Heating and Cooling with Solar Powered Peltier Elements

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  • ISRN LUTMDN/TMHP-14/5308-SE

    ISSN 0282-1990

    Heating and Cooling with Solar

    Powered Peltier Elements

    - The next generation of sustainable heat pumps?

    Alexandra Thedeby | Master Thesis at the Environmental

    Engineering Program

    Department of Energy Planning | Division of Efficient

    Energy Systems

    Faculty of Engineering | Lund University

  • Heating and Cooling with Solar

    Powered Peltier Elements

    - the next generation of heat pumps?

    Alexandra Thedeby

    2014-05-19

  • Freliggande examensarbete p civilingenjrsniv har genomfrts vid Avd. fr Energihushllning, Inst fr

    Energivetenskaper, Lunds Universitet - LTH samt vid Energiteknik i Teckomatorp AB. Handledare p Energiteknik AB:

    Mikael Jo; handledare p LU-LTH: Bitrdande Lektor Patrick Lauenburg; examinator p LU-LTH: Professor Jurek

    Pyrko

    Examensarbete p Civilingenjrsniv

    ISRN LUTMDN/TMHP-14/5308-SE

    ISSN 0282-1990

    2014 05 19 (Alexandra Thedeby) samt Energivetenskaper

    Energihushllning

    Institutionen fr Energivetenskaper

    Lunds Universitet - Lunds Tekniska Hgskola

    Box 118, 221 00 Lund

    www.energy.lth.se

  • Abstract The purpose of this project has been to investigate the possibility of heating and cooling air by

    connecting Peltier Elements to a PV panel. The idea was initiated by Energiteknik i Teckomatorp

    AB, a company that provides heat pumps and coolers to small scale businesses and private

    customers. The climate panel developed is to be used as a compliment to an existing heating

    system in order to pre-heat and pre-cool the air coming into the house. By decreasing the heating

    demand in winter and cooling demand in summer the panel could contribute to lowering the

    annual energy need and thereby save money. The aim of this project has been to investigate the

    potential for such a panel, and to perform an economic evaluation in comparison to common

    Swedish heating systems.

    The result presented in this report is based on theoretical and practical simulations. A prototype

    design has been developed along with the company and tested in their workshop. The results

    showed that the panel has an annual energy output of 1 300 kWh, which corresponds to 9% of the

    heating and 5% of the total energy need for a normal Swedish house. The economic viability of the

    panel depend on which heating system it is used along with, and the pay-back time vary between 3-

    10 years. There are many uncertainties connected to the theoretical model and the practical results

    and further testing is needed to fully evaluate the system. The conclusion is that there is great

    potential in developing this product, and that it can be used as a complement to an existing heating

    system to save both energy and money. Using solar energy to boost the heat production of a

    building is a sustainable way to reduce the environmental impact and cut the costs, which is why

    the climate panel should be developed further.

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    District Heating

    Bio Fuel Heat Pump

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  • Foreword This report is the final product of a Master Thesis Project performed at Energiteknik i Teckomatorp

    AB, in cooperation with the Division of Efficient Energy Systems at Lund University, Faculty of

    Engineering. The project duration has been 20 weeks, which corresponds to 30 hp. It concludes the

    Masters Degree in Energy System at the Environmental Engineering Program of five years, 300 hp.

    Acknowledgements I would like to thank my supervisor Patrick Lauenburg at the Division of Efficient Energy Systems

    for all the help and encouragement I have received during this project. Thanks to Mikael Jo at

    Energiteknik for initializing this project and given me the chance to use the companys resources.

    Thumbs up to all the employees at Energiteknik for helping me out in the workshop and taking

    cover when I put the equipment on fire. I send my best wishes to Per Buch, whom without I would

    not have found the motivation to keep going as things went wrong and equipment broke down.

    Without the organization Miljbron I would never have come across this project or the company to

    begin with, so lastly I thank Helena Ensgrd for believing I was the right person for the job.

  • Table of Contents 1. Introduction .......................................................................................................................................................................... 1

    1.1 Description of the company .................................................................................................................................... 1

    1.2 Objective ......................................................................................................................................................................... 2

    1.3 Question formulation.......................................................................................................................................... 2

    1.4 Method ............................................................................................................................................................................. 3

    1.5 Report structure .......................................................................................................................................................... 3

    1.6 System boundaries ..................................................................................................................................................... 4

    1.7 Explanation of words, units and expression used in this report ............................................................. 5

    2. Theory and background ................................................................................................................................................... 7

    2.1 Basic concept of energy and power ..................................................................................................................... 7

    Heat machines and heat pumps ............................................................................................................................... 7

    2.2 Solid State Physics ...................................................................................................................................................... 9

    Semiconductors .............................................................................................................................................................. 9

    Doping .............................................................................................................................................................................. 10

    Thermoelectric devices ............................................................................................................................................. 10

    Seebeck voltage ............................................................................................................................................................ 10

    Peltier effect ................................................................................................................................................................... 11

    Relation between the Seebeck and Peltier effect ............................................................................................ 12

    Thermoelectric heat pumps and coolers ............................................................................................................ 12

    Thermoelectric refrigeration .................................................................................................................................. 15

    2.3 Solar cells ...................................................................................................................................................................... 15

    PV design and function .............................................................................................................................................. 16

    Module structure .......................................................................................................................................................... 17

    Improving PV efficiency with air cooling ........................................................................................................... 18

    2.4 Energy usage in buildings and indoor comfort ............................................................................................. 19

    3. Previously performed experiments .......................................................................................................................... 21

    Thermoelectric small-space air conditioner..................................................................................................... 21

    Active Building Envelope prototype .................................................................................................................... 21

    Pre-heating and pre-cooling of air for a two-story house ........................................................................... 22

    Designing wall for air duct in PV panel ............................................................................................................... 22

    4. Prototype design and theoretical model ..................