Sökning: "förnyelsebar energi"
Visar resultat 1 - 5 av 36 avhandlingar innehållade orden förnyelsebar energi.
1. Energy Savings Using a Direct Current Distribution Network in a PV and Battery Equipped Residential Building
Sammanfattning : Energy from solar photovoltaic (PV) are generated as direct current (DC) and almost all of today’s electrical loads in residential buildings, household appliances and HVAC system (Heating Ventilation and Air-conditioning) are operated on DC. For a conventional alternating current (AC) distribution system this requires the need for multiple conversion steps before the final user-stage. LÄS MER
2. Food or fuel? : trade-offs between food and biofuels globally and in small-scale organic agriculture
Sammanfattning : There are great expectations on agriculture to provide both food and fuels in the future. Previous attempts to estimate the global bioenergy potential have produced varying results, indicating major uncertainty. This thesis investigated the global theoretical 'potential', or limit, for biofuels based on current agricultural systems. LÄS MER
3. Biorefinery systems for energy and feed production : greenhouse gas performance and energy balances
Sammanfattning : The current dependence on fossil fuels is problematic because these are a finite resource and because their combustion causes environmental degradation. Biorefineries produce a variety of valuable products from biomass that can replace products from petroleum refineries. LÄS MER
4. Life Cycle Assessment of Novel Biomethane Systems : energy performance and climate impact
Sammanfattning : Climate mitigation and supply of renewable energy are global challenges. The main cause of climate change is anthropogenic activities, including consumption of fossil energy sources and land use change. Biomethane, a biomass-derived renewable energy carrier, is interchangeable with fossil-based natural gas and can provide energy services (e.g. LÄS MER
5. Adoption of bioenergy technologies for a sustainable energy system
Sammanfattning : A future sustainable energy system must achieve great improvements in energy efficiency and the energy supply must be based on renewable energy sources. Bioenergy will be an important part of this system. LÄS MER