Modern Transportation and Photovoltaic Energy for Urban Ecotourism

This study proposes an innovative integrated transportation/photovoltaic energy system that will enable the Pompeii Municipality to develop a set of urban ecotourism policies and instruments for the preparation and adoption of an environmental sustainable mobility strategy to be applied in their future municipality urban plan. The innovative character of the study resides in two principal aspects: the technologies applied, namely, the use of thin film photovoltaic (hereafter PV) panels (copper-indium-gallium-(di)selenide cells) on a flexible support, and the way these technologies are applied. A combined energy/mobility approach based on ‘Zero km and zero emission energy production for zero emission electric transportation strategy’ to be implemented in the Public Urban Plan (Piano Urbanistico Comunale) of the town of Pompeii is presented. According to the technology to be adopted (thin PV film on flexible supports integrated in the parking shelters roofs), to the foreseen PV plant of 700 sqm parking lots, and to an innovative multifunctional design approach (bio-mimicking sun track roof), an improved yearly power production of 100.0 MWh is foreseen with a 20- 25% increase of power production with respect to standard fixed PV panels of the same type.


Introduction
Tourism is changing rapidly as nature, heritage and recreational destinations become more important and easy to reach, and, therefore, it should be forced to meet tougher environmental requirements, especially in urban environment where its anthropic impact overlaps local criticism.
The balance between economic growth, social wellbeing and environmental protection is a growing concern of industrial research development.
This will be at the base of the future development of our technosphere, the virtual space where techno diversity interacts with the biosphere ( Sustainability is a serious issue in the long run, for the future of the world, but it is particularly critical in Europe due to their rapid and uncontrolled industrial growth in an environment that should preserve its cultural history. The rational use of energy by adopting greener sources and by controlling production will improve our valuesphere (the scientifi c environment accounting for ecological issues while protecting occupation and welfare).
Touristic cities' authorities are asked to face a double challenge: they have to be able to respond to the expectations and the needs of the growing numbers of tourists, while ensuring that tourism is developed and managed in such a way that it benefi ts the resident population, does not contribute to the deterioration of the urban environment, but rather to its enhancement, and does not become a fi nancial burden (Malkin, 1999).
Campania is a region of Italy with a strong tourist vocation: it is the territory that att racts the majority of tourism in Southern Italy especially for the presence of the touristic highly att ractive poles: Capri, Ischia, Sorrento, Amalfi and Pompeii. Such world cultural heritage has to share the territory with a highly inhabited town, and an area of intense tourism and fl ower farming. As noted by the World Bank (1999), 'Cultural tourism can encourage the revival of traditions and the restoration of sites and monuments. But unbridled tourism can have the opposite eff ect'.

Tourism cities anthropic impact
The most recent trends and forecasting studies by the World Tourism Organization (2017) indicate that cities will continue, especially in the areas of great cultural interest such is Pompeii, to be in high demand by tourists of all sorts (cultural and religious). In fact, the modern town has grown on the ancient Roman ruins (Figure 1). If we consider archaeological cities, such is the town of Pompeii, we note that there is a lot of pressure in terms of time and space caused by a concentrated tourist infl ux, which adds to other factors of anthropic origin but of a diff erent nature, such as the rapid urban growth of the town and the presence of the Catholic Sanctuary of the Madonna (Blessed Virgin Mary). The presence of the Sanctuary att racts an even greater and continuous fl ux of pilgrims: numerically, it is about 7 million people yearly (2.5 million people for the excavations, and 4.5 million for the Sanctuary; see Figure 2).
Such huge numbers of incoming people (meanly 20,000 a day over a population of 25,000 people) concentrated in the same area (the ruins entrance and the Sanctuary are in close proximity) creates an additional intense and signifi cant traffi c of buses (about 400 daily) and cars (100 daily) in a range of 3 km (the distance from the highway to the center of the town, where the excavations and Sanctuary are located) that is equivalent to a total of 1,000,000 km of bus journeys (based on a medium sized diesel bus).
Noise and gaseous pollutants emissions are a serious concern for the livability and fruition of the town (European Commission, 1996, 2001, 2005: collectively these vehicles emit in a year 120 tonnes of CO 2 , 1.4 tonnes of CO, 0.4 tonnes of Nitrogen Oxides (NO x ) and 0.4 tonnes of Volatile Organic Compounds (VOCs), with a noise pollution that has been measured in a preliminary soundscape study carried out by the University of Campania for the external rush hours road traffi c of 60-70 dB (A) centered on a The problems associated with the daily handling of this growing mass of tourists (7 million a year, 20,000 a day) will have to be more systematically tackled by all parties concerned with a bett er management of urban areas through integrated environmental management at the local level. At the present time, a rational plan to reduce the anthropic impact of this intense form of city tourism does not exist at local level.
Our project proposes an innovative prototype integrated transportation/energy system that will enable the Pompeii Municipality to develop, from the results of the demonstration activities of the study, a set of urban ecotourism policies and instruments for the preparation and adoption of more environmentally sustainable mobility strategies to be applied in the future PUC (Municipality Urban Plan).
A map of the Pompeii town with indication of the principal areas of touristic interest (ancient town excavations and Sanctuary), and the nodes of the proposed study are reported in Figures 1 and 4.

Combined energy/transportation strategies
The innovative character of our approach resides in two principal aspects: -the technologies applied: the use of thin fi lm fl exible photovoltaic panels (copper-indium-gallium-(di)selenide cells); and -the way these technologies are applied: the combined energy/mobility approach 'Zero km and zero emission energy production for zero emission electric transportation strategy' to be adopted and implemented in the Public Urban Plan (Piano Urbanistico Comunale) of the town of Pompeii.

Innovative urban ecotourism policies
A more sustainable tourism can be achieved by the implementation of existing EU environmental policies for urban eco-tourism in highly inhabited areas. The 'Zero km and zero emission energy production for zero emission electric transportation strategy' derives from the above mentioned energetic and environmental considerations and is to be adopted in a context where sustainable development needs specifi c and targeted policies to be developed and adopted by the Pompeii Municipality.
The proposed demonstrative integrated transport and energy model for an urban green management is based on the following points: -'Pompeii, The Clean Energy Town'; -'Zero Emission -Zero Km Energy' (solar electric energy local production); and -'Zero Emission Transportation System' (electric minibus city mobility plan).

Environmental benefi ts of an integrated clean energy/transportation strategy
The environmental benefi ts to be achieved with the future application in the Pompeii urban planning of the policies developed in the framework of this project implementation will att ain abatements of the above-mentioned values of pollutants and noise (busses will be completely banned from the town traffi c through the activation of external BIPV -Building Integrated Photo Voltaic -parking and electric shutt les).
A similar touristic anthropic load is occurring in the Chinese touristic site of Xi'An, and in this case the electrically based transportation solution has been adopted (Figure 3).
Ordinary energy consumption requirements for parking areas (no night lighting is considered since tourism in this town is concentrated in the daylight hours), for air conditioning and energy consumption of bus shutt les have been evaluated in terms of TPE (Tonne Petroleum Equivalent), while considering conventional energy sources, and then compared to our foreseen PV energy production.
Considering that, in the proposed mobility plan the use of shutt les from the parking to the areas of interest (excavation and Sanctuary) is expected to run at least 25 round trips (4 km) a day for each minibus for a total of 32,000 km in a year (320 operating days) leading to a consumption of 2,500/3,750 liters of fuel. In terms of TPE, this corresponds to a consumption of about 2.8/4.0, and an energy consumption requirement of 32/46 MWh.
An equivalent electric minibus can operate at 10 kWh for 100 km: over the same distance of 32,000 km a year, the energy consumption requirement is of 4.5 MWh that theoretically (considering the above mentioned PV power potential of 700 sqm PV roofs of 100 MWh) permits the use of 20 electric minibuses (7,500-10,000 passengers). -the potential parking areas locations (violet on the map) where the PV parking shelter roofi ng could be implemented; -electric bus trip (grey in the map) from parking lots to the areas of interest; -pedestrian area (green) that is expected to be closed for private car traffi c in order to ensure the project implementation, and the noise and pollution claimed levels of maintenance; -the historical ancient town (excavations, light red); -the Sanctuary and related structures (orange); -the highway exits (A in a light blue circle), the state railway station (Fs in a light blue circle); -the private 'circumvesuviana' railway station (Fv in a light blue circle); -the foreseen electric shutt les stops (red circle); and -the public greenhouse (municipality) involved in the project (green circle) have been marked on this fi rst map.

Cost/benefi t analysis and sustainable development in high historical and cultural heritage cities
Photovoltaic systems per se are not a good choice of a 'cost-benefi t' analysis in terms of tonne of eqCO 2 reduction. However, this is not the exclusive aim that this study has been based on. Even if signifi cant results on tonne of eqCO 2 reduction can be att ained by the initiative (it is expected to signifi cantly reduce the heavy tourist buses traffi c in the area of excavations and Sanctuary), this study evaluates and presents new strategies specifi cally addressed to contribute to the implementation, updating and development of community environmental policy and legislation that include the integration of the environment into other policies, thereby contributing to sustainable development in areas of intense tourism. Moreover, sustainable development in areas of high historical and cultural heritage values necessitates a specifi c and targeted approach going well beyond ordinary indicators. The area of the study has been inscribed by UNESCO as a world heritage with the following justifi cation: '(…) the impressive remains of the towns of Pompeii and Herculaneum and their associated villas, buried by the eruption of Vesuvius in AD 79, provide a complete and vivid picture of society and daily life at a specifi c moment in the past that is without parallel anywhere in the world' (European Commission, 2012).
Such world cultural heritage has to share the territory with a highly inhabited town, and an area of intense tourism and fl ower farming. The proposed initiative is balancing environmental, cultural and socio-economic needs in order to achieve a set of new policies to be adopted by the municipality in its Urban Plan in order to improve the inhabitants' quality of life and the quality of tourists' services, while preserving this unique historical treasure from degradation.
Our project adopted the strategies for sustainable development underlined in the Presidency conclusion document of the Göteborg European Council (European Council, 2001): -Dealing with economic, social and environmental policies in a mutually reinforcing way to promote sustainable development (point 19); -Adding a third, environmental dimension to the Lisbon strategy, and establishing a new approach to policy making (point 20); and -Developing a broader use of new environmentally friendly technologies in sectors such as energy and transportation (point 21).
The proposed study refers to the 'Clean Air for Europe' programme (European Commission, 2001) and the European Community INSPIRE initiative (Directive 2007/2/EC) aimed at reducing pollution by 2020. The reduction of atmospheric pollution, such as that caused by transportation and fuel based energy generation, also implies a reduction of noise pollution.

Innovative sustainable technical solutions
The innovative character is based on these principal aspects: -the technology to be adopted (thin PV fi lm on fl exible supports integrated in parking shelters fl exible roofs); -the foreseen mean PV plant of 700 sqm; and -an innovative multifunctional design approach (fl exible tracking roof) ( Figure 5).

Source: Authors' own contribution
A self sun-tracking system based on the use of composite laminates containing properly oriented glass fi bers and piezoelectric fi bers in its diff erent laminae is proposed. Such laminate, when electrically stimulated, could warp according to the intensity and position of the stimulated lamina. This electrical stimulation can be automatically driven by the position of the sun hitt ing sensors in diff erent areas of the PV roof. Figure 5 shows the functional principle of the proposed system.
An improved yearly power production of 100.0 MWh is foreseen with a 20-25% increase of power production with respect to standard fi xed PV panels of the same type.

Thin fi lm fl exible photovoltaic modules
Tensile Photovoltaic structures are lightweight, modular systems that provide shade while producing solar power. A thin fi lm PV technology using Copper Indium  This choice has been driven by the fact that this is a promising technology that is rapidly growing and that could supply interesting commercial products that can be applied on fl exible support and used in new design solar tracking modules (of the type presented here). Effi ciency for this type of cell could reach 20% in the next few years. However, the use of lower cost technologies of deposition is able to guarantee 10/15% effi ciency at lower plant costs. National Renewable Energy Laboratory forecasts a maximum development of these technologies for the years 2015-2020 (NREL 2015).
The use of such thin fi lms on fl exible polymeric substrates permits the application of an innovative sun tracking system (based on biomimetic self sun-tracking system) production of the plant. For such a system a conservative effi ciency of 10% has been considered.
The use of a piezoelectric smart system allows warping and redirecting the composite laminate substrate in the direction of the sun (Figure 7). This occurrence increases the amount of sun-light that is captured by the PV fl exible module. A 100 square meters array of 140 modules has the following foreseen year power production: -traditional -12 MWh; and -bio-inspired sun tracking system -15 MWh.
A 700 sqm plant has been considered in our study with a potential 100MWh power production.
The energy competitive advantages of the proposed coupled PV energy production and electric transportation new approach arise from diff erent technical considerations: -the use of electric transportation that needs (over the year for each vehicle) 4.8 MWh vs. 32/46 MWh needed by traditional shutt le buses (internal combustion engines);

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-the use in the electric transportation of locally generated electricity from PV instead of electricity from traditional sources (which strongly depend on thermoelectric). In fact, considering real process effi ciency in conventional thermoelectric power plants, the actual TPE consumption for traditional energy sources should be at least doubled; and -the use of electric transportation from peripheral parking lots and the central historical area (centrum of the town) reduces the heavy noise and gas pollution by tourist busses.
Campania is a region of Italy with a strong tourist vocation: it is the territory that att racts the majority of tourism in Southern Italy especially for the presence of touristic highly att ractive poles: Capri, Ischia, Sorrento, Amalfi and Pompeii.
Tourism's economic impact is signifi cant and still growing. Tourism can make an important contribution to economic development; however it can generate a variety of other impacts, both positive and negative. It can help keep traditions alive and finance the protection of the cultural and natural heritage, as well as increase visitors' appreciation of that heritage.
Conversely, tourism can damage heritage when it is not managed well. Thus, there is a tension between tourism and cultural and natural heritage preservation.
The proposed initiative is balancing environmental, cultural and socio-economic needs in order to achieve a set of new policies to be adopted by municipalities in their urban plans in order to improve the inhabitants' quality of life and the quality of tourists' services, for preserving this unique historical treasure from degradation. Similar initiatives could have positive impact also in other large cities in order to improve the quality of transportation and energy effi ciency, especially in the downtown areas where traffi c gas and noise pollution are important issues. The adoption of such strategies can drastically reduce traffi c while improving the quality of air and contribute to a sound environment.
However, such new strategies are not only addressed to achieve environmental benefi ts, but they can also result in local economic benefi ts. In fact, high innovative electric transportation could signifi cantly enhance certain economies, at least in Europe and the USA, especially when these economies hold high technology based industries, which will be benefi cial for research and development, and direct support for companies' expansion (i.e., factories fi nancing).
The use of innovative solutions (Figure 8), such as fl exible and self sun-tracking systems driven by piezoelectric or shape memory alloy smart materials , structural colors (Aversa et al., 2016c), developed in the framework of an evo-lutionary design approach , could lead to more sustainable and environmental friendly solutions. If we consider archaeological cities, such as the town of Pompeii (the modern town grown on the ancient Roman ruins as reported in Figure 1), there is a lot of pressure in terms of time and space caused by a concentrated tourist infl ux, added to other factors of anthropic origin but of a diff erent nature such as the rapid urban growth of the town and the presence of the Catholic Sanctuary of the Madonna (Blessed Virgin Mary) that att ract an even greater and continuous fl ux of pilgrims.

Conclusions
A combination of energy and mobility strategies based on 'Zero km and zero emission energy production for zero emission electric transportation strategy' could be introduced in the Public Urban Plan (Piano Urbanistico Comunale) of the town of Pompeii.
The environmental benefi ts to be achieved with the future application in the Pompeii urban planning of the policies developed in the framework of this proposed approach could att ain high enhancements of pollutants and noise abatements (busses will be completely banned from the town traffi c through activation of external BIPV -Building Integrated Photo Voltaic -parking and electric shutt les).
The environmental benefi ts that are strictly related to the project implementation are limited (but, anyway, signifi cant) to the partial closure of the centrum to busses that will reduce 1/6 of the gaseous emissions: namely, 20 tonnes of CO2, 0.2 tonnes of CO, 80 kg of Nitrogen Oxides (NOx), and 80 kg of VOCs. Due to the closure of the contemporary Pompei Centrum (which corresponds to the Sanctuary and main excavation entrance) to heavy and private vehicles traffi c, it is expected to lower the noise pollution.
This study proposes an innovative integrated transportation/photovoltaic energy system that will enable the Pompeii Municipality to develop a set of urban ecotourism policies and instruments for the preparation and adoption of an environmentally sustainable mobility strategy to be applied in their future municipality urban plan.
New developments in electric transportation are att racting great public interest and they are fi elds with great dynamism driving continuous changes in national policies. Germany, China, and South Korea are leaders in innovation followed by France, United Kingdom, United States, and Austria, while policies stimulating innovation, such as research and development and industrial pilot projects, are not yet sufficiently adopted in the Netherlands, Belgium, Denmark, Norway, Portugal, Italy, and Spain (Weeda et al., 2012, pp. 14-16).
The innovative technological character of the proposed study resides in two principal aspects: the technologies applied, namely, the use of thin fi lm photovoltaic panels (copper-indium-gallium-(di)selenide cells) on a fl exible support, and the way these technologies are applied.
According to the technology to be adopted (thin PV fi lm on fl exible supports integrated in the parking shelters roofs), to the foreseen PV plant of 700 sqm parking lots, and to an innovative multifunctional design approach (bio-mimicking sun track roof), an improved yearly power production of 100.0 MWh is foreseen with a 20-25% increase of power production with respect to standard fi xed PV panels of the same type.