LENR vs Solar/Wind, and emerging Green Technologies.

Only quoting our famous naturalist on observing the rapid disappearance of our natural world, Sir David Attenborough. Over-population id the only real problem facing the human race - we either expand to populate the stars or exercise effective birth control.

Quote from JedRothwell

Yes, it has zero carbon footprint, because new trees are planted, and the carbon is extracted from the atmosphere and put back into the wood. It is a form of solar energy.

If you do not plant enough new trees, and you end up reducing the total mass of wood on the continent, then this method adds to carbon in the atmosphere. You have to grow enough trees to equal consumption.

I grew up in a very rural area and for a long time when I was young we burned wood as our primary heat source. Having to split that wood with an axe, I remember quite well the amount used.

The problem with any "grown renewable source" is the time difference to grow the source and the time to burn it. A tree that was 25 years old may have lasted us a week at the most in cold weather. We had a fire burning 24 /7. It is very unlikely that renewable sources can grow as quickly as it is burned / consumed. Even corn, which is widely used in ethanol production, takes several months. Subtract all the energy used in tilling, planting, harvesting, transporting and then converting, one gets a very reduced amount of fuel, which would be burned/consumed in a much shorter time than it took to grow it.

And the immediate high volume release of carbon into the air, is not reduced in the same time frame by growing, which would still result in atmospheric carbon issues. Decades of growth consumed carbon is released in a matter of hours.

I believe it impossible to grow fuel sources quickly enough to meet consumption demand, including food. Renewables is a red-herring. Not that it unwise to use by-products or waste, but to say we can grow a significant amount of our energy does not seem a plausible solution.

Without much improved battery storage, cost, cycle life and clean disposal, solar and wind will only be a partial answer as well.

The lack of a realistic radioactive waste disposal system for nuclear fission does not make it a long term solution either.

So the planet's long term energy options seemingly are out of candidates unless something such as as LENR is found to be usable. (Or battery storage is exponentially improved upon)

Quote from Bob#2

The problem with any "grown renewable source" is the time difference to grow the source and the time to burn it. A tree that was 25 years old may have lasted us a week at the most in cold weather. We had a fire burning 24 /7. It is very unlikely that renewable sources can grow as quickly as it is burned / consumed. Even corn, which is widely used in ethanol production, takes several months

That only applies to burning wood from a few acres of land. With thousands of acres, or on a continental scale, the wood grows as quickly as you cut it. That is why lumber and paper production in North America do not reduce our total forest cover. They used to, but nowadays, lumber and paper companies grow trees as quickly as they cut them. They will never run out at present consumption rates. That is to say, one tree on average may grow only a meter or two per year, but with millions of trees, in one day, as much lumber grows as you get from hundreds of trees. For every ton of wood that is harvested, another ton is produced by photosynthesis, albeit over a large area. It takes about 15 to 20 years for a pine forest to grow from nothing to harvest. That is 20 times longer than it takes to grow wheat or corn to maturity, so you need to wait longer to harvest one acre, but overall the amount of photosynthesis and the mass of product grown per acre per day is the same as food crops.

https://edis.ifas.ufl.edu/fr159

In other words, when you grow corn on 2,000 acres of land, you harvest about 6,000 to 8,000 tons (U.S. tons) of corn per year, from all 2,000 acres. When you grow pine trees on 2,000 acres, you harvest 100 acres per year, and you get about 3,800 tons of wood. You might be able to harvest 133 acres (15 years growing time), giving 5,000 tons. It is in the same ballpark. Photosynthesis is about as efficient in all plants. Sources:

https://fyi.extension.wisc.edu…14/01/BuyingSellingCS.pdf

"On this basis, 'waist-high' corn 3-4 feet tall will yield about 3 to 4 tons per acre of silage at 30 percent dry matter."

https://www.nrs.fs.fed.us/fia/maps/nfr/descr/xlivebiohw.asp

"On average, by county, there are 38 tons of live hardwood tree biomass per acre of timberland."

Quote from Bob#2

Decades of growth consumed carbon is released in a matter of hours.

Not if you have thousand of acres. In that case, the trees overall grow as much in a matter of hours as you consume. Your comparison is like saying that a small stream cannot produce a significant amount of hydroelectricity. That is true, but when hundreds of streams flow into a large river, it can produce megawatts of electricity.

Quote from LeBob

No need to go back to timber fires.

Timber fires would not be used. It is like converting corn to ethanol. Chemical processes are used, a lot is left over (which is useful), and only the hydrocarbon fuel is burned. I do not think this would be a good idea, but you should not characterize it as a "timber fire." That is like saying we are burning huge piles of corn to run our cars on ethanol. Not directly, we aren't. Most of corn does not burn.

Quote from Bob#2

Subtract all the energy used in tilling, planting, harvesting, transporting and then converting, one gets a very reduced amount of fuel, which would be burned/consumed in a much shorter time than it took to grow it.

That is a problem with ethanol from corn, according to Pimentel & Pimentel, "Food, Energy and Society" p. 265.

Quote from Dr Richard

Over-population id the only real problem facing the human race - we either expand to populate the stars or exercise effective birth control.

With cold fusion we can reduce the impact of population on earth by 2 or 3 orders of magnitude, as I showed in my book. For example, by eliminating outdoor agriculture, and by using in vitro meat production, we could produce all of the field crops now grown in the U.S. in an area roughly the size of Greater New York City, with no pesticides and with hundreds of times less water.

Then we can always genetically modify plants to increase biomass yields - eg the hemp plant has been modified to produce very high levels of THC (by the Dutch) which is now proving to be medically useful, and even CBD levels (a natural tranquillizer) produced selectively at high levels in Colorado. So with the recent legalization it seems a prime candidate for biomass creation since the stems, leaves and roots could be dried and made into briquettes for heat production. Vast acreages are being planted as we speak to capitalize on cannabis sales so some enterprising company just needs to go round and collect the waste products. In colder climates as JR points out millions of conifers will always provide as steady biomass supply - and aside from that biomass fuelled boilers are becoming all the rage in the UK with government grants etc.

Be nice to have a fusion reactor though humming away in the basement to provide all our energy needs as well, but we're still not there yet. Energy production on the domestic level will never be a major problem, with a little intelligence and state subsidies. The major disappointment as far as space travel is concerned is that we are still reliant on H2 & O2 burn to reach orbit - which is OK as far as a bit of Musk & Branson-inspired space tourism is concerned but it won't be until we really discover how to harness fusion energy in a controlled way that we'll carry on being stuck in this boring neck of the Milky Way without faster than light travel. Sci-fi has advanced much further in ideas than Sci-fact, my favorite is the Culture series by Ian M Banks.

Quote from Bob#2

I grew up in a very rural area and for a long time when I was young we burned wood as our primary heat source. Having to split that wood with an axe, I remember quite well the amount used.

The problem with any "grown renewable source" is the time difference to grow the source and the time to burn it. A tree that was 25 years old may have lasted us a week at the most in cold weather. We had a fire burning 24 /7. It is very unlikely that renewable sources can grow as quickly as it is burned / consumed. Even corn, which is widely used in ethanol production, takes several months. Subtract all the energy used in tilling, planting, harvesting, transporting and then converting, one gets a very reduced amount of fuel, which would be burned/consumed in a much shorter time than it took to grow it.

And the immediate high volume release of carbon into the air, is not reduced in the same time frame by growing, which would still result in atmospheric carbon issues. Decades of growth consumed carbon is released in a matter of hours.

I believe it impossible to grow fuel sources quickly enough to meet consumption demand, including food. Renewables is a red-herring. Not that it unwise to use by-products or waste, but to say we can grow a significant amount of our energy does not seem a plausible solution.

Without much improved battery storage, cost, cycle life and clean disposal, solar and wind will only be a partial answer as well.

The lack of a realistic radioactive waste disposal system for nuclear fission does not make it a long term solution either.

So the planet's long term energy options seemingly are out of candidates unless something such as as LENR is found to be usable. (Or battery storage is exponentially improved upon)

Display More

As Jed says, massive commercial-scale planting works.

The way to think about it is that growing a tree for wood takes 20 years: but you can have very very large areas of growing forest untouched until needed.

Biofuel does work out, and it provides carbon-free energy that is available any time, similar to fossil fuels

https://onlinelibrary.wiley.com/doi/pdf/10.1111/gcbb.12013

However - is it optimal? Probably not. And to get storage from PV all we need is efficient electrolysis, H2 storage, fuel cells.

PV on its own for immediate power is a no brainer, it is clean and cheaper than all else (even now)

Solar power + storage has many different solutions, of which PV + batteries is just one, not the best for long-term storage but at the moment it seems optimal for daily (overnight) storage. I expect though that the equaltion tehre will chnage at some point unless batteries get much cheaper or things like flow batteries end up being effective.

There are so many technologies now being developed which have the potential for solving storage - we just don't know which will end up being cheapest.

THH

Quote from Dr Richard

Then we can always genetically modify plants to increase biomass yields . . .

This has been done. The best yields are with algae, which oil companies and others are bioengineering to make synthetic oil. The algae is grown in plastic bags of water. Overall efficiency to chemical energy is around 2%, as I recall. Photosynthesis is usually around 0.1% to 1%. However, 2% is dismal compared to PV solar electricity. PV now reaches around 20% with no need to convert from chemical fuel to useful energy. Algae and other biofuels were promising years ago, but I think they have been overtaken by solar and wind. Coal has also been overtaken, and so has concentrated solar power with mirrors. Progress in one technology will inevitably put an end to rival technologies.

Solar has other advantages. It can be used on rooftops, or in desert areas where food crops or timber cannot be grown. It does not compete for resources the way corn ethanol does. I once computed that the food value of the corn needed to produce a full tank of ethanol gas in an SUV is roughly enough to feed an adult for a year. In other words, every time you fill up your car with "all-green" ethanol, you are taking away a year's worth of food from someone. Since millions of people are starving, this is an obscene thing to do. Also, if Pimentel is correct, it takes more energy to produce the ethanol than you get out of it.

All in all, biomass energy is bad idea, except with things like agriculture leftovers or organic garbage-to-gas schemes. They can produce a little fuel. To get a sense of how much, think about how much organic garbage you throw away compared to the food you eat. The food provides ~2000 kCal per day, or 8.4 MJ. About as much as 200 g of gasoline. I suppose garbage has considerably less caloric value than the food, so that's about 100 g of gasoline, which is not much. Garbage is converted to fuel using thermal depolymerization, which has significant energy overhead. So if all garbage were converted to fuel we would get the equivalent of approximately 70 g of gasoline per capita, which is 0.02 gallons.

Quote from JedRothwell

Photosynthesis is about as efficient in all plants.

However, it varies tremendously with environmental conditions, such as the amount of sunlight, temperatures, water and fertilizer available. Sunlight alone is not the only controlling parameter. Cacti grow very slowly, despite being exposed to intense sunlight. Most of the sunlight is not converted into chemical energy.

As I said, efficiency can be improved with bioengineering. It can also be improved with ideal conditions in a food factory, for example by increasing the CO2 concentration in air, and by providing optimum lighting 24 hours a day. See my book, starting on p. 130:

https://lenr-canr.org/acrobat/RothwellJcoldfusiona.pdf

The money would be better spent on LENR technology. Heading for catastrophic failure like ITER, Boris.

Quote from Shane D.

For arguments sake, say LENR is proven an artifact. How many years will it be before all the green alternatives provide 50/75, and finally 100% of the planets energy needs?

Exclude nuclear fission plants from consideration. Not that I am against them, but just because I think they have been effectively politicized out as a solution.

2050 for 100% is quite achievable, allowing offsets. UK has signed up for that and may end up being even more aggressive. I'm not excluding fission since we are building a new one (may be more). But by then it may be we have better (cheaper) solutions for base load.

Quote from interested observer

A great episode of the West Wing way back when depicted a fierce squabble between wind advocates and solar advocates. People are inexorably tribal. Even people who claim to care deeply about “saving the planet” mostly care about saving it using their chosen solution. The nuke people say that wind and solar power are “useless”. And the LENR community seems to believe they have the only answer. And so it goes.

There are quite a lot of people, like all the power academics, who see a mix of renewables as necessary to try and make non-fossil grids sustainable with a relatively low storage cost.

Example: solar tends to be high when wind is low and vice versa.

Those people are the ones who actually inform policy.

Quote from Shane D.

It is experiences like that which make me doubt THH's optimistic forecast, of 100% renewables by the year 2050. Throw in NIMBY, inefficient government bureaucracies, costs, and I would be amazed if it happened in less than 50 years.

US is behind EU in popular awareness, way behind in political action, partly because of cheap shale oil and gas. But necessity is the mother of invention and when Trump goes it will catch up.

Extinction Rebellion and their like are here to stay - and no-one can ignore the next generation forever. (Not saying I approve of ER - they ask for too much - but they are a needed political recalibration after so many years of too little being done).

Quote from interested observer

A great episode of the West Wing way back when depicted a fierce squabble between wind advocates and solar advocates. People are inexorably tribal.

No power company executive would say that, nor would anyone with knowledge of energy. There is little or no solar energy in North Dakota, but there is tremendous potential wind energy. There is no potential wind energy in Georgia, but lots of solar. It makes no sense to say that one or the other is the best solution.

Quote from interested observer

And the LENR community seems to believe they have the only answer.

No one advocates cold fusion more than I, and I would never say that. That's absurd. Of course there are other potential solutions. Wind or solar in the U.S. alone, or in north Africa, could easily power the entire world, with hydrogen or synthetic liquid fuel. However, cold fusion would be hundreds to thousands of times cheaper when the technology matures, so it is a better alternative. See:

https://www.lenr-canr.org/acrobat/RothwellJcoldfusionb.pdf