Sökresultat:
1628 Uppsatser om Low energy - Sida 33 av 109
Bioenergi från röjningsgallringar : en jämförande studie av fyra flödeskedjor från avlägg till förbrukare
When the Swedish Forestry Act was changed in 1994, brushing of young stands became non mandatory. Since then the annual need for brushing in the country has increased by about 100 000 hectares per year. In later years the price for biomass energy has increased to the same level as pulp wood. The high price on biomass energy and the large areas of stands in the need of brushing has created a new market with its own technical, economical and environmental conditions. There is a development of various techniques to manage the forestry stands with late brushing.
Torkning och pelletering av organiskt hushållsavfall - en konstruktionslösning
The research in this paper aims to producing a home version machine thatcan dry and make biological waste into compact pellets. This product ismade primarily for those who want to improve the environment and reducethe energy consuming process of separating the biological leftovers fromother waste in the large processing plants and save money due to reducedpickups of waste. Since there is no commercially available product thatdoes what we want to achieve we had to start from the beginning with boththe design and the mechanical aspects. The result is a machine, that fits inour homes, and in an easy and inexpensive way reduces the amount ofbiological waste that needs to be collected by the public wastetransportation system. This is done without reducing any of the energy inthe waste and it can still be used to compost or by large-scale plants that usethe waste to make electricity.
Uppföljning och analys av Stockholms stads solcellsanläggningar
During 2007 the City of Stockholm installed five grid connected photovoltaic systems. The aim of this master thesis is to quantify the amount of produced energy and recommend routines to collect and analyse production data, to make production data accessible by the public and to gain experience for future installations.The total amount of produced energy until March 2009 is 227 000 kWh, with an annual rate of 150 000 kWh. The expected annual rate was 148 000 kWh.All system owners are positive about their plants and see economical benefits in scaling up such systems.The installations need very little attendance and maintenance, however it is recommended that an alarm function is installed for automatic feedback in case of a system failure. All future systems should be inspected during full operation to determine if the actual capacity is matching the installed capacity..
Hållbara uppvärmningsalternativ för hotellstugorna på Grinda : En kvantitativ studie gällande hållbara uppvärmningsalternativ på en skärgårdsö
Skärgårdsstiftelsen, which is responsible for several of the archipelago islands in Stockholm, has chosen to explore the possibilities for more sustainable heating systems in buildings on the islands in collaboration with KTH. A reduction of energy use and improving the efficiency of existing heating systems are included as part of the environmental work. This report studies the island of Grinda, which is located outside the area of Vaxholm in Stockholm. The study area consists of a guesthouse consisting of a restaurant as well as conference facilities and four neighboring cottages used for overnighting. The cottages now run solely on direct electricity, both for heating and hot water.
Engagerade ungdomar : en hållbar energistrategi
The consumption and energy use in today's society contributes to the on-going climate change that creates a debt of life quality for future generations (www, DN, 2007, a). The resources that are used by humans exceed by far what is sustainable (www, Regeringen, 2007, a).
The purpose of this paper is to examine how a message about energy conservation should be designed to reach youths. This will be attempted by showing their thoughts on energy and environmental issues and also what it would take for them to get more involved in these issues. The views of the youths are gained by a number of focus group-interviews, which where carried out in the fall of 2007, with kids in the ages 12 to 19. Apart from these interviews, interviews where also conducted with representatives from different youth organisations in Sweden, which gave their views on how to get a message across to kids.
Förslag på ytterväggskonstruktion för småhus : Analys med hänsyn till energi, statik, fukt och kostnad
I detta examensarbete studeras kommande energikrav för byggnader i Sverige och i synnerhet kraven påspecifik energianvändning. Detta mot bakgrund av EU-kommissionens och EU-parlamentets direktiv,EPBD2, om nära nollenergibyggnader 2020. Därefter bearbetas ett förslag på en nyytterväggskonstruktion som med lägre U-värde än den befintliga ytterväggen ska sänkaFiskarhedenvillans olika hustypers specifika energianvändning. Syftet med sänkningen är att möjliggöraför Fiskarhedenvillan att uppfylla de kommande energikraven.Det är många parametrar som måste uppfyllas och det nya ytterväggsförslaget analyseras förutom urenergisynpunkt även med hänsyn till statik, fukt och kostnad. Beräkningar för statik och specifikenergianvändning har gjorts för ett referenshus.Resultatet av att byta ut den befintliga ytterväggskonstruktionen mot det framarbetade förslaget medca 33 % lägre U-värde gav endast en sänkning med ca 6 % av den specifika energianvändningen.
Jämförande analys av drivlinor och dess bränslesorter för fordon av hybrid, elektrisk och traditionell typ
The development of solar photovoltaic (PV) is increasing,with declining module prices and with a strongenvironmental profile. Policies are developed around theworld to achieve the targets set for renewable energy.In Helsingborg, the local power company Öresundskraft isworking with solar PV to achieve the goals of the city.With their vision: - Energy for a Better World and Powerfor the Region, their work with developing the local solarPV market is continuing and the next step is to create asolar PV policy. Today their offer is 1 SEK/kWh for theexcess electricity delivered to the grid.It turns out that compensating the customer is a vitalpolicy and it has to be dynamic to follow the decisions ofpolitics. The same survey shows indeed, thatenvironmental and technical part is of interest. Solar PVwill be supported locally to act on environmentalsustainability and locally produced electricity and withthis Öresundskrafts vision will be achieved..
Återvinning av industriell restvärme som värdeskapande process : En fallstudie på SSAB EMEA i Borlänge
The industrial sector accounts for a large share of greenhouse gas emissions. To reduce its negative impact on the environment is crucial in the quest for a sustainable future. In discussions of the industrial sector's impact on the environment guidelines have been highlighted as a tool to assist the industries in their efforts to change the relationship between the consumption of energy and production. This by improving energy efficiency and a shift to the best available technology. During the past 30 years the steel industry has reduced its energy consumption per ton of steel produced by 50 percent.
LCA av dricksvattendesinfektion : en jämförelse av klor och UV-ljus
Disinfection methods for drinking-water produced at the two water works of Stockholm Water Co are compared in this study. Three different nethods are compared; disinfection with chlorine gas, disinfection with sodium hypochlorite and disinfection with UV-light and monochloramine. The method used is Life cycle assessment, LCA. LCA is defined as the compilation and evaluation of the inputs, outputs and potential environmental impact of a product system shroughout its life cycle. The environmental burden is compared for the three different disinfection methods.
Beräkning av koldioxidutsläppet från bostadssektorn i Stockholms län
During the last decades the housing sector has increased continuously, and housings and services accounted for 40 % of the energy usage in Sweden during 2011. The expansion in number of buildings in society has resulted in an increase in both energy usage and emissions of greenhouse gases. It is crucial to enable a sustainable development of society and as a result, the demand to reduce the emissions of carbon dioxide is a current question. In this study, the carbon dioxide emitted from the housing sector in Stockholm is estimated. The housing sector can be divided into different types of houses such as apartment blocks, single-family houses and holiday houses. By collecting information of the energy purchased in respective households, a computational model is generated that calculates the total emission of carbon dioxide.
Val av komplementmaterial för våtkompostering av klosettvatten
Emissions of insufficiently treated wastewater, mainly blackwater (i.e. wastewater from toilets), contributes to the eutrophication of lakes and seas. At the same time, blackwater is a fraction with a low content of heavy metals and, after sanitization, it can recirculate plant nutrients to arable land using the liquid composting treatment method. Liquid composting means that organic material is degraded under aerobic conditions. For sanitization, the blackwater needs to be treated together with energy-rich complementary material.
Turbinkretspump system - Kraftvärmeverket i Borås
The Rya power plant in Borås produces district heating, district cooling and electricity. The plant is owned by Borås Energi och Miljö AB and is run by Dalkia Facility Management AB.In order to get the best heat exchange from the district hot water a pair of twin pumps and a turbine circuit pump are used as return pumps. Turbine circuit pumps are used to increase the pressure through the heat exchangers at the power plant. The pumps are in use when the flow is over 2 000 m3 h-1 and during the summer when re-cooling is used to improve the effectivens of the heat boilers.Since the pumps, that are parallel connected, rotating at a fixed rate per minute, the pressure is regulated with regulating valves. This report shows that during the 4,300 hours that the pumps where in use, energy corresponding to 590 MWh was wasted.
Torrefaction of biomass : a comparative and kinetic study of thermal decomposition for Norway spruce stump, poplar and fuel tree chips
Stump biomass is energy rich and stump harvesting for use as fuel become more and more
interesting in Sweden. Swedish Forest Agency (2009) has estimated that stump harvesting in
Sweden would respond to an annual energy supply of 57 TWh/year. However, stump has not
been recognized as a bioenergy resource in Sweden. Suitable methods for pre-treatment of
stump are probably of great importance to make it accepted as fuel. It is therefore rewarding
to carry out an investigation in this area for stump.
This report represents results from a diploma project, which was aimed to develop a fixed bed
reactor for experimental study of biomass torrefaction, followed by TG analysis and kinetic
modelling employing Ozawa method and different kinetic models including one-step and
three-pseudo-component models.
Utvärdering av laddningskoncept för lastbilsbatterier
When drivers overnight in the truck lots of electric energy is consumed by heaters, fans, lights and other extra equipment. If the engine is not running, this energy is taken from the lead/acid batteries of the truck which then needs to be recharged during operating hours. The fact that the charge acceptance of the lead/acid batteries is dependent on the temperature makes it hard to fully recharge the batteries at lower temperatures. A negative charge balance can lead to starting problems within a few days use in cold climate.In this thesis work, the effects of different battery charging concept are evaluated on the most common Scania battery (175Ah). A battery model is implemented in Matlab and some simulations of charging are made.
Utvärdering av möjligheten att tillvarata energi ur processvatten : En undersökning gjort vid Olofsfors AB på uppdrag av UMIA AB.
The company Olofsfors AB manufactures drive belts for forest machinery, known as ECO-Tracks, and abrasion-resistant steel and cutting edges for graders, excavators and tractors, known as Bruxite and SharqEdges. Manufacturing these products requires the steel to be heated and molded, then submerged in water and hardened. The water used in the hardening of steel is pumped to the process from pits below the floor and then pumped back to the pit after it?s been used. Since the temperature of this water rises after being used to harden the steel the temperature of the pumping pit needs to be adjusted to maintain its setpoint of 21°C.