G Model RSER-1447; No. of Pages 12 ARTICLE IN PRESS Renewable and Sustainable Energy Reviews xxx (2011) xxx–xxx Contents lists available at SciVerse ScienceDirect Renewable and Sustainable Energy Reviews j ournal homepage: www.elsevier.com/locate/rser Small-hydropower integration in a multi-purpose dam-bridge for sustainable urban mobility a,∗ a b b a Aníbal T. de Almeida , Carlos Inverno , J. Lopes de Almeida , J. Alfeu Sá Marques , Bruno Santos a ISR, University of Coimbra, Department of Electrical Engineering, Polo II, 3030 Coimbra, Portugal b IMAR, University of Coimbra, Department of Civil Engineering, Polo II, 3030 Coimbra, Portugal a r t i c l e i n f o a b s t r a c t Article history: This paper describes a project for the integration of mini-hydro renewable energy in the trolleybus trac- Received 16 December 2010 tion lines and in the electric battery operated mini-buses. Given the nearby hydropower resource of Accepted 18 July 2011 the Mondego river, a study was carried out in order to assess the technical and economical feasibility Available online xxx of hydropower production at an already existing multi-purpose mobile dam-bridge, located in Coim- bra, Portugal, where a very low head run-of-river small-hydropower plant can be installed. As the main Keywords: civil works have already been done, the hydropower installation costs are significantly reduced because Renewable energies the investment mainly resumes to hydro-mechanical, hydro-electrical and electrical equipment, with Renewable generation mix Small-hydropower expected low hydraulic structure impact, as well as minimum environmental and visual impacts. The optimization of the hydroelectric production takes into account the seasonal water supply demands Sustainable urban mobility for agricultural, municipal and industrial use, the water discharges from the upstream reservoir system of Aguieira–Raiva–Fronhas, the very low head turbines state of the art technology, the physical con- straints of the structure and the special feed-in tariff for renewable power plants. The small-hydropower plant, coupled with the electric public urban transportation fleet, will contribute to a sustainable clean mobility concept, reducing electric grid transportation losses by decentralized production and reducing greenhouse gases emissions, contributing to urban air quality improvement and to the Kyoto Protocol fulfillment. © 2011 Elsevier Ltd. All rights reserved. Contents 1. Introduction . 00 2. The Coimbra dam-bridge . 00 2.1. Introduction . 00 2.2. Main characteristics . 00 2.3. Actual exploration and discharge control . 00 2.4. Secondary channels . 00 2.4.1. Right bank channel . 00 2.4.2. Left bank irrigation channel . 00 2.4.3. Fish passage. 00 3. The Coimbra dam-bridge small hydro project. 00 3.1. Primary considerations . 00 3.2. Hydrological analysis . 00 3.2.1. Flow duration curve . 00 3.2.2. Headwater and tailwater curves . 00 3.3. Examples of minimum impact hydropower layouts. 00 3.4. Similar projects . 00 Abbreviations: UNFCCC, United Nations Framework Convention on Climate Change; EU, European Union; GHG, Greenhouse gases; EC, European Commission; CO2, Carbon dioxide; SMTUC, Coimbra Municipality Urban Transport Services; AHM, Hydraulic Mondego Development; INAG, National Water Institute. ∗ Corresponding author. Tel.: +351 239 796 218/201; fax: +351 239 406 672. E-mail address: [email protected] (A.T. de Almeida). 1364-0321/$ – see front matter © 2011 Elsevier Ltd. All rights reserved. doi:10.1016/j.rser.2011.07.047 Please cite this article in press as: de Almeida AT, et al. Small-hydropower integration in a multi-purpose dam-bridge for sustainable urban mobility. Renew Sustain Energy Rev (2011), doi:10.1016/j.rser.2011.07.047 G Model RSER-1447; No. of Pages 12 ARTICLE IN PRESS 2 A.T. de Almeida et al. / Renewable and Sustainable Energy Reviews xxx (2011) xxx–xxx 3.5. Estimated hydropower production and revenues . 00 4. Conclusions . 00 References . 00 1. Introduction As a party of the Kyoto Protocol of the UNFCCC, Portugal, in accordance to the EU burden-sharing commitment, agreed on the objective of limiting the growth of GHG emissions to 27% of the 1990 levels, during the period of 2008–2012. The EU, as a whole, agreed with an 8% reduction of GHG emissions. More recently, in December 2009, during the UN climate summit held in Copenhagen (Denmark), the negotiations between developed and developing countries failed and the summit ended without new target goals for GHG emissions cuts. In order to achieve Kyoto emissions reduction target goals, the EC in March of 2007, established several key targets, known as the Fig. 1. Portuguese Mainland-installed power of renewable sources [5]. 20/20/20, for the year of 2020: • to the Portuguese National Climate Changes Program, from 1990 Reduction of at least 20% of GHG emissions. 2 • to 2005, emissions in the energy industries and transportation 20% share of renewable energies in the total EU energy consump- tion. subsectors increased respectively about 60% and 104% [4]. This situ- • ation reflects the country heavy dependence and demand increase 20% energy saving through improvements in the energy effi- ciency. in the past few years on fossil fuels, for electric energy produc- tion and transportation and the necessity of changes regarding the energetic policies. The EC in order to achieve these targets, decided to develop The Portuguese electric production system suffered in the last legislative and non-legislative frameworks to cut CO2 emissions, few years significant positive changes in order to reduce the emis- reduce oil dependence and also improve mobility inside European sion of pollutant gases. In the thermal production system, there cities supporting and financing several programs like CIVITAS – was an increase of the efficiency, especially with the integration of CIty, VITAlity and Sustainability. The CIVITAS program “for bet- combined-cycle natural gas and cogeneration power plants. In the ter and cleaner transport in cities” included the Portuguese city of pollutant coal power plants, scrubbers and electrostatic precipita- Coimbra in the 3rd phase of the main project, the CIVITAS PLUS, in tors were installed in order to reduce gases and particles emissions. the MODERN – MObility, Development and Energy use ReductioN Wind power had by far the largest increase in the production mix, – Project, supported by the 7th RTD Framework Program of the EC. since 2003. Wind power and hydropower represented in 2008, One of the main measures for the city of Coimbra is the feasibility respectively 38.3% and 47.8% of the total renewable production and study of the implementation of a small hydro power plant in the the share of renewable sources represented 27.8% of total produc- already existing Coimbra dam-bridge. tion [5]. Fig. 1 presents the evolution of renewable energy installed Beyond the concept of sustainable urban mobility, the measure’s capacity in the Portuguese electric production mix from 2001 to main goal is the production of electricity in order to satisfy the elec- 2008. tricity consumption of the electric traction lines of the trolleybuses The largest improvement was, with no doubt the wind power, and electric mini-buses of the Coimbra’s urban public transporta- with an average yearly growing rate of 58%, from 2001 to 2008. tion fleet. From 2000 to 2008, the average consumption of the Hydropower schemes with capacity above 30 MW, between 30 and trolleybuses traction lines was about 760 MWh. The electric mini- 10 MW and less than 10 MW had a low average yearly growing rate bus provides a transport service for the historical zone of Coimbra, of respectively 1.6%, 2.3% and 3.0% from 2001 to 2008. Solar power characterized with high slopes and narrow streets, and from 2005 plants installed capacity also increased from 4.8 MW in 2006 to to 2007, the average consumption was about 145 kWh per 100 km 38.1 MW in 2008, but is not significant in the whole production. [1]. Each mini-bus travels an average distance of 45 km per day, In 2007, the Portuguese National Government established the so the total electricity consumed by the electric fleet of the pub- commitment of upgrading the electrical renewable share, from 39 lic transportation system can be approximated to 800 MWh/year to 45% of all electricity consumption by the end of 2010. To the [2]. When compared to equivalent diesel buses, the electric trol- fulfillment of this target, the most important objectives defined for leybuses and mini-buses present some advantages like: non-local 1 various renewable energy sources were [6]: emissions, gases emissions reduction in a global scenario, higher performance and overload capacity, low maintenance, low noise • emission, longer life and lower operation costs. Wind power: To increase installed capacity, by the year 2012, to According to the Portuguese National Inventory Report on GHG, a total 5100 MW (600 MW by equipment upgrade). • in 2006, total Portuguese GHG emissions without land-use, land- Hydropower: Reinforce of capacity of current.