Present Work

Hybrid energy harvester

A hybrid energy harvester is an electric power system comprising two or more energy that supply power to a single output. In this project, there are 3 difference situation to place thermoelectric cell for measure and analysed what situation can generate more electricity. Whereby for the first situation place the thermoelectric cell inside the wall room with low temperature condition. Second situation is place the thermoelectric cell outside the wall  room and the third situation is place the thermoelectric cell for both situation which is inside and outside the room.  After do testing with the prototype,  the computer will display the electrical properties by using LABVIEW. The main objective of this research is to measure the best output from 3 different situation at thermoelectric.

In theoretically, by using seebeck effect knowledge. Thermoelectric is describes the potential generated when the junction of two dissimilar metals experiences a temperature difference. That means, the more difference between cold and hot temperature, the more electric will be generate. Then, from basic knowledge will know situation three will generate more electricity because this situation have more differences between hot temperature and cold temperature.

           

This project is generally have reduced fuel consumption, reduced maintenance, and provide highly reliable electric power compared with non-hybrid generators. Most non hybrid engine-driven electric generators run continuously and at a high, fixed RPM, resulting in excess fuel consumption when the load is low. Hybrid energy automatically shut the engine off when sufficient alternative energy sources are available to meet the demand load.

 Previous Work

The thermoelectric effect was discovered by Thomas J Seebeck in 1821. He discovered that when heated different metals, as the temperature get hotter a small voltage will increase. By bonding the metals like iron with constants, for example, and then heating the bonded junction area, a small voltage is generated.

This bonded junction called a thermocouple is widely used as a control device in applications and equipment where heat in used. For example, natural gas devices including furnaces, hot water heaters, gas fireplace inserts and outdoor propane barbeque grills use this thermocouple process to verify the pilot flame is burning prior to allowing the main gas valve to open.  The newer discoveries with the p-n junction are leading to new technologies in P-N thermoelectric usage.

Both N-type and P-type Bismuth Telluride thermoelectric materials are used in a thermoelectric cooler. This arrangement causes heat to move through the cooler in one direction only while the electrical current moves back and forth alternately between the top and bottom substrates through each N and P element. N-type material is doped so that it will have an excess of electrons (more electrons than needed to complete a perfect molecular lattice structure) and P-type material is doped so that it will have a deficiency of electrons (fewer electrons than are necessary to complete a perfect lattice structure).

The extra electrons in the N material and the "holes" resulting from the deficiency of electrons in the P material are the carriers which move the heat energy through the thermoelectric material. Most thermoelectric cooling modules are fabricated with an equal number of N-type and P-type elements where one N and P element pair form a thermoelectric "couple." For example, the module illustrated above has two pairs of N and P elements and is termed a "two-couple module". Cooling capacity (heat actively pumped through the thermoelectric module) is proportional to the magnitude of the applied DC electric current and the thermal conditions on each side of the module. By varying the input current from zero to maximum, it is possible to regulate the heat flow and control the surface temperature

LITERATURE REVIEW

 

INTRODUCTION

            On this chapter,  it will discuss about the literature review which is about the history of the previous project  and present work. The references of the explanation are done by referring to the books, internet, journals, articles pamphlet and other sources. While there are two main methods for hybrid energy (thermoelectric and photovoltaic,), the literature review is to discuss about this two types of sources.

 

HISTORY

 Previous Work

PV (Photovoltaic) refers to a SOLAR PANEL. A flat panel that you place in the Sunlight which makes electricity directly from Sunlight. Photo refers to light and Voltaic refers to voltage or electricity. These panels do not produce Heat this make electricity.

 

The photoelectric effect was first noted by a French physicist, Edmund Bequerel, in 1839, who found that certain materials would produce small amounts of electric current when exposed to light. In 1905, Albert Einstein described the nature of light and the photoelectric effect on which photovoltaic technology is based, for which he later won a Nobel prize in physics. The first photovoltaic module was built by Bell Laboratories in 1954. It was billed as a solar battery and was mostly just a curiosity as it was too expensive to gain widespread use. In the 1960s, the space industry began to make the first serious use of the technology to provide power aboard spacecraft. Through the space programs, the technology advanced, its reliability was established, and the cost began to decline. During the energy crisis in the 1970s, photovoltaic technology gained recognition as a source of power for non-space applications.[2]

One common style of solar cell is build using a fused silicon wafer stack. This arrangement is called a P-N Junction sandwich. The bottom plate of the stack is a conductive plate. The next layers in order are the p-type crystal material layer, the n-type material layer, a conductive screen contact area, and a protective covering that allows the light through.[3] This p-n junction is the foundation of the semiconductor process and will be described in more detail in the general semiconductor section later in the book.

           

 

LITERATURE REVIEW

• This part will discuss about history, previos work and present work.
• Do some research about the history of photovoltaic and thermoelectric effect. 
• Find another existing project that are almost same with the present project.

PROBLEM STATEMENT

Photovoltaic-thermoelectric hybrid energy harvester on building wall is a combination of solar cell and thermoelectric cell into single electric generator. This project show that the hybrid system can be used to supply the output power more efficient. So that, hybrid system can be used to backup the supply when one of the source is not function well. Most of  problem in this project occur when the weather is bad. Such as, the sunlight to produce thermo source are not satisfactory and no wind blowing. Because of this problem, the project are fail to generate electricity. Other than that, the reason why the project is not functioning well is because of failure of components or module , lack of maintenance, environment factors and system overload.

This is flexible system that can adapt to most building types , orientations and climate. It has the ability to provide varying degrees of opacity to modulate heat gain, light transmission and view. Because of modular design, it will be able to include more efficient and less expensive photovoltaic modules once those products are available and cost effective Other than that, efficiencies of the solar thermal power system having been develop in which solar energy is used as main heat source are not satisfactory. In addition, solar energy utilization is subject to the change of season and weather.

 INTRODUCTION

 

A solar cell in which the sun's energy is first converted into heat by a sheet of metal, and the heat is converted into electricity by a semiconductor material sandwiched between the first metal sheet and a metal collector sheet. 

A thermoelectric cell is a device that converts heat (temperature differences) into electricity, using a phenomenon called the "Seebeck effect" (or "thermoelectric effect").  Their typical efficiencies are around 5-10% [1]. This effect can be used to generate electricity.

The objective of this project is to develop and performance analysis of photovoltaic – thermoelectric (PV – TE) energy harvester prototype on building wall using LABVIEW. This project function is to evaluate the best performance when thermoelectric cell place at wall building. The output from project will connect to DAQ using LABVIEW software. This project will more focus about thermoelectric cell. The performance of the result will compare with 3 type of thermoelectric cell place difference situation. The output will combine with photovoltaic output.  

      In everyday life, the electricity are used by consumption of fossil fuel which produce carbon dioxide and can give negative impact of our environment, because of solar energy is clean, free and easy to get, this source is getting more attention nowadays. The concept of developing solar thermal is by combining two sources of energy which are solar and thermal into single output. Furthermore, these types of energy are suitable in Malaysia because in Malaysia it received a huge amount of sunlight.

        The advantage of this project are power is free of cost because its get from the sunlight. Then the power is zero emission. Silent production energy and lastly  is power is available “on the go”.  Nowadays, most of the building especially houses are using solar panels as their power generators. But there has a some difficulty by used this solar panel which is solar panel is expensive and having high installation cost and  much weight.