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Post by cyrilr on Apr 4, 2013 18:10:40 GMT 9.5
Solar hot water, I have my doubts about this. Usually hot water demand is fairly stable seasonally. Not a good match for solar. In fact, I need a lot more hot water in winter due primarily to lower feedwater temperature from the drinking water supply system (ie requires more heating to get to the required 35-55 degree Celsius that I need). This puts solar hot water at a disadvantage in my mind. The main advantage is how simple it is, in fact I understand that the power saved by not needing to heat as much water already makes it worthwhile in reasonably sunny places. But you will always need large amounts of backup power or fuel (methane/propane etc.). Whereas aircon could be standalone solar powered with >90% solar (with maybe 10% grid backup as emergency in odd hot-but-not-sunny weather). PV powering aircon is very simple. Making chilled water for thermal store is among the simplest and cheapest of tasks I can imagine. Aircon itself is much more complicated, yet that hasn't stopped rapid growth. Personal computers are extremely complicated, yet every home has one.
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Post by sod on Apr 4, 2013 18:24:12 GMT 9.5
Sod's rebuttal is that 70-80% fossil is acceptable. Whereas the climate scientists make it clear than 80% reduction is needed. Considering economic and population growth, we're talking about 90% reduction. Reality is that Germany is the world's biggest user of brown coal, the dirtiest type of coal. Oops! Never mind, be happy, look at the pretty solar panels. Denmark, the biggest champion of wind in Europe, gets a bigger percentage of its power from coal than almost any other European country. Oops! Nowhere did i say that 70% fossil is acceptable. I said that 30% renewables is becoming pretty easily achievable. And prices of renewable power are still dropping. You are bringing up problems that have no connection to wind or solar power. For example the use of brown coal in Germany is increasing, because of the failure of CO2 certificates. (too many have been handed out) Sod claims that my assertions are false, but provides no evidence or even claim that shows this is the case (or even that Sod has read my comment at all). i did provide evidence: reneweconomy.com.au/2013/how-rooftop-solar-is-reshaping-energy-market-in-s-australia-18272/sa_2008_td_time_of_day_averagethe peak is in the afternoon, if you do not restrict your view to households. Sod further asserts that I am wrong about industrial demand; apparently claiming that industries don't use power at night. Sod completely misses the point, as usual. So I will repeat: the issue is not peaking, it is total energy supply. PV and wind combined cannot supply the needed 90% reduction, therefore they are dangerous distractions. People like Sod use wind and solar as an excuse to not build nuclear plants, which is a recipe for failing on all climate targets. i did not claim that industry doesn t use power at night. and obviously solar PV is not a solution to night time power demand. But PV will cut deep into the much more relevant day time power demand. The best synergy so far that I can imagine is for solar to provide airconditioning in hot sunny regions, reducing peak demand, possibly with the help of some ice making air conditioning as buffer, and then the remaining demand is much more baseload so can be serviced with nuclear. Airconditioning is typically less than 5% of total grid demand, so a 5% solar, 90% nuclear, 5% fossil (preferably natgas) is probably a realistic option. yes, all hot places will benefit from PV solar. It will also decrease the impact of a major source of growing power demand.
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Post by cyrilr on Apr 4, 2013 19:27:54 GMT 9.5
Wow, PV will solve the 10% problem and in turn we require the other 90% to be mostly fossil fuels.
Renewables enthusiasts such as Sod will throw in the kitchen sink and still get no further than 20% renewable. 30% is not easily achievable at all, only countries that have large amounts of hydro (not easily expandable by a large factor) or excellent interconnections to fossil fuel powered neighboors or hydro neighbours, can do this. At great cost and not solving the 70% problem.
Sod keeps missing the main point and focusses on sideshows.
The main point is this. You cannot power a country on windmills and solar panels. You just cannot. You can try, as many countries have, and end up locked into fossil fuel "backup" - the understatement of the century - forever.
I don't know how to make this point any more dumbed-down than this.
You can never do just one thing in the world of energy. You can put in 30% wind+solar+other unreliables but the implication for the other 70% is that it needs to be exclusively flexible (inefficient) fossil fuel generation. How does that solve our problem?
We're currently at 31 billion tonnes CO2eq. We're rapidly heading towards 40 billion tonnes CO2eq, at a time that we need to cut back to under 5 billion tonnes CO2eq ASAP. We need 90% solutions not 20% distractions.
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Post by sod on Apr 4, 2013 19:53:46 GMT 9.5
Wow, PV will solve the 10% problem and in turn we require the other 90% to be mostly fossil fuels. 10% PV is an awful lot, do you understand that? why should the rest be fossil? You folks keep telling me, what great load following capacities new nuclear power plants have. you also keep telling me, how cheap they are. Your type of nuclear power plants should do very good in a scenario with high renewables! [quote author=cyrilr board=bncblogposts thread=389 post=2698 time=1365069474Renewables enthusiasts such as Sod will throw in the kitchen sink and still get no further than 20% renewable. 30% is not easily achievable at all, only countries that have large amounts of hydro (not easily expandable by a large factor) or excellent interconnections to fossil fuel powered neighboors or hydro neighbours, can do this. At great cost and not solving the 70% problem.[/quote] Connections to neighbours? these are a good thing. hydro storage? also good. you make it sound as if these were problems, not solutions! 20% is easy. 30% is becoming more and more easy, as several countries show by now. [quote author=cyrilr board=bncblogposts thread=389 post=2698 time=1365069474The main point is this. You cannot power a country on windmills and solar panels. You just cannot. You can try, as many countries have, and end up locked into fossil fuel "backup" - the understatement of the century - forever.[/quote] yes you can. This has been shown by multiple studies by now: this one is pretty recent: cleantechnica.com/2012/12/11/wind-solar-storage-could-power-full-electric-grid-cost-effectively-99-9-of-the-time-by-2030-report/here is a list of links: cleantechnica.com/70-80-99-9-100-renewables-study-central/read: "
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Post by cyrilr on Apr 4, 2013 20:43:44 GMT 9.5
All nonsense showing Sod has not understood or even read my comments.
Iceland is almost all hydro and geothermal, useful where they are available. Availability on a global scale is poor, these sources will never be able to provide majority of power (not to mention primary energy which is much bigger than just power). There's virtually no wind and solar in Iceland.
Denmark is among the biggest proportions of fossil fuels in the electric mix, plus among the most expensive in power of all European nations. Like the pinguin said, not a winner combination.
Denmark is well interconnected to countries with lots of hydro and fossil fuels. They can use these grids as fossil fuel batteries. Not applicable to a holistic approach where all of Europe, and indeed the world, must decarbonize.
Nicaragua, Uruguay: tiny countries not relevant to global energy picture, and again almost all that 90+% renewable is hydro not wind and solar. That is to say, not "new" renewables. There's almost no wind and solar in Nicaragua and Uruguay.
Good old hydro. Where would renewables people be without it?
Then there's biomass, which is very damaging (encroaching, obliterating ecosystems) to environments and very polluting compared to nuclear. Bad bad bad.
10% is not a lot. If I solve a problem 10% I haven't solved the problem well at all. If I fix my clients problems 10%, they will fire me for not solving their problems 90%. A 90% solution is often acceptable to my clients, because they realise getting the last 10% is often not cost effective.
If my glass of beer is 10% full, it's time for me to order another round or go home, not cheer at how full my glass is.
Sod proves my point, but he or she does not understand it yet. Wind and solar are marginal energy sources that are at best useful niche players in our energy transition, and at worst near complete distractions, which is very dangerous at our current predicament. We cannot delay further with false solutions.
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Post by cyrilr on Apr 4, 2013 20:49:33 GMT 9.5
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Post by anonposter on Apr 4, 2013 21:01:54 GMT 9.5
But you will always need large amounts of backup power or fuel (methane/propane etc.). True, but not as much as you'd otherwise need. It'd be a marginal contribution, but a useful one. Whereas aircon could be standalone solar powered with >90% solar (with maybe 10% grid backup as emergency in odd hot-but-not-sunny weather). Refrigerative aircon takes quite a bit of power, I doubt rooftop PV would be able to provide enough for it. PV powering aircon is very simple. Making chilled water for thermal store is among the simplest and cheapest of tasks I can imagine. To my knowledge that technology hasn't been deployed. Aircon itself is much more complicated, yet that hasn't stopped rapid growth. Personal computers are extremely complicated, yet every home has one. Personal computers also benefit from Moore's law, which almost nothing else does (air conditioning doesn't, nor do PV cells). Nowhere did i say that 70% fossil is acceptable. I said that 30% renewables is becoming pretty easily achievable. And prices of renewable power are still dropping. But what if you can't exceed 30%? We know that we could get ~80% nuclear if we need (France already did it) and that 100% hydro is possible, but we don't have enough rivers for 100% hydro everywhere. You are bringing up problems that have no connection to wind or solar power. For example the use of brown coal in Germany is increasing, because of the failure of CO2 certificates. (too many have been handed out) I thought it was because they closed carbon neutral power plants and wind and solar were unable to take over as the greens said they would. i did not claim that industry doesn t use power at night. and obviously solar PV is not a solution to night time power demand. So what are we meant to do on still nights anyway? 10% PV is an awful lot, do you understand that? It's nothing compared to 80% nuclear. why should the rest be fossil? You folks keep telling me, what great load following capacities new nuclear power plants have. you also keep telling me, how cheap they are. Your type of nuclear power plants should do very good in a scenario with high renewables! Whilst those bird blending and shiny panels would do better when paired with nuclear reactors, you could improve things even further by getting rid of the renewable crap. Hydro and geothermal (the two useful renewables), says nothing about wind and solar junk. Most expensive electricity in the world, and not very clean either. Second most expensive electricity in the world, also not very clean. They are aiming at, doesn't mean they'll come anywhere near reaching those targets.
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Post by trag on Apr 5, 2013 1:26:59 GMT 9.5
All nonsense showing Sod has not understood or even read my comments. Iceland is almost all hydro and geothermal, Denmark is among the biggest proportions of fossil fuels Nicaragua, Uruguay: tiny countries not relevant to global energy picture, Good old hydro. Where would renewables people be without it? Then there's biomass, which is very damaging Excellently well said. Sod is an archetypical example of the "green" renewables fanatic who is impervious to external input. I find it exhausting to mentally refute all his BS as I read it. I applaud you for having the skill and energy to refute it in writing and refute it well. That continuous wearing-down is one of the ways the unreliables crowd win the argument and destroy the ecology. They seem to have an infinite supply of almost-authoritative sounding lies mixed with a few misleading facts.
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Post by sod on Apr 5, 2013 4:53:17 GMT 9.5
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Post by anonposter on Apr 5, 2013 7:13:21 GMT 9.5
sorry, but you can not simply ignore my points. This one is a scientific study, showing that 100% renewables is possible. Far enough in the future that by the time 2030 comes along and 100% renewable hasn't happened and doesn't look like it will happen everyone will have forgotten it. you also only come up with the same lame excuses , like denmark has expensive electricity (everything is pretty expensive in Denmark!). How do prices compare with Sweden and Norway? This does not allow you to ignore the massive progress being made with wind and solar PV. Basically all that's happening with bird blenders is that they're making each of them bigger because wind energy is at the end of the technology lifecycle (i.e. obsolete). Solar they're focusing on reducing cost at the expense of efficiency but even if they could make the panels for free they'd still be too expensive because energy storage on the scale you'd need is still an unsolved problem. It also isn t you who can decide, which renewables count and which don t. look at Japan: it is only now moving back into geothermal power. No it's not, but it is a fact that hydro and geothermal are actually useful while wind and solar are expensive distractions, it is also a fact that we can't get all our energy from hydro and geothermal (only Iceland can do that). But renewable is a term we should really ditch as it does tell us anything about the properties of an energy source we actually give a s*** about.
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Post by edireland on Apr 5, 2013 10:28:44 GMT 9.5
It is worth noting that the Melbourne study indicates you can configure for reliable peak shaving or for maximum PV energy production, but not both.
Solar power produces most power when the solar flux is highest, which tends to occur around or shortly after midday.
Air conditioning demand scales by the integral of solar flux, which means it happens quite a lot later (around here temperature starts to peak at 3-4pm).
Which means that solar output is already falling off when air conditioning demand reaches its peak.
EDIT:
The Scottish 100% target excludes balancing. This means they just have to attract as much of possible of the mandated "renewable energy" capacity for the entire UK into Scotland.
They also appear to be close to abandoning the target.
It is possible to go for 100% renewables with internal grid balancing, but it would be insanely expensive because of the huge amounts of grid storage required.
Cover the country with pumped storage plants and battery banks.
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Post by anonposter on Apr 5, 2013 17:29:29 GMT 9.5
It is possible to go for 100% renewables with internal grid balancing, but it would be insanely expensive because of the huge amounts of grid storage required. Cover the country with pumped storage plants and battery banks. There are concerns over getting enough materials to make those battery banks at the scale we'd need for the entire planet, or even just the US and Europe.
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Post by sod on Apr 5, 2013 17:36:42 GMT 9.5
Basically all that's happening with bird blenders is that they're making each of them bigger because wind energy is at the end of the technology lifecycle (i.e. obsolete). That is plain out false. Wind power is growing exponentially. en.wikipedia.org/wiki/File:GlobalWindPowerCumulativeCapacity.pngand off-shore has not really kicked in yet... Solar they're focusing on reducing cost at the expense of efficiency but even if they could make the panels for free they'd still be too expensive because energy storage on the scale you'd need is still an unsolved problem. that is also completely false. If panels were free, we would have storage within a decade. (you do understand how hydrogen is produced? you do understand that hydrogen could be simply injected into our gas pipelines, as we are doing with "windgas" right now?)
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Post by Nuclear on Apr 5, 2013 17:52:08 GMT 9.5
A technically feasible option to store large-amounts of power over long periods of time would be the production of hydrogen or synthetic methane.
The round-trip efficiency is awful though and the cost per kWh of stored electricity would be staggering.
Another important question is, how much electricity can variable renewable energy sources effectively provide without storage (but backup by natural gas) given a normal demand profile.
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Post by sod on Apr 5, 2013 20:01:25 GMT 9.5
A technically feasible option to store large-amounts of power over long periods of time would be the production of hydrogen or synthetic methane. True. And the costs would not matter, as ina "free solar panels" scenario negative prices would PAY for it. this is a good question. And the paper by Graham Plamer gives an answer: (page 5 of the pdf) and i basically agree with Graham on those numbers.
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Post by anonposter on Apr 5, 2013 20:24:06 GMT 9.5
That is plain out false. Wind power is growing exponentially. Or maybe it's a sech function. The bubble will burst sooner or later, hopefully sooner. If panels were free, we would have storage within a decade. That is not something that can be backed up as we do not know of a technology that could do the job on the scale we need it to even if PV were free. (you do understand how hydrogen is produced? Steam reforming of methane, it's hardly a carbon neutral process. you do understand that hydrogen could be simply injected into our gas pipelines, as we are doing with "windgas" right now?) The gas pipelines aren't designed to handle hydrogen. the article above speaks of a potential of 23 GW geothermal in Japan. This could replace half the nuclear power plants (or more than half of their coal power) This is significant. Actually it isn't though it'd be helpful (≈15% or so of their electricity). Though that article also notes that most of their potential geothermal power is in national parks and also notes that there are impacts on the environment from it (hot spa resorts won't like it). True. And the costs would not matter, as ina "free solar panels" scenario negative prices would PAY for it. If the solar panels are consistently offering negatively priced electricity then even free solar panels will be losing money unless government is stupidly paying for their electricity.
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Post by edireland on Apr 5, 2013 22:51:35 GMT 9.5
Offshore wind's capital costs have been shown to be >$10,000/kW.
I believe a project in the UK came out with a capital cost of >$25,000/kW.
And then there are the huge maintenance costs of having your plant in the middle of the sea all winter to consider.
"Exponential Increase" may be occuring, but that is because the whole industry is like an opium addict who has been put in charge of a drug dispensary. The whole thing is just a giant subsidy junkie.
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Post by Graham Palmer on Apr 6, 2013 9:19:52 GMT 9.5
One of my key findings was that the "extended EROI" of PV drops below the minimum useful threshold when broader boundaries (storage, distribution etc) are included, thereby essentially disqualifiying PV from a primary energy role with current technology and the sort of technology likely to be available in the foreseeable future. It would be interesting to get some feedback from BNC readers on this topic.
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Post by Pete Bergs on Apr 6, 2013 10:06:43 GMT 9.5
Having had a simple thermosyphon solar HW system on my roof in Brisbane AU for the last 16 years, I can peronally attest to it's efficacy. ;D
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Post by Graham Palmer on Apr 6, 2013 16:01:05 GMT 9.5
Pete, good point. When I was in China, I saw thousands of these, and particular in regions that experience electricity blackouts, they provide more reliable hot water. The basic difference with PV of course is that low-grade heat is relatively easy and efficient to both collect and store in one neat package and highly suited to domestic use.
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Post by edireland on Apr 6, 2013 20:32:37 GMT 9.5
Israel requires solar hot water equipment on pretty much all new homes I believe.
They will probably require a "warm water" tank for boiler feedwater to work properly in temperate climes though.
Looking at the price of systems in Israel, even adjusting for insolation differences you can see that systems in most of the west are very very expensive.
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Post by cyrilr on Apr 7, 2013 1:02:53 GMT 9.5
Sod seems to think that electrolysis equipment and hydrogen storage and handling equipment, not to mention the many safety equipments, are all free.
That just shows how clueless Sod is about the engineering and business side of this. The operations and capital cost of the electrolysis equipment, storage, pipelines, safety cost etc. is higher than the cost of generating electricity with conventional sources.
In other words, even if PV would be free - another absurd notion since PV is the least productive and one of the most costly of all energy sources - we would still not generate a majority of our power with PV+hydrogen energy storage.
That doesn't stop people like Sod from making shotgun statements about a flurry of subjects that Sod is not the least qualified in.
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Post by David B. Benson on Apr 7, 2013 10:54:46 GMT 9.5
Graham Palmer --- Earlier, so one some other, older thread I worked out the economics of a grid mostly powered by NPPs but with enough solar for 30% of daytime demand (just around noon, you know what I mean). The storage component was thermal stores hung on the NPPs; this is much less expensive than batteries. But 30% was the maximum solar PV penetration before overall costs began to climb again.
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Post by cyrilr on Apr 7, 2013 17:11:26 GMT 9.5
Graham Palmer --- Earlier, so one some other, older thread I worked out the economics of a grid mostly powered by NPPs but with enough solar for 30% of daytime demand (just around noon, you know what I mean). The storage component was thermal stores hung on the NPPs; this is much less expensive than batteries. But 30% was the maximum solar PV penetration before overall costs began to climb again. If you have thermal store on the nukes, use that with an extra turbine on the nuke site for peaking. Skip the expensive and undependable PV, just add a cheap turbine. I looked at this for a molten salt fuelled or cooled reactor; simply enlarge the third nitrate salt loop and store in a big insulated tank. This is very cost effective for half a day of storage (which is all you'll need in a nuclear grid).
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Post by sod on Apr 7, 2013 17:15:33 GMT 9.5
Sod seems to think that electrolysis equipment and hydrogen storage and handling equipment, not to mention the many safety equipments, are all free. That just shows how clueless Sod is about the engineering and business side of this. The operations and capital cost of the electrolysis equipment, storage, pipelines, safety cost etc. is higher than the cost of generating electricity with conventional sources. In other words, even if PV would be free - another absurd notion since PV is the least productive and one of the most costly of all energy sources - we would still not generate a majority of our power with PV+hydrogen energy storage. the general consensus on this board is, that PV solar is absolutely useless. (right up to the completely absurd statement by Anon above, in which he claims that even free PV solar panels would still be too expensive and that storage is an unsolved problem, which it is not) every time i show specific examples of advantages of solar, people have to admit that PV solar makes sense under certain conditions. without grid (most admit this fast), in high price scenario (the anthony watts example in california), with air conditioning (south australia) and so on. But this doesn t change the basic opinion of many here at all. they still keep making their false claim, that PV (apart from offgrid) is useless. Even the Graham Palmer paper (page 5 of the pdf) gives the number of 5% PV solar power which can be easily accomodated into the system. (and this is a pretty high PV penetration, which only very few countries reach today) on hydrogen storage, i found two papers giving numbers within a few minutes. page 16 of this pdf shows a cost comparison between a wind turbine and the necessary electrolyzer to limit overspill. it looks like with free PV solar, we would could store power at the cost of wind power, which is the cheapest today. www.nrel.gov/hydrogen/pdfs/48360.pdfthis pdf shows costs and target costs of hydrogen storage by kW and kWh. The costs are high, but this is not an unsolved or unsolvable problem. www.hydrogen.energy.gov/pdfs/htac_june2011_renewables_wg2.pdfPS: the german gas grid can take up to 5% hydrogen. some time ago it could take 50%. so storage is not a problem at all.
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Post by never again on Apr 7, 2013 18:03:28 GMT 9.5
One of my key findings was that the "extended EROI" of PV drops below the minimum useful threshold when broader boundaries (storage, distribution etc) are included, thereby essentially disqualifiying PV from a primary energy role with current technology and the sort of technology likely to be available in the foreseeable future. It would be interesting to get some feedback from BNC readers on this topic. i would be interested in such a discussion. But i still do not know, about what level of penetration you are talking about. In short, i think you are comparing apples to oranges. www.mdpi.com/2071-1050/5/4/1406For example on page 13 of the pdf, you are using extremely strict standards for the lifetime of PV solar moduls. But at the same time you are comparing costs to actual costs of running plants, most of which are far beyond their lifetime.
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Post by sod on Apr 7, 2013 18:07:13 GMT 9.5
sorry, last post was mine. Had to reenter catcha phrase and hit the wrong box...
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Post by Graham Palmer on Apr 7, 2013 19:06:56 GMT 9.5
i would be interested in such a discussion. If you look at figure 10, the "extended ERO" drops siginificantly with a small amount of storage, and since storage is essential, it follows that the EROI drops below the minimum useful threshold to permit PV to provide surplus energy to society (which is the whole point of energy systems). The penetration matters but storage essentially overwhelms the other factors.
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Post by Graham Palmer on Apr 7, 2013 19:13:47 GMT 9.5
Earlier, so one some other, older thread I worked out the economics of a grid mostly powered by NPPs but with enough solar for 30% of daytime demand (just around noon, you know what I mean). The storage component was thermal stores hung on the NPPs; this is much less expensive than batteries. But 30% was the maximum solar PV penetration before overall costs began to climb again. I think there is value in exploring nuke for baseload and PV (with storage) for network support in grids (like in Australia) that have summer peaks. But it will require improvements in battery technology. I'm not sure about your suggestion for a synergy between NPP thermal storage and solar. I'd argue that the strength of PV with inbuilt storage (or nearby storage such as on concrete pads next to distribution transformers) is that it is embedded within the low-voltage network.
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Post by Graham Palmer on Apr 7, 2013 19:26:27 GMT 9.5
on hydrogen storage, i found two papers giving numbers within a few minutes. Hydrogen fuels cells were used in the Apollo space missions of the 1960s, and hydrogen was until recently being used in the Space Shuttle. You can go to Jaycar today and buy a kit car with hydrogen electrolyser and fuel cell. The technology exists, that is not the issue. It has low round-trip efficiency, electrolysers are expensive, fuel cells are expensive and short lived, hydrogen is impractical to store and transport, etc. Maybe all of the issues will eventually be resolved but they are not trivial. There is no lack of optimistic researchers who are waiting for their next research grant that need to spruik the benefits of hydrogen. Read Eisler's historical account of fuel cells which I cite (email me if you want a copy).
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