رویکرد GIS به تعریف ظرفیت و تولید سقف کاذب از فن آوری های انرژی های تجدید پذیر

There are no discrepancies about the advantages of achieving a sustainable energy system based on locally available natural resources. However, supporters of green energy generation system were lacking some scientific and consistent study to defend their proposals. In order to have such a study, Greenpeace commissioned Technology Research Institute at the Pontificia Comillas University to carry out a study to assess ceilings for the potential and generation of renewable technologies in Spain. It demonstrates firstly a far greater renewable potential than the targets set by long term policies, and secondly, the viability of meeting the entire electricity demand projected for 2050. GIS was used to add the geographical dimension to the original project in order to generate a technical analysis linked to the specific constrictions imposed by territory (natural and anthropogenic) and not just designed to cover a certain demand. Therefore, GIS spatial analysis took into account local conditions producing a more accurate assessment than evaluations made upon “virtual” electrical spaces. This approach could be applied to other small scale general studies in order to assess the maximum contribution of renewable energy sources to particular energy generation mix and to help set development policies supporting high participation of renewable technologies.

The globalized world we inhabit is facing an energetic crisis which becomes evident in environmental, economic, social and spatial aspects. There have been several proposals and attitudes adopted towards this crisis and there have been multitude organisations which have taken a stance based on an increasing share of energy produced by renewable sources. However, not enough studies have been carried out to determine renewables potentiality accurately. Apart from hydroelectric, only wind energy has managed to overcome the barrier and be included within the commercial interests so private investments could help to develop a more efficient generation system. Other technologies like concentrated solar power (CSP), biomass, solar photovoltaic, solar chimneys and waves (all of them considered significant potential contributors to our electrical generation system) are quite far from being real contributors. The maximum percentage that a particular technology could provide to generation system remains as a technical doubt that hinders the renewable energies support: is it feasible a system based completely in renewable sources? Is it absolutely needed to maintain nuclear or thermal contributions to control the generation system and the electricity transport? It is becoming imperative to find a technical solution to the current situation, which is mainly defined by partiality, empiricism and improvisation. It will be then possible to speed up the introduction of renewables within a planned process. As an example, it was thought that wind energy could only contribute in 5% to electricity generation. Later it was proven to reach around 10% and nowadays it seems possible to contribute in 25%. Meanwhile, in Denmark they have already satisfactorily checked the viability of an electricity generation system with 50% of wind energy contribution. There is no doubt the hesitancy constitutes a significant obstacle for those technologies at earlier stage of development but with enormous prospects for large-scale development. Generation technologies based on renewable energies involve an important technical challenge to the generation system and transport capacity of the electricity network due to the discontinuity and randomness of renewable sources. However, because of the great diversity in renewable generation technologies used in our country, it could be possible to reduce those technical restrictions taking advantage of the technological synergy and the spatial distribution.

This paper presents the results obtained in the SIGER project in relation with potential and capacity ceilings. A scenario for 2050 in Spanish peninsula was taken into account in order to set the energy demand and give some percentages of the demand that could be covered by renewable energy technologies. It should be remarked that a conservative approach was taken in terms of technology, which implies that technological improvements would lead to even higher generation ceilings than the estimations presented. GIS was used to add the spatial dimension to the analysis. GIS tools were used first, to analyse spatial distribution of renewable energy resources; second, to impose spatial restrictions related to land suitability (land use, slope, potential productivity, etc.); and thirdly, to calculate capacity and generation ceilings based on available sites. The results were both cartographical (see the figures included) and numerical, used to estimate capacity and generation ceilings of renewable energy technologies according to prospected Spanish conditions in 2050. The estimated ceilings show a great renewable potential in peninsular Spain, and the approach could be applied in other country or region to assess the maximum contribution that renewable energy sources could have in a more sustainable generation mix. This type of studies would help not only supporters of increasing renewable energies participation in national generation mixes, but also governments to set development targets more adapted to renewables potential. In the case of Spanish peninsular, a 100% renewable generation mix would be viable to meet total energy demands projected for 2050.