Solar, Wind Renewable Energy

[NW-Bound]

Laymen often say "When a region cannot generate power from wind or solar, it can borrow from its neighbors".

Fine, but the source of the neighbor's power would better be coal or nuclear. And lots of it, if that neighbor has to carry everybody on his back. It's because wind and solar generation often goes down for almost the whole continent!

See below:

 

[Jerry1]

Build Nuke plants!

I used to believe this was the answer but no one has an answer for disposing of the spent fuel. Worse, while I agree it is very uncommon, when you see what happened in Japan, it’s hard to get behind such a process. The results of an accident are just too steep. Too bad too because in all other respects it seems like the answer.

It also bothers me that they build these plants on the coast due to the water need. Especially here in the Midwest, I can’t get over that they build these plants on fresh water (the Great Lakes).

Maybe dispersion is the answer. More, smaller units. I don’t know.

 

[Totoro]

Wasn't saying there aren't large storage issues to work out, there are. I was just trying to convey that the perception that solar & wind causing coal to soar isn't correct for Germany. It's the nuclear phase out that caused the energy mix in favor of coal.

On the intermittency, most studies I've seen indicate that a strongly connected European grid - on the current investment schedule - can cover 80%+ of power needs with wind, sun and water. Geothermal is a nice addition. No major storage required.

The rest will have to be a combination of nuclear, storage or fossil fuels, maybe biomass for some.

A few other things: wind can be predicted quite well about two weeks out, solar same thing, and they tend to be complementary. It is windy when it isn't sunny and vice versa.

The generation charts from 2013 are also quite outdated, off-shore and on-shore winds behave differently and quite a bit of off-shore capacity has been added. Off-shore winds are more stable. Wind power in the UK and Germany have both almost doubled since 5 years.

 

[NW-Bound]

...
A few other things: wind can be predicted quite well about two weeks out, solar same thing, and they tend to be complementary. It is windy when it isn't sunny and vice versa...

Not 100% complementary.

The problem is we rely on power being there 24 hours, 365 days a year (+1 day for leap years of course ).

If we just run short for a day, it wreaks havoc on industrial production, commerce, food storage, transport, etc... We will need to have many conventional power plants on standby, and with fuel storage just in case.

I am sure that the power industry thinks about all these things, hence they proceed with caution. The moment there is rolling black out, the public will scream bloody murder. They are too ignorant to know it ain't easy.

 

[NW-Bound]

Here's a more recent power production chart for Germany power production.

I will see if I can find that chart in the winter that I saw, showing solar power going to zero on many days.

 

[samclem]

I used to believe this was the answer but no one has an answer for disposing of the spent fuel.

We have (IMO) a very good answer for nuclear waste: Put it all in one place and watch it. The awfulizing about how long it remains radiactive is just that (IMO). Does it matter? Hundreds of years, thousands of years? All the high-level nuclear waste we would make in hundreds of years of producing nuclear power would fit in a very small space. We just avoid that small spot (maybe 100 square miles max on a globe with 57.5 million square miles). And, maybe in a thousand years or so, we'll have a use for it. The concentrated and easily collected nature of nuclear waste is a great and advantageous feature, not a bug.

Worse, while I agree it is very uncommon, when you see what happened in Japan, it’s hard to get behind such a process. The results of an accident are just too steep. Too bad too because in all other respects it seems like the answer.

There are designs that do not depend on active cooling and hold promise of being are 100% "walk away" safe. Various types of "pebble bed" reactors are one approach.

 

[braumeister]

All the high-level nuclear waste we would make in hundreds of years of producing nuclear power would fit in a very small space.

I have a few suggestions for where that space could be.

 

[ERD50]

We have (IMO) a very good answer for nuclear waste: Put it all in one place and watch it. The awfulizing about how long it remains radiactive is just that (IMO). Does it matter? Hundreds of years, thousands of years? All the high-level nuclear waste we would make in hundreds of years of producing nuclear power would fit in a very small space. We just avoid that small spot (maybe 100 square miles max on a globe with 57.5 million square miles). And, maybe in a thousand years or so, we'll have a use for it. The concentrated and easily collected nature of nuclear waste is a great and advantageous feature, not a bug. ...

I've followed some discussions with people in the industry, that just leaving it on site is the best plan. A pretty high percent of it decays pretty quickly (months, years). Just leasve until we know what to do with it.

I'm optimistic they will find a use for it in far less than 1,000 years. It was only ~ 60 years between having some understanding of how atoms are structured and building an actual nuclear power plant. I can't imagine how far we will be in another 60 years even.

... There are designs that do not depend on active cooling and hold promise of being are 100% "walk away" safe. Various types of "pebble bed" reactors are one approach.

I sure hope that smaller, safer designs come to fruition. The progress has been slow though, pretty much vapor-ware for now.

-ERD50

 

[ncbill]

Everyone's forgetting that nuclear plants also produce very large quantities of low-level radioactive waste.

Which has its own disposal issues, and is not going to fit in a neat, compact space the relatively small amount of high-level waste will.

And innovative designs?

Forget it.

Here in the U.S. if you want to build a new reactor you're stuck with some variant of PWR.

Since we never even had a standardized design for that the cost has proven prohibitive.

There were until recently several reactors under construction or actively in the design stages.

IIRC, all but one have already been abandoned & I fully expect that last project to stop construction in the near future..

 

[Popeye]

Different kind of battery

Pumped Storage Hydropower

https://youtu.be/ehskGrg8hEA

No idea how much this could be scaled up and all of the wind turbines I have actually seen were in the flat Midwest but this intrigued me.

Here’s an installation in Swiss Alps.

https://youtu.be/IGDASBgrIRc

 

[samclem]

Everyone's forgetting that nuclear plants also produce very large quantities of low-level radioactive waste.

Which has its own disposal issues, and is not going to fit in a neat, compact space the relatively small amount of high-level waste will.

I don't know if anyone is "forgetting it." But the low-level waste from a nuclear plant per kwh is >tiny< compared to the fly ash from a coal plant (which is also radioactive, and is a cocktail of many heavy metals that is much more problematic than the low-level wastes produced during operation of a nuclear power plant.) If this global warming thang is really threatening the habitability of the planet, I'm guessing we can figure out how to store some dirty gloves and air filters, and that the public will support that. The problem of low-level waste is not a technical one.

Here in the U.S. if you want to build a new reactor you're stuck with some variant of PWR.

As above, the hurdles aren't technical or even economic.

Since we never even had a standardized design for that the cost has proven prohibitive.

I agree 100%. If we had standardized designs then design/production costs and safety issues would be reduced (because a problem found at one plant or a lesson learned is directly applicable elsewhere, instead of having scores of unique installations). If the major components were modularized, smaller (road transportable) and built in central locations (as we build ships) the quality control would be easier, costs would be lower, and decommissioning would be much less expensive.

 

[aja8888]

I suspect the French have figured out the technical and waste management aspects of nuke plants as they have been running many of them for years now. Maybe we could speak a peek?

 

[samclem]

I suspect the French have figured out the technical and waste management aspects of nuke plants as they have been running many of them for years now. Maybe we could speak a peek?

They did a good job with the management of their program, especially with standardization across their system. There is a joke: "In France, we have 3 kinds of nuclear power plants and 200 kinds of cheese. In America, it is exactly the opposite."


The advantages of standardization and modular plant construction are huge. Even when the equipment at a plant is decommissioned after decades, the old equipment can be trucked away and stored compactly and the next generation of equipment can be put on the same pads and running soon.

 

[NW-Bound]

Pumped Storage Hydropower

https://youtu.be/ehskGrg8hEA

No idea how much this could be scaled up and all of the wind turbines I have actually seen were in the flat Midwest but this intrigued me.

Here’s an installation in Swiss Alps.

https://youtu.be/IGDASBgrIRc

This is a very old idea. For example, SRP (Salt River Project) in Phoenix has been in operation since 1906, pumping water between multiple reservoirs on the Salt River.

The problem with hydro storage is that most of the suitable sites have already been exploited. And most of them only store enough for day/night load shifting; they pump upstream during the night when electric demand is low, then let water flow downstream to generate power during the day.

To store enough power for a few days, we are talking huge lakes. Maybe Lake Tahoe can work? Fill it to the brim, then drain it to the bottom if necessary? For the entire US, maybe the Great Lakes?

 

[NW-Bound]

For a perspective, let's look at some numbers.

The Bath County Pumped Storage Station in Virginia has the most capacity in the world due to its unique advantageous location. It can store 24,000 MWh.

The largest lithium battery Tesla recently built in Australia can store 129 MWh.

How do the above numbers compare with, say the usage of Los Angeles County? I have not found the highest daily number, but in the year of 2016, LA County used 69,615 GWh or 69,615,000 MWh (from cdms.energy.ca.gov).

Dividing the above number by 365, I get 190,726 MWh. Obviously, in the summer it is going to be a lot higher than that average.

That daily number is 8x the capacity of the Bath Pumped Storage, the largest in the world. And it would take 1,478 of the largest Tesla lithium bank.

All that just for LA county.

 

[Winemaker]

I don't know if anyone is "forgetting it." But the low-level waste from a nuclear plant per kwh is >tiny< compared to the fly ash from a coal plant (which is also radioactive, and is a cocktail of many heavy metals that is much more problematic than the low-level wastes produced during operation of a nuclear power plant.)

The materials in fly ash already exist in nature but are not as concentrated as they are distributed over thousands of tons. Fluidized bed combustion byproducts have been mixed with cement, and/or gypsum to make concrete, or drywall, thus diluting any fly ash toxic "cocktails".

 

[samclem]

Fluidized bed combustion byproducts have been mixed with cement, and/or gypsum to make concrete, or drywall, thus diluting any fly ash toxic "cocktails".

Yes. We have found a way, acceptable to the public, to deal with toxic fly ash (apparently). So dealing with the much smaller amount (per kwh) of less problematic low-level nuclear waste poses an easier trchnical problem that we can also handle and accept.

 

[braumeister]

The materials in fly ash already exist in nature but are not as concentrated as they are distributed over thousands of tons. Fluidized bed combustion byproducts have been mixed with cement, and/or gypsum to make concrete, or drywall, thus diluting any fly ash toxic "cocktails".

The world's largest drywall factory is near here. Barges collect the stuff from the scrubbers at coal-fired power plants along the Ohio River and deliver it to the factory for conversion into gypsum and manufacture of drywall.

 

[samclem]

Electricity is wonderfully versatile form of energy, but unfortunately we just don't have a way to economically store it in bulk.

It may prove far more practical to store solar energy as a liquid. One way to do this is to use the sun to grow algae, the algae creates lipids that are later burned (as we burn jet and diesel fuel) to produce mechanical energy or electricity. It won't be as cheap as direct PV conversion, but it can be available when PV (or wind) isn't. It is carbon neutral (CO2 taken out of the air or a waste stream to grow the algae, then put back into the air when the fuel is burned). The current processes can produce up to 2500 gallons of fuel per acre/year devoted to the bioreactors.

Other algae types and processes can be used to produce ethylene.
Liquid fuels produced from solar energy via algae are not yet cost-competitive with conventional petroleum, but research is at a fairly early state. There's lots of room for improvement in the selection/engineering of algae types and enhancing the efficiency of the processes. Again, if greenhouse gasses are an issue, this is preferable to burning petroleum. Algal biofuels are already being used (on an experimental scale) for large aircraft and other transportation uses where power density requirements make batteries impractical.

If we want a way to store massive quantities of solar energy for use when the sun isn't out, biofuels may be more economically feasible than batteries, pumped storage, etc.

 

[ERD50]

Pumped Storage Hydropower

https://youtu.be/ehskGrg8hEA

No idea how much this could be scaled up and all of the wind turbines I have actually seen were in the flat Midwest but this intrigued me.

Here’s an installation in Swiss Alps.

https://youtu.be/IGDASBgrIRc

This is a very old idea. For example, SRP (Salt River Project) in Phoenix has been in operation since 1906, pumping water between multiple reservoirs on the Salt River.

The problem with hydro storage is that most of the suitable sites have already been exploited. And most of them only store enough for day/night load shifting; they pump upstream during the night when electric demand is low, then let water flow downstream to generate power during the day.

To store enough power for a few days, we are talking huge lakes. Maybe Lake Tahoe can work? Fill it to the brim, then drain it to the bottom if necessary? For the entire US, maybe the Great Lakes?

Hydro storage does have some attractive aspects, but as you say, it is limited due to geography. Though I was surprised to read a while back of the pumped hydro that is on the Great Lakes. But I don't think there are many areas of 'steep' (relatively - ~ 300 feet) bank area along the Great Lakes.

https://en.wikipedia.org/wiki/Ludington_Pumped_Storage_Power_Plant

And it is has more storage capacity than I thought - nine hours at rated output of 2172 MW. For perspective, that's roughly the equivalent of the output of 3 coal plants. But of course, RE could dip for far longer than 9 hours. It was installed to help level the day/night demand for a nearby nuke.

Now another interesting number - 70% efficiency. Gotta use the correct the denominator to evaluate that. To get X MW-hrs out, you will actually need to put ~ 43% more RE in (not 30% more). 1.43 X .7 = 1.001.

So even before we account for the costs associated with the storage, we need to consider we need 43% more RE to maintain the same output.

-ERD50

 

[unclemick]

Circa 1974 a NASA engineer took me (transferred down as a contractor) out in the 'cow pasture' between the research buildings and showed me the vertical and horizontal wind 'mills' along with the solar powered air conditioner which took up 1/2 of a mobile home. BTY before NASA he was a TVA engineer.

Time marches on.

heh heh heh - 2018, 25th year of ER 'the Farm' has a solar power pond aerator, modified Westinghouse 3 wheel Marketeer and 2011 Polaris EV with mail order Lithium battery swap outs and a Canadian Solar panel on each roof. 3/4 of the way though a roof mounted wind mill and solar panel 'hobby level' unit on a pole barn. Further projects await.

And yes the farmhouse still has co-op electricity and propane heat. All praise to 'Bogle's Folly' and the hand grenade version of the 4% rule.

P.S. We have 'share' in the community solar farm in town. More a symbolic dent in in our coal fired electric bill than any thing heavyweight. Yet. Evolution not revolution speaking engineering wise.

 

[NW-Bound]

Electricity is wonderfully versatile form of energy, but unfortunately we just don't have a way to economically store it in bulk.

It may prove far more practical to store solar energy as a liquid. One way to do this is to use the sun to grow algae, the algae creates lipids that are later burned (as we burn jet and diesel fuel) to produce mechanical energy or electricity...

I do recall reading about this some years ago, and seeing some algae farms on TV. Have not heard anymore about this lately.

Search the Web, and this is what I found:

From 2005 to 2012, dozens of companies managed to extract hundreds of millions in cash from VCs in hopes of ultimately extracting fuel oil from algae.

CEOs, entrepreneurs and investors were making huge claims about the promise of algae-based biofuels; the U.S. Department of Energy was also making big bets through its bioenergy technologies office; industry advocates claimed that commercial algae fuels were within near-term reach.

Jim Lane of Biofuels Digest authored what was possibly history's least accurate market forecast, projecting that algal biofuel capacity would reach 1 billion gallons by 2014. In 2009, Solazyme promised competitively priced fuel from algae by 2012. Algenol planned to make 100 million gallons of ethanol annually in Mexico’s Sonoran Desert by the end of 2009 and 1 billion gallons by the end of 2012 at a production rate of 10,000 gallons per acre. PetroSun looked to develop an algae farm network of 1,100 acres of saltwater ponds that could produce 4.4 million gallons of algal oil and 110 million pounds of biomass per year.

What happened to these ventures?

Read: Lessons from the great algae biofuel bubble.

 

[NW-Bound]

To store enough power for a few days, we are talking huge lakes. Maybe Lake Tahoe can work? Fill it to the brim, then drain it to the bottom if necessary? For the entire US, maybe the Great Lakes?

Hydro storage does have some attractive aspects, but as you say, it is limited due to geography. Though I was surprised to read a while back of the pumped hydro that is on the Great Lakes. But I don't think there are many areas of 'steep' (relatively - ~ 300 feet) bank area along the Great Lakes...

I was sarcastic, but could be too subtle.

I once sat down trying to figure out how much energy could be stored by pumping water between Lake Ontario and Lake Superior, which have the most elevation difference.

I was trying to see how much energy one could get by willing to have the lake water level vary as much as 100 ft (a huge environment disruption), then compare that with the energy consumption of the US or Canada to see if it makes a dent.

I don't know what I have done with that.

 

[Totoro]

Reminds me of Atlantropa - damming the strait of Gibraltar.

https://en.wikipedia.org/wiki/Atlantropa

 

[ERD50]

I was sarcastic, but could be too subtle. ...

Oh no, I 'got it'.

It just tweaked my (inferior) memory about the hydro storage that actually is on the Great Lakes, and was surprised it had as much capacity as it did, so thought it was worth mentioning.

-ERD50