Zero Energy Tunnel: Renewable Energy Generation and Reduction of Energy Consumption R. Dzhusupova Eindhoven University of Technology R.Dzhusupova@tue.nl J.F.G. Cobben Eindhoven University of Technology J.F.G. Cobben@tue.nl W.L.Kling Eindhoven University of Technology W.L.Kling@tue.nl Abstract- Creating a zero energy environments is a hot topic. The developments in this field are based on the concept of the “Trias Energetica”: reducing energy consumption, using of renewable energy, and efficient using of fossil fuels. Zero energy environment concepts can be also applied to road tunnels to improve the energy performance by means of reducing energy consumption, introducing of renewable energy generation and by this way lowering energy bills. Nowadays the energy consumption in the road tunnel is high, up to 6.6 MWh/km per year during normal operation conditions. Thus, the reduction of energy consumption even by 5-10 per cent could bring greatly benefit to tunnel owners. This paper presents the framework of zero energy tunnels and highlights the major innovative aspects. These aspects include various technological approaches to reduce energy consumption, to extract thermal energy from the tunnel and to improve air quality inside and outside the tunnel. Furthermore, it discusses the introduction of renewable energy generation for tunnel constructions. Index Terms-- Air quality, distributed generation, energy consumption reduction, energy system, renewable generation, zero energy environment. I. INTRODUCTION In tunnel construction the lighting system consumes the most of the electric energy. Currently, there is much of electric energy wastage in tunnel lighting due to its design based on maximum light level outside the tunnel and maximum traffic density. According to average data from list of tunnels located in the Netherlands the share of energy consumption in a tunnel for the lighting system is around 39%. Tunnel ventilation also consumes very significant amount of energy in case of fire in the tunnel and during rush hours. Another important aspect is the emissions from the vehicles inside and outside of the tunnel. At present, in the Netherlands there are no air cleaning systems implemented in the tunnel construction. The only exception is the Coentunnel Amsterdam, where emission shafts are applied. However, the energy consumption in this particular tunnel is 6.6 MWh/km per year [1]. The difference between the requirements for the emission limit according to Dutch Ministry and Dutch Expert Committee on Occupational Standards DECOS is significant, i.e. 4 mg/m 3 and 0.5 mg/m 3 respectively [2]. This fact raises serious doubts about the wellbeing of people living near to tunnel portals. This paper focuses on the energy consumption associated with the operation of the tunnel services: ventilation, lighting, air cleaning systems, thermal heat extraction from the tunnel and the possible use of renewable energy generation. The research is based on a ‘typical’ Dutch tunnel with length of 1 km, two tunnel tubes with a cross section of each tube is 75 m 2 and traffic flow of 5000 vehicle per hour during rush hours. The paper is structured as follows: section II focuses on “zero energy” tunnel framework aspects. Section III describes solution to reduce energy consumption. Section IV relates to the ventilation system in the tunnel and to the air quality inside and outside the tunnel. Some investigation results are presented in this chapter as well. The possibilities to extract thermal power from the tunnel and to use renewable energy are presented in sections V and VI respectively. II. ZERO ENERGY TUNNEL FRAMEWORK The goal of this research is to create the framework of a new tunnel design which will be energy independent from the main grid and environmental friendly. However, a new design must bring benefits to the tunnel contractors to make them interested in implementation. To satisfy these requirements only the proven technologies are considered in zero energy tunnel concept. Based on data from the different tunnels in the Netherlands provided by one of a large tunnel contractor CROON and the Ministry of Transport, Public Works and Water Management (Rijkswaterstaat), it is possible to subscribe tunnel subsystems and their energy consumption. In general, according to tunnel energy consumption there are several subsystems: • Energy subsystem. Provides energy for the high voltage equipment rooms. • Lighting. Includes tunnel lighting system. • Drainage. Most of the tunnels in the Netherlands are located under water. Thus, there is a permanent water leakage in the tunnel. • Ventilation. Keeps the air quality within acceptable level and reduces smoke during fire situation. • Traffic installations. Includes different types of signals, signs, etc. • Fires distinguish subsystem. Includes pumping system designed for fire situations • Communication installation. Includes security cameras and video surveillance systems, phone communications, etc. • Building service. Heating and cooling systems for data rooms and office buildings.