[spa] El desarrollo desigual de las economias en el pasado constituye un factor determinante de la distinta capacidad de los paises para aprovechar las mejoras tecnológicas. En algunos casos, 10s menos, el atraso económico puede jugar un papel positivo, al reducir las resistencias que toda innovación genera. En los más, sin embargo, la debilidad del desarrollo anterior constituye un lastre dificil de superar. Suele destacarse, en este sentido, que en las sociedades de menor nivel de desarrollo las disponibilidades de capital para nuevas inversiones acostumbran a ser escasas, y que la demanda, estimulo indispensable, está limitada por los bajos niveles de renta. Pero se olvida a menudo que el resultado de un desarrollo económico lento es siempre una infraestructura muy limitada, que puede significar una dificultad considerable en el momento de plantear una mejora de los procesos de producción.

[eng] A comparative study of present energy consumption in Spain demonstrates the predominance of petroleum products over natural gas. The two principal reasons for this situation are: the low per capita consumption of gas based fuels and the preference for bottled butane gas, a petroleum derived product little used elsewhere. The widespread use of natural gas in Europe dates from the early 1960s. Its introduction was favoured by the extensive pipeline network already existing, and the high number of consumers of gas based fuels. The considerable increase in the consumption of bituminous coal gas from the middle of the nineteenth century onward proved to be a decisive catalytic factor in the rapid spread of natural gas one hundred years later. In Spain, on the other hand, the development of the traditional gas industry had been sketchy and uneven right from the outset. It was only in Catalonia that a relatively high number of gas factories were established. The advent of electricity towards the end of the last century paralized the expansion of gas at a time when only 75 Spanish settlements were furnished with piped gas. No improvements were carried out in the first half of this century. Gas consumption and its distribution infrastructure were maintained at relatively low levels. This was in fact a reflexion of the slow and tardy nature of Spanish industrial development prior to 1960. The changed situation after the ccstabilization Plam of 1959 found piped gas in totally unsatisfactory conditions to meet increasing demand. The politicians' answer was the massive commercialization of petroleum-derived liquified gas (butane and propane) for which the infrastructure requirements are limited to a number of bottling plants and a distribution system by lorry. In such circumstances, natural gas, which was at this period being adopted in many European countries, was introduced only in Catalonia, the one region with suficient potential consumption and an adequate distribution network. The low price petroleum in the 1960s did not encourage any possible modificacions in the pattern of Spanish energy consumption to bring it into line with other countries. Hence, when petroleum prices rose spectacularly between 1973 and 1979, Spain was among the countries most dependent upon petroleum, and so suffered immediate effects on the balance of payments and on the Spanish economy since the nineteenth century, and the subsequent deficiencies in infrastructure, have retarded the adoption of new techniques in the energy sector and have contributed, in this way, to increment the negative repercussions of the international crisis in Spain.