measurements; it enables time-domain calculations, taking into account the different operating modes of the device. The validation of the system showed satisfactory compliance of the model with the measurements: for the period modeled of 24 h, the error in the heat generation fluctuated in the range 0.31–4.50%, the error in the electricity generation was in the range 2.48–4.70%, the error in the natural gas consumption was in the range 0.26–4.59%, and the engine’s runtime error was in the range 0.14–8.58%. The modelling process is easily applicable to other energy systems for detailed analysis.