Synergic and conflicting issues in planning underground use to produce energy in densely populated countries

In densely populated countries there is a growing and compelling need to use underground for different and possibly coexisting technologies to produce ‘‘low carbon’’ energy. These technologies include (i) clean coal combustion merged with CO2 Capture and Storage (CCS); (ii) last-generation nuclear power or, in any case, safe nuclear wastes disposal, both ‘‘temporary’’ and ‘‘geological’’ somewhere in Europe (at least in one site): Nuclear wastes are not necessarily associated to nuclear power plants; (iii) safe natural gas (CH4) reserves to allow consumption also when the foreign pipelines are less available or not available for geopolitical reasons and (iv) ‘‘low-space-consuming’’ renewables in terms of Energy Density Potential in Land (EDPL measured in [GW h/ha/year]) as geothermics. When geothermics is exploited as low enthalpy technology, the heat/cool production could be associated, where possible, to increased measures of ‘‘building efficiency’’, low seismic risks building reworking and low-enthalpy heat managing. This is undispensable to build up ‘‘smart cities’’. In any case the underground geological knowledge is prerequisite. All these technologies have been already proposed and defined by the International Energy Agency (IEA) Road Map 2009 as priorities for worldwide security: all need to use underground in a rational and safe manner. The underground is not renewable in most of case histories [10,11]. IEA recently matched and compared different technologies in a unique ‘‘Clean Energy Economy’’ improved document (Paris, November 16–17, 2011), by the contribution of this vision too (see reference). In concert with ‘‘energy efficiency’’ improvement both for plants and buildings, in the frame of the ‘‘smart cities’’ scenarios, and the upstanding use of ‘‘energy savings’’, the energetic planning on regional scale where these cities are located, are strategic for the year 2050: this planning is strongly depending by the underground availability and typology. Therefore, if both literature and European Policy are going fast to improve the concept of ‘‘smart cities’’ this paper stresses the concept of ‘‘smart regions’’, more strategic than ‘‘smart cities’’, passing throughout a discussion on the synergic and conflicting use of underground to produce energy for the ‘‘smart regions’’ as a whole. The paper highlights the research lines which are urgent to plan the soundest energy mix for each region by considering the underground performances case by case: a worldwide mapping, by GIS tools of this kind of information could be strategic for all the ‘‘world energy management’’ authorities, up to ONU, with its Intergovernmental Panel on Climate Change (IPCC), the G20, the Carbon Sequestration Leadership Forum (CSLF) and the European Platforms such as the ‘‘Zero Emissions Fossil Fuel Power Plants’’ (EU-ZEP Platform), the Steel Platform, the Biomass Platform too. All of these organizations agree on the need for synergistic and coexistent uses of underground for geological storage of CO2, CH4, nuclear waste and geothermic exploitation. The paper is therefore a discussion of the tools, methods and approaches to these underground affecting technologies, after a gross view of the different uses of underground to produce energy for each use, with their main critical issues (i.e. public acceptance in different cases). The paper gives some gross evaluation for the Lazio Region and some hints from the Campania Region, located in Central Italy. Energy Density Potential in Land (EDPL), is calculated for each renewable energy technology (solar, wind, geothermal) highlighting the potentiality of the last. Why the Italian case history among the densely populated countries? on the Italian territory is hard to find suitable areas (mostly if greenfields) to use the own underground, with respect to other European countries, due to the presence of seismotectonic activity and many faulted areas characterized by Diffuse Degassing Structures (DDSs, which are rich in CO2 and CH4). In this cases, public acceptance must be facilitated by the concerted efforts of researchers, universities, NGOs and policy-makers.