Alternative energies to replace oil
The urban energy model is based on imports from external sources. The continuous increase in energy demand due to development and population growth implies growing resource requirements. The alternative is to use renewable energies that take advantage of urban resources. The diversity of city typologies in terms of resources, demands, architectural conditions, infrastructure or density, makes a specific analysis necessary. This paper identifies fourteen factors concerning the planning process that would allow choosing the most appropriate technology for a given city. Through a consultation with 78 experts, it is defined that the existence of the resource is the most important factor, followed by economic conditions; on the other hand, environmental aspects such as global warming, eutrophication or acidification are found to be the least important when selecting the most appropriate technology for a given city.
Alternatives to the use of fossil fuels
“We have a global energy supply system that relies heavily on fossil fuels; replacing them with new arrangements based on renewable energies is a task that will necessarily occupy us for generations to come.” The scientist and professor emeritus of the University of Manitoba, Vaclav Smil, made this statement in Madrid, in the second session of the ‘talkson’ cycle of conferences of the Naturgy Foundation.
For Smil, the main global challenges are to “reduce the use of coal in the short term, increase the use of natural gas, reduce energy intensity and increase efficiency”. And he mentioned another of the energy goals in this more long-term transition: “to displace the fossil carbon used in the pillars of our civilization: the production of primary iron, cement, ammonia and plastics. We have no large-scale alternatives that can be deployed immediately”.
Also an advocate of renewable energies, he also called for an exercise in realism in implementation forecasts. The scientist explained that there are important differences between regions and countries, and that is why one cannot bet only on renewables, because there are places where there is no sun or wind for long periods of time. “Not all places are ideal for renewable energies, so it is important to bear in mind that this is where natural gas has a role to play,” he said.
Renewable energies are profitable
To halt climate change, countries must progressively replace the use of fossil fuels, such as oil and coal, with renewable energies (wind, solar thermal, photovoltaic, geothermal).
According to the REN 21 Renewable Energy Report, 80% of the world’s electricity generation sources come from fossil fuels. This figure does not yet represent the efforts throughout the planet to connect us to other sources of energy, which are indeed renewable and clean, such as the sun, wind energy, biomass and hydroelectric power, among others.
Countries such as China, the United States, Germany, Japan and Italy are investing enormous resources in the development of renewable energies. Bloomberg New Energy Finance indices show that by 2012 China had invested as much as US$68 billion in renewable energy.
The decision to adopt renewable energies for electricity generation in the world is due to the proliferation of supportive policies, reduced investment costs, financial risk mitigation, increased energy security, climate and environmental protection, sustainable industrial and economic development.
Dependence on fossil fuels
Fossil fuels have been the source of energy used during the industrial revolution, but at present, their use presents two main problems: on the one hand, they are finite resources, and reserves (especially oil) are expected to run out in the near future, depending on the various studies published. On the other hand, the burning of these fuels releases large quantities of CO2 into the atmosphere, which has been accused of being the main cause of global warming. For these reasons, different options are being studied to replace the burning of fossil fuels with other sources of energy that do not have these problems. The use of fossil fuels in energy production is not a common classification.
Not everyone agrees in classifying nuclear energy as an alternative energy source because, like fossil fuels, it is a finite resource and also presents significant environmental problems, such as radioactive waste management or the possibility of a nuclear accident. However, the low CO2 emissions of this technology, and the still insufficient capacity of renewable energies to completely replace fossil fuels, make nuclear energy an alternative subject to strong controversy.