Almost Plausible Solar Takeover Plan

[Lord Crc]

Here in Norway grid-scale direct solar PV is a non-starter, due to climate and terrain. We rely heavily on indirect solar power though, in the form of hydro.

In an effort to reduce spending on infrastructure upgrades, residential installations will soon have to pay a "power fee", which depends on the maximum instantaneous power draw. The industry has been charged this since way back but now regular citizens will have to pay this as well.

In addition they will introduce hourly prices for electricity.

The wanted effect is to move more load to night time, reducing the peak demand on the grid.

Something like that would be contrary to a 100% solar grid though it seems to me, then you'd want the load concentrated when the sun's out. So seems it might also require more infrastructure investments to handle higher sustained near-peak loads?

 

[bhobba]

What other reason is there then for pursuing solar and wind if the ultimate goal is not related to the e word, or c word? (ahem a different c word...)

Out here in Aus, because we have a lot of sun, it is relatively easy to reduce your power bill to zero via solar panels and solar heated hot water systems. They are very popular and becoming even more popular as batteries become cheaper, and the panels themselves become cheaper. The issue we are finding is not that in a number of niches solar power makes perfect sense, its that when excess power is fed back into the grid may be causing fluctuation problems that need fixing:
https://www.abc.net.au/news/2018-10...-warn-excess-solar-could-damage-grid/10365622

Regardless of other issues such as peoples attitude toward CC, I think, due to advancing technology, we will have a greater mix of power sources. Exactly what that mix will be will depend on many factors, some of which will be political, and the public's view of sources such as coal, nuclear etc.

Thanks
Bill

 

[Lord Crc]

I mentioned it already, but I reiterate that I find it disappointing that such studies does not take electric vehicles into account.

They will add a lot of additional demand on the grid. However they potentially could also provide a lot of flexibility by acting as grid batteries.

In a 100% solar grid you'd want the electric car charging at work, but it could then provide power for the home during evening and night.

For us with a majority of hydro you'd want the car charging at night, but it could then also provide power for cooking, reducing that peak load.

There are probably a lot of other interesting and important interplay effects I've not considered.

 

[anorlunda]

I mentioned it already, but I reiterate that I find it disappointing that such studies does not take electric vehicles into account.

No no. It's not true that they don't take EVs into account. In fact the switch to EV means that the electric sector demand will increase very substantially. But when discussing how to meet the total demand, it is unnecessary to mention each of the uses that contribute to the demand. From an earlier thread:

The power grid may have problems expanding fast enough to meet the demand for electric vehicles. The figure below is from

https://www.eia.gov/energyexplained/?page=us_energy_home
As you can see, to totally shift the transportation sector onto the electric sector means nearly doubling the electric capacity. But some transport such as ships and planes do not switch to EV, so let's say in round numbers 50% more electric power.

That is more than just power plant capacity, but also the transmission lines, distribution, and perhaps even upgrading the electric service entrance to every house and building. That can be done, but not overnight and not at zero cost.

View attachment 246642

 

[mfb]

Topaz (https://en.wikipedia.org/wiki/Topaz_Solar_Farm) is 550MW peak. It covers an area of about 19km^2.

It is built in a desert where area doesn't matter. It would be possible to make it more compact, but why bother? At ~20% efficiency you need ~5 km² per GW, let's be conservative and double that for tracking panels, that's still a factor 4 more compact than the total Topaz site area.

Keep in mind, only about 3% of the total land area of the US is "developed"...

I don't know where that number comes from, but that suggests plenty of undeveloped area to use. The US has large deserts, so everything close to a desert won't have any issue with area.

 

[Lord Crc]

No no. It's not true that they don't take EVs into account. In fact the switch to EV means that the electric sector demand will increase very substantially. But when discussing how to meet the total demand, it is unnecessary to mention each of the uses that contribute to the demand.

But in this case they take today's demand, which is unrealistic, and no mention of using EV to shift demand.

If they had angled it as "this is how it could have looked today", the fair enough. But then don't talk about "we can build this by 2030", because it is irrelevant.

There may well be studies that do take this into consideration, so not trying to pan all of them.

 

[Baluncore]

But in this case they take today's demand, which is unrealistic, and no mention of using EV to shift demand.

The article has a paragraph on the subject of EV.
The electrification of transportation will increase demand, so it will obviously increase the capacity that must be installed. But EV comes with some storage so the same degree of overbuilding is not required.

 

[Baluncore]

The unusual thing about the article linked in the OP is that it considers changing the game when considering renewables. It does that by inverting the fraction of the installed capacity. Instead of 1/4 of peak demand, the renewables go to 4 times the peak demand. Advances in storage technology and storage capacity now allow that analysis step to be considered.

The article made it clear that the analysis was for the USA, not Norway, nor Australia. That does not mean that the same analysis cannot be applied in Norway with hydro and wind, or differently in Australia with wind and solar. It is a mistake to think that if there is one difference or exception, the overbuilding analysis fails locally or globally. Everywhere is an exception and needs to be analysed in it's own way. The article does not consider the USA as a single regime. It considers different states as needing different solutions.

The article also made it clear that the electrification of transportation was not part of the analysis. That future issue may be worrying for some people, but it does not change the inverted analysis and the need for overbuilding. The economy of scale will come into play sooner with the transition to EV.

It is clear that as the renewables share of energy production increases, it threatens the profits of the fossil fuel energy generators. But it is not the increasing capacity of renewables that is the problem, it is the reduced need for the fossil fuels. The problem is going to be crossing that economic bridge. When that happens, the market will be turned on it's head and the fossil fuel generators will become fossils themselves. The only hope is to economically tie the installed renewables to the fossils. At some point subsidies to renewables will need to reverse, to subsidise the fossils during their transition to extinction.

 

[hmmm27]

But it is not the increasing capacity of renewables that is the problem, it is the reduced need for the fossil fuels.

Depends : is it cheaper to strip the H's out of water, or out of petroleum ?

 

[russ_watters]

This article:
Overbuilding solar at up to 4 times peak load yields a least cost all renewables grid.

So...is there a paper associated with this model, or is that article and the graphical presentation of results on the website all there is? Unfortunately, without the details of the basis for the model, there's really nothing to evaluate (unless we guess what they did, which I'd rather not).

The premise is that if you start from scratch with only the hydro we currently have, what would the lowest-cost all-"renewable" grid look like. That's a little bit "out there" for my taste and I think the "almost" in your title is a generous characterization.

 

[Baluncore]

Depends : is it cheaper to strip the H's out of water, or out of petroleum ?

Cheaper economically or environmentally?

 

[hmmm27]

Cheaper economically or environmentally?

yes.

 

[russ_watters]

yes.

Economically: fossil fuels (mostly methane)
Environmentally: water

Stripping hydrogen from fossil fuels does not substantially change their climate impact because the combustion products remain the same whether you do it in one step or two.

 

[hmmm27]

Stripping hydrogen from fossil fuels does not substantially change their climate impact because the combustion products remain the same whether you do it in one step or two.

Specifically, I was thinking of having C - not CO2 - as a (by)product.

 

[russ_watters]

Specifically, I was thinking of having C - not CO2 - as a (by)product.

As far as I know, there is no process for that, and if there was it would necessarily be more expensive. The goals are opposites of each other because of the innate chemistry of the processes.

 

[Baluncore]

Specifically, I was thinking of having C - not CO2 - as a (by)product.

Water is cheaper and excess energy is free.
You are missing the top-down point of the article by getting bogged in the myriad possible bottom-up details. Just how energy will be stored is variable in place, time and economy. The cheapest path now will almost always cost more in the longer term.

 

[hmmm27]

You are missing the top-down point of the article by getting bogged in the myriad possible bottom-up details.

The segue was reacting to "the fossil fuel industry is toast"(paraphrased) ; I'd happily argue that for the next century or so, the industry will still be going strong : the "trick" would be making it clean and ghg-free.

 

[Svein]

In his novel "Friday", Heinlein introduces the "Shipstone", a very efficient rechargeable (and high-power) battery. It is recharged by solar power in the deserts. Are we looking for a realizable version of a "Shipstone"?

 

[anorlunda]

So...is there a paper associated with this model, or is that article and the graphical presentation of results on the website all there is? Unfortunately, without the details of the basis for the model, there's really nothing to evaluate

I was attracted to the article for the same reason you were in #7 --- a novel way to approach the capacity factor problem. But in #26, I give a reason why it would be rejected as a national plan.

Like many engineers, I am interested in limiting cases. They help us to clarify our thinking. I was hoping to make a thread where I forced the limiting case by assuming 100% of one source. Then we could explore that. I did not intend for it to expand into CC, or environment, or the "best" energy future, or national energy policy, or EV, or solar versus other power sources. Alas, that didn't work. Some public discussion topics are too "hot button" to be contained.

 

[Lord Crc]

As I mentioned, 100% solar seems to require a bit different usage patterns than normal. You'll want to shift load to be peaky, like the solar panels, and avoid night time load. Instead of people charging their EV at home at night, it seems they should charge during work.

On the other hand, with V2G they can then use the car to help out with their cooking etc once they get home.

Alternatively one would have to install quite the battery backup, if people are to use the grid more or less in the same pattern as now. I don't know what is cheapest, but I assume it is easier to go for huge batteries, rather than substantially upgrade infrastructure in cities.

Nuclear plants will have to be decommissioned at non-trivial cost, though I'm not sure how many are expected to provide service until 2050 or beyond (2030 + 20 years).

It would certainly be interesting to see a more detailed dive into a potential 100% PV future.

 

[anorlunda]

It would certainly be interesting to see a more detailed dive into a potential 100% PV future.

See #26, the eggs in one basket problem.

 

[Lord Crc]

I would be even more interested in a 100% clean energy grid deep dive, but I got the impression you wanted to rail the thread back to the original premise of 100% PV :)

 

[anorlunda]

I would be even more interested in a 100% clean energy grid deep dive, but I got the impression you wanted to rail the thread back to the original premise of 100% PV :)

Maybe your right. Limiting the scope of this thread won't work. Go for it.

 

[russ_watters]

Quick clarification; the title may give a false impression, but the article/model are about a 100% renewables grid, not a 100% solar grid. So, for example, the stated 4.3x solar overbuild may actually much larger after the other sources are subtracted out.

I'm disappointed I don't get to see the details, but my guess is that last MW of solar only produces 10% as many MWH as the first, so what they are saying is storage is 10x too expensive to be viable and can only be used when it is actually required, independent of economics.

edit: Er...or maybe it's simply that the amount of solar needed to satisfy the grid in winter yields a 4.3x overcapacity in summer. That the summer-winter capacity issue is worse than the day/night one.

 

[anorlunda]

so what they are saying is storage is 10x too expensive to be viable

My reading is that with overcapacity as the base case, then the amount of storage is capped at the amount needed until the next day. With anything less than complete overcapacity, then the worst case need for storage gets into the multiple day region, and there is no definitive way to define the worst case storage required.

Maybe it appeals to me because I'm an analyst. Rating PV capacity by the worst case day greatly simplifies the analysis. Said in other words, it makes PV like more like base load generation.

 

[russ_watters]

Yeah, see my late edit; maybe it is more a matter of physical need than cost. A quick google tells me the summer-winter output variation in my area is 5.6x and the summer-winter load variation is 1.4x. Divide and you get 4x. That's how much peak summer overcapacity you need to satisfy the average midwinter load.

 

[anorlunda]

That's how much peak summer overcapacity you need to satisfy the average midwinter load.

I think that's exactly right. But I did not see in the article where they made allowance for catastrophes such as hurricanes or ice storms, where a significant fraction is destroyed and needs replacement. That's why I doubled the 400% to 800% in the OP.

War is also a necessary consideration. Recall that during the 2003 war in Iraq, the allies used weapons specifically designed to attack the power grid. Without any specific knowledge of future weapons, we must assume that such weapons will exist. The primary defense is diversity. Also in the OP, I mentioned cybersecurity as an advantage of solar PV. Cyber attacks sound highly likely.

 

[mfb]

Yeah, see my late edit; maybe it is more a matter of physical need than cost. A quick google tells me the summer-winter output variation in my area is 5.6x and the summer-winter load variation is 1.4x. Divide and you get 4x. That's how much peak summer overcapacity you need to satisfy the average midwinter load.

Bad news for Europe then. We have similar summer to winter production ratios, but demand is ~10-20% higher in winter.

 

[Svein]

That's how much peak summer overcapacity you need to satisfy the average midwinter load.

Yes - and as I have said repeatedly, the simplest way to store intermittent power supply is to use it to pump water up in an elevated dam. Then use it to generate power whenever you want.

 

[artis]

pardon if this comes across as ignorant, I'll admit I haven't put in a ton of research into this.

if space was not an issue like in the deserts or rural areas could we use flywheel storage to compensate within 24h time frames the overproduction at day and under production at night problem?
I am not sure about the energy density and cost comparison between battery technologies and flywheels but as for longevity and robustness I'm sure flywheels take the upper hand.