On “Renewables”

Because humans do seem to have a hive mind and because that is accentuated by our repeater medias, I saw several things that talked about heating this week. As in heating living and working spaces in the winter, not as in climate heating, though that was part of it. All were framed in a “we need more renewables on this project” fashion. And yes, we do. But we need to be realistic about goals, potential benefits, and potential harm that comes from transitioning away from systems that largely burn fossil fuels to generate heat — either directly or indirectly by first turning stored carbon energy into electricity. And some of these articles were rather sneeringly dismissive of the solutions that some people have turned to in turning away from fossil fueled heat. I don’t find this helpful.

First, let me address the process directly. Heat is a by-product of translating phases or changing chemical composition. It can be produced through friction or through increasing concentration and therefore pressure. But it mainly comes from burning — which, frankly, we still don’t understand. But the shorthand is that as the energy in a system is increased, chemical compounds are broken apart and new compounds are created. This transformation releases some waste energy which we sense as heat. Some transformations produce little heat, some quite a lot. Plants, or rather the chloroplasts that are found living in plant cells, figured out long ago that carbon compounds have the potential to release a lot of energy, much of which is heat. Plants turn the energy from the sun into carbon compounds which they then store for later use, much of which seems to be spent in trade with symbiotic organisms that can’t make their own food. When the carbon compounds are broken apart again in metabolism, energy is released to the organism. The heat from this reaction would be lost if these transformations happened in an open system. If the reaction takes place in an organism though, that heat is not lost but turned into increased system energy levels. 

The point of all that is that the best way for humans to heat themselves is through eating food. The next best way is through burning dried plant matter in an enclosed space. “Dried” because water dampens the heat release. Literally. Using renewables to heat a space is not very effective for a number of reasons, but it can be done. Solar panels can store the heat from sunlight (which is a massive burning ball of gas, throwing off so much transformational energy our planet is bathed in the waste heat). These panels are not the photovoltaic solar panels that are being thrown on roofs these days, but photo-thermic panels that were put up in the 1970s when people were still thinking clearly about addressing needs and not trying to profit from them. We had them on our roof when I was a kid. It was called the “solar attic” in my house; I don’t know if that was a general name even where they existed generally. Our solar attic did a fairly good job of warming the basement in our home. But we needed a wood stove to heat much of the rest of our rather vertical house.

A solar heat panel is basically a greenhouse with some mass that readily absorbs heat and some means of transferring that heat into the space that needs to be warmed. Water is most efficient as it absorbs quite a lot of energy, including heat, and is easily moved around. Over short distances, from rooftop to basement, very little of the stored heat is lost even in metal piping. But this is not practical over distances greater than a few meters. So you can’t put a solar heat panel farm in some centralized place and expect it to heat a home somewhere else. In other words it is impractical to centralize solar heat generation. Moreover, the construction of solar heat panels is pretty basic. As I said, it’s just a shallow greenhouse. A box that takes in solar energy and does not let it back out. Even I can build a basic solar heating panel. (And have…) So while it’s efficient at meeting the need for heat in small spaces and in climates that don’t need too much heating, it’s not a process that will generate “jobs” or profits.

When people are talking about switching to solar, they are not often talking about solar heat panels even when they are talking about heating spaces. They are talking about solar electric panels that turn sunlight into stored electrical capacity. In fact, most often they are talking about creating a centralized system of electricity generation that is supplied by solar panels and wind or water turbines. This system would use massive installations of collectors and wind/water turbines to create electrical flow that is then distributed through massive installations of metal cabling. Then the electricity is used in buildings to generate heat through electrical resistance, which is essentially restricting electron flow to increase pressure in the electrical stream. The resultant heat is either radiated directly into a space or, more often, transferred to some fluid mass that can be moved about the space. Usually fan-driven air in ductwork.

At all points in this this process energy (electrical charge) and heat are lost. Worse, turning electrical flow into heat is a rather destructive process. That heating is breaking down the conducting wire, the more so the hotter it becomes. This means not nearly as much heat can be created through electrical resistance as in burning a carbon-rich mass. So turning sun energy to electricity, transporting that electricity elsewhere, and turning that electricity into heat, waste energy is rather inefficient. Which might be fine if on balance it can do the job with less pollution than alternatives. This is true for fossil fuel energy systems; it is not true for burning plant matter. Turning electricity into heat is resource intensive and comparatively expensive over burning wood. The process also doesn’t generate as much heat overall, and much of the heat that is generated is lost before it can be used to warm a human body. This is not an effective path toward heating a space. (But it is an effective way to generate profit.)

Nonetheless, this is what is being called for when people say we need to move to renewables. I think many of these statements are evidence of desperation. There may be more involved. After all, some people would profit enormously if we chose to apply this solution to the problem everywhere. But I think most people are terrified and are turning to just anything that might work. We feel driven to do something. Now! “Here’s this technology solution. Let’s do that.” There is little logical analysis of either the problem or the solution. “Solar panels on every surface” seems like an easy fix as long as you don’t look too closely at the processes involved. Solar electric panels are great at generating electricity. That is not the issue though. What we need is heat. And solar electric panels are just shy of useless in heat generation. 

I might forgive the desperation if there were less sneering. Many of these recent exhortations to apply renewables to the problem of heat generation were written in response to burning other plant materials than coal, oil and natural gas. I saw two articles talking about pollution flowing from wood-burning stoves. There were numbers thrown out that aimed to show that wood stoves are dangerous and damaging. And yes, many are. Probably most older stoves are. But the point seemed to be that this method of heating a space was an unqualified bad, as bad or worse than burning fossil fuels, wherever it was adopted and however it was installed. And the authors made it sound like anyone who would do such a thing — when renewables are cheap! — was an ignorant peasant who desperately needed expert guidance.

Except they didn’t provide much guidance. They said, “Wood burning is bad; switch to renewables.” There was no attempt to say what sort of renewables, never mind analysis of how renewables could heat these homes. Or any homes. There were negative numbers, but no positives. 

Numbers and measurement are human inventions, approximations of reality, not reality itself. Numbers explain what we see, or what we want to see. Numbers are limited by human limits of knowledge and perception. But more significantly, numbers are limited by human choices. In this case, there were numbers to make it seem like wood stoves were bad, but there were no numbers to show that renewables are good (or at least not bad like wood stoves). This may have been sloppy reporting, but it may also be bias, conscious or otherwise. These writers very likely believe in the inherent and universal goodness of renewables. So in their minds, of course, renewables are the answer. No need for supporting numbers. No need to even define “renewables”. 

But “renewables” is not the universal answer. There is no universal answer. And that is the core of the heating problem, as well as the underlying problem in these articles on heating. The desperation we feel inclines us toward easy, quick and universal solutions — when there is not one problem, so there can’t be one solution everywhere. And some of these problems are not going to have solutions. (In my darker days, I think that’s true of most of our problems.) Heating spaces is certainly not the same problem everywhere. So how could “renewables” be the solution everywhere? Or… anywhere?

There are many problems with tossing up “renewables” for all the energy production that fossil fuels currently perform. I talked about the inefficiencies in turning electricity into heat, but there are more issues.

First we don’t have the infrastructure to heat spaces with renewables. Advocates will respond that — duh! — this is why we need to install solar panels. But the solar panels that turn sunlight to electricity are not turning that electricity into heat. So we need to install some sort of electric heater in addition to the solar panels. Which is not such an easy fix. It’s one thing to put flat panels on a roof and connect them to the building’s electrical wiring (though even that is difficult); installing a new heating system is a much more difficult proposition. Worse, there aren’t many heaters that use electricity because we’ve known for some time that electrical systems don’t generate heat as efficiently as burning does. Electric heaters always break down with use, and they quite frequently become overloaded, leading to electrical fires. We haven’t made many of these electrical heaters for very good reasons that are not going away just because now we want to use electricity to make heat.

So already the problem has grown in scope from throwing a solar panel on the roof to renovating the building interior with infrastructure that first needs to be manufactured. The problem now includes substantial construction and resource use and will generate waste before any solar panels are installed. But say that we figure out how to convert our various furnaces to electrical heaters powered by solar panels without generating a whole lot of mess and without using a substantial portion of our dwindling resources in the process. (Uh-huh.) Will solar panels then be the solution? Not everywhere.

Many of these writers seem not to consider that there are many different climates apart from the one they live within. The problem of heating varies substantially with geography — especially latitude. It takes far more energy to warm an interior space if the exterior temperature is 25°F than if it’s 45°F outside. It is not merely that there is more heating needed to make up the difference. It is that heat will dissipate quicker if there is a large temperature difference — a temperature gradient. It helps to picture it as an actual slope. Heat will flow down the gradient, from high heat (high energy) to low heat (low energy). Like flowing water, heat will move faster if there is a large gradient, a large slope. If it’s 25°F outside and 58°F inside, the energy in the warmer interior will find a way to get outside much more quickly than if it’s only a small gradient like 58°F inside and 45°F outside. Insulation is great and should be installed everywhere (because it also protects from excessive outside heat in places where that is a problem). But it won’t stop vigorous heat dissipation.

A colder climate needs more heat, both absolutely (raising the temperature more degrees) and as a result of greater heat dissipation flows (losing more of that raised temperature). This should be obvious but it doesn’t seem to be. There seems to be an assumption that it takes the same amount of energy to heat a home in Canada as in New York City where temperatures are 10-20° warmer on any given winter day.

And now consider that the flows of renewable energy are also climate-dependent variables. Wind and water turbines are limited to places where wind and water flow. These are so place-dependent that even unquestioning “renewables” cheerleaders often omit turbines from their discussions. But then they also ignore another glaring problems (see that?). Solar panels need to be exposed to the sun. During winter, when heat is most needed, there are few hours of sunlight. And of course, night happens as well, and it too is colder, driving up the need for heat production when there is no sun-created electricity flowing. Solar panels do not produce electricity for use in heating when heating is most needed. So energy collected from solar panels has to be stored somehow for use when the sun is not shining — which is not coincidentally also the coldest and, in climates like New England, the cloudiest time of the year. Yet even with storage there are places, like New England, that don’t get enough energy out of the weak sun that is occluded by clouds more days than not to ever generate sufficient electricity for heating a space 30-50°F over outside temperatures.

So how’s that quick fix looking now? We have to renovate structures to accommodate electric heat. We have to manufacture, perhaps invent better electric heaters, ones that don’t degrade quickly, definitely ones that don’t catch on fire. We have to make and install the solar panels and connect them to the building’s wiring, which at least involves cutting holes in the roof and the walls. We need to insulate so that any heat produced will be kept from flowing to lower temperature. We need a battery storage system to provide electricity at night and in cloudy weather. And we may still not be able to generate enough heat with the inefficient electrical heater to raise interior temperatures much more than 10-15°F above outside temperature.

Not so quick or easy, is it. In some places it is not a fix at all. And that’s not even addressing the last big concern I have with stating that “renewables” are universally good: few places can make and maintain renewable infrastructure. 

This should be obvious, but those that write from a position of superiority are often urbanites. And urbanites have a huge blind-spot that comes with being an urbanite. Everything in an urbanite’s world is imported from someplace else. This is necessary because a city can provide for zero human needs and actually creates more needs than a more dispersed population arrangement. (Rural people have far less need for waste disposal, for example, even at similar levels of consumption to urbanites, which itself is not normal.) So urban writers tend not to reckon on local resource availability. Nothing is local for them; they regard this as the baseline. But it is not and can not be in a future of increasing transport costs. The bulk of a community’s needs will need to be locally sourced. And this is simply not possible for photovoltaic panels. Even in communities that have the necessary skills and the manufacturing infrastructure. This is because these panels rely upon rare minerals that are found in sufficient quantity, density and accessibility to mine in only a few locations worldwide. So every place else in the world must import these minerals, in most places transporting them long distances, just to have the basic building blocks of a photovoltaic cell.

That’s the beginning of what is needed in this highly resource intensive manufacturing process. The end is much worse. These panels — and everything associated with them, from the heating coils to the batteries to the panel support frames — break down with use. And very few parts are actually renewable. Or even recyclable. A solar panel is the toxic trash of twenty years down the road. We don’t actually have the technology or the capacity to dispose of it. Our current method is to ship the waste to pile up “elsewhere”, meaning where people who have no power to stop us live. If there is research on a new method of disposal, I do not know of it. (Please, someone tell me there is…) But even so, if it does not exist at all now, it is not likely to be everywhere in the near future when the early-adapter roof-top solar installations need to be replaced. This is a dire need that can’t be met by nearly all communities. And, I think, it is a need that tips the balance away from using renewables to generate heat. There will be more resource use and more waste — more poisonous waste — produced than if heating needs were met with more localized solutions.

Like wood stoves…

Now, burning wood is not a panacea either. That’s the point. There is no one solution everywhere. Even so, we need improvements in wood burning that will fit within existing infrastructure. Better stoves. Better ways of producing and transporting wood fuel. Much better insulation. But burning wood to make heat in places that have long burned wood to make heat will be less resource-sucking and less polluting than using solar electric panels to make electricity that then makes heat. With increased gas recycling in wood stove design and community forests for locally grown fuel, a place like Vermont could produce all the heat it needs with very little resource use and even less waste. Wood stoves last quite a long time. And a well-managed wood lot is, in fact, a renewable resource. 

But all places need to look to their own resource lists and come up with ways to meet needs without importing stuff or exporting waste. In some places, like New Mexico, solar panels — solar heat panels, that is — are the perfect solution to heating needs. In others, there may be little need for heating other than the sun through windows as long as there is insulation. (Though one does wonder what summer is like in these places where it’s warm in winter.) One thing is certain: “renewables” is not the generic solution.

Those who give it don’t know what the problem is.

©Elizabeth Anker 2021

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