Is it possible that all consumption from renewable energy by 2030?

The recipe consisitría in the construction of four million wind turbines of 5 MW, 1,700 million 3 kW PV roofs, 90,000 solar plants of 300 MW (including both solar photovoltaic and from), plus a small amount of geothermal energy, wave and of the tides.

The calculations leave aside the biomass (pollution issues and occupation of the territory) and nuclear energy as well as all non-renewable energy. Wind turbines are larger than those currently operating, even if you have built some wind farms with turbines of 5 MW.

Renewable energy can provide 100 per cent of world energy, eliminating all fossil fuels. By Mark Z. Jacobson (Stanford University) and Mark A. Delucchi (University of California-Davis).

Wind and solar energy in the right places would reduce the energy consumed in the world. The authors reject biofuels and nuclear energy.

The authors plan calls for 3.8 million large wind turbines of 5 MW, 90,000 solar thermal and photovoltaic installations and numerous geothermal, tidal and solar roofs worldwide.

The cost of generating and transmitting power would be less than the projected cost per kilowatt-hour of fossil fuels and nuclear energy. Shortages of some special materials, together with the lack of political will, appear as major obstacles.

In December, leaders from around the world gathered in Copenhagen to try to reach an agreement on reducing emissions of CO2 and other greenhouse gases for decades. The most effective way to fulfill that goal would be a huge change from fossil fuels to renewable energy sources. If leaders can have confidence that such a transformation is possible, can commit to an historic agreement. We think we can do.

A year ago, former Vice President Al Gore threw a glove off and back on America with 100% CO2-free electricity within 10 years. We began to assess the feasibility of this change and take an even greater challenge: to determine how 100 percent of the energy consumed worldwide, to all intents and purposes, could be supplied by wind, water and sun, and as early as 2030. Our plan is presented here.

Scientists have been accumulating parts to the present moment in less than a decade, analyzing different parts of the challenge, you can achieve 100% target of renewables. More recently, in 2009, a study by Stanford University energy systems classified according to their impact on global warming, pollution, water supply, land use, wildlife and other problems. The best options were, in order, wind, solar, geothermal, tidal and hydroelectric power - all of which are driven by wind, water or sunlight (known by the acronym in English WWS). Nuclear power , coal with CO2 capture and ethanol were the worst options, as well as oil and natural gas. The study also found that battery electric vehicles and hydrogen fuel, could largely eliminate pollution in the area of ​​transporte.Nuestro plan needs millions of wind turbines, hydro and solar photovoltaic and solar thermal well. The numbers are great, but the scale is not an insurmountable obstacle, our society and has achieved massive transformations before. During the Second World War, the United States ended up adapting automobile factories to produce 300,000 airplanes and other countries produced 486,000 planes.

In 1956, the U.S. began the creation of the state highway system, which 35 years later were extended to 47,000 miles, changing business and society. Is it possible to transform energy systems in the world? Could be done in two decades? The answers depend on the technologies chosen, the availability of critical materials and economic and political factors.

Only clean technologies

Renewable energy from sources seductive wind, which also produces waves, water, including hydropower, tidal and geothermal (hot rocks heated water), sun, including solar photovoltaic and thermoelectric focus sunlight to heat a fluid that drives a turbine to generate electricity. Our plan includes only the technologies currently in operation or are close to today's large-scale production, rather than those that may need 20 or 30 years of preparation from hoy.Para ensure that our stay clean energy system, we consider only technologies that have near-zero emissions of greenhouse gases and air pollutants throughout their life cycle, including construction, operation and decommissioning. For example, when burned in vehicles, even the most ecological sources of ethanol create air pollution that causes the same level of mortality than when burning gasoline. Nuclear power produces up to 25 times more carbon dioxide emissions than wind power, when considering the construction and enrichment of uranium and transport. Carbon capture and sequestration technology can reduce carbon dioxide emissions from power plants, but will increase the emission of air pollutants and shall extend to all the other harmful effects of mining, transport and processing of coal, because you have to use more coal to meet energy demand in the capture and storage stages.

We also consider only technologies that do not have waste disposal or risks of being used by the terrorismo.En our plan, WWS would provide electricity for heating and transport (industries that would be renewed if the world has any hope of stopping climate change). We have assumed that more fossil fuels (heating and stoves) can be replaced by electric vehicles and fossil fuels can be replaced by battery electric vehicles and fuel cells. The hydrogen produced by electrolysis with electricity from WWS, feed the fuel cell to produce electricity in the industry and would be used in aircraft engines.

Large supplies

Today the maximum power consumed in the world at any given time is about 12.5 trillion watts (terawatts, or TW) according to the Energy Information Agency U.S. EIA. The agency forecasts that in 2030 the world will require 16.9 TW of power due to population growth and overall living standards, with about 2.8 TW in the United States. The planned mix of sources would be similar to today, and depend heavily on fossil fuels. If, however, the planet was completely moved by WWS, there would be no burning of fossil fuels or biomass, and produce a saving in primary energy consumption. Global demand for energy is reduced to only 11.5 TW, and U.S. demand would be 1.8 TW. This decline occurs because, in most cases, electrification is a more efficient use of energy. For example, only between 17% and 20% of the energy in gasoline is transformed into mechanical energy to move the vehicle (the rest is wasted as heat), while 75 to 86% of the electricity delivered by the battery to an electric vehicle, is transformed into movement.

Consider also that in the production of electricity by power plants, over 60% of the fuel energy is wasted as heat that goes to the atmófera. The same is true in transportation where all engines are térmicos.Aunque demand increased to 16.9 TW, WWS sources could provide this energy, in fact the potential supply of renewable energy is huge. Detailed studies by us and others indicate that the potential energy of the wind, around the world, is about 1,700 TW. The solar photovoltaic and thermal, would reach the 6,500 TW. It is clear that the wind and sun on the open seas, over high mountains and protected in all regions would not be available. If we subtract these areas and others where there is little wind, we are still left with 40 to 85 TW for wind and 580 TW for solar energy, far above any future demand. Currently only generate 0.02 TW of wind power and 0.008 TW of solar energy. As shown these sources contain an incredible amount of untapped potential WWS explotar.Las other technologies help create a flexible system and a wide range of options.

Although all renewable sources can expand greatly in practice, the wave power can be extracted only in coastal areas. Many geothermal sources are too deep to be exploited from the economic point of view. And although the hydro now exceeds all other sources WWS, most large reservoirs are adequate and in operation.

PLAN: We need renewable energy plants

Clearly, there is enough renewable energy profitable. How can we make the transition to a new infrastructure to provide the world with 11.5 TW? We opted for a mix of technologies include wind and solar, with about 9% of demand supplied by hydroelectricity. (Other combinations of wind and solar could be equally appropriate). The Wind would supply 51 percent of demand (5.75 TW) provided by 3.8 million large wind turbines (each about five megawatts) around the world. Although that amount may seem huge, it is interesting to note that the world produces 73 million cars and light trucks each year. Another 40 percent of energy come from photovoltaics and solar thermal power plants of concentration. The PV would supply 30 percent. Approximately 89,000 would be needed to rooftop photovoltaic plants and soil, as well as concentrating solar thermal power plants with an average of 300 megawatts each. Our mix also includes 900 hydroelectric power plants worldwide, 70 percent of which are already installed. Only about 0.8 percent of wind power above (5.75 TW) is installed to date . To get an idea of ​​the area occupied by all the turbines in the world, that is, 3.8 million wind turbines occupy less than 50 km2 (less than the area of ​​Manhattan).

Occupy the space that could be used, however for farming or ranching. PV plants installed in the ground and concentrated solar power plants would occupy about 0.33 percent of the world's land. The creation of such plants involves extensive infrastructure will take time. But they also needed to build the current system with its central and networks. And remember that if we keep using fossil fuels, demand will increase to 16.9 TW 2030 instead of the 11.5 TW, which will require about 13,000 new coal-fired power plants or natural gas, which in turn would occupy much more land, as well as mining and gas pipelines to supply.

The obstacle of the materials

The WWS-scale infrastructure is a barrier. But a few materials needed to build it, they could run out or be subject to the handling of cement and steel precios.Existen enough for the millions of wind turbines and both products are fully recyclable. The most problematic materials can be rare earth metals such as neodymium used in gearboxes of wind turbines. Manufacturers are moving toward gearless turbines, so this limitation may become dependent discutible.Las photovoltaic amorphous or crystalline silicon, cadmium telluride or copper indium selenide and sulfur. The limited supply of tellurium and indium may reduce the prospects of some types of thin-film solar cells, but not for all, the other could lead to occupy the unused space. The large-scale production may be restricted by requiring the silver cells, but could cope with it by finding ways to reduce the silver content. Recycling old cell parts could also improve components materiales.Tres difficulties could represent challenges for the manufacture of millions of electric cars: rare earth electric motor, lithium-ion battery lithium and platinum for fuel cells .

More than half of the world's lithium reserves are in Bolivia and Chile. This concentration, combined with rapidly growing demand, prices could increase significantly. More problematic is the notice given by Meridian International Research, there is not enough economically recoverable lithium to build the number of batteries needed in a global economy of electric vehicles. Recycling could change the equation, but the economics of recycling depend in part on whether the batteries are made easy recycling in mind, a problem that the industry is aware. The long-term use of platinum also depends on the recycling of current available stocks could maintain the annual production of 20 million fuel cell vehicles, along with existing industrial uses, at least for 100 years.

SmartMix for sustainability

A new energy infrastructure must provide at least as reliable as the existing infrastructure. WWS technologies generally suffer less downtime than traditional sources. Coal plants in the USA are, on average, 12.5% ​​a year offline for scheduled maintenance and unscheduled. Modern wind turbines have a downtime of less than 2 percent on land and less than 5% offshore. Photovoltaic systems also stand less than 2 percent. Also, when a wind turbine, solar inverter is not working, only a small part of the installation is affected and its loss is a small fraction of the production when a plant loses its connection to natural gas or coal, or nuclear, is loses a large part of the main challenge for producción.El WWS, is that the wind does not always blow and the sun always shines on a particular location. Intermittent problems can be mitigated by an intelligent balance of sources, including the generation of geothermal base with waves and tides or nergy storage. The wind is often abundant at night when there is no sun, or solar power for the day when there may be no wind.

Sometimes a trusted source like hydropower can log on and off quickly to meet peak demand or reduce supply. Also available in case of pumping can be stored. Another example: wind farms are only 100 to 200 miles away can compensate for hours of zero power from other wind farms where they have no wind. It is also useful to interconnect geographically distant sources that can support each other, the installation of smart electricity meters in homes that automatically recharge electric vehicles when demand is low or deliver electricity to the grid when loaded and unemployed. It is encouraging the development of electricity storage systems to compensate for fluctuations in production of intermittent renewable sources. In this regard it should be noted the storage of salts and other methods in solar thermal power plants currently in operation already.

As cheap as coal

The combination of our WWS sources reliably plan would provide the residential sector, and commercial, industrial and transportation. The next question is: would it cost to make the change, compared with the current system of fossil fuels? . For each technology cost is calculated as a producer to generate and transmit energy through the network. We included the annualized cost of capital, land, operation and maintenance, energy storage to compensate for deviations from intermittent supply and transmission. Today the cost of wind, hydro and geothermal are less than July 7 cents per kilowatt-hour (¢ / kWh), marine and solar are higher. But from 2020 onwards is expected to wind, marine and hydro are in the 4 ¢ / kWh or menos.Como comparison, the average cost in the U.S. in 2007 for conventional power generation and transmission, was 7 ¢ / kWh and projections are 8 ¢ / kWh in 2020. Wind generation, for example, costs the same or less than that made from a new plant from natural gas, or coal and in the future it is expected that wind power is the least expensive of all options.

The competitive cost of wind today has made it the second largest source of new electricity generation plants in the United States over the past three years, behind natural gas and solar energy carbón.La front of both photovoltaic and concentrating solar thermal is now relatively expensive, but will be competitive by 2020. A careful analysis by Vasilis Fthenakis Brookhaven National Laboratory suggests that within 10 years, the costs of photovoltaics could be placed about 10 ¢ / kWh, including transmission over long distances and the cost of compressed air storage you can use it at night. Similarly, analysis of the estimates of solar thermal systems with enough thermal storage to generate electricity 24 hours a day in spring, summer and autumn, indicating that it could provide electricity to 10 ¢ / kWh or less in that transport fecha.El in a World WWS will be determined by batteries or fuel cells, so we must compare the economics of these electric vehicles with vehicle internal combustion engine. Detailed analysis made by one of us (Delucchi) and Tim Lipman, University of California, Berkeley, said that mass production of electric vehicles with advanced batteries or lithium ion batteries nickel metal hydride batteries, could have a cost per mile or km throughout his life (including battery replacement), comparable to that of gasoline vehicles when gasoline is sold to more than $ 2 per galón.Cuando takes into account the so-called external costs ( the monetary value of damage to human health, environment and climate) of fossil fuels in transportation, WWS technologies are even more competitivas.El general construction cost of a WWS would be around 100 billion dollars around the world in 20 years, not being included transmission costs.

But this is money distributed among all governments and consumers. Furthermore, this investment is repaid through the sale of electricity and energy. And once again remember that if we depend on traditional sources, would go from 11.5 to 16.9 TW, which would require thousands more of these plants, at a cost of approximately $ 10 billion, not to mention tens of billions of dollars more in health, environment and safety. The WWS plan gives the world a new, clean and efficient energy instead of an old, dirty and inefficient.

Political will

Our analysis strongly suggests that the costs of WWS will be competitive with traditional sources. Meanwhile, however, certain forms of energy WWS will be significantly more expensive than fossil energy. Some combination of WWS, subsidies and carbon taxes, therefore, be necessary for a while. A type of premium Feed-inTariff production (FIT) to cover the difference between the cost of generation and wholesale price of electricity is particularly effective in helping new renewable technologies. Combining FIT with a call auction sale at decreasing prices, in which the right to sell power to the system is given to the lowest bidders, provides a continuous incentive for developers to reduce costs WWS. As this happens, the FIT can be phased out gradually. The ITF have been implemented to a large number of European countries and some U.S. states and have been quite successful in stimulating Alemania.Gravar solar energy in fossil fuels or use to reflect its environmental damage also makes sense. But at least the fossil energy subsidies such as tax benefits for exploration and extraction must be removed to level the match.

A promotion mistaken less desirable alternatives such as agricultural subsidies and biofuel production must end because it delays the introduction of cleaner systems. For its part, the development of appropriate policies by lawmakers must find ways to resist the pressure to be produced by the currently established industries energía.Por Finally, each nation must be willing to invest in a system solid and long transmission distance that can carry large amounts of energy from the WWS of remote regions where it is often higher, such as in the U.S. Great Plains in the case of wind and the desert Southwest for solar energy, the consumption centers, usually in cities. Reduce consumer demand during peak periods also requires an intelligent network of generators and consumers much more control over the use of electricity by large-scale horas.Viento, water and solar energy system can provide significantly reliable needs world, which will benefit the climate, air quality, water quality, ecology and energy. As we have shown, the obstacles are mainly political, not technical.

The combination of FIT incentives for service providers to reduce costs, the elimination of subsidies to fossil fuels and a smart grid large enough, could be enough to ensure fast deployment. Of course, changes in the power system and transport industries originate above the existing investment in infrastructure that would irrecuperables.Pero with sound policies, countries could set a target of generating 25 percent of its new supply WWS energy sources in 10 to 15 years and almost 100 percent of the new offering in 20 to 30 years. With more aggressive policies could theoretically remove all existing capacity of fossil fuels and replaced in the same period, but in a more modest, probably the complete replacement of the system, a non-fossil, can last 40 to 50 years. Either way, clear leadership is needed, or nations continue to use technologies promoted by industries rather than those promoted by the científicos.Hace a decade, it was clear that a global system of WWS would be technically or economically viable. Having shown that it is possible, we hope that world leaders can learn how to make politically feasible WWS.

They can start by committing to achieve emissions reduction targets to halt the change climáticoy promote renewable energy.