Energy Return on Energy Invested for Solar PV

Calliban · 2024-04-03 12:39:52

Recent discussions with Spaniard have raised scepticism over the accuracy of EROEI calculations for solar projects. In particular, there is controversy over a study carried out by Prieto and Hall that calculated an EROEI of 2.45 for solar power in Spain as of 2008. I have therefore decided to carry out screening calculations to determine if these results are overly pessimistic. The study I carry out here is not a complete EROEI study, as I can only base the analysis on the embodied energy of raw materials. I cannot account for additional energy consumed in machining and manufacture. I can account for transmission losses, but cannot account for the embodied energy of transmission infrastructure. Nor can I account for embodied energy in energy sinks like roads. I cannot include the embodied energy of labour, nor can I quantify energy costs associated with maintenance in service. So the values of energy out / energy in, will inevitably be greater than the actual EROEI. But these calculations should provide a bounding value from which we can evaluate Prieto and Halls' work. They should also allow some discussion of how EROEI can be improved and where effort should be concentrated.

Other assumptions: (1) Polycrystaline solar cells are assumed, with efficiency 13 - 16%. (2) Solar project lifetime is taken to be 25 years. (3) Solar panel age related degradation is 0.5 - 0.8% per annum. An average of 0.65% is assumed. This means that a solar powerplant will have 83.75% of its BOL capacity after 25 years. Assuming that decline is linear, average capacity over whole life will be 0.9188 BOL.

I begin with this reference, which gives the approximate quantity of materials needed for a 1MWp PV powerplant.
https://solaredition.com/raw-materials- … lant-2017/

The quantities involved are:
Glass: 70,000kg
Steel: 56,000kg
Concrete: 47,000kg
Aluminium: 19,000kg
Silicon: 7000kg
Copper: 7000kg
Plastics: 6000kg

The reference doesn't give any details on the efficiency of the PV panels at beggining of life. This is important because a lower panel efficiency will require a greater surface area of panels to achieve a 1MWp power output. The quantity of supporting materials needed will therefore by inversely proportional to efficiency. Polycrystaline PV cells have substantially lower cost than monocrystaline and they tend to dominate the market sales for PV. I am going to assume that the quantities above apply to an average plant with 14.5% efficiency. I then calculate a range of values.

For the embodied energy of materials, I rely upon Wikipedia, which is quoting work carried out by University of Bath (UK).
https://en.m.wikipedia.org/wiki/Embodied_energy

The following embodied energy data is extracted from the reference:
Glass: 15MJ/kg
Steel (low alloy): 20.1MJ/kg
Concrete: 1.11MJ/kg
Aluminium: 155MJ/kg
Copper: 42MJ/kg
Plastics (PVC): 77.2MJ/kg

Multiplying the embodied energy values by the quantities above, gives a total of 5,929,970MJ embodied energy, excluding silicon. The embodied energy of polycrystaline silicon is listed as 4070MJ/m2. A 1m2 panel that is 14.5% efficient will generate 145W under full sun. We therefore need some 6897m2 of panels for out baseline plant. This adds an energy cost of 28,068,966MJ. Total embodied materials energy for our baseline plant is therefore 33,998,936MJ. If solar panel efficiency is higher than 14.5%, then embodied energy will be proportionately reduced. If lower, they will increase. On this basis embodied energy can be expressed as:

Eb = 30,811,536 - 37,921,890MJ.

The electrical energy yield (Ey) of the plant is a function of capacity factor. This is primarily driven by local environment, but there will inevitably be downtime for maintenance. I am going to express capacity factor as a product of the availability (A) (initially assumed as 1.0 i.e. 100%) and time averaged insolation (I), such that Fc = A x I. Age related degradation factor (Fd) is 0.9188. Power conversion losses are the losses that occur up until power enters the busbar of the grid. These are DC conductor losses, inverter losses and AC cable losses. From the below reference, I estimate these to be about 5%, given Fl of 0.95.
https://www.solarempower.com/blog/10-so … el-output/

Putting these factors together, allows the energy yield of the plant to be calculated of 25 years:

Ey = 1MJ/s x (3600 x 24 x 365.25 x 25) x Fc x Fd x Fl = 788,940,000.Fc.Fd.Fl

Insolation in Spain varies from 1600 - 1800kWh/m2/yr. In Britain, insolation is 700-1000kWh/m2/yr. This gives a weather induced capacity factor range of:

I = (1600 > 1800)/(1 x 24 x 365.25) = 0.1825 - 0.205 for Spain. For the UK, the range is 0.08 - 0.1141.

Solving for these values gives a total energy yield of 125,675,736 - 141,170,005MJ for Spain and 55,090,733 - 78,573,159MJ for UK.

Now to calculate net energy return. Assuming a 13% panel efficiency.

For Spain: Ey/Eb = (125,675,736 > 141,170,005MJ)/(37,921,890) = 3.31 - 3.72
For UK: Ey/Eb = (55,090,733 - 78,573,159MJ)/(37,921,890) = 1.45 - 2.07
Assuming 16% panel efficiency:
For Spain: Ey/Eb = 4.07 - 4.58
For UK: Ey/Eb = 1.78 - 2.55

Discussion:
The embodied energy analysis carried out above fails to include a great many of the energy costs that were accounted for by Hall and Prieto. No account is taken of transmission embodied energy costs, maintenance energy costs, downtime, labour, transportation, wastage or the energy used in fabricating components from materials. Even so, Ey/Eb is <5.0 in the best locations in Spain and <3.0 in the best locations in UK. Accounting for other energy costs, an average EROEI value of 2.45 for all solar projects in Spain would appear to be quite plausible. For the UK, it is entirely possible for EROEI to be <1.0 in northerly locations, i.e. an outright energy sink.

Last edited by Calliban (2024-04-03 12:51:51)

tahanson43206 · 2024-04-03 12:43:43

This post is reserved for an index to what I hope will be ** very ** interesting posts on an important subject.

Best wishes to all embarked upon this journey.

While the focus will be on Earth, it seems to me that Mars is a likely environment for significant development of solar power, in addition to nuclear fission and eventually fusion.

Life on Mars will require lots of energy.

Index:
Post 35: A solar thermal plant looks like a far more workable solution than a PV plant.
Sodium nitrate has a melting point of 308°C and a heat of melting of 197KJ/kg.
Calliban: http://newmars.com/forums/viewtopic.php … 62#p221362

Update 2024/04/07 Post by kbd512: http://newmars.com/forums/viewtopic.php … 60#p221460
This post provides detailed comparisons of solar thermal, PV and nuclear power generation methods.

Update 2024/04/08 Post by kbd512 http://newmars.com/forums/viewtopic.php … 07#p221507
This post provides a snapshot of "SkyFuel" which is reported to be working on a solar trough energy collector

(th)

kbd512 · 2024-04-03 13:48:14

How to Destroy The Myth of Cheap Wind and Solar - If Wind and Solar Are So Cheap, Why Do They Make Electricity So Expensive?

Pictures > Words (only for people who can't be bothered to read)

Calliban · 2024-04-03 15:12:13

One outcome from this energy balance study that surprised me - the energy cost of the polysilicon PV material accounts for 82.5% of total embodied energy of all materials in the plant. The aluminium, copper, steel, plastic and concrete, all add up to less than 1/5th of the total embodied energy. I knew that making semiconductor grade silicon was energy intensive. But I wasn't expecting it to be quite so much. It does suggest that if future technologies can reduce the amount of energy needed to produce the PV material, we could see some significant improvements in PV EROEI. Thin films might be a way forward.

The study does give me some confidence that solar thermal power could provide a better way forward. A trough mirror can concentrate solar heat onto an oil containing tube, heating it to temperatures up to 400°C. The boiler temperatures probably won't be high enough to superheat the steam, but even a wet steam cycle can generate with a 30% efficiency. The solar troughs will scatter some solar radiation away from the tubes and the hot tube will also radiate heat. Even so, overall capture and conversion efficiency should rival monocrystaline PV. But the heat tubes and troughs are simple steel shells, with micron thin aluminium coatings on the steel trough plates. This gives me confidence that overall embodied energy per m2 of collector should be a small fraction of what was calculated for PV. Solar thermal has another rather huge and unappreciated advantage. It collects energy as heat. Heat can be stored in really cheap bulk materials. A phase change material like a salt, will have comparable energy storage density to a chemical battery. But it will be orders of magnitude cheaper and far less energy intensive to produce.

Last edited by Calliban (2024-04-03 15:27:30)

Calliban · 2024-04-03 17:51:01

Terraformer raised an interesting idea a couple of days ago about using diurnal temperature variations to generate power. The US rocky mountains have some of the highest daily temperature variations in the world - up to 20°C across the day. During the heat of day, a flat plate collector could reach 80°C. At night, atmospheric temperature woukd drop down into the 20s. So a simple flat plate collector with normal soda lime cover glass could exploit a 60°C temperature range in summer months. The hot and cold could be stored in water tanks, allowing 24/7 generation.

An estimate of Carnot efficiency: n = Th - Tc / Th = (350 - 290) / 350 = 17.1%.

Maybe a vapour cycle could get a 10% efficiency. This is only 2/3rds the efficiency of polycrystalline PV panels. But the embodied energy of flat plate panels would be much lower. We could actually cast the panels out of concrete, with cooling channels actually cast into the concrete. The cover glass sheet would slot onto the top of each concrete panel and would be glued into place using silicone rubber. The concrete panels would be angled according to latitude, by placing them on soil berms, which would also provide insulation to the back of the panel. The exposed concrete can then be painted with pitch to keep water out.

One way of achieving an even greater temperature rise would be to sit a field of these panels atop a reservoir, which would be covered with a thick layer of soil. During winter months when temperature is beneath freezing, we use the panels to dump heat, freezing the reservoir to a depth of several metres. During summer months, the panels would reach 80°C during the day. The reservoir woukd serve as a heat sink with a constant 0°C temperature.

An estimate of Carnot efficiency: n = Th - Tc / Th = (350 - 273) / 350 = 22%.

The embodied energy of the reservoir would not be trivial. So this kind of project only works if we are really building for the long term. That is to say building infrastructure that we intend to use for a century or more into the future.

Last edited by Calliban (2024-04-03 18:03:13)

kbd512 · 2024-04-03 17:57:19

When cost to the consumer doesn't matter, materials consumption and embodied energy doesn't matter, and EROEI doesn't matter, we're de-facto admitting that only our belief about what we're doing matters, and any piece of evidence or data that doesn't support the conclusion we've arrived at is wrong or irrelevant. This can absolutely be true of religion, politics, or personal likes and dislikes. Unfortunately for us, it's not true for any long-term sustainable energy generating and storage system. Take away the subsidies or the literal mountains of coal that backstops all of it, and this silly emissions shell game falls on its face in most places on Earth. Can it provide some marginal return to reduce coal and gas demand? If it's intelligently deployed, then I believe it can. The problem arises when every problem looks like a piece of coal and every solution looks like a wind turbine or solar panel or battery.

We have people complaining today that energy costs too much to be affordable, there's too much material consumption and pollution, but we're going to switch to a new metals-based energy system that outright demands 10X to 1,000X more materials consumption per Watt-hour of electricity generated, but we're not going to have any over-consumption and subsequent depletion of materials that we can't easily replace or substitute in short order, there's not going to be any dramatic increase in energy demand and thus pollution during that conversion process, all presently ignored energy storage demands will be magically taken care of by something that isn't coal or natural gas or nuclear, and of course, all of this is going to be sustainable / circular / green, and no governments are going to collapse under the weight of their new energy choices, similar to what happened in Sri Lanka after they "went green". They "went green" so hard that the government responsible for the greening is no longer anywhere to be found. If that's not setting yourself up for a nasty surprise, then I don't know what qualifies.

Something tells me we're not playing with a full deck here. The probability of all of that happening precisely as we want it to, based upon what we're demanding that this new energy generating and storage system does for us, in the time frame we want it done within, is functionally nonexistent. I sincerely hope I'm wrong, but all the warning signs are present and they're all being ignored because it doesn't agree with the agreed upon belief system about our bright shiny green circular future.

Long story short, EROEI is very real, it places real constraints on what is or isn't sustainable over the long term, and it's not a concept that's amenable to anyone's beliefs about energy. If it takes another 25 years for us to figure out what will or won't work, then I guess that's what will be required. Right now, it looks like we're throwing stuff at the wall to see what sticks, which is never a sign that we understand the nature and scale of the problem. You only do stuff like that when you don't know what the solution should be. At the end of that process, if we're no further along than we are today, then those who are responsible for pushing this religious ideology over pragmatism ought to be prepared to have all of their beliefs and desires about energy ignored, because that's what they did to everyone else during their discovery process. I don't think that will be a good outcome, even if they're wrong about the limits of using electronics to generate energy at a global scale.

Calliban · 2024-04-03 18:43:04

Kbd512, all true I think. A big part of the problem so far as I can see is that the people most ethusiastic about the green electric revolution, are political idealists on the left of the spectrum. These people tend to talk a lot about things like 'climate justice', 'social inclusion', 'diversity' and all sorts of other socialist political ideological nonsense. Unfortunately, these people tend to be bereft of genuine analytical skill. If they have any scientific background at all, it will be in social science or psychology. Very few have enough understanding to even ask the right questions, let alone analyse a concept using simple maths. And they tend to be idealistic. Certain truths become sacred and they aren't even capable of the introspection needed to critically assess their own ideas. They just tend to take things on faith. Their usual reaction to having their ideas questioned is anger and impatience. They tend to view people with different opinions as enemies that they need to crush. So they aren't capable of learning about the limitations of their ideas. This is why disasterous ideas that any outsider could see were unworkable, end up being tested to destruction. We see it with energy polucy, transport policy, migration, crime, gun control, wherever the left have a pet opinion.

The left seems to attract a certain type of person. A person that is weak and frightened of the world and needs the comfort of a rigid ideology to provide them with emotional security. These people end up causing havoc. They are the rot of democracy everywhere, because the core value of any democratic system is complete freedom to discuss and challenge any idea. To anyone on the left that is deeply threatening. Because discussing something that they have already decided and set their worldview upon, threatens their emotional security. Hence they get triggered and offended. They are anti-democrats by their nature and are constantly trying to shut the democratic process down, because they see that outcome as bringing order to chaos. I have never met a lefty that didn't have severe emotional problems. They are as incapable of critically assessing the mistakes in energy policy as with every other policy they have.

Last edited by Calliban (2024-04-03 18:54:26)

Spaniard · 2024-04-04 01:25:03

Well... It seems that the source of data matters.

While "badboysenergy" claims PV LCOE of 471$/Mwh

Here I come with different sources

Projected 2027 (USA) - (including extra costs like network)
Solar standalone - $36.09 $/Mwh
Solar + 4hr battery - $58.62 $/Mwh
https://www.eia.gov/outlooks/aeo/pdf/el … ration.pdf

Out World in Data. 2022, worldwide 0.05 $/kwh (second cheapest after onshore wind)
https://ourworldindata.org/grapher/leve … ?tab=table

Lazard - Utility scale from 24 up to 96 $/Mwh
https://www.lazard.com/media/2ozoovyg/l … l-2023.pdf

In 2020. Past confirmed data
$56/MWh average in Spain $68/MWh in Italy
https://www.argusmedia.com/en/news-and- … -in-europe

OR... you can believe BadBoysEnergy and think that Solar costs 471$/Mwh with a methodology of their own invention that nobody uses to obtain a value that nobody in the market cares.

we developed a model to calculate the levelized cost of intermittency (LCOI)

That's how FUD works.

Last edited by Spaniard (2024-04-04 01:26:58)

Spaniard · 2024-04-04 01:41:56

Oh. About the author of that article

https://www.americanexperiment.org/abou … /isaac-orr

Isaac has written extensively on hydraulic fracturing, frac sand mining and electricity policy, among other energy and environmental issues. His writings have appeared in The Wall Street Journal, USA Today, the New York Post, The Hill, Orange County Register, The Washington Times, and many other publications.

https://www.google.com/url?q=https://tw … 4Y_Nh4HnNo

TheFrackingGuy

How surprising, a advocator for massive fossil fuel industry to reach a LCOE 5x-8x higher than any serious study and real confirmed projects reach.

If you think that FUD is a myth, here you have a clear real example what a FUD spreader is.

kbd512 · 2024-04-04 01:51:56

3 Energy Realities That Renewable Advocates Can’t Answer - What renewable energy advocates never fully address about the failures of wind and solar

This is the IMF claiming that "Climate Change" is a "fossil fuel industry" subsidy:

The hydrocarbon fuel industries are the ones who are actually keeping the lights on at the present time.

As an experiment, we prevent NRC from having the ability to dictate if new nuclear reactors can be built, give nuclear power a $60/MWh subsidy, take that same amount of money away from solar, and then let's see which energy source cannot compete with the other. If it turns out that the only real reason solar is competitive is that massive direct federal subsidy, we remove that for the next 10 years since solar has had that level of subsidization for the past 30 years now, and then observe what happens to solar power projects.

Reframing Curtailment: Why Too Much of a Good Thing Is Still a Good Thing

Video Explains How Having More than Enough Renewable Energy Capacity Can Make the Grid More Flexible

What the video doesn't explain is who is paying for all that extra grid capacity that is not required when it's provided by a reliable energy source, such as a nuclear reactor receiving the same level of subsidization as solar. It also doesn't explain where all that extra material is coming from.

Overbuilding and Curtailment - The cost-effective enablers of firm PV generation

They never state who this "overbuilding and curtailment" scheme is cost-effective for, because it sure as hell isn't the people paying their electricity bills. Public utilities have figured out how to use wind and solar to escape their golden handcuffs regarding how much they may charge the consumer, so of course they're exploiting the stupidity of the average person to the maximum extent they think they can get away with.

Flip to Page 8 of this "over-build and curtailment" silliness:

The results in Table II demonstrate that while unconstrained PV production costs will reach very low targets--well below the often quoted, “grid parity” threshold, delivering firm, “high-penetration-ready” electricity, i.e., achieving real grid parity, is considerably more expensive. Achieving real grid parity would be economically unacceptable using storage-only solutions. The results also show that overbuilding PV and dynamically curtailing production could produce firm generation costs that are considerably closer to acceptability. This oversizing/proactive curtailment “effect” is illustrated in Figure 4 where the LCOEs reported in Table II with, and without operational curtailment are graphically contrasted for the long-term utility-scale optimistic scenario.

SINGLE LOCATION PV GENERATION
long-term utility scale conservative Unconstrained PV kWh: $0.024
long-term utility scale conservative Firm PV kWh without curtailment: $2.575
long-term utility scale conservative Firm PV kWh with optimal dynamic curtailment: $0.211

STATEWIDE DISTRIBUTED PV GENERATION
long-term utility scale conservative Unconstrained PV kWh: $0.023
long-term utility scale conservative Firm PV kWh without curtailment: $2.460
long-term utility scale conservative Firm PV kWh with optimal dynamic curtailment: $0.145

STATEWIDE DISTRIBUTED PV GENERATION with 5% NATURAL GAS
long-term utility scale conservative Unconstrained PV kWh: $0.023
long-term utility scale conservative Firm PV kWh without curtailment: $1.892 <- Notice the $0.568 drop in cost?
long-term utility scale conservative Firm PV kWh with optimal dynamic curtailment: $0.097

The part that goes unstated is what curtailment actually means from the standpoint of a gas turbine or nuclear power plant operator. The solar power operator gets to decide when it's advantageous to them to simply dump power into the ground. Meanwhile, the gas turbine operator is forced to keep their generator spinning, burning fuel and accruing maintenance and operating costs. Even with the utterly ridiculous subsidies to wind and solar, and being allowed to dump power on the grid when it works best for them, they still require another scheme to make their power somewhat less unaffordable than it truly is.

Look at the graph of electrical power demand in the New York metro area vs the power available from PV on Page 2. Since they don't want to build any battery storage to buffer PV power onto the grid, because then their entire value proposition is immediately shot to hell, their silly scheme is to over-build the PV array, and then arbitrarily cut off power from it whenever it suits them, forcing the gas turbines to remain spinning 24/7/365, which is exactly what happens with wind power here in Houston, Texas where I live.

Did you notice that 2 GIGAWATT vertical drop in power from PV when a cloud passed overhead?

You are NOT going to have a functional grid without electrochemical batteries, because nothing else except a supercapacitor or flywheel can respond that fast to a PV power output drop of that magnitude and speed. The total capacity of all super capacitors and flywheels is even more insufficient than batteries. You will cease to have an electric grid without one of these technologies.

The only reason we still have functional grids right now are those gas turbines or coal or nuclear power plants that never quit running, burning fuel the entire time, which is why I think our CO2 emissions will only go UP, never down, unless those Lithium-ion batteries are included as part of the PV installation. It should be a package deal, wherein no PV is allowed to be installed without at least 5% of nameplate capacity in terms of MWh of battery backup. If a 1GW PV farm doesn't have at least 50MWh worth of battery power, then a semi-graceful hand-off to a gas turbine is essentially impossible, so we can't even have the gas turbine idling. Nuclear power doesn't cost $2.50 per kWh. Those are gasoline prices for 1 lousy kiloWatt-hour of electricity! That is what our Sun worshippers will subject us to if their silliness is not ended by people who can do basic math.

Sorry, but this doesn't work. If you have to charge $2.50/kWh because you have to over-build the PV and wind generating capacity to that absurd degree to avoid paying for any amount of battery storage, then you don't have an argument about LCOE. If you include battery storage to avoid loss of grid whenever a cloud passes overhead or the wind dies down a bit, then you no longer have an argument about LCOE.

I think we've plunged the entire katana, Kill Bill style, into this fanciful idea that wind and solar are cheaper than anything else when scaled up to the degree required to deliver a "firm" kWh of electrical power, or backed up with sufficient battery capacity to simply deal with the wild minute-to-minute power fluctuations when we would rightfully expect it to produce power. Reality gave it a half-turn for good measure. PV should produce maximum at high noon, except that its output dropped to 1/3rd of nominal output there in New York City, because clouds happen. Wind or solar plus any kind of storage or backup is dramatically more expensive than any kind of thermal power plant alone, full stop. Worse than that, the coal and gas full backup power plants we're running right now, 24/7/365, are still emitting CO2.

If we have to overbuild, then we need to build 18GW of PV to assure 6GW of "firm power". That means America's 750GW of coal and gas power will likely need to be "firmed up" with 2.25TW of PV capacity for equivalent power for a mere 8 hours per day. We can store the rest with enough storage, but only with sufficient battery capacity.

The idea that a firm kWh of power delivered by PV or wind is remotely comparable to gas, coal, or nuclear power in terms of cost is errant nonsense. Best case scenario, there's a hydro dam or nuclear power plant backstopping the unreliable power. We're playing a dumb shell game with gas, coal, and nuclear. Since most of every grid in the world is coal or gas, not nuclear or hydro, they're uselessly spewing out CO2, messing up the climate worse than it already is, to prop up these wind and solar vanity projects. When the investment capital dries up, it's over, because there's no economics case to be made without the subsidies.

Calliban · 2024-04-04 02:25:54

Spaniard wrote:

Oh. About the author of that article
https://www.americanexperiment.org/abou … /isaac-orr
Isaac has written extensively on hydraulic fracturing, frac sand mining and electricity policy, among other energy and environmental issues. His writings have appeared in The Wall Street Journal, USA Today, the New York Post, The Hill, Orange County Register, The Washington Times, and many other publications.
https://www.google.com/url?q=https://tw … 4Y_Nh4HnNo
TheFrackingGuy
How surprising, a advocator for massive fossil fuel industry to reach a LCOE 5x-8x higher than any serious study and real confirmed projects reach.
If you think that FUD is a myth, here you have a clear real example what a FUD spreader is.

Spaniard, the whole point of the article is that LCOE as Lazard calculates it, is not a reliable metric for assessing the true cost of PV. This is because PV doesn't produce reliable power. Trying to make the power reliable without burning fossil fuels pushes up cost enormously. Which is what the author is saying. And it is self evident in the soaring electricity prices that people are actually paying. The kWh cost of my bill is $0.3/kWh. And then there is the standing charge.

Last edited by Calliban (2024-04-04 02:44:04)

Spaniard · 2024-04-04 03:02:38

kbd512 wrote:

3 Energy Realities That Renewable Advocates Can’t Answer - What renewable energy advocates never fully address about the failures of wind and solar

Seriously kbd512. Are you unable to recognize a FUD site that only spread lies full of (intentionally) bad data?

kbd512 wrote:

Video Explains How Having More than Enough Renewable Energy Capacity Can Make the Grid More Flexible
What the video doesn't explain is who is paying for all that extra grid capacity that is not required when it's provided by a reliable energy source, such as a nuclear reactor receiving the same level of subsidization as solar. It also doesn't explain where all that extra material is coming from.

From the same site we obtain current materials. Why they need to answer an obvious question? Why you repeat the same question over and over again like it weren't answered?
You can disagree with the answer, but it's tiresome to return to the same question again and again.

The extra grid capacity also is needed to the electrification anyway. Remember that we want to remove fossil fuels from the mix for multiple reasons. We can do it slower or faster, but it's need to be done.

Also there are multiple studies around renewables+storage. Because YES, storage is A COMPLETELY DIFFERENT MATTER.
It's connected, of course. We already know that for high mix of renewable storage is a must. And storage is still non competitive although costs are changing quickly.

But use storage as a sure thing for blame solar to have a high cost is not how it works. Because that costs depends on a lot of factors.
Network capabilities. Total storage capacity and kind of storage. Demand flexibility. Etc. etc.

That's the reason why electricity network coordinators are limiting the quantity of renewable integrated in the networks, and working in the best way to adapt all of this. While the storage is limited or too expensive, they just won't allow integrate more renewables.
Still, there is plenty of room for growth, while storage technology become cheaper.

Some countries has a better situation than others. For example, in my country, Spain, we have some pump hydro and there are proposals for a significant increasing of that.

Curtailment is generally low. Just a minor number of days. And it's clearly a symptom that we lack storage. We all know. LCOE usually already integrate in their predictions moderate levels of curtailment. Because it's low, it does affect little and it's still far cheaper than other sources of energy.

If the levels increases in the future, the speed of renewable installations in my country will slow because we have already a high penetration level of renewable. The government will limit the ability to add more renewable into the network. We will continue to use a mix as we have now.
Still the renewables will continue to grow as we add electrification of things, so while the percentage of renewables could stuck until cheap scalable storage becomes available, a lot of old fossil fuel will be changed by a mix with high levels of renewable.

And that's my country. In the planet, there is plenty of countries with networks still to integrate that levels of renewable.

Overbuilding and Curtailment - The cost-effective enablers of firm PV generation

There are multiple calculations there.
It depends on multiple variables. If you consider the price of energy extremely cheap or a lot cheaper than storage, then high levels of curtailment has more economic sense.

As there is a lot of debate which level of price we can reach in any of the technologies involved, this needs to be taken with a pinch of salt.
Also "curtailment" is generally accepted as "energy dissipated". But there is an immense potential for the concept of "under LCOE generation". Curtailment could be seen as a extreme case of that.
The concept of "under LCOE generation" is that it's cheaper to create non-optimal but cheap consumers adapted to absorb generation peaks.
Anyway, this study take the things to the extreme. Put solar without storage and try to produce the demand curve. It's most a theorical thing that anything.
It's obviously a lot more reasonable a good combination of some curtailment, storage and demand adaptation. The problem of the projected costs in that study are that they are based on old data of storage. Things have changed a lot. Although still not enough.

Because storage prices are not in the competitive level, that's the reason why electricity renewable penetration remains currently limited.

And the LCOE is low, not that absurd numbers of the FUD.

You are NOT going to have a functional grid without electrochemical batteries, because nothing else except a supercapacitor or flywheel can respond that fast to a PV power output drop of that magnitude and speed. The total capacity of all super capacitors and flywheels is even more insufficient than batteries. You will cease to have an electric grid without one of these technologies.

That's the reason why some operators are demanding a minimal level of storage on close to saturation networks.
But that level of batteries are not very expensive, as I posted earlier.
It's not the same the storage need to regulate frequency than to fill the network to 100% renewables.

You can check the experience of Australia with Tesla Megapack. The model works. I insist, not in the price we really want, although batteries are already very close to competitive level if it's for frequency/peak manage.

Sorry, but this doesn't work. If you have to charge $2.50/kWh because you have to over-build the PV

That numbers are not realistic, at least, not with current prices. It could be right using old data.

Current batteries are already at 100$/kwh and going even lower. We will see what price we can reach with sodium-ion.
So when you divide by the cycles that it can support, let's say 1000 (and stationary storage usually can do better) you have 0,1 $/kwh

To reach 2,5 you have to add a lot more costs. That's not current costs of solar + some hours of batteries.

That's the reason the link I post before projected around 60$/Mwh WITH BATTERIES.

But as anyone can see, to dismiss PV, a lot of assumption of future model is used. Instead of current LCOE and reasonable analysis about how to build a profitable model, it's needed to project absurd curtailment levels of old storage prices instead of projected curves of expected future storage costs.

Last edited by Spaniard (2024-04-04 04:10:53)

Spaniard · 2024-04-04 03:36:17

This a very interesting report about the same matter

https://iea-pvps.org/wp-content/uploads … ration.pdf

It's a compendium of studies, that includes the link to your previous study.

But it includes some others, a lot more optimistic.

Spaniard · 2024-04-04 04:08:25

Also I must notice how the debate has changed to deviate from the original intention.

Lets remember how it was.

Calliban - PV can't reduce cost and are fossil fuel extenders because they use a lot of energy to build the materials. (EROEI studies linked)

Me - That EROEI studies are outdated or wrong, because the energy involved in PV using that studies contradict LCOE values of PV. They aren't even enough to pay the energy claimed embedded in the EROEI studies.

Now another thread about EROEI is opened.

But to claim that LCOE of PV is high, they don't use LCOE of PV standalone, but PV + STORAGE. And the raise of the price is in the storage part, not the PV that is dirty cheap.

But the argument about low EROEI was claimed about the energy costs to make the PV panels, not the storage part.

Isn't it obvious that the argument has changed?

The EROEI of PV ALONE should be compared with LCOE of PV ALONE. Not to mix debates and use the values of one case to another.

LCOE of PV ALONE is pretty cheap, and that's a fact of the (recent, yeah) past. That means that EROEI of PV ALONE should be a lot higher than you claim.

Calliban · 2024-04-04 04:56:21

Spaniard, are your LCOE figures calculated before or after interest rates rose dramatically in 2022 - 2023? For a high capital energy source, it makes a very big difference.

The first post in this thread, which I posted only yesterday, is a net energy analysis that I carried out for solar PV built in UK and Spain. It is based upon embodied energy data from University of Bath. It confirms the EROEI calculated by Prieto and Hall. You can check the data yourself if you like. The discussion has shifted to LCOE because that is what you stated that you consider to be important.

As I said in the other thread, the cost of PV imported from China, is only weakly dependant on EROEI. This is because they are using forced labour and otherwise stranded coal to build this product. They can and do produce panels very cheaply this way. Just as child labourers in Congo produce cheap cobalt. But it clearly isn't sustainable.

Last edited by Calliban (2024-04-04 04:58:07)

Spaniard · 2024-04-04 05:21:19

Calliban wrote:

The first post in this thread, which I posted only yesterday, is a net energy analysis that I carried out for solar PV built in UK and Spain. It is based upon embodied energy data from University of Bath. It confirms the EROEI calculated by Prieto and Hall. You can check the data yourself if you like. The discussion has shifted to LCOE because that is what you stated that you consider to be important.

But you are shifting my argument from PV along to PV + STORAGE.

LCOE is based on cost, so a lot can affect. But one thing is sure. Costs include energy costs. So it's impossible to cost less than the energy embedded on it.

So if LCOE is cheap then the EROEI is a lot higher than claimed.

But because my argument is about the energy embedded in PV, the LCOE should be also about PV alone.

If you change the debate speaking about PV + STORAGE, you aren't rebating my argument against PV EROEI, because you are speaking about a different thing.

Last edited by Spaniard (2024-04-04 05:22:01)

Calliban · 2024-04-04 06:11:57

Spaniard wrote:

LCOE is based on cost, so a lot can affect. But one thing is sure. Costs include energy costs. So it's impossible to cost less than the energy embedded on it.

Agreed.

Spaniard wrote:

So if LCOE is cheap then the EROEI is a lot higher than claimed.

Not true. As I have said before, the Chinese are making their polysilicon in Xinjiang. They are using forced labour to extract coal which is then burned to produce electricity in powerplants at the minehead. This results in some of the cheapest electricity in the world. It is entirely possible for panels to have an EROEI that is <1 in many locations, but still to be cheap to buy. This happens because the energy being used to make the panels is so cheap it is almost free. The problem is that the panels can only remain cheap if the coal based energy used to make them remains cheap.

Spaniard wrote:

But because my argument is about the energy embedded in PV, the LCOE should be also about PV alone.

The problem is that you cannot power an electrical grid with PV alone. Supply has to balance demand at all times. A cloudy day may reduce PV generation by 80%. On a mid-winter day, it may only be 10% what it is at the height of summer. So any realistic LCOE assessment needs to consider the whole system that you will need to keep the lights on. That may mean solar + batteries + natural gas. It may mean massively overbuilding solar, so it generates enough to cover demand in winter. It could mean solar + long term storage. However it is done, LCOE needs to capture these other costs if it is to be a realistic representation of prices.

Spaniard wrote:

If you change the debate speaking about PV + STORAGE, you aren't rebating my argument against PV EROEI, because you are speaking about a different thing.

As I stated above, storage and backup are an integral part of the system if PV is added to the grid, because it cannot work without them. Could a society adapt to using PV / wind power without grid electricity storage, i.e adjusting demand to supply? That is an interesting thing to think about. But we havn't managed that so far. It probably is the only way intermittent renewables can work in the long term. But it would require every part of society to adjust its energy use and workrate to balance demand to supply, rather than the other way round. That would be a very different way of life to what we have now.

Last edited by Calliban (2024-04-04 06:18:04)

Terraformer · 2024-04-04 06:26:58

It's pretty clear that EROI for solar panels very strongly depends on where they're placed. It would not surprise me if the studies claiming the highest EROI are based on desert installations with high efficiency panels.

Which... sure, if you're looking to make synthetic fuel or ammonia, that's not necessarily a problem. If you're looking to produce electricity for non desert regions however, you find yourself needing very large scale investment in politically risky high voltage power lines...

tahanson43206 · 2024-04-04 07:05:55

For Terraformer re #18

I am replying to your post because it seems to offer an opportunity to ask a question that the folks working this topic might find interesting...

Is it feasible to make solar panels using only solar panel supplied energy as the energy source?

I don't know the answer. All I know for certain is that the advocates of nanotechnology have been talking about this very ideas for many decades.

"Engines of Creation" was published in 1986, and it was inspired by earlier work by Richard Feynman. Feynman is reported to have introduced the concept of nanotechnology in 1959, at a meeting of the American Physical Society.

Since nanotechnology was introduced to the public, a number of thinkers (who were also writers) have imagined nanotechnology harnessed to build complex systems from only a seed, using solar energy as the sole power source. None of this has actually happened in the sense of what humans have done.

However, Nature has populated the entire planet Earth with complex systems using solar energy as the sole energy source.

It seems to me reasonable to suppose that if Nature could fill every nook and cranny of an entire planet with complex systems using nothing but solar energy as the energy source, then humans should be able to solve the problem of making solar panels using nothing but solar energy.

The fact that no one in the present company has any experience undertaking a project on this scale does NOT mean that it cannot be done.

What the members of THIS community CAN do is to work out how this (hypothetical) plant would operate.

We have seen reference to manufacture of solar panels fueled by coal. The use of fossil fuels to make solzr panels is the ONLY way known to the present generation of humans. However, there is nothing standing in the way of transitioning to all-solar energy input, that I can see.

(th)

Calliban · 2024-04-04 07:34:10

Terraformer wrote:

It's pretty clear that EROI for solar panels very strongly depends on where they're placed. It would not surprise me if the studies claiming the highest EROI are based on desert installations with high efficiency panels.
Which... sure, if you're looking to make synthetic fuel or ammonia, that's not necessarily a problem. If you're looking to produce electricity for non desert regions however, you find yourself needing very large scale investment in politically risky high voltage power lines...

Using coal to make solar panels, which then make synthetic fuels. If EROI is low, why not just turn the coal into liquid fuel and skip the solar PV panels altogether? And it isn't as if PV is the only energy option we have. Kbd512 has made a strong case for solar thermal power. It would need a lot of steel, but it obviates the need for semiconductor grade silicon. EROEI should be much better than for PV and energy can be stored cheaply as heat. We also have wind power, wave power, tidal power, geothermal, hydro and fission.

HVDC power transmission has made long distance transmission more cost effective. Power electronics allow inverters to build an AC waveform without need for cumbersome motor-genedator sets. In some cases, it is able to make use of undersea PE insulated cables. But it is costly. And it hasn't yet been used across transcontinental distances. A good test case would be to generate power for the US east coast using solar thermal powerplants in Texas and New Mexico. Most of the transmission route could be undersea if land use is a problem.

Much of the southern US has reasonable deep geothermal resources as well. We could build hybrid powerplants in these locations. Geothermal energy could be used to preheat the feed water that enters the boilers of solar thermal powerplants.

Last edited by Calliban (2024-04-04 07:41:33)

Calliban · 2024-04-04 07:49:08

Spaniard wrote:

Also I must notice how the debate has changed to deviate from the original intention.
Lets remember how it was.
Calliban - PV can't reduce cost and are fossil fuel extenders because they use a lot of energy to build the materials. (EROEI studies linked)
Me - That EROEI studies are outdated or wrong, because the energy involved in PV using that studies contradict LCOE values of PV. They aren't even enough to pay the energy claimed embedded in the EROEI studies.

The net energy study at the head of this thread is less than 24 hours old. It pretty much confirms the most pessimistic EROEI calculations for PV. Poor EROEI is not contradicted by a low LCOE calculation. It happens because the energy used to make the panels is cheap.

Spaniard · 2024-04-04 08:20:40

Calliban wrote:

Spaniard wrote:
LCOE is based on cost, so a lot can affect. But one thing is sure. Costs include energy costs. So it's impossible to cost less than the energy embedded on it.
Agreed.
Spaniard wrote:
So if LCOE is cheap then the EROEI is a lot higher than claimed.
Not true. As I have said before, the Chinese are making their polysilicon in Xinjiang. They are using forced labour to extract coal which is then burned to produce electricity in powerplants at the minehead. This results in some of the cheapest electricity in the world. It is entirely possible for panels to have an EROEI that is <1 in many locations, but still to be cheap to buy. This happens because the energy being used to make the panels is so cheap it is almost free. The problem is that the panels can only remain cheap if the coal based energy used to make them remains cheap.

You are saying two incompatible things.

While I don't agree with your exaggeration about China, it doesn't matter. Just for the sake of the argument I will ignore it like it were true.
Still, you are claiming low EROEI, while the LCOE is less than the energy you are assuming it has. It doesn't matter if they use magic free robots that move the coal from the mine to the furnaces, the energy of the raw materials is still there. It is not possible so low LCOE JUST ONLY ACCOUNTING THE ENERGY YOU CLAIM IS USED IN THE PROCESS. Because if you calculate that energy as coal, copper, etc. costs in the market, you obtain more money that TOTAL LCOE. That's even removing labor costs so the slave work argument doesn't change anything.

LCOE includes a lot of other concepts and it was getting cheaper and cheaper. Are you claiming that China used better labor BEFORE and it's worsening to pay the gap?
Because wages were only increasing. LCOE under the Prieto & Hall was done in a time where PV costed around one order of magnitude higher.

Last edited by Spaniard (2024-04-04 08:52:57)

Spaniard · 2024-04-04 09:01:52

Calliban wrote:

The net energy study at the head of this thread is less than 24 hours old. It pretty much confirms the most pessimistic EROEI calculations for PV. Poor EROEI is not contradicted by a low LCOE calculation. It happens because the energy used to make the panels is cheap.

I'm gonna explain it in a simple way.

When Prieto & Hall claimed that 2008 Spain PV EROEI was around 2, PV had a LCOE around 200-400$/Mwh

So they claim that at least 100-200$ where energy costs.

Now the PV panel costs around 30-50$. So they can't have more than 50$ in energy costs. And obviously can't have so much. Probably around 20$ at most and going down.

If the energy costs drops x5, and the panel generates similar energy, How it's possible that the peakoil community claim the same EROEI?

--- EDIT ---

Here I did a mistake.

"So they claim that at least 100-200$ where energy costs." -> That sentence is not true. It's not "at least" but "as maximum"

As there is a fraction of non-energy and energy costs, only the fraction of energy costs should be applied to the EROEI factor.

Still, to claim that the EROEI remain fixed, something like claiming that in the past, most cost was non related to energy, and now it's is needed to force the result. There is no reason that to be true.

Any how know something about the inside PV knows that the manufacture of PV, mainly drive by manufacturing costs (including energy) has gone down, to the argument remains almost the same.

Last edited by Spaniard (2024-04-04 09:33:26)

Calliban · 2024-04-04 09:19:24

Spaniard wrote:

Calliban wrote:
The net energy study at the head of this thread is less than 24 hours old. It pretty much confirms the most pessimistic EROEI calculations for PV. Poor EROEI is not contradicted by a low LCOE calculation. It happens because the energy used to make the panels is cheap.
I'm gonna explain it in a simple way.
When Prieto & Hall claimed that 2008 Spain PV EROEI was around 2, PV had a LCOE around 200-400$/Mwh
So they claim that 100-200$ where energy costs.
Now the PV panel costs around 30-50$. So they can't have more than 50$ in energy costs. And obviously can't have so much. Probably around 20$ at most and going down.
If the energy costs drops x5, and the panel generates similar energy, How it's possible that the peakoil community claim the same EROEI?

Spaniard,

Do you understand what LCOE and EROEI mean? Do you understand that these are two different things? EROEI is a ratio of useful energy out / required energy in. Levelised cost of energy is measured in dollars, pounds or euro per MWh. It is an estimated monetary cost of energy. Two different things. A low EROEI may have the effect of increasing the LCOE. But that isn't automatically the case in all situations. It will depend on the cost of the energy used to make the energy source and the cost of labour. Do you understand why that is the case?

Spaniard wrote:

While I don't agree with your exaggeration about China, it doesn't matter. Just for the sake of the argument I will ignore it like it were true.

No need to ignore it. Here is the proof as clear as day.
https://www.bbc.com/news/world-asia-china-57124636
https://www.skynews.com.au/australia-ne … ddad7a6e48
https://www.theguardian.com/environment … d-turbines
https://www.msn.com/en-us/money/compani … r-BB1kOFP2

China made solar power cheap through use of coal, subsidies and forced labour, not efficiency.
https://www.forbes.com/sites/michaelshe … fficiency/

If the coal, subsidies and forced labour go away, what happens to the price of those solar panels?

Last edited by Calliban (2024-04-04 09:58:02)

Spaniard · 2024-04-04 09:39:34

Calliban wrote:

Spaniard,
Do you understand what LCOE and EROEI mean? Do you understand that these are two different things? EROEI is a ratio of useful energy out / required energy in. Levelised cost of energy is measured in dollars, pounds or euro per MWh. It is an estimated monetary cost of energy. Two different things. A low EROEI may have the effect of increasing the LCOE. But that isn't automatically the case in all situations. It will depend on the cost of the energy used to make the energy source and the cost of labour. Do you understand why that is the case?

I know how it works. Still, PV "skeptics" wants to use China as a escape goat.
But that argument drops when you compare old chinese costs with recent chinese costs.

Of course skeptics always force western vs China to make like the argument has weight.

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