Why I Advocate Renewable Energy Sources

[lpetrich]

In response to bilby's thread on why he advocates nuclear energy, I have created this thread.

Why do I advocate renewable energy sources?

I advocate them because without energy we cannot do anything else, and also because I want for our industrial civilization to outlast fossil fuels and last as long as our homeworld remains habitable, if not longer. Like for as long as accessible parts of the Universe have usable energy. We will also need such sources as we exhaust the higher-grade ore bodies of various raw materials and become forced to extract such materials from ordinary rock, seawater, and garbage.

Renewable-energy sources are also good for avoiding the sort of climate changes that we are getting from using fossil fuels, climate changes resulting from increased atmospheric carbon dioxide and its resulting increased greenhouse effect. They do so by enabling us to maintain our lifestyle without spewing a lot of CO2 into the air.


I will be going into more detail in subsequent posts.

 

[steve_bank]

The problem is that large scale decentralization of electric power through home solar is a threat to the energy establishment.

Utilities in Ca and Hawaii stopped subsidizing home photovoltaics though buying electricity because it started to affect profits and rate structures.

If we put all the money spent on Iraq and Afghanistan to put solar on homes we could have forgotten about them.

 

[bilby]

In response to bilby's thread on why he advocates nuclear energy, I have created this thread.

Why do I advocate renewable energy sources?

I advocate them because without energy we cannot do anything else, and also because I want for our industrial civilization to outlast fossil fuels and last as long as our homeworld remains habitable, if not longer. Like for as long as accessible parts of the Universe have usable energy. We will also need such sources as we exhaust the higher-grade ore bodies of various raw materials and become forced to extract such materials from ordinary rock, seawater, and garbage.

Renewable-energy sources are also good for avoiding the sort of climate changes that we are getting from using fossil fuels, climate changes resulting from increased atmospheric carbon dioxide and its resulting increased greenhouse effect. They do so by enabling us to maintain our lifestyle without spewing a lot of CO2 into the air.


I will be going into more detail in subsequent posts.

So basically for the exact same reasons that I advocate for nuclear power - which, by the way, is also a renewable energy source.

We have the technology to extract uranium from seawater for a similar cost to mining it*; And the rate of accumulation of new uranium in seawater is greater than any conceivable demand for it. It's not 'renewable' in the most pedantic sense, but then, nor are wind, solar or hydro, if it comes to that. The resource will not be exhausted within a reasonable estimate of the lifetime of humanity on this planet.

I don't think we are really in disagreement; The main thing is to stop burning fossil fuels. Any technology which achieves that is good; It's just that nuclear is the best, by any reasonable measure, of the renewable options.








*http://scholar.google.com.au/scholar_url?url=https://www.nature.com/articles/280665a0&hl=en&sa=X&scisig=AAGBfm32i0MT3nHW39KSkEvPN_oDrpUQBg&nossl=1&oi=scholarr(paywall)
http://pubs.acs.org/toc/iecred/55/15#UraniuminSeawater
https://www.forbes.com/sites/jamesconca/2016/07/01/uranium-seawater-extraction-makes-nuclear-power-completely-renewable/

 

[lpetrich]

Renewable energy sources are not new. In fact, for most of the history of humanity, most of the energy that people have used has come from renewable sources. The main exception was coal burning in places like China.

The beginning of the end of this first era was the development in eighteenth-century Britain of practical steam engines and the resulting beginning of the Industrial Revolution. At the beginning of the eighteenth century, Britons were consuming trees fast enough to start mining coal as an alternative. Though trees are renewable, they can nevertheless be cut down faster than they can grow back. Thomas Newcomen invented the first usable steam engine around 1812, and Newcomen engines were used to pump water out of coal mines, improving on horse-driven pumps. Horses are powered by hay and the like, and those also are renewable. Around 1765, James Watt devised an improvement on the Newcomen engine, and late in the 18th cy., his engines became common. These engines and their successors were efficient enough not to need to be at coal mines, and they became used for powering factory machinery, and later, vehicles. So coal triumphed because of the deficiencies of premodern renewable sources.

It was James Watt who invented "horsepower", a unit of energy rate, as a way of promoting his engines. A 100-horsepower one would deliver as much mechanical energy as 100 horses. But horses would continue to be used to pull plows and wagons and the like until internal combustion engines became common.

Despite renewable sources becoming overshadowed by fossil fuels, one renewable source nevertheless became common: hydroelectric electricity generation. Though it can be cheap, it nevertheless requires big gravitational-potential drops, and it is not very feasible away from mountainous areas. Furthermore, most of the usable rivers are now dammed up, so it is hard to expand hydroelectric generation by very much. Hydroelectric generation is also vulnerable to drought -- lack of water -- and it disrupts rivers.


The beginning of the end of the fossil-fuel era was likely in the late 1970's, with efforts to develop alternatives to fossil fuels. The most successful ones so far have been wind turbines and photovoltaic cells. With increasing use and development, their prices have dropped dramatically to the point where they are competitive with fossil fuels for electricity generation. So we are in the beginning of the Second Era of Renewable Energy.

Consider Photovoltaic solar energy converters for space vehicles - Present capabilities and objectives - IEEE Journals & Magazine. From Google Scholar's blurb:

… Ibid., vol. 78, Nov. 1959, pp. 457-61. Photovoltaic Solar Energy Converters for Space
Vehicles—Present Capabilities and Objectives … Large-scale production of solar cells should
reduce the price of solar power delivered to below $300/watt …

Using the US Consumer Price Index, that is $2550/watt in 2018 dollars. Production costs are nowadays as low as 50 cents per watt and lower, though I found that the complete cost for installing solar panels in my area is about $4.50/watt. So by installation costs, it is a factor of 570, and by production costs, a factor of 5100.

 

[bilby]

The beginning of the end of the fossil-fuel era was likely in the late 1970's, with efforts to develop alternatives to fossil fuels mid 1950s, with the development of the first commercial nuclear fission reactors. This accelerated in the late 1970's, with efforts to develop alternatives to fossil fuels

FTFY.

Ignoring something that has a major role, but doesn't fit neatly into your narrative is not very intellectually honest. Nuclear power is comparable in size to hydropower for generating electricity today, and both of these make more electricity than all other renewable sources combined.

 

[DrZoidberg]

I will be going into more detail in subsequent posts.

I hope the detail includes some sort of mathematical model showing how it is theoretically feasible.

 

[bigfield]

How do you scale up renewables? To supply a country like Germany with 100% renewables, you need excess capacity and storage to maintain supply when generators are offline or generating a fraction of their capacity.

Can this be done with existing technology, and if not, how much longer until we have the technology? If we're still decades away from scaling up to country-wide supply, then renewables cannot replace fossils in time to combat climate change.

 

[bilby]

How do you scale up renewables? To supply a country like Germany with 100% renewables, you need excess capacity and storage to maintain supply when generators are offline or generating a fraction of their capacity.

Can this be done with existing technology, and if not, how much longer until we have the technology? If we're still decades away from scaling up to country-wide supply, then renewables cannot replace fossils in time to combat climate change.

Indeed. And no fair comparing costs on an 'installed MW' basis; The actual costs to consumers are the costs of the 'long-term rsupplied MW', after including all installation, maintenance, storage, transmission, and (where necessary) backup systems.

Cheap power, that's only available when nobody wants it, is not good value.

 

[DBT]

Rather than one or the other, the future will probably entail a combination of solar, wind, etc, along with Nuclear.

 

[fromderinside]

I think I'd reject any plant generated renewable source since they carry the same baggage as does fossil fuel. Solar cell technology is limited by rare earth availability, fresh water technologies have huge problems with ecosystems, and transmission is a problem for all given constraints one needs to impose to protect living systemes environments form waste and processing.

All that aside, there are workarounds for each in the offing I still think a human nature based argument is necessary for us to move forward. Mankind's recent bump into our tribal nature should convince most of that.

 

[bilby]

I think I'd reject any plant generated renewable source since they carry the same baggage as does fossil fuel. Solar cell technology is limited by rare earth availability, fresh water technologies have huge problems with ecosystems, and transmission is a problem for all given constraints one needs to impose to protect living systemes environments form waste and processing.

All that aside, there are workarounds for each in the offing I still think a human nature based argument is necessary for us to move forward. Mankind's recent bump into our tribal nature should convince most of that.

Plant based fuels are carbon neutral - Burning them only puts back into the atmosphere the same CO₂ that they absorbed when they grew.

The problem with fossil fuels is that they add CO₂ that has been locked away underground for millions of years, and so they increase the atmospheric CO₂ concentration in a way that plant based fuels do not.

Or do you mean 'plant' as in 'large industrial unit'? If so, then you are also wrong, for a similar reason - sure, it takes fossil fuel to build such facilities today, but not as much as is needed for smaller distributed units totalling the same capacity. And of course, the more renewable plants we have, the lower the carbon footprint due to future construction becomes. So the idea that such plants 'carry baggage' is rather like deciding that it's better to remain penniless than to pay for training to get a well paid job - it's shortsighted and idiotic.

So whichever sense of the word you intended, that you suggest that plant generated fuels carry the same baggage as fossil fuels rather suggests that you are currently unqualified to express any opinion at all on the subject. This is really basic stuff; If you don't know the basics, perhaps it would be wise to learn before you comment.

 

[fromderinside]

I refer to plant as living organisms that are used primarily as a fuel source. As far as I can tell fuel is a convenience. It is not in a fitness sense a necessity unless one takes the view that if we can do it it is necessary. So from that perspective fuel plants take away from food plants and atmosphere balance plants. Obviously fuel plants usurping resources from plants needed to maintain oxygen carbon dioxide and nutrition balance is not neutral.

If one argues that fuel provides more real estate available for food and atmosphere functions one then needs to account for where that gain in resource capacity is being increased. It's obviously mostly from northern regions where there is a trapped volume of increased carbon being trapped by climate as permafrost which when released produces huge changes in atmosphere heat trapping gases.

That must be taken into account when one suggests shifting resources or increasing resources to attain sufficient food and power.

Fuel plants are not carbon or themal trapping neutral.

 

[lpetrich]

I first wish to concede an aspect of solar electric generation that startled me. Some years ago, as I started getting interested in renewable energy, I thought that photovoltaic cells would never do as well as concentrated solar power, reflecting sunlight onto some spot to produce high temperatures. That was because PV cells are made using the same sort of technology as computer-chip making uses, and I thought that that would keep PV cells' prices high. But a few years ago, PV started becoming much more common than I expected, and I concluded from that that they do not need super high quality silicon. The more expensive and high-quality PV cells are made with single crystals of silicon, but less expensive ones are made with polycrystalline silicon or even amorphous silicon.


I now wish to address a common criticism of wind and solar energy systems: intermittency. That is indeed a problem, but that can be partially alleviated by having wind turbines and solar panels distributed over a large area. Wind turbines where wind is blowing can fill in for becalmed ones, and solar panels away from clouds can fill in for solar panels shadowed by clouds. That is only a partial solution, and that has led to intensive research into storage technologies like improved batteries.

The most commonly-used storage technology is pumped hydroelectric generation. It is often used with nuclear reactors, because nuclear reactors cannot be throttled very fast. The reactor pumps water uphill into a reservoir at night, and during the day, the water is let back down through turbogenerators, making electricity to supplement the reactor's electricity. This technique has a problem that is shared with hydroelectricity in general: the need for rugged topography to produce big height differences for making big gravitational-potential differences.

That is why are a variety of alternatives are currently being researched: improved lithium-ion batteries, flow batteries, compressed air in mines, even loaded railcars pulled uphill then allowed to go downhill.

But storage technologies have lagged behind wind and solar development, so the gaps are usually filled in by natural-gas "peaker" powerplants. These ones use combustion turbines, sort of like stationary jet engines. These can be adjusted with timescales of several minutes, making them useful for capturing peaks in demand. That is not as fast as hydroelectric generation or batteries, which can do it in seconds, but it is still fast enough to be widely useful. Peakers were originally developed to supplement steam-cycle powerplants like natural-gas combined-cycle ones (combustion turbines with waste heat powering steam turbines), coal ones, and nuclear ones. Peakers are often kept idling as "spinning reserve", like leaving one's car idling instead of stopping its engine.

But as utility-scale battery installations become more common, we will see less spinning reserve, and eventually fewer peakers.

 

[Politesse]

Scale is an insurmountable issue whenever anyone talks about converting the entire power grid to one source; we wouldn't be able to convert the entire grid to nuclear plants very quickly or cheaply either. But I think replacing carbon-emitting sources whenever feasible is a good idea, and one that has transformed rural economies for the better across much of my own nation. It seems patently obvious to me that we should take advantage of local environments when possible. It's logical to derive power from sun in sunny areas. It's logical to derive power from wind in consistently windy areas. The potential power is there whether you take advantage of it or not, so you might as well take advantage, especially given the relatively low cost of many of these solutions. It's illogical to ship coal out to an island that could easily supply its needs with tidal or geothermal energy. I understand using other means (yes, such as nuclear) in locations without any other feasible options, but I do not see it as ideal given the disposal crisis we're facing with the spent fuel. Were a better solution developed for that problem, I would be more comfortable with that option.

 

[bilby]

I first wish to concede an aspect of solar electric generation that startled me. Some years ago, as I started getting interested in renewable energy, I thought that photovoltaic cells would never do as well as concentrated solar power, reflecting sunlight onto some spot to produce high temperatures. That was because PV cells are made using the same sort of technology as computer-chip making uses, and I thought that that would keep PV cells' prices high. But a few years ago, PV started becoming much more common than I expected, and I concluded from that that they do not need super high quality silicon. The more expensive and high-quality PV cells are made with single crystals of silicon, but less expensive ones are made with polycrystalline silicon or even amorphous silicon.


I now wish to address a common criticism of wind and solar energy systems: intermittency. That is indeed a problem, but that can be partially alleviated by having wind turbines and solar panels distributed over a large area. Wind turbines where wind is blowing can fill in for becalmed ones, and solar panels away from clouds can fill in for solar panels shadowed by clouds. That is only a partial solution, and that has led to intensive research into storage technologies like improved batteries.

The most commonly-used storage technology is pumped hydroelectric generation. It is often used with nuclear reactors, because nuclear reactors cannot be throttled very fast. The reactor pumps water uphill into a reservoir at night, and during the day, the water is let back down through turbogenerators, making electricity to supplement the reactor's electricity. This technique has a problem that is shared with hydroelectricity in general: the need for rugged topography to produce big height differences for making big gravitational-potential differences.

That is why are a variety of alternatives are currently being researched: improved lithium-ion batteries, flow batteries, compressed air in mines, even loaded railcars pulled uphill then allowed to go downhill.

But storage technologies have lagged behind wind and solar development, so the gaps are usually filled in by natural-gas "peaker" powerplants. These ones use combustion turbines, sort of like stationary jet engines. These can be adjusted with timescales of several minutes, making them useful for capturing peaks in demand. That is not as fast as hydroelectric generation or batteries, which can do it in seconds, but it is still fast enough to be widely useful. Peakers were originally developed to supplement steam-cycle powerplants like natural-gas combined-cycle ones (combustion turbines with waste heat powering steam turbines), coal ones, and nuclear ones. Peakers are often kept idling as "spinning reserve", like leaving one's car idling instead of stopping its engine.

But as utility-scale battery installations become more common, we will see less spinning reserve, and eventually fewer peakers.

Nice handwave in that last paragraph. When is 'eventually'?

We cannot wait for some hypothetical new technology to be developed, and hope it becomes cheap enough to be practical; The best tome to slash CO₂ emissions was when the French did it forty years ago. The second best time is right now.

Those gas peaker units render intermittent renewables completely impotent to reduce emissions.

Lets do something that has been shown to be effective, rather than cross our fingers and hope that one day our wishes might come true.

Be like France, not like Germany. Emissions count. Good intentions merely pave a well known road.

 

[Treedbear]

...
That is why are a variety of alternatives are currently being researched: improved lithium-ion batteries, flow batteries, compressed air in mines, even loaded railcars pulled uphill then allowed to go downhill.
...

Now that's interesting. I would think raising a solid weight to some height could be done much more efficiently than pumping water. Anyone know the relative efficiency of the two concepts, assuming a more refined mechanism than using railcars per se? It should be possible to eliminate most of the frictional losses. And it would respond very quickly and be scaleable from large installations to individual households. How much weight would I need to lift to what height in order to generate 8 kwh electricity?

ETA- Never mind. My calculations show that I'd need to raise 323 tons to a height of 10 meters. Oh well.

 

[bilby]

Scale is an insurmountable issue whenever anyone talks about converting the entire power grid to one source; we wouldn't be able to convert the entire grid to nuclear plants very quickly or cheaply either. But I think replacing carbon-emitting sources whenever feasible is a good idea, and one that has transformed rural economies for the better across much of my own nation. It seems patently obvious to me that we should take advantage of local environments when possible. It's logical to derive power from sun in sunny areas. It's logical to derive power from wind in consistently windy areas. The potential power is there whether you take advantage of it or not, so you might as well take advantage, especially given the relatively low cost of many of these solutions. It's illogical to ship coal out to an island that could easily supply its needs with tidal or geothermal energy. I understand using other means (yes, such as nuclear) in locations without any other feasible options, but I do not see it as ideal given the disposal crisis we're facing with the spent fuel. Were a better solution developed for that problem, I would be more comfortable with that option.

I completely agree regarding diversity of options. Every technology likely has some part to play.

But your repetition of the myth that there is a disposal crisis with spent nuclear fuel I find deeply depressing. There is no such crisis. Spent nuclear fuel has never hurt a fly; It's the only power generation waste product able to make that claim; And our existing systems for handling it are already massively over engineered.

The nuclear waste 'problem' cannot be solved, for the same reason that the unicorn droppings problem cannot be solved - it doesn't exist.

https://thoughtscapism.com/2017/11/04/nuclear-waste-ideas-vs-reality/

 

[Politesse]

Scale is an insurmountable issue whenever anyone talks about converting the entire power grid to one source; we wouldn't be able to convert the entire grid to nuclear plants very quickly or cheaply either. But I think replacing carbon-emitting sources whenever feasible is a good idea, and one that has transformed rural economies for the better across much of my own nation. It seems patently obvious to me that we should take advantage of local environments when possible. It's logical to derive power from sun in sunny areas. It's logical to derive power from wind in consistently windy areas. The potential power is there whether you take advantage of it or not, so you might as well take advantage, especially given the relatively low cost of many of these solutions. It's illogical to ship coal out to an island that could easily supply its needs with tidal or geothermal energy. I understand using other means (yes, such as nuclear) in locations without any other feasible options, but I do not see it as ideal given the disposal crisis we're facing with the spent fuel. Were a better solution developed for that problem, I would be more comfortable with that option.

I completely agree regarding diversity of options. Every technology likely has some part to play.

But your repetition of the myth that there is a disposal crisis with spent nuclear fuel I find deeply depressing. There is no such crisis. Spent nuclear fuel has never hurt a fly; It's the only power generation waste product able to make that claim; And our existing systems for handling it are already massively over engineered.

The nuclear waste 'problem' cannot be solved, for the same reason that the unicorn droppings problem cannot be solved - it doesn't exist.

https://thoughtscapism.com/2017/11/04/nuclear-waste-ideas-vs-reality/

A myth? We have no long-term storage option. Our entire stock of the stuff is in "temporary storage" with no ultimate plan for what to do with it all. How is this a lie?

And I've seen the Yucca Mountain facility myself; the concerns about it are not imaginary. Even if, as your link claims, a failure of the facility wouldn't cause mass contamination of the countryside, a seismic event would still end its usefulness as a storage facility; you'd have to start over elsewhere, and the whole sixty year long debacle would hit reset.

 

[lpetrich]

I think I'd reject any plant generated renewable source since they carry the same baggage as does fossil fuel. ...

You mean biofuels, I'm sure.

The current generation of biofuels has a lot to be desired. One of the most notable ones is American-corn ethanol, used as an additive in gasoline. It has a great difficulty: the amount of energy one gets from it is close to the amount of energy one puts into it. Such a poor return on energy investment is tolerable for specialty fuels, like aviation gasoline, but not for broadly-used ones.

This ratio is called Energy Returned on Energy Invested (EROEI) or Energy Returned on Investment (EROI).

I've seen the theory that this is for building up a biofuels infrastructure, but so far, it has been an embarrassment.

However, improved sorts of biofuels have been researched.

One kind closely parallels corn ethanol but with a major difference. Instead of breaking down the starch in corn kernels, it breaks down the cellulose in nearly all of the plant. Though cellulose is a close chemical relative of starch, it is much more difficult to digest, and cellulose-digestion biofuels have barely gotten started. Cellulose digestion may use switchgrass as an input, harvested like hay, by mowing it.

Another kind is growing algae in vats and ponds, collecting it, and then baking it to make hydrocarbon fuels. That is still in an experimental stage, as far as I can tell.


Such preindustrial fuels as wood and dried dung are low-tech forms of biofuel, and fossil fuels are biofuels from long ago, buried and baked in our planet's crust. Most coal deposits are from the late Paleozoic, the Carboniferous and Permian, but coal has formed much less since then, due to cellulose-eating fungi and termites. Oil is formed from the remains of marine algae that did not decompose because the oceans were relatively warm, something that happened a lot in the Mesozoic. So a lot of oil is contemporary with the dinosaurs, though it was not dinosaur flesh itself.

 

[bilby]

...
That is why are a variety of alternatives are currently being researched: improved lithium-ion batteries, flow batteries, compressed air in mines, even loaded railcars pulled uphill then allowed to go downhill.
...

Now that's interesting. I would think raising a solid weight to some height could be done much more efficiently than pumping water. Anyone know the relative efficiency of the two concepts, assuming a more refined mechanism than using railcars per se? It should be possible to eliminate most of the frictional losses. And it would respond very quickly and be scaleable from large installations to individual households. How much weight would I need to lift to what height in order to generate 8 kwh electricity?

A tonne dropping a metre will get you about 10kW; do that every second for an hour , and you get 10kWh - less losses due to the efficiency of your turbine and other losses, you will get about 8kWh of usable electricity.

36 tonnes dropping 10 metres would do it; or 3.6 tonnes dropping 100 metres. (That's vertical metres - a 36 tonne railcar on a steep 1:10 incline will need 100 metres of track to drop the required ten metres).

The benefits of water are that it is easy to efficiently extract the power as electricity; and because it rains, some of the lifting is done for free by the sun. It's also possible to store billions of tonnes of water more easily than billions of tonnes of railcars. And you needn't manufacture water, it's just sitting around ready to use. Railcars need ore mined, smelted, cast, worked and fabricated, and then they need to be maintained to roll without increasingly large frictional energy losses; Water doesn't get less effective at flowing as it gets older.

Every house having a ten metre (30ft) crane with a 36 tonne weight on it isn't going to be anywhere close to as cheap or as practical as a pumped storage hydropower plant in the mountains.