Convocatoria 2018 de proyectos I+D+i "Retos investigación"

File No: RTI2018-095923-B-C22

Execution Period: 2019-2021 

Financial institutions: 

Ministerio de Ciencia e Innovación (MCI)

Agencia Estatal de Investigación (AEI)

Fondo Europeo de Desarrollo Regional (FEDER) 


Recovery of waste energies from light-duty vehicles. Technological Impact. (RECOVER) 



IP 1 COORDINATOR 1: Octavio Armas Vergel 


Recuperación de energía térmica residual en vehículos ligeros. Impacto tecnológico. (RECUPERA-TE) 

Recovery of waste thermal energy from light duty vehicles. Technological impact. (RECOVER-THE) 


IP COORDINATOR 1: Jordi Viñolas Prat

IP COORDINATOR 2 : José Luis Olazagoitia Rodríguez


Recuperación de energía mecánica residual en vehículos ligeros. Impacto tecnológico. (RECUPERA-ME) 

Recovery of waste mechanical energy from light duty vehicles. Technological impact. (RECOVER-ME)

State of the Art and motivation

Among the options that have been used to "recycle" or “harvest” the energy that would be lost one finds solutions such regenerative braking systems [1], exhaust pipes with thermoelectric generation [2], energy generation from the combustion gases of internal engines [3], generation of energy with piezoelectric materials in the rims [4], energy recovery in suspensions [5], etc. This is the topic that this proposal is focused on and one will understand better by describing briefly the achievements of both research teams over the past three years (01/01/2015-31/05/2018) as a result of the project entitled "Potential for recovery of waste energy in internal combustion engines. Energy and environmental implications (POWER), Ref. ENE2014-57043-R" financed in the RETOS 2014 call "Society Challenges".


Fig. 1 Energy Flow Diagram in an Internal Combustion Vehicle (Presented by Siang Fiu et al. [2])


1. L. Li, Y. Zhang, C. Yang, B. Yan, and C. Marina Martinez, “Model predictive control-based efficient energy recovery control strategy for regenerative braking system of hybrid electric bus,” Energy Convers. Manag, vol. 111, pp. 299–314, Mar. 2016.

2. X. Liu, C. Li, Y. D. Deng, and C. Q. Su, “An energy-harvesting system using thermoelectric power generation for automotive application,” Int. J. Electr. Power Energy Syst., vol. 67, pp. 510–516, 2015.

3. R. Saidur, M. Rezaei, W. K. Muzammil, M. H. Hassan, S. Paria, and M. Hasanuzzaman, “Technologies to recover exhaust heat from internal combustion engines,” Renew. Sustain. Energy Rev., vol. 16, no. 8, pp. 5649–5659, 2012.

4. J. Lee and B. Choi, “Development of a piezoelectric energy harvesting system for implementing wireless sensors on the tires,” Energy Convers. Manag., vol. 78, pp. 32–38, 2014

5. P. Múčka, “Energy-harvesting potential of automobile suspension,” Veh. Syst. Dyn., vol. 54, no. 12, pp. 1651–1670, 2016.


Objectives and expected results

1. Designing, modelling for parameters optimization, bench testing and vehicle testing of a shock absorber with energy recovery capacity (EHSA, Energy Harvesting Shock Absorber). In addition, to provide the ESHA of a control for variation of damping characteristics: ESHA-semi-active.

2. To quantify, as a function of vehicle, traffic conditions and road conditions, the energy levels from vibrations to be recoverable in the suspension. Modeling and testing. Since tests will be carried out with only one type of vehicle and under certain conditions, the objective is to extrapolate the results to other conditions and vehicles.

3. To evaluate the potential of the thermal energy recovery (in coordination with activities of sub-project 1) with a thermo-acoustic Stirling cycle system (TA-SLiCE, Thermo-acoustic Stirling-Like Cycle Engine).

4. Designing, modelling for parameters optimization and manufacturing a prototype of a thermo-acoustic system.

5. Comprehensive evaluation of the different energy recovery technologies in a vehicle taking into account the driving conditions, road and type of vehicle. Virtual evaluation.


Project structure of subproject 2 and its connection with subproject 1




Results so far and expectations

From the point of view of mechanical energy recovery, references [17,18] highlight the work of the POWER project in what refers to the recovery of mechanical energy (vibration) in shock absorbers. These references explain the variety of ideas but also disparities in the published work regarding a critical aspect: how much power can be retrieve?. One can find values of "potential recoverable energy" from 46W to 7500W!. POWER quantified in a realistic way the recoverable energy, the table is no more than a small sample of data from tests with a Renault-Twizzy.


Speed Twizy


Road average roughness




rms  (W)

80 Km/h



100 Km/h



120 Km/h



80 Km/h



100 Km/h



120 Km/h



These values vary with the type of vehicle, speed and road surface, but it is realistic to expect an average car to be able to recover around 140 W per shock absorber in an urban circuit [19]. The latter are rather interesting figures, and there is an actual interest on this technology, but is true that there are quite a few open paths for progress: these are the tasks presented in this sub-project 2, ranging from the design optimization of the shock absorber, the possibility of varying the damping characteristic of the shock absorber electronically (semi-active energy harvesting shock absorber) and the assessment of the potential for recovery in variable conditions combined with the proposed solutions of thermal energy recovery (in the sub-project 1 thermoelectric systems and thermo-Acoustic 2, both taking advantage of the source of the exhaust gases.

17. Lincoln Bowen, Jordi Vinolas, José Luis Olazagoitia, “Methodology for comparing the functional performance of energy harvesting shock absorbers”, International Journal of Applied Electromagnetic and Mechanics, vol. 55, pp. 545–564, 2017.

18. Lincoln Bowen, Jordi Vinolas, José Luis Olazagoitia, “Diseño y fabricación de un banco de ensayo para validación de un modelo computacional de un cuarto de coche utilizando un amortiguador para recuperación de energía”, Revista DYNA, vol. 93, pp. 82–95, 2017.

19. L. Bowen, “Estudio teórico-experimental de sistemas de recuperación de energía en la suspensión de un vehículo automóvil”, Tesis doctoral, Universidad Nebrija, julio 2018

Expected impact

The project is aligned with this strong and common-sense message that is driving many of the European green initiatives: valuable things cannot be wasted, and energy has to be used wisely. On the other hand the automotive sector provides jobs to many people in Europe. This proposal seeks to improve the sustainability of the automotive industry and its components. The competitiveness of European producers is based on the optimization of performance and costs, in particular tractive power systems. While the previous POWER project focused its objectives on study of potential and experimental thermal and residual energy recovery systems design proposal, this proposal aims at the methodological improvement of the design and experimentation to achieve prototypes for energy recovery able to be commercially integrated into the automotive industry. The prototypes are intended to be integrated in engines and vehicles taking into account the limitations and requirements imposed by the manufacturers of modern light vehicles.