Tag Archives: EROEI

How Renewable Energy Models Can Produce Misleading Indications

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The energy needs of the world’s economy seem to be easy to model. Energy consumption is measured in a variety of different ways including kilowatt hours, barrels of oil equivalent, British thermal units, kilocalories and joules. Two types of energy are equivalent if they produce the same number of units of energy, right?

For example, xkcd’s modeler Randall Munroe explains the benefit of renewable energy in the video below. He tells us that based on his model, solar, if scaled up to ridiculous levels, can provide enough renewable energy for ourselves and a half-dozen of our neighbors. Wind, if scaled up to absurd levels, can provide enough renewable energy for ourselves and a dozen of our neighbors.

There is a major catch to this analysis, however. The kinds of energy produced by wind and solar are not the kinds of energy that the economy needs. Wind and solar produce intermittent electricity available only at specific times and places. What the world economy needs is a variety of different energy types that match the energy requirements of the many devices in place in the world today. This energy needs to be transported to the right place and saved for the right time of day and the right time of year. There may even be a need to store this energy from year to year, because of possible droughts.

I think of the situation as being analogous to researchers deciding that it would be helpful or more efficient if humans could change their diets to 100% grass in the next 20 years. Grass is a form of energy product, but it is not the energy product that humans normally consume. It doesn’t seem to be toxic to humans in small quantities. It seems to grow quite well. Switching to the use of grass for food would seem to be beneficial from a CO2 perspective. The fact that humans have not evolved to eat grass is similar to the fact that the manufacturing and transport sectors of today’s economy have not developed around the use of intermittent electricity from wind and solar.

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Understanding Why the Green New Deal Won’t Really Work

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The reasons why the Green New Deal won’t really work are fairly subtle. A person really has to look into the details to see what goes wrong. In this post, I try to explain at least a few of the issues involved.

[1] None of the new renewables can easily be relied upon to produce enough energy in winter. 

The world’s energy needs vary, depending on location. In locations near the poles, there will be a significant need for light and heat during the winter months. Energy needs will be relatively more equal throughout the year near the equator.

Solar energy is particularly a problem in winter. In northern latitudes, if utilities want to use solar energy to provide electricity in winter, they will likely need to build several times the amount of solar generation capacity required for summer to have enough electricity available for winter.

Figure 1. US daily average solar production, based on data of the US Energy Information Administration.

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Rethinking Renewable Mandates

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Powering the world’s economy with wind, water and solar, and perhaps a little wood sounds like a good idea until a person looks at the details. The economy can use small amounts of wind, water and solar, but adding these types of energy in large quantities is not necessarily beneficial to the system.

While a change to renewables may, in theory, help save world ecosystems, it will also tend to make the electric grid increasingly unstable. To prevent grid failure, electrical systems will need to pay substantial subsidies to fossil fuel and nuclear electricity providers that can offer backup generation when intermittent generation is not available. Modelers have tended to overlook these difficulties. As a result, the models they provide offer an unrealistically favorable view of the benefit (energy payback) of wind and solar.

If the approach of mandating wind, water, and solar were carried far enough, it might have the unfortunate effect of saving the world’s ecosystem by wiping out most of the people living within the ecosystem. It is almost certain that this was not the intended impact when legislators initially passed the mandates.

[1] History suggests that in the past, wind and water never provided a very large percentage of total energy supply.

Figure 1. Annual energy consumption per person (megajoules) in England and Wales 1561-70 to 1850-9 and in Italy 1861-70. Figure by Tony Wrigley, Cambridge University.

Figure 1 shows that before and during the Industrial Revolution, wind and water energy provided 1% to 3% of total energy consumption.

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The climate change story is half true

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The climate change story is true in some respects: The climate is indeed changing. And CO2 emissions do seem to affect climate. Burning fossil fuels does indeed make a difference in CO2 levels.

The problem I have with the climate change story is that it paints a totally inaccurate story of the predicament the world is facing. The world’s predicament arises primarily from too little affordable resources, especially energy resources; climate change models tend to give the illusion that our problem is one of a superabundance of fossil fuels.

Furthermore, the world economy has no real option of using significantly less energy, because the economy tends to collapse when there is not enough energy. Economists have not studied the physics of how a networked economy really works; they rely on an overly simple supply and demand model that seems to suggest that prices can rise endlessly.

Figure 1. Supply and Demand model from Wikipedia.
Attribution: SilverStar at English Wikipedia CC BY 2.5 (http://creativecommons.org/licenses/by/2.5)%5D, via Wikimedia Commons

The quantity of energy supply affects both the supply and demand of finished goods and services. History shows that the result of inadequate energy supplies is often collapse or a resource war, in an attempt to obtain more of the necessary resources.

Climate scientists aren’t expected to be economists, but have inadvertently picked up the wrong views of economists and allowed them to affect the climate models they produce. This results in an over-focus on climate issues and an under-focus on the real issues at hand.

Let’s look at a few issues related to the climate change story. Continue reading →

How the Peak Oil story could be “close,” but not quite right

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A few years ago, especially in the 2005-2008 period, many people were concerned that the oil supply would run out. They were concerned about high oil prices and a possible need for rationing. The story was often called “Peak Oil.” Peak Oil theorists have also branched out into providing calculations that might be used to determine which substitutes for fossil fuels seem to have the most promise. What is right about the Peak Oil story, and what is misleading or wrong? Let’s look at a few of the pieces.

[1] What Is the Role of Energy in the Economy?

The real story is that the operation of the economy depends on the supply of  affordable energy. Without this energy supply, we could not make goods and services of any kind. The world’s GDP would be zero. Everything we have, from the food on our dinner table, to the pixels on our computer, to the roads we drive on is only possible because the economy “dissipates” energy. Even our jobs depend on energy dissipation. Some of this energy is human energy. The vast majority of it is the energy of fossil fuels and of other supplements to human energy.

Peak Oilers generally have gotten this story right, but they often miss the “affordable” part of the story. Economists have been in denial of this story. A big part of the problem is that it would be problematic to admit that the economy is tied to fossil fuels and to other energy sources whose supply seems to be limited. It would be impossible to talk about growth forever, if economic growth were directly tied to the consumption of limited energy resources.

[2] What Happens When Oil and Other Energy Supplies Become Increasingly Difficult to Extract? Continue reading →