Prometheus Project

Production Method Of Electrical Energy by Enhanced Thermal Electron Emission by the Use of Superior Semiconductors

Project Summary

The ProME3ThE2US2 project aims to create, validate and implement high efficiency innovative solid-state mechanism to covert solar energy into electric energy. The primary demand for these systems comes from energy market because of its high cost effectiveness.

The energy conversion process used exploits high density radiations with enhanced electron emission using the energy from the incoming light by utilizing physical properties of semi conductors to work at high temperatures (~1000 degrees). The high operating temperatures are also connected to the possibility of exploiting the residual thermal energy into electric energy by thermo-mechanical conversion. It is estimated that the proposed technology could achieve a conversion efficiency of 45% higher if used under high intense solar irradiations.

The project will develop a “proof-of-concept” converter working under vacuum conditions composed of a radiation absorber able to provide temperature increase, a semiconductor cathode properly deposited on it, and a work-function-anode, separated from cathode by inter-electrode spacing.

The concept is based on:

  • Use of both band gap (photoelectric effect) and over band gap (thermalization) energy
  • Use of sub-band gap IR radiation to augment the thermionic emission from the cathode
  • Advanced engineered semiconductors
  • Experimentation of cathode for emissions enhancement and
  • Recovery of exhaust heat from the anode by thermo-mechanical conversion.

Vaccum encapsulation

There are various technological-scientific challenges of the project, supported by significant simulation activity, which can be distinguished in different technological-scientific levels:

  • The material science challenge is represented by development of a multilayered cathode to satisfy the requirements at high temperatures 1) proper energy band-gap 2) high quantum efficiency 3) high electron mean-free-path 4) engineered electron affinity for minimizing energy barriers towards vacuum escaping;
  • The technological challenge is represented by a monolithic integration and matching of IR selective absorber with the efficient electron-emitting cathode and with other advanced materials composing the converter.
  • The industrial challenge is represented by design, analysis and integration of a secondary thermal recovery that contributes to thermal-to-electric conversion efficiency.

A   specifically designed converter will be implemented and its efficiency is measured under solar simulators and solar furnace. The directly converted electric energy and the residual thermal energy will be accurately measured in lab level systems. The electrical conversion efficiency will give a feed back to tailor the active materials physical properties, whereas design of heat recovery system will be based on value of thermal energy produced. The performance will be compared with similar systems in terms of output power, production cost, durability and reliability with the main focus on scalability.

Data output will be collected to establish real achievements by the project towards the semi conductor and energy industry. The success of the project will offer a significant alternative to the most advanced photovoltaic cells for high-temperature operation, by overcoming issues correlated to the junction-structure intrinsic temperature limitations and by allowing maximum use of the thermal energy, actually wasted in photovoltaic (PV) conversion.

Objectives

Objective1: To analyse solar radiation conversion under vacuum conditions in order to allow the emission of electrons from the cathode and their collection at the anode, minimizing also degradation of materials and avoiding thermal energy losses

Objective2: To develop an advanced solar radiation absorber able to provide temperatures in the range 200-1000 oC as a function of radiation concentration ratio.

Objective3: To design and fabricate an innovative active cathode, that efficiently emits electrons both via thermionic and photo-enhanced mechanisms for the direct solar to electrical energy conversion.

Objective4: To carry out a monolithic integration of different components with mechanical, optical, electrical and thermal matching.

Objective5: To design and perform simulation of an indirect thermodynamic-to-electric recovery system.

Project Details

Full Title Production method of electrical energy by enhanced thermal electron emission by the use of superior semiconductor
Acronym ProME3ThE2US2
Contract Type Collaborative Project
Topic Addressed FP7-ENERGY-2012-10-2-1: Future Emerging Technologies
Start Date 1st May 2013
Duration 36 months
End Date 30 May 2016
Project Status Execution
Funding 2,995,259.00 €
Total Costs 4,210,827.20 €