Research activities carried out by the Renewable Energy group aim to contribute to the transition to a low carbon energy system, in line with the EU priorities for Secure, Clean and Efficient Energy. These challenges require both the development of concepts, technologies and services for an increasing clean energy generation, energy efficiency and sustainable development of urban areas. Energy use has strong implications with the environment requiring also cooperation with other IDL groups, in particular regarding climate change. The group aims to bring innovative ideas to the industry, society and fellow research institutes. The research in this group is divided in 3 main areas: 1) Solar Energy, covering PV (photovoltaics) technology, systems and remote electrification; 2) Renewable Energy Resources (in cooperation with the Atmosphere, Ocean and Climate group), covering solar resource analysis and renewable resources in the urban environment; 3) Energy & Environment in Buildings covering simplified models for building energy simulation, studies on natural ventilation among others. Emerging areas of interest within the group are energy storage and mobility.

Group Leader: João Serra

Scientific Highlights 2016

Pilot plant with photovoltaic panels aerial scheme (Erasmus project).

Microalgae biomass production using wastewater: Treatment and costs Scale-up considerations
This work was part of a cooperation with the Nacional Laboratory of Energy and Geology (LNEG). LNEG has a pilot wastewater treatment plant that grows microalgae in a vertical tubular photobioreactor (PBR) prototype (150 L). Within the LIFE project, urban wastewater was used and inoculated with three different microalgae: Chlorella vulgaris (Cv), Scenedesmus obliquus (Sc) and Consortium C (ConsC), isolated from the effluent. ConsC is probably the best option for further uses, such as biofuel, biofertilizer and bioplastic production. Electrocoagulation was tested and resulted in an energy saving of 89%, compared with centrifugation alone. For drying the biomass, a solar dryer was used. The electrical energy needs are still high (323 kWh/kg) and need a drastic reduction to achieve the production cost target value of $0.5/kg. The use of microalgae to produce “cleanwater” must be carefully analysed to achieve the same cost as conventional wastewater plants (0.2 €/m3). The use of photovoltaic panels in the pilot plant for self-consumption and additional energy injected in the grid was exploited within an Erasmus project.

Concert hall audience and temperature measurements.

Simulated and measured performance of displacement ventilation systems in large rooms
Displacement ventilation (DV) systems were initially developed as an efficient buoyant pollutant removal strategy for Scandinavian industrial halls in the 1970´s. In the following decades these systems started to be used in mechanical cooling of office buildings and auditoriums. There is a lack of measurements that investigate the performance of DV systems in occupied large rooms. With the goal of reducing this knowledge gap, this paper presents a set of detailed temperature and CO2 measurements in two occupied large rooms with recently designed DV systems. The measurements and subsequent analysis were used to assess the actual performance of large room, state of the art, DV systems. In addition, these measurements were used to determine the modeling error of the three-node DV model implemented in EnergyPlus when simulating large rooms. Comparison between simulations and measurements revealed a good agreement: the average simulation error obtained by averaging the error of all measurements in all temperature nodes is 5.9%, with the largest deviation occurring in the floor level node (7.1% ≈ 0.4ºC).


Abi Babadji

PhD Student

Ana Filipa Silva

PhD Student

Ana Rita Montes

PhD Student

Ângelo Casaleiro

PhD Student

António Vallêra

Senior Researcher

Carla Silva

Senior Researcher

Cristina Catita

Senior Researcher

Daniel Albuquerque

PhD Student

Danilo Arcentales

PhD Student

David Pêra

PhD Student

Filipe Serra

PhD Student

Guilherme Carrilho da Graça

Senior Researcher

Ivo Costa

PhD Student

Joana Baptista

PhD Student

João Bravo Dias

PhD Student

João Serra

Senior Researcher

João Silva

PhD Student

Jorge Maia Alves

Senior Researcher

José Silva

Postdoctoral Researcher

Killian Lobato

Senior Researcher

Marta Panão

Senior Researcher

Miguel Centeno Brito

Senior Researcher

Nuno Martins

PhD Student

Nuno Mateus

PhD Student

Pedro Nunes

Postdoctoral Researcher

Raquel Figueiredo

PhD Student

Rita Almeida

PhD Student

Rodrigo Silva

PhD Student

Sara Freitas

PhD Student


EDP, Portugal
imec, Belgium
NTNU, Norway
Open Renewables, Portugal
SDSIL, Portugal
Sintef, Norway
Universidade de Coimbra, Portugal
Universidade do Porto, Portugal
Universidad de Navarra, Spain
Universidad Politécnica de Madrid
, Spain
Université de Strasbourg, France
Université Toulouse III Paul Sabatier, France



Correia JM, Bastos A, Brito MC, Trigo RM (2016) The influence of the main large-scale circulation patterns on wind power production in Portugal, Renewable Energy, 102, 214-223, ISSN 0960-1481, DOI: 10.1016/j.renene.2016.10.002

Nunes P, Figueiredo R, Brito MC (2016) The use of parking lots to solar-charge electric vehicles, Renewable and Sustainable Energy Reviews, 66, 679-693, ISSN 1364-0321, DOI: 10.1016/j.rser.2016.08.015

Garrido H, Vendeirinho V, Brito MC (2016) Feasibility of KUDURA hybrid generation system in Mozambique: Sensitivity study of the small-scale PV-biomass and PV-diesel power generation hybrid system, Renewable Energy, 92, 47-57, ISSN 0960-1481, DOI:10.1016/j.renene.2016.01.08

Neves D, Brito MC, Silva CA (2016) Impact of solar and wind forecast uncertainties on demand response of isolated microgrids, Renewable Energy, 87, 1003-1015, ISSN 0960-1481, DOI: 10.1016/j.renene.2015.08.075

Panão MO, Santo C, Mateus NM, Carrilho da Graça G (2016) Validation of a lumped RC model for thermal simulation of a double skin natural and mechanical ventilated test cell, Energy and Buildings, 121, 92-103, ISSN 0378-7788, DOI: 10.1016/j.enbuild.2016.03.054

Mateus NM, Simões GN, Lúcio C, Carrilho da Graça G (2016) Comparison of measured and simulated performance of natural displacement ventilation systems for classrooms, Energy and Buildings, 133, 185-196, ISSN 0378-7788, DOI: 10.1016/j.enbuild.2016.09.057

Kosonen R, Lastovets N, Mustakallio P, Carrilho da Graça G, Mateus NM, Rosenqvist M (2016) The effect of typical buoyant flow elements and heat load combinations on room air temperature profile with displacement ventilation, Building and Environment, 108, 207-219, ISSN 0360-1323, DOI: 10.1016/j.buildenv.2016.08.037

Vale S, Heber L, Coelho PJ, Silva CAM (2016) Numerical Simulation of a Thermoelectric Generator for a Road Vehicle Application. Journal of Physics , 745, Technical sessions. DOI: 10.1088/1742-6596/745/3/032004

Marques S, Reis L, Afonso JL, Silva CAM (2016) Energy rating methodology for light-duty vehicles: geographical impact. Environ Dev Sustain (2016) 18: 1501. DOI: 10.1007/s10668-016-9776-9

Gouveia L, Graça S, Sousa C, Ambrosano L, Ribeiro B, Botrel EP, Neto PC, Ferreira AF, Silva CAM (2016) Microalgae biomass production using wastewater: Treatment and costs: Scale-up considerations. Algal Research (2016), 16, 167–176. DOI: 10.1016/j.algal.2016.03.010

Cassiano DR, Ribau J, Cavalcante F, Oliveira M, Silva CAM (2016) On-board Monitoring and Simulation of Flex Fuel Vehicles in Brazil. Transportation Research Procedia, 14, 2016, Pages 3129–3138. DOI: 10.1016/j.trpro.2016.05.253

Panão MO (2016) The overall renewable energy fraction: An alternative performance indicator for evaluating Net Zero Energy Buildings. Energy and Buildings, 127, 736-747. DOI: 10.1016/j.enbuild.2016.06.057

Carrilho da Graça G, Linden P (2016) Ten questions about natural ventilation of non-domestic buildings, Building and Environment, 107, 263-273, ISSN 0360-1323, DOI: 10.1016/j.buildenv.2016.08.007

Daish NC, Carrilho da Graça G, Linden P, Banks D (2016) Impact of aperture separation on wind-driven single-sided natural ventilation, Building and Environment, 108, 122-134, ISSN 0360-1323, DOI: 10.1016/j.buildenv.2016.08.015

Bellanger P, Slaoui A, Minj A, Martini R, Debucquoy M, Serra JM (2016), First Solar Cells on Exfoliated Silicon Foils Obtained at Room Temperature by the SLIM-Cut Technique Using an Epoxy Layer, IEEE Journal of Photovoltaics, 1–8. DOI: 10.1109/JPHOTOV.2016.2567070


Almeida RH, Brito MC (2015) A review of technical options for solar charging stations in Asia and Africa, AIMS Energy, 3 (3), 428-449. DOI: 10.3934/energy.2015.3.428

Barros B, Guerra S, Barros Z, Catita C, Fernandes J (2015) Uso de imagens de satélite para cálculo de volume em floresta de eucalipto no município de botucatu/sp, Energia na Agricultura (unesp. Botucatu), 30, 60-67. DOI: 10.17224/EnergAgric.2015v30n1p60-67

Bellanger P, Bouchard PO, Bernacki M, Serra JM (2015) Room temperature thin foil SLIM-cut using an epoxy paste: experimental versus theoretical results, Material Research Express, 2, 046203. DOI: 10.1088/2053-1591/2/4/046203

Carrilho da Graça G, Daish NC, Linden PF (2015) A two-zone model for natural cross-ventilation, Building and Environment, 89, 72-85. DOI: 10.1016/j.buildenv.2015.02.014

Freitas S, Catita C, Redweik P, Brito MC (2015) Modelling solar potential in the urban environment: State-of-the-art review, Renewable and Sustainable Energy Reviews, 41, 915-931. DOI: 10.1016/j.rser.2014.08.060

Freitas S, Serra F, Brito MC (2015) PV layout optimization: String tiling using a multi-objective genetic algorithm, Solar Energy, 118, 562-574. DOI: 10.1016/j.solener.2015.06.01

Mateus NM, Carrilho da Graça G (2015) Simplified modeling of displacement ventilation systems with chilled ceilings, Energy and Buildings, 108, 44-54, DOI: 10.1016/j.enbuild.2015.08.054

Mateus NM, Carrilho da Graça G (2015) A validated three-node model for displacement ventilation, Building and Environment, 84, 50-59. DOI: 10.1016/j.buildenv.2014.10.02

Neves D, Pina A, Silva CA (2015) Demand response modeling: a comparison between tools, Applied Energy, 146, 288–297. DOI: 10.1016/j.apenergy.2015.02.057

Neves D, Silva CA (2015) Optimal electricity dispatch on isolated mini-grids using a demand response strategy for thermal storage backup with genetic algorithms, Energy, 82, 436–445. DOI: 10.1016/

Nunes P, Farias T, Brito MC (2015) Day charging electric vehicles with excess solar electricity for a sustainable energy system, Energy, 80, 263–274.  DOI: 10.1016/

Nunes P, Farias T, Brito MC (2015) Enabling solar electricity with electric vehicles smart charging, Energy, 87, 10-20. DOI: 10.1016/

Reis F, Guerreiro C, Batista F, Pimentel T, Pravettoni M, Wemans J, Sorasio G, Brito MC (2015) Modeling the Effects of Inhomogeneous Irradiation and Temperature Profile on CPV Solar Cell Behavior, IEEE Journal of Photovoltaics, 5 (1), 112-122. DOI: 10.1109/JPHOTOV.2014.2358080

Silva JA, Platte B, Brito MC, Serra JM (2015) New doping method to obtain n-type silicon ribbons, Journal of Crystal Growth, 428, 29-34. DOI: 10.1016/j.jcrysgro.2015.07.00