Wind, water and sun are all we need

By Bryan Walker 22/10/2009


Climatechallenge Wind, solar and water sources are sufficient to provide the world’s energy by 2030. Scientific American has a front cover article coming up in November to demonstrate that. Written by Mark Jacobson (left) and Mark Delucchi, it’s heartening information according to a Stanford University report. Turning away from combustion to electricity from renewable sources results in a striking lowering of global power demand. The reason is that fossil fuel and biomass combustion are inefficient at producing usable energy. For example, when gasoline is used to power a vehicle, at least 80 percent of the energy produced is wasted as heat. With vehicles that run on electricity, it’s the opposite. Roughly 80 percent of the energy supplied to the vehicle is converted into motion, with only 20 percent lost as heat. Other combustion devices can similarly be replaced with electricity or with hydrogen produced by electricity. The authors estimate a consequent 30 percent decrease in global power demand, which is a promising start and helps to make renewables ultimately cheaper than fossil or nuclear generation.

Lester Brown’s latest Plan B book, reviewed on Hot Topic recently, made confident claims that the transition to renewable energy can produce very large cuts in emissions by as soon as 2020. This is not pie in the sky if Jacobson and Delucchi are right.

First of all, there is plenty available. Analyzing only on-land locations with a high potential for producing power, they found that even if wind were the only method used to generate power the potential for wind energy production is 5 to 15 times greater than what is needed to power the entire world. For solar energy, the comparable calculation found that solar could produce about 30 times the amount needed. And that’s without considering water or geothermal energy.

It has to be captured. The world would have to build wind turbines; solar photovoltaic and concentrated solar arrays; and geothermal, tidal, wave and hydroelectric power sources to generate the electricity, as well as transmission lines to carry it to the users. The long-run net savings would more than equal the costs, according to Jacobson and Delucchi’s analysis. The transition to renewables and electricity eliminates the need for 13,000 new or existing coal plants.

Meeting the projected (reduced) power demand for 2030 would not require vast amounts of space. The wind turbines themselves would fit into an area smaller than the borough of Manhattan. Allowing the necessary space between them would cover 1 percent of Earth’s land area, but the spaces between are available for crops or grazing if suitable. The various non-rooftop solar power installations would need about a third of 1 percent of the world’s land. 

But what about the inherent variability of wind speed and sunshine? The study provides examples of how a combination of renewable energy sources could be used to meet hour-by-hour power demand, and demonstrates that between them they can consistently produce enough power. Expansion of transmissions grids is an essential part of the change.

The researchers also considered availability of certain materials that are needed for some of the current technologies, such as lithium for lithium-ion batteries, or platinum for fuel cells. They are not currently barriers to building a large-scale renewable infrastructure. But efforts will be needed to ensure that such materials are recycled and potential alternative materials are explored.

So what’s to stop us?  The authors conclude that perhaps the most significant barrier to the implementation of their plan is the competing energy industries that currently dominate political lobbying for available financial resources. We’re back in the world of policy and politics — the real world as some delight to call it.

Can you see our Minister of Energy losing his enthusiasm for oil drilling and coal prospecting, and getting behind a major drive for wind and marine power?  I have to admit to an impoverished imagination at this point. But then I think of Stephen Chu, the US Secretary of Energy, of Ed Miliband the UK Secretary of State for Energy and Climate Change (sensibly coupled as they no longer are in NZ), or of Connie Hedegaard, the Danish Minister of Climate and Energy. Who’s to say there can’t be a major shift which will put fossil fuel combustion behind us, and say bad luck to the industries which have to close down as a result?