Renewables, land, and trade-offs

March 27, 2009

in Economics, Geek stuff, The environment

Distorted keys

Whether it is solar power, wind farms, dams, or biofuel crops, renewable energy tends to be land-intensive. Indeed, that is one of the major reasons for which improving efficiency in sectors like buildings and vehicles is some important. Improving their efficiency can allow us to reduce our fossil fuel use, both out of concern for climate change and in response to their inevitable depletion, while engaging in the decades-long project of deploying the kind of renewable infrastructure we are going to need to power human civilization in the future. If we want to have an acceptable balance between areas used for energy generation, those used for all other human purposes, and those where nature is meant to be dominant, we will need to improve the efficiency of both our energy production and our energy use.

There are many trade-offs to be considered. For instance, the best sites for wind farms and solar facilities are often far away from centres of energy demand. That establishes a trade-off between producing power at the best sites and managing losses across long distances. While there is a lot of excitement about highly distributed forms of electrical generation, it may well prove to be the case that the most economically and ecologically sound approach is based on big renewable facilities linked to cities through efficient transmission systems, such as high voltage direct current (HVDC) lines.

There are also ecosystem trade-offs: dams block rivers, biofuel plantations are generally sterile monocultures that can lead to deforestation, and solar facilities crowd the dessert. That being said, fossil fuel extraction certainly causes harm to ecosystems, a well. There is direct harm from both deliberate actions (open pit oil sands extraction, coal mining, etc), near-term indirect harm from accidents like oil and coal ash spills, and the potentially massive long-term harm associated with climate change. Indeed, that final issue alone may be a strong justification for converting large amounts of land towards renewable energy generation; in that way, ecosystem harm can be made to occur in a planned way within large but controlled spaces, rather than globally and chaotically as the consequence of temperature increases, precipitation changes, and ocean acidfication.

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{ 18 comments… read them below or add one }

Milan March 27, 2009 at 4:57 pm

Incidentally, today’s photo was shot with my broken 50mm lens. Holding the two pieces of my lens together, I held it backways against my Rebel XS body.

Unbroken 50mm lenses can actually make decent macro lenses in this arrangement, though you have to be careful about light leaks. Since the elements are no longer properly aligned, my broken lens makes for more distorted macro shots.

Sarah March 27, 2009 at 7:43 pm

Wind farms aren’t necessarily land intensive since the best resources are often found offshore in areas that may not be used much for any other human purpose, although it might conflict with the needs of seabirds etc.

Sarah March 27, 2009 at 7:46 pm

There’s also a discussion of the land use issue in a recent issue of New Scientist, in which they explore how one would make best use of available land & energy resources if the planet grew 4 degrees C warmer .

R.K. March 27, 2009 at 7:49 pm

Nice photo.

Tristan March 28, 2009 at 2:57 pm

Maybe one way to think about the “heavy land use” of renewables is that it is not so much as they are heavier land users than non-renewables, but that the land they use is explicitly put to work. The excess production of C02 causes damage to land everywhere, so that “being put to work for the sake of energy production” of the land is hidden, spread out, not noticed. Externalized, in a word.

Perhaps the more explicit putting-to-work-of-the-land required by renewable energy will increase our self-consciousness of our mastery over nature, and help us become the stewards of the earth. The guiding question: are we ready to become the masters/stewards of all we survey?

Milan March 28, 2009 at 5:09 pm

In a sense, we are already masters of all we survey. We are just negligent ‘masters’ who usually fail to think things through.

As Sarah points out, there are also opportunities for renewable energy with a fairly small footprint. For instance, there is offshore wind and the possibility of adding wind turbines to areas that are productive in other ways (say, agriculturally). Run-of-river hydro probably falls into this category as well. I don’t think the hydro station between my home and work has caused any significant enlargement of the Ottawa River.

Tristan March 28, 2009 at 6:18 pm

I don’t dispute that we are not “masters of all we survey”. The question is, are we ready?

Certainly, make kings have become masters of all they survey before they were ready. And it didn’t always end well…

Milan March 28, 2009 at 7:39 pm

I think it’s obvious that we are unready. So far, we have done a pretty poor job of acting as stewards of the natural world under our control.

Milan March 28, 2009 at 7:44 pm

See also:

Extreme environmental recklessness
December 12, 2008

. May 9, 2009 at 3:12 pm

Bioelectricity Promises More ‘Miles Per Acre’ Than Ethanol

THURSDAY, MAY 7, 2009

STANFORD, CA – Biofuels such as ethanol offer an alternative to petroleum for powering our cars, but growing energy crops to produce them can compete with food crops for farmland, and clearing forests to expand farmland will aggravate the climate change problem. How can we maximize our “miles per acre” from biomass? Researchers writing in the online edition of the May 7 Science magazine say the best bet is to convert the biomass to electricity, rather than ethanol. They calculate that, compared to ethanol used for internal combustion engines, bioelectricity used for battery-powered vehicles would deliver an average of 80% more miles of transportation per acre of crops, while also providing double the greenhouse gas offsets to mitigate climate change.

. June 11, 2009 at 6:02 pm

North America’s non-solar renewables aren’t enough for North America to live on. But when we include a massive expansion of solar power, there’s enough. So North America needs solar in its own deserts, or nuclear power, or both.

The 600 km by 600 km square in North America, completely filled with concentrating solar power, would provide enough power to give 500 million people the average American’s consumption of 250 kWh/d.

. July 7, 2009 at 8:19 pm
. August 13, 2009 at 3:42 pm

Saturday, August 1, 2009

A new graph, showing countries’ power per unit area

Conclusion: All countries whose power consumption per unit area is bigger than 0.1 W/m2 are countries who should expect renewable facilities to occupy a significant intrusive fraction of their country, if they ever want to live on their own renewables. Countries with a power consumption per unit area bigger than 1 W/m2 (eg UK, Germany, Japan, Netherlands, Belgium) would have to industrialize most of their countryside, if they want to live on their own renewables. Alternatively, their options are to radically reduce consumption, use nuclear power, and/or to buy renewable power in from other countries.

. November 4, 2009 at 12:42 pm

Ethanol

“Ethanol is difficult to scale up to become a major gasoline substitute. Ethanol production requires a large amount of corn to produce relatively little gasoline. Ethanol production requires 2.8 bushels of corn per gallon of ethanol. At present, approximately 25% of US grown corn produces 7 billion gallons, or 3.3% of the energy content of gasoline (and only 1.5% of all US finished oil products) consumed in the US. If the entire corn crop was used to produce ethanol, it would only offset 6% of total US oil consumption.”

Downey, Morgan. Oil 101. p.193 hardcover

Biodiesel

“It takes about 7.3 pounds of soybean oil to produce one gallon of B100 biodiesel. Soybean oil is the most commonly produced oil in the US with approximately 17 billion pounds of soybean oil currently produced each year… If the entire US soybean oil production was diverted to replace middle distillate then it could only replace 13 days of current annual US distillate demand. One has to be realistic, therefore, about the current capacity of soybean oil production and accept that biodiesel is not a realistic alternative for mass scale implementation.”

Downey, Morgan. Oil 101. p.213-214 hardcover

. May 8, 2011 at 11:27 am

Low carbon electricity means, to most greens, renewables. They were never well-loved, but now, in the places in which major deployment is taking place, they are provoking something approaching a full-scale revolt. Here in mid-Wales, for example, and in the Highlands of Scotland, public anger towards wind farms and the power lines and hubs required to serve them is coming to dominate local politics. While there are plenty of stupid myths circulating about the inability of wind turbines to produce electricity and about the greenhouse gases released in constructing them, in other respects the opposition to them is not irrational. People love their landscapes, and so they should.

Those of us who support renewables find ourselves in a difficult position: demanding the industrialisation of the countryside, supporting new power stations, new power lines and (for the electricity storage required) new reservoirs. Even offshore power, whose landscape impacts are much smaller, means more grid connections and more storage.

. July 30, 2011 at 10:58 am

MORE than 100 days after the earthquake that hit Japan in March, 30,000 survivors still huddle in shelters, politicians have returned to their bickering and Japan Inc to business as usual. Two of Japan’s most prominent entrepreneurs think this is not good enough.

The quake caused a nuclear disaster. So Masayoshi Son, the boss of Softbank, a big mobile operator, believes it is time to rethink Japan’s dependence on nuclear power. He is talking to around 20 prefectures about building ten solar-power plants. Converting one-fifth of Japan’s unused farmland to solar would generate 50 gigawatts, he says, which is equivalent to the peak output of TEPCO, Japan’s largest electricity firm (and a quasi-monopoly).

. November 12, 2011 at 8:09 pm

Some firms are building vast fields of mirrors in the Mojave desert to focus the sun onto water boilers and use the steam to spin turbines. But this also requires costly power grids to carry the electricity to the distant cities. Unexpectedly, it has also drawn the ire of some environmentalists, who love renewable energy but hate the mirrors (or wind farms) that ruin landscapes. In the Mojave they fret about a species of tortoise. Elsewhere they have gone to court for the blunt-nosed leopard lizard and the giant kangaroo rat.

. March 4, 2012 at 7:29 pm

Previous efforts have been directed mainly at stopping the mirrors shading each other, which tends to mean spreading them out. Dr Mitsos and Mr Noone also wanted to save space. In trying to do so they stumbled on an unusual arrangement that had the desired effect. When they showed this layout to a third researcher, Manuel Torrilhon of Aachen University in Germany, he recognised the spiral patterns within it, and this prompted the trio to test a design specifically modelled on nature.

That design was a pattern known as a Fermat spiral, in which each element is set at a constant angle of 137° to the previous one. It is most familiar as the arrangement of the florets that make up a sunflower head. When the three researchers programmed their model to arrange PS10’s mirrors in front of the tower in a segment from such a spiral, they both improved the efficiency of the collection process and saved space. The improvement in efficiency was, admittedly, quite small (about half a percent), but the space saving was significant—almost 16%.

If solar power is to make up much of the world’s electricity output in future, as supporters of alternative energy hope it will, a lot of land will be needed for the power stations. Reducing that requirement by a sixth, as this discovery promises, would be a big gain. It would also show that if you look hard enough, there really is nothing new under the sun.

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