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> That's not the argument of peak oil. It's not about price or quantity of oil available in the planet. It's an argument about thermodynamics.

... that hasn't been the traditional argument behind peak oil, from its original adherents (checks notes) 70 years ago. The traditional theory is a pretty bare oil demand inevitably increases while fields run dry because we extract all the [usable] oil first--and one of the main points of the theory is to ask what you're going to do when you need oil and there is none left. It may be that newer adherents are arguing peak oil on the basis of energy-invested-on-energy-returned basis, but that's not the traditional argument for the theory.

While it is true that newer oil sources require more energy to extract, but that's not particularly relevant for a few reasons. For one, on current trends, it looks like demand for oil will peak well before economical supply of oil will be exhausted (which is the main point of the theory). But even being net-negative on energy production isn't necessarily a deal breaker, for there can well be cases where there's no realistic alternative to oil as an energy source due to its great energy density (see airplanes, for example).

If you can read French, this guy https://fr.wikipedia.org/wiki/Jean-Marc_Jancovici has published a lot of vulgarization on the topic - with numbers.

If my memory of reading one of his books serves, fracking now costs 50% of the energy it produces (in addition to non-energy environmental impact, which is pretty large), up from ~10% for the easy oil we had ~50 years ago. Current-tech solar panels are in the same order of magnitude (again, not counting non-energy environmental impact). Nuclear energy has the highest yield. I seem to remember that coal is the worst, unless it's burnt at the point of extraction.

That doesn't pass the smell test. A "raw" solar panel in China costs about 25 cents / W, and each watt should produce about 45kWh over its lifetime (5W per day for 25 years). If the embodied energy in the panel is half of the lifetime energy, that means that there is 22kWh of embodied energy in that W of solar panel, and they're selling that embodied energy for about 1 cent / kWh. And that assumes that there are no costs to the panel other than the embodied energy.

A rule of thumb is that embodied energy in a finished manufactured product sells for about $1/kWh. By that rule of thumb, the embodied energy in a solar panel is about 0.5% of the energy it will produce over its lifetime.

Interesting counterpoint, thanks.

> A "raw" solar panel in China costs about 25 cents / W, and each watt should produce about 45kWh over its lifetime (5W per day for 25 years).

I imagine that you're making assumptions on having sufficient luminosity all year round, right? So perhaps that depends on where on Earth you are.

According to Jancovici [1], in most of Europe, solar panels produce about 100 kWh/m²/year, assuming that they are oriented correctly (I don't know if e.g. the necessity of cleaning them up is factored in). From the same source, in terms of energy used to build the panel (is shipping included?), it takes 1 to 4 years to reimburse that energy but that's under the assumption that all the energy from the panel can be used. In practice, solar panel installations produce energy at a rhythm that depends on nature, which means that for many uses, the electricity needs to be stored somewhere if we want to actually use it at a different rhythm, e.g. when you're actually at home/in the office/etc.

Unfortunately, storing electricity at scale with current-tech is energy-expensive (both to build the batteries and because of energy loss during storage), e.g. storing it as hydrogen has a yield of ~30%, couldn't find the yield of other technologies of batteries including the energy cost of building/shipping/disposing of the battery. So, in the worst case, these 100 kWh/m2/year turn into ~30 kWh/m2/year, which means 3 to 12 years for recouping energy cost.

So, by this calculation, the worst hypothesis maps to the number I was quoting above and the best one is at least one order of magnitude better. My bad.

Now, there is the problem that current-tech battery often relies on metals (i.e. Lithium) that are only available in limited amounts.

[1] https://jancovici.com/transition-energetique/renouvelables/p...

The numbers in your linked article are from 2000. The price of solar panels per watt is about 5% of what it was in 2000. Most of that cost reduction was from reduced energy use, so you need to multiply Jancovici's numbers by 5%.

You're also assuming that you have to store 100% of the energy to get to a green grid. But in a grid with a good mix of different renewable sources, grid ties large enough to cover areas with different weather, substantial amount of nuclear, hydro and a large number of EVs that can charge while energy is cheap means that very little energy needs to be stored. So you also have to multiply your storage numbers by about 5%.

And since the edit window is gone, replace "multiply by 5%"with "divide by 20". Same thing, but much more clear.

Good point. Thanks for the insight.

> Is the energy that a solar panel generate in its life enough for its normal use, plus extracting the minerals that it's made of, plus push the panel, through the ocean all the way from China? or are we fooling ourselves using oil for all that?

This is such a thoroughly debunked line it's barely worth discussing.

Here's a sufficient proof.

The dirtiest cheapest coal is about $1-2/GJ at the mine front. A good brown coal power plant is about 50% efficient.

Current unsubsidized solar module cost (not whole project) for large scaleprojects is in the $0.2-0.3.

At 25% capacity factor a dollar of solar at $0.3 will produce 500MJ over 20 years and still be 80% productive.

Thus even if the only activity required to build a solar panel were burning brown coal as it comes out of the ground, it could not be profitable to burn more fossil fuels than the energy the panel released.

The energy delivered by a solar panel is overwhelmingly more than needed to make it. The gain is enormous. There is simply no contest.

Consider that makers of solar panels, and of the materials that go into them, get no break on their power bills. Each and every kWh that goes into making the panel is paid for, and necessarily has its cost folded into the price of the panel. Otherwise they would be paying power out of their own pocket, to give it to you for free.

Furthermore, the fraction of the energy used in making the panel that comes from renewables goes up every year, as their share of the total generated increases.

The same argument applies to wind turbines, tidal turbines, wave engines, dams, and (in their way) storage media.

One could look for more direct sources, but the summary is that energy payback happens in 1-4 years out of current 25 year "life". And that 25 years is typically a warranty to 80% of original capacity. Year 26 of operation is not a sudden drop.

https://www.solarmelon.com/faqs/solar-panels-use-energy-manu...

Yes, panels at 80% have good resale value. If you have room, you just add 20% more. If not, you sell them and buy more.

Costs have dropped an order of magnitude since that study. Many of which scale with energy.

4 years is now a massive overestimate. Depending on how much you include (frames, inverter, grid tie in etc) 0.5-2 is more realistic.

Unless I'm mistaken, that's based on the assumption that you're in position to use 100% of the energy produced during the day, exactly when it's produced. I'm sure that there are scenarios in which that's true (e.g. keep the refrigerator on all day long, use some other energy source for the night) but if your main use for the energy is not correlated with the sun being up (e.g. power your computer when you're back home in the evening), you need to add the actual energy cost of storage, which is typically really bad.

This considerably increases the time to energy payback. Still probably worth it, though.

Panels are so cheap now that they pay even if you waste most of what they could have produced. A smallish battery that captures only some of the excess, and delivers it when you need it, suffices. Battery cost is still falling fast as new chemistries come online. Hydrogen synthesis and storage might displace batteries for domestic use, particularly if hydrogen-fueled cars succeed. (Advice: keep all that equipment outside!) If not, zinc/bromine battery tech looks strong.

Are you tokey of monetary cost or the total amount of energy needed to actually build/deliver/install/maintain/dispose of these technologies?

If the former, you are clearly right.

If the latter, I'm not so sure (with current tech).

Monetary cost, as already noted, reveals an exact upper bound on the amount of energy needed to build and deliver the goods: people doing those get no discount on their power bill. The price also includes labor, administrative and marketing costs, tariffs, taxes, and whatever profit was taken, less any public subsidy or loss-leader discount.

It’s pretty silly as we’ve discovered efficient synthesis routes since.