The Energy Economy, Part 2: EROI, efficiency and the grid

[For the large-print, easy-reading version of this post, click here.]fractal image

Besides the EROI (see previous post), another measure of the various energy options is ‘efficiency’. This is usually applied to mechanical systems and given as a percentage: a machine which turned all of its energy input into a useful output (without wasting any of it) would be ‘100% efficient’. In practice, of course, this never happens. ‘Zero waste’ may be a noble ideal when it comes to materials, but it is unattainable in the realm of energy usage – which of course is the realm inhabited by all living beings.

One of the basic laws of physics, namely the second law of thermodynamics, tells us that there is no way of using energy without wasting some of it by converting it unintentionally into useless forms. ‘Wasted’ or ‘lost’ energy is called entropy (which can also be mathematically described as randomness in contrast to order). Of course, the usefulness of anything is relative to who’s using it, and for what purpose. Many scientific sources refer to entropy as ‘heat’, because they have machines in mind, and heat is an unwanted byproduct of the work most machines are designed to do. But in another context – surviving a northern Ontario winter, for instance – heat can be very useful indeed. That’s why our four-legged neighbours have evolved ways to generate and conserve it (for instance fur).

Efficiency is a useful measure for comparing various devices which convert one specific form of energy into another. For instance, if you expose two solar cells to the same amount of sunlight, and Cell A generates more electrical energy than Cell B, then Cell A is more efficient. However, if it costs more in resources or energy to make Cell A, then its EROI – the ratio of energy output to the energy input required to generate that output – may not be higher. In other words EROI is the more comprehensive measure for use in making decisions about what technology to use.

The catch is that EROI may not be easy to calculate in practice, because the energy consumed by production and maintenance of any device or system may be difficult to measure. Like entropy (a.k.a. waste), guesswork can’t be entirely eliminated from the decision-making process, but we have to do the best we can if we hope to make the transition to a sustainable energy economy. And sometimes your guesswork has to rely on information you can only get from sources other than your own experience. How we can judge the reliability of a source is a problem i’ll take up in a future post.

Some of the decisions we face are related to the electrical grid. At the provincial level, it’s an obvious problem that a major part of the energy on the grid is generated from non-renewable (and polluting) sources such as coal. Current Ontario government policy is to reduce the amount of ‘dirty’ energy on the grid and bring more renewable sources online (hydroelectric, solar, wind). Some opponents of the latter option have argued that the grid itself is the problem, because it is inefficient: the greater the distance between energy source and user, the more is lost to heat. But this argument makes sense only if there is an alternative with a better EROI. I have yet to hear anyone suggest any such alternative, let alone compare its EROI with that of the existing grid.

Besides, the extended reach of the electrical grid also confers some advantages: not only economies of scale, but also the wide distribution of sources feeding into it – and this advantage increases as more renewable sources come online. The wind doesn’t blow all the time, but it does blow at night, and in the winter, when solar and some hydro sources are not producing much. And when the wind isn’t blowing, other sources may be able to make up the difference. The technology of matching demand with supply on electrical grids is already fairly advanced and customized to specific regions. One district in England has two reservoirs, one much higher than the other; so when they have surplus energy, they pump water from the lower one to the higher one, and when demand exceeds supply, they release the water through a turbine system that generates power as the water flows back down. Other innovative storage methods are always in development, and so is the ‘smart grid’ which can anticipate loads and direct energy where it’s needed.

Of course, there is one advantage to burning fuels as a way of generating energy: when demand increases, you can meet it by simply burning more. This advantage will be lost (along with all the disadvantages of fossil fuels) as we make the transition to renewable sources, and even the smartest grid won’t be able to supply everyone with energy on demand. Part of the transition, then, will be a change in our habits, as we learn to adjust our energy demands to the rhythm of our actual supply. Ontario Hydro is already pushing us in this direction by making energy more expensive at peak demand times. The loud complaints about this, and about rising energy prices generally, show how difficult it is for people to shift their consumption habits, once they’ve got used to having cheap energy on demand. But again, what alternative do we have in the long run?

If you are more ready than most to change your habits, you might consider getting off the grid as an alternative. Certainly it would force you to live within the limits of your household energy economy. But how viable that option is will depend on how much energy you are willing and able to do without. If you are off the grid, and your primary energy source is not producing (for instance solar panels on a long winter night or dark winter day), then what do you do? Go without energy until the sun reappears? If you value the usefulness of an energy supply, you will probably prefer to invest in an alternate source (such as a gasoline generator) or a system that stores enough energy to get you through the night (such as a bank of batteries). But even if you can afford all this, it seems unlikely that the EROI of your off-grid system is higher than the EROI of Ontario’s electrical grid. If anyone can show me that it is, using reliable estimates, i’ll be happy to eat those words. (Especially since we’ve already installed a solar-and-battery system here at gnusystems headquarters.)

Even if going off-grid is a viable option for you personally, that doesn’t make it viable as a provincial policy. At our place we heat with wood, but if everyone in the province did that, just think what effect it would have on Ontario’s carbon footprint and air quality, not to mention the forests … For the province as a whole, asking everyone to go off-grid is about as practical as asking everyone to burn wood. Whether it’s even practical for a typical Manitoulin household is no easy question. On the provincial level (and above), we are not likely to make the transition to sustainability by eliminating the grid. The more sensible course is to clean it up and diversify the sources feeding into it – and work out ways of dealing with whatever new problems accompany that shift. My next post will look at some of those.

Energy Return On Investment (The Energy Economy, Part 1)

[For the large-print, easy-reading version of this post, click here.]

photo by John Caddy

photo by John Caddy

The darkness of the winter solstice is a good time to step back and reflect on the year’s activities. On this Resilient Manitoulin blog, the activity has been irregular. Justin Tilson, who launched it, has been occupied elsewhere; so has Gary Fuhrman (that’s me), the only other person who’s posted here. We hope for a greater diversity of voices in the coming year – anyone following the blog who would like to become a co-author is welcome to contact gnusystems for any help you need.

But in the meantime, perhaps i can contribute more regularly here myself, hopefully without being taken for an expert in resilience. This is also part of the gnusystems mission of ‘accounting for what really counts.’ When it comes to the basic principles of resilience, there are other factors that really count more than money.

Take energy, for instance. The money economy as we know it is either a delusion or a spinoff from the energy economy. The dream of perpetual economic ‘growth’ is nothing but the shadow of surplus energy. The explosive growth of the 20th Century was driven by cheap energy from oil. Hence the 21st Century faces the challenge of coping with the decline of cheap energy – that is, with peak oil.

The latest oil production figures indicate that we are already past peak oil and starting on the downward slope, which is likely to prove just as steep on the way down as it was on the way up. Production of some other fossil fuels may peak later, but it’s all headed in the same direction. (That’s true of many other materials as well – ‘peak everything’, as they say – but for the moment let’s focus on energy.)

The era of cheap energy is coming to an end because it is increasingly expensive, in both money and energy inputs, to produce any given quantity of high-quality fossil fuel. The problem facing us is how to make the transition from an unsustainable economy based on fossil fuels to one that is sustainable. Add to this the climate change caused by our carbon footprint, and we have even more incentive to get past our oil addiction. But how? Perhaps the one thing we can all agree on is that it won’t be easy. We will have to make some difficult choices.

Curbing our waste of energy is certainly part of the solution, but it’s not enough – we will always need some energy, and resilience itself calls for more than a bare minimum. It follows that making the transition must involve using what’s left of the fossil fuels to power a shift to renewable sources. Waiting until the fossil fuel supply dries up is not an option – especially when the credit bubble (the money economy) could burst at any time. This means we will have to be careful how we use what’s left of cheap energy sources.

The key concept in making these difficult energy choices is energy return on investment (EROI). For any potential energy source, the question is: how does the energy we will get from it compare with the energy we have to invest in order to realize that potential? The answer is expressed as the ratio of energy output to energy input. For instance, the Alberta tar sands is generally said to have an EROI of around 3 to 1. If we use ‘barrels of oil’ as our measure of energy, this means that in order to get 3 barrels out of the tar sands, we have to use up one barrel’s worth of energy. In the early days of cheap energy, the ratio for oil was typically 40 to 1 or higher. Compared to that, the oil sands project is well on the way toward 1 to 1 – at which point, of course, it doesn’t pay (in energy terms!) to produce the stuff at all. The same goes for deep-sea or Arctic oil drilling, especially if we count the environmental damage they risk as part of the ‘investment.’ And to the extent that the money economy is dependent on the energy economy, oil production will cease to be profitable well before the EROI reaches 1 to 1. (Profit is surplus.)

If we are going to use the dwindling oil supply to power a shift to sustainable energy supplies, then the EROI is a very important measure. There’s no point investing energy in renewables if we’re not likely to get more out of them than we put in. Depending on how they are produced, some fuels (such as ethanol and hydrogen) currently have a very low EROI, even less than 1 to 1 in some cases. Photovoltaic solar also has a low EROI, at least in these northern latitudes. By far the best option yet in this part of the world, with an EROI of around 20 to 1, is wind energy – and the bigger the turbines, the higher the ratio (thanks mostly to economy of scale).

Obviously – especially to Manitoulin Islanders – there are other factors involved in wind farms besides the EROI. In order to think realistically about this or any other energy option, we have to take all predictable factors into account, giving each its proper due. We also have to take into account that a viable transition will have to work at every level – local, provincial, federal and global – and conflicts between levels will have to be addressed as they arise. But since the whole multidimensional picture is framed by the necessity of a shift to sustainable energy sources, we can’t make realistic choices if we leave out the EROI factor.

I hope to deal with some of the issues related to this transition in further posts, as time allows. And i hope that readers, in their comments, will point out any flaws they see in my analysis, so we can correct any mistakes along the way.

Movie review: Home

HomeNew DVD at the Honora Bay Resource Library:

Home, a 2009 feature film shot by noted aerial photographer Yann Arthus-Bertrand, is a visual spectacular in the tradition of Koyanisqaatsi and the rest of Godfrey Reggio’s trilogy. Like those earlier films, it aims to show us humans how we are changing life on this planet. But there the resemblance ends. The Reggio trilogy, and similar films like Ron Fricke’s Baraka, let the images speak for themselves. Home on the other hand is dominated by its script, a powerful sermon aimed at changing our relationship with the biosphere.

Although it delivers its message mostly in scientific rather than religious terms, i call it a ‘sermon’ because it is aimed directly at our moral and spiritual sensibilities. The scope of it, beginning with the advent of life on Earth 4 billion years ago, matches the magnificent sweep of the visuals. Having given us in the first hour an overview (in every sense!) of where we come from, the second hour of the film draws our attention directly to climate change and the rest of the planetary crisis caused by our collective habits. The final few minutes show us how various communities have actually changed their habits in ways that help to head off disaster. The central focus is on overconsumption – which is entirely appropriate, given that the 20% of humans who consume 80% of the Earth’s resources are the likely audience for this film, although the impoverished majority have a starring role in it.

The script makes excellent use of factual information, along with the visual feast, to ‘go for the gut’ and inspire an informed response. The delivery is not perfect – the voice-over by Glenn Close includes some minor but annoying blunders, especially when she says ‘climactic’ when the word should be ‘climatic’. There are also moments when the you don’t know what you’re seeing on the screen, and the narrative doesn’t tell you. However there’s little point in quibbling with details, either of fact or pronunciation, when the main message comes across so clearly. Home is the kind of wake-up call we will continue to need until we manage to shake off our wastefully consumptive habits.

Wind farm worries?

The Manitoulin Coalition for Safe Energy Alternatives now have their own blog – the place to go if you have questions about the impact of the proposed wind farm in Northeastern Manitoulin.