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Solar Heliostats - Molten Salt - HVDC power transmission

I am becoming increasingly frustrated listening to all the talk about actions to achieve “carbon zero”.  So much talk, so little action.  My belief is that there is only one core solution - other initiatives including wind farms, PV panels, battery storage, nuclear etc. are all just side shows promoted by those with vested interests.

More than enough energy from the sun strikes the earth in one day to provide all the energy used by mankind in a year.  An international HVDC power transmission network could efficiently transmit power long distances - only 3.5% losses per 1,000km.  Molten salt can store energy for up to 10 hours, to be used through (relatively) conventional heat exchangers to drive alternators with steam turbines.

This would require cooperation between nations rather than the current game of “my targets are bigger than yours” favoured by politicians.  It might also need a commitment from all nations to pledge a percentage of GDP to build the network - rather like the NATO commitment of 2% of GDP, except that if the climate change arguments are to be believed, the whole world should be fighting the same war to save the planet.

I doubt that we can rely on politicians to take the necessary action before it is too late - their only time horizon is their next election.

15 Replies
broadgage
977 Posts

Not very keen on heliostats and molten salt as they appear to involve a lot of moving parts and thus potential for breakdowns.

PV modules by contrast have no moving parts and should produce power for decades with very little attention.

My view is that in the near term, that the UK should install wind and solar generation sufficient to produce say 110% of UK demand under favourable circumstances, export the surplus 10%

This would still require natural gas when wind and solar are lacking, but at at least reliance would be reduced. In the longer term we should move away from all fossil fuels including natural gas, but let us make a start by reducing gas consumption urgently.

You may find this site to be of interest with regard to renewable energy and climate change concerns. http://forum.powerswitch.org.uk/viewforum.php?f=53

Thank you for your reply.  To make myself clearer, I probably should have put more emphasis on the words “ONLY ONE CORE SOLUTION” – whilst virtually everyone continues to emphasise “in the near term”

I certainly agree, there are many other initiatives which have a part to play.  And PV panels are the front runner in my view.  I could debate the relative complexity of moving parts between heliostats and wind turbines – the latter being an extraordinary engineering achievement to reliably harness power from the fickle wind.

Given the unpredictability of wind we have fossil fuel burning power stations running at sub-optimal efficiency ready to pick up the slack when the wind dies!

The first two paragraphs of my post were as concise as I could make them. The last two paragraphs are the core of the message I wished to convey.

Gideon
48 Posts

I guess the key point is to transport solar power from where it's plentiful and quite reliable, to where it's not (here).

Is it more beneficial to use HVDC/salt or hydrogen (or some other chemical form of) transmission & storage? Have you or anyone worked up a case for it?

I guess you could even try it bilaterally UK/some Saharan nation? There's a fairly direct sea route for a cable or pipe. It would not be 100% reliable, but might make a big difference to gas consumption if it shifted solar availability significantly. Again, is there a worked case?

Thanks for your thoughts.  It would be good to do some comparative numbers and it may well be that a hydrogen pipeline is more cost effective than HVDV transmission.  HVDC losses per 1,000 km are compared to 6.5% for AC transmission.  So about 10% losses from the sahara to London with HVDC compared to 20% with AC - may not be worth the cost difference.  But it would be relevant to consider passing power both East and West from where it is light to where it is dark - Africa to North America around 10,000 km - where the benefit of HVDC really counts.  You'd still only lose 30% of the power.

Whilst a hydrogen pipeline may be less expensive to build and maintain, electricity remains the most flexible form of power and if one was to convert heat to electricity to hydrogen and back to electricity again I'm thinking the losses are cumulatively greater - but I haven't done the maths yet.  I could do with some help with this!

By way of illustration, 29% of the earth’s surface is covered in land. 20% of the earth’s land area is covered in sand, about 33% is desert.  More power from the sun strikes the earth in one hour than mankind uses in a year.  So by using/reclaiming 10% of the world’s desert for solar power generation would represent about 1% of the total surface area of the earth.  Allowing for a ballpark efficiency of only 10% covering just 1% of the earth’s land mass with solar power storage and electricity generating capability would provide all mankind’s power needs in 1,000 hours.  This may not be accurate but it's not an order of magnitude out!

Gideon
48 Posts

Not sure about the east-west aspect. The political aspects of placing “our” solar panels or their cables in, err, Russia or the Middle East sound like an unwelcome replay of a scratchy old record…. 

Adrian Girling: 

By way of illustration, 29% of the earth’s surface is covered in land. 20% of the earth’s land area is covered in sand, about 33% is desert.  More power from the sun strikes the earth in one hour than mankind uses in a year.  So by using/reclaiming 10% of the world’s desert for solar power generation would represent about 1% of the total surface area of the earth.  Allowing for a ballpark efficiency of only 10% covering just 1% of the earth’s land mass with solar power storage and electricity generating capability would provide all mankind’s power needs in 1,000 hours.  This may not be accurate but it's not an order of magnitude out!

I think the math is likely right. But getting it to work practically would mean that humanity agrees on a common project to help out all of humanity. Hasn't happened yet in 10,000 years of (occasionally) trying :-( It doesn't even work in the small, as those now living in Jersey know……

Back to quoting from my original post “the whole world should be fighting the same war to save the planet”.  I'd hoped we could leave politics out of this, but inevitably it raises its ugly head - and I do mean ugly.  The West really should be making friends with Russia whilst a competent strong leader is still in control - why the EU sabre rattles with Russia when we depend so much on their gas supply truly astonishes me.  We are facing a threat far greater than we have seen in the last 10,000 years - maybe it's finally time to come together.  

Adrian Girling: 
 

Back to quoting from my original post “the whole world should be fighting the same war to save the planet”.  ……. The West really should be making friends with Russia whilst a competent strong leader is still in control - why the EU sabre rattles with Russia when we depend so much on their gas supply truly astonishes me.  We are facing a threat far greater than we have seen in the last 10,000 years - maybe it's finally time to come together.  

You are presumably talking about anthropogenic climate change? To see what “mak[ing] friends” might entail, see Peter Stott's Hot Air, Chapter 4, for an account of a mission by a group of UK climate scientists under UK Chief Scientific Officer Sir David King to a (nominally) scientific meeting about climate change in Moscow in 2004. 

It is not clear how the problem gets solved by “mak[ing] friends” with people who deny there is a problem;  neither, evidently, was it clear to any British member of that delegation. 

There are general reasons of Realpolitik for this, no matter who is in charge in Russia. It has to do with their economy. 

Thanks Peter, I've just ordered the book online.  Yes, I'm talking about anthropogenic climate change.  I confess, in 2004 I was skeptical but I believe most skeptics are slowly coming around.  So if we can't rely on politicians to put together international cross-border systems how about lobbying large successful companies and wealthy philanthropists to put something together?

Adrian Girling: 
 if we can't rely on politicians to put together international cross-border systems how about lobbying large successful companies and wealthy philanthropists to put something together?

I think we can rely on some politicians, for example the lot about to become the German government. As far as wealthy philanthropists go, Bill Gates is already very much on board. His book “How to Avoid a Climate Disaster” is a surprisingly good and easy read as well as insightful (this is not a surprise, because he is actually putting money into ventures). He goes through all the technologies he thinks we'll need. He has a concept called a Green Premium. That is, %-wise how much (usually extra) it costs to do something carbon-neutral. Run your powerplant or car on biomass. Heat your home. Make concrete (you can't - making cement follows the laws of chemistry and there is a big “+ CO2” on the right side of the reaction formula). He uses it to classify the issues. 

Adrian Girling: 
 if we can't rely on politicians to put together international cross-border systems how about lobbying large successful companies and wealthy philanthropists to put something together?

Some more info came up this morning. Mark Lynas et al have performed a literature survey of (peer-reviewed) climate science since 2012. Their dataset contained 88,125 papers. They picked 3,000 of them randomly to examine (that is about 1 in 29). Four of those papers were implicitly or explicitly sceptical of anthropogenic global warming in their abstract. In addition, they used a sceptical-keyword search and found 28 papers that were implicitly or explicitly sceptical. 

They express this as usual as percentage+95%CI, but I don't think one has to. 28 out of 3,000 is tiny. Extrapolated to the entire corpus that would be 822 papers in 88,125. It is entirely feasible for a small research group to find all of those (using the Lynas technique), to see what they say, and thereby to summarise the entire peer-reviewed sceptical argument. 

It is also possible to scan that literature for later refutations of those sceptical arguments, where they have occurred.

Then, when anyone turns up on a forum such as this, or a political venue, with a sceptical trope, one can reply with (a) the original source of the contention; (b) a sourced refutation of it where one exists; or (b) a note that such a claim has not been made successfully in the established literature and a direct request for the reasoning that is supposed to establish this new piece of information. 

Even more interesting, one could relatively easily automate this. One would have a scientifically definitive bot that would authoritatively out-bot the bots :-)

https://iopscience.iop.org/article/10.1088/1748-9326/ac2966

Lynas M, Houlton BZ and Perry S, Greater than 99% consensus on human caused climate change in the peer-reviewed scientific literature, 2021, Env. Res. Lett. 16 114005.

Published yesterday, open access.

Politics, however, is way behind the science, at least in some places.

The general public does not yet understand how certain experts are, nor is it reflected in political debate. This is especially true in the US, where fossil fuel companies have funded a disinformation campaign that falsely suggests the science is not yet settled……

The paper cites a 2016 study by the Pew Research Center that found only 27% of US adults believed that “almost all” scientists agreed the climate emergency was caused by human activity.

Many senior Republicans continue to cast doubt…. 30 US senators and 109 representatives “refuse to acknowledge the scientific evidence of human-caused climate change”. 

https://www.theguardian.com/environment/2021/oct/19/case-closed-999-of-scientists-agree-climate-emergency-caused-by-humans

So politics really does have to catch up with science, at least in the US. (There is a sociopolitical phenomenon there, of course. You could write similarly about US politicians and Covid-19 and vaccination. Or, 2-3 decades ago, about tobacco and deadly disease.)

In Germany, where I live, I have met nobody who is the least bit sceptical about the phenomenon of anthropogenic global warming, although there are divergences of opinion on how fast we need to reduce greenhouse-gas emissions. There is a political party which will form part of the next government for whom this was their major election campaigning point (and, for example, they won all the central districts in my city in September's election. Nobody would have guessed such an outcome before the election).

In Britain, I am not sure anyone has surveyed MPs and councillors to find out who thinks what on anthropogenic climate change. It is surely time to do so. 

 

 

 

 

Thanks for sharing.  I spent nearly seven years living and working in Germany (Frankfurt, Freiburg, Nürnberg, Wuppertal) so I'm reasonably familiar with the way German people think and act - thoughtful, pragmatic and hard working.  I'm not sure if it's still the case, but their adoption of PV solar power with grid-tie inverters was way ahead of the rest of the world, encouraged by a comprehensive state subsidy which the UK chose to mimic for a while until it seemed to be costing too much money.  Sorry, but I don't have much faith in UK MPs and councillors - largely people who have a confidence to competence ratio way in excess of 1.00 and have failed at their chosen profession. 

In a nutshell, there is now more than enough evidence that something needs to be done urgently.  So much effort has gone into studying the problem without enough effort to come up with a solution.  Engineers can solve the problem but it needs money.

Gideon
48 Posts

Peter Bernard Ladkin: 
 

Adrian Girling: 
 if we can't rely on politicians to put together international cross-border systems how about lobbying large successful companies and wealthy philanthropists to put something together?

I think we can rely on some politicians, for example the lot about to become the German government. As far as wealthy philanthropists go, Bill Gates is already very much on board. His book “How to Avoid a Climate Disaster” is a surprisingly good and easy read as well as insightful (this is not a surprise, because he is actually putting money into ventures). He goes through all the technologies he thinks we'll need. He has a concept called a Green Premium. That is, %-wise how much (usually extra) it costs to do something carbon-neutral. Run your powerplant or car on biomass. Heat your home. Make concrete (you can't - making cement follows the laws of chemistry and there is a big “+ CO2” on the right side of the reaction formula). He uses it to classify the issues. 

Re “laws of chemistry and there is a big “+ CO2” on the right side of the reaction formula” 

Admittedly from memory, but isn't the CO2, that's discarded during manufacture of cement, effectively reabsorbed when it's deployed with water and left to set? Is that correct? 

Obviously still an awful lot of heat needed to make it though? 

Gideon: 
 

[PBL] “laws of chemistry and there is a big “+ CO2” on the right side of the reaction formula” 

Admittedly from memory, but isn't the CO2, that's discarded during manufacture of cement, effectively reabsorbed when it's deployed with water and left to set? Is that correct? 

Now you're asking – my last inorganic chemistry class was 55 years ago. 

Let's see, you heat calcium carbonate (in the form of limestone) and you get calcium oxide (cement) and CO2, in pretty equal proportions, I understand. That is, getting a tonne of cement produces also a tonne of CO2. (That is also what Bill Gates says on p104 of his book How to Avoid a Climate Disaster, Allen Lane Penguin Press, 2021.)

Let me assume that is so. You are suggesting that mixing a tonne of cement absorbs a tonne of C02? How could that be? There isn't that much C02 in the atmosphere surrounding your mixer! 

Gates does say, though (p109) that there are technologies being developed whereby recaptured CO2 is injected back into the cement at mixing/deployment time. He says this technique can get about 10% back in, but the company deploying it hopes eventually for 33%.

Gideon
48 Posts
So I looked it up, as I should have done initially. I was right and wrong. Modern, and common, cement nowadays is "hydraulic cement" and doesn't adopt atmospheric CO2 as it sets. So wrong. Older forms of cement, now known as "non-hydraulic cement", do indeed set by a chemical reaction capturing CO2, effectively the turning back into the limestone - Calcium Carbonate - it was made from. But these types are cement are little used nowadays (English Heritage perhaps). https://en.m.wikipedia.org/wiki/Cement

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