Archive for Water

Watts and Revolts- more Intermountain Rural Electric controversy

 

In the September issue  of Watts & Volts, IREA management attempts to make three arguments:

  1. They say the investment in Comanche 3 will save their customers money relative to gas generation.
  2. “There is no way to produce large amounts of reliable power without CO2.”
  3. They attempt to brand members who oppose their actions as extreme environmentalists who want to ruin our economy and send us back to the Stone Age by imposing gigantic taxes on CO2 emissions.

None of these arguments hold water.  I will deal with each in the order I’ve listed them above. Read the rest of this entry »

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National (and Colorado) Tour of Solar Homes, October 6

Note: This post was originally for the 2006 Tour. The 2007 Tour of Solar Homes will be on October 6, 2007. See the original post after the break.

———————Info about 2007 Tour of Solar homes————————

Colorado Solar Tour link
Colorado Tour of Solar Home Flyer
For Southwest Colorado, there’s some info on the SWCRES website.
For Fort Collins area tour, see NCRES Website
For other states, go to the National Solar Tour link

———————Info about 2006 Tour————————
Read the rest of this entry »

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Distributed Water

Ever since the green revolution of the middle of the last century, food, at least in the developed world, has not been a scarce commodity.  By the introduction of more productive varieties of cereals, mechanization, as well as the (often unsustainable) application of chemical fertilizer and
irrigation, yields increased dramatically, leading to food becoming a smaller and smaller portion of the budget of the first-world 
 consumer.

 

That green revolution has gone about as far as it can go.  A combination of more erratic and warmer weather due to global warming, and the over-exploitation of aquifers are making water for farming a much scarcer resource.  Meanwhile, rising fossil fuel prices due to increasing demand, combined with flat or diminishing supplies are making chemical fertilizer a much greater cost to the farmer, as well as making it much more costly to run farm equipment.

 

On top of this, biofuels are a new and growing source of demand for agricultural products. 

I see a new pattern emerging.  Water, food, and energy are each becoming scarcer, and as it becomes easier to convert one into another of the triad, their prices are becoming increasingly coupled, as they rise in unison.

 

I’ve written elsewhere how conventional electricity generation technologies require vast amounts of water.   Biofuels allow us to use food as energy.  As cities turn increasingly to desalinization, energy can be converted to potable water.

 

Rising energy prices are generally a good thing (so long as they don’t rise too quickly), in my mind, because they increase the incentives to switch to new, less polluting forms of energy.  Rising food prices will be a force for rural revitalization in the rich world, and may make third world farming more economic… so long as they have reliable access to water, which makes wise investment in water infrastructure all the more important.

 

A study from the Consultative Group on International Agricultural Research finds that large scale water projects are much less cost effective than small scale efforts.  I can’t find a link to the study, but here are some excerpts from the Economist article where I read about it.

 

A recent study of vegetable farmers in
Ghana, for example, found that those irrigating their fields with wastewater carried by buckets earned a 230% return on their investment, versus 30% for big state-sponsored schemes.

 

The assessment argues that modest outlays on rain-fed agriculture, in particular, could drastically improve the productivity of farming in poor countries and so help both to raise farmers’ incomes and also to cut the need for an expansion of agriculture elsewhere. More than half of the world’s food comes from rain-fed farms, as opposed to irrigated ones. If the rains fail, so do the crops. Channels to harvest and direct rainfall and small, sealed reservoirs or tanks to store it, would not only see farmers through dry spells, but also allow them to entice bigger or more valuable harvests out of the same fields. More reliable income, in turn, allows farmers to invest more in seeds, fertilizer and machinery.

 

Like our energy infrastructure, our water infrastructure needs to become more diverse and distributed.  “Think globally, act locally,” as they say.  I like to add, “Unless you can act globally,” which is what the financial markets allow us to do… but this is one problem that the financial markets are not suited for.  Just because I have a hammer, does not mean every problem is a nail, and wishing it were so will not change that.

 

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Water and energy

Last month, several nuclear power stations in Europe had to shut down during a heat wave (and consequent period of extreme electricity demand) to avoid releasing overheated water back into the environment.  As many other astute observers have pointed out, this pokes another big hole in the arguments that nuclear is our best choice of carbon-neutral generating technology.  A power plant that goes down precisely when you need the most power is almost useless for the current grid.

It also brings up the broader point of the role of water in electricity generation.  Nuclear is not the only technology that uses water for cooling.  Coal plants, including “next generation” IGCC plants mostly use water for cooling (air cooling can be used, but it makes them less efficient, and hence more expensive to run, and is seldom used in practice.)

This is a problem because water, in most countries is under-priced.  Resources that are under-priced tend to be overused, since the user does not have to bear the full cost of supply.  This is the cause of a large number of ills, such as the drying up of the Aral sea due to irrigation for cotton farming.  It is not only poor countries who don’t have enough water.  In the US, mispricing means that almost every aquifer is being pumped at much faster than sustainable levels.  In this context, it seems certain that power plants are also paying too little for the water they use for cooling.

 With a looming need to increase farming to supply biofuels, it is more important than ever that water be priced appropriately, especially in planning scenarios for power plants.  When water is under-priced, generation technologies which use more water are likely to be inappropriately favored in comparison to technologies which use little or no water for generation.

 Like nuclear, thermal electric systems are usually water cooled.  Fossil-fueled power plants account for approximately 39 percent of the water used in the United States, second only to agriculture. For coal plants, this typically amounts to 3 gallons of water (Texas study) or 0.5 gallons (NREL study) for every kWh produced (25 gallons are used for cooling, but only 3 evaporate in the process).  Nuclear, Biomass, and Oil fired plants also require large amounts of water lost as steam in the cooling process.   Some Solar thermal technologies also require significant water for cooling.

Water use by large hydropower projects is more complex, since water in reservoirs is more useful for some purposes (recreation) but often less useful for wildlife.  However, there is no question that reservoirs increase evaporative losses.  An NREL study quantifies these losses in the US.  Overall, in the US evaporative losses average over 18.2 gallons per kWh of hydroelectric power generated.  These numbers vary widely depending on the reservoir, from 2-3 gallons per kWh in cool northern states, up to over 100 gallons per kWh in KY, OK, SD, and WY.  Keep in mind that a lot of these reservoirs have other uses besides power generation, such as storing water for dry seasons, but the numbers can be mind-boggling.

Technologies which use little water include gas turbines (both natural gas and gas from renewable sources such as landfill gas), and geothermal (the water is typically re-injected into the ground).

Wind, photovoltaic, and wave power require no water to generate electricity. 

Energy efficiency, by its nature, uses no water.  Readers will recognize that as an ongoing theme: Given the choice, it is better to avoid using a kWh than it is to generate a kWh (regardless of source… even renewables have environmental impact.)

Renewable energy advocates should also be advocating for more rational water pricing, especially in planning scenarios.  Water use in generation will eventually come to be recognized as a significant cost (and source of uncertainty, as France found out last month).  The sooner this happens, the better for everyone.  Pricing water properly will not only save water, it will help move us to renewable energy technologies.

Investors may do well by concentrating their investments on low water use technologies, especially in parts of the world where water is (or will soon be) scarce.

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