Utilizing energy flexibility in households through smart steering of appliances has received attention as one way to reduce power peaks and adapt demand to a renewable energy system. Heating is a big part of the electricity consumption in households, and heat pump technology is growing in popularity for heating detached houses. While there is ongoing research calculating the technical potential for energy flexibility from heat pumps, few studies combine remote control of heat pumps with qualitative research on how households experience this control. The purpose of this study is to find out how long-term steering of heat pumps is experienced by households, how it affects their heating practices, and how they make sense of remote steering as a service. The data originates from an interdisciplinary project combining a field trial where heat pumps of selected Swedish households were remotely controlled for two winter periods, with qualitative interviews with the households. We conducted interviews with 12 participants, before and after the trial.The results show that households were overall positive towards offering flexibility through remote-controlled heat pumps, and that the steering of the heating blended well with normal temperature variation associated with having a villa in Sweden. However, the respondents were mystified by the procedure, which created a ghost in the heat pump. Furthermore, remote steering as a service comes with challenges related to reliability, security, and agency over the heat pump. Important social conditions for adopting flexibility through remote steering of heat pumps are discussed.
This thesis is performed to analyze harmonics in HVDC-connected offshore windfarms and investigates different approaches to damp grid resonances so that the resulting harmonics are within standardized levels. This is done using Hitachi Energy’s inhouse developed MATLAB-tools.
This thesis comprises background and theory on modelling of offshore windfarms equipment such as cables, wind turbines, transformers, and converters. Harmonics and amplification of harmonics have been calculated in the windfarm for numerous system configurations, and with different mitigation approaches such as active control damping and passive damping using filters.
This thesis presents three different passive mitigation options; Platform filters which will be implemented to each PCC, String filters connected to each string and Wind Turbine filters placed in all wind turbines.
The results have shown that without any mitigation the system is inherently undamped resulting in extreme amplification of harmonics. Using only active control damping does not help to damp the amplification of harmonics and passive damping is required. When utilizing Passive filters such as Platform filters, String filters or WTG filters the damping has been successfully implied to the system and the THD complies with the design limits.
Energy-efficient technologies are not just objects that might enable households to carry out more sustainable practices; they are tools, and using them effectively requires certain skills and knowledge. Households' difficulties in handling home heating and hot water technologies in particular have been highlighted as an obstacle to meeting energy conservation objectives. This has given rise to calls for improved support based on how the households define their activities and handle these technologies. By deploying a socio-cultural theory of learning and using in-depth interviews with households that have recently purchased renewable heating systems, this paper examines various situations in which people have learnt to use the technologies, and it discusses lessons learnt that may be useful for developing support. The results demonstrate three common learning approaches and identify situations where the learning process runs smoothly and where it does not. The conclusions suggest strategies for helping households overcome the resistance embedded in the interaction with the technologies, and they highlight the importance, when developing support, of starting with what creates meaning in various situations.
Think tanks are a special type of civil society organization engaged in research and advocacy. They produce and deliver social analysis to policymakers and the wider public, aiming to influence policy in a given direction while declaring themselves detached from vested interests. This chapter focuses on how the image of independence rhymes with think tanks’ need for significant economic resources, revealing two main strategies to resolve the resulting funding dilemma. The first strategy entails diversification of funding sources; the second is avoiding certain types of funding outright. The concrete sources that individual think tanks eschew turn out to be linked to their ideological profiles: conservative institutions highlighted foreign funding as the most problematic, while market liberal and centrist liberal institutions shunned state funding.
Renewable energy education is an important aspect when developing renewable energy. This applies to school level, university level, technical and mechanical training, educating policy makers, project developers, educators, and common public. In this report, we discuss the importance of laboratory work when teaching renewable energy. We have also included a large number of examples in renewable energy school activities are presented.
Renewable energy education is an important aspect when developing renewable energy. This applies to school level, university level, technical and mechanical training, educating policy makers, project developers, educators, and common public. In this report, a large number of issues and challenges in renewable energy education are addressed. We have also included a fair number of recommendations for development of good renewable energy courses.
To achieve the climate goal and reduce carbon dioxide emissions, electrification of transport and sales of rechargeable vehicles has increased rapidly in recent years. To meet the development, an available charging infrastructure must be prepared. The report examines the principles for installing public charging stations at a supermarket and provides suggestions for charging stations that can be used. 19 Semi-fast chargers with double sockets and an output of 22 kW are placed together with four quick chargers with double sockets and 50 kW power in a car park belonging to the Bäckebol’s shopping center on Hisingen in Gothenburg.
The installation is dimensioned for both the maximum power (alternative 1) which is calculated at 1236 kW and also for a reduced power with the help of load balancing (alternative 2) which is combined to 741 kW. Load balancing is used for various reasons but mainly to protect the system from congestion and minimize costs for network connection by reducing the need for security. High and low voltage cables made of PEX insulation and aluminum conductor, dimensioned with associated fuses, and checked with regards to load capacity and tripping condition based on suitable standards. The power station is placed as close to charging stations as possible to avoid high costs during excavation and cable laying. The station contains a transformer whose size varies depending on the power it needs to be dimensioned for.
The cost of the investment is presented for both alternatives and includes both the charging stations and the electricity grid. Alternative 1 has a total investment cost of SEK 3 million and a repayment period of 6.6 years. For alternative 2 with a total basic investment of SEK 2.3 million, the repayment period will be 5 years. The costs are reported with regards to the investment support from the Swedish Environmental Protection Agency, which is limited to SEK 15,000/Charging point. Revenue may vary depending on the number of visitors while costs may include other services such as billing and maintenance.
The study is based on various assumptions and according to the authors, the project should be performed with load balancing to reduce costs for the investment and to protect the plant against overload. A profitable and efficient charging solution for customers requires an overall analysis of the customer flow in the shopping center as well as an evaluation of various suppliers inthe market