How cheap does solar power need to get before it takes over the world?

It's easy to get ridiculously excited about solar power these days. The panels keep getting cheaper and cheaper as technology improves. Large photovoltaic arrays are sprouting up around the globe. Sure, solar still produces only 1 percent of the world's electricity, but it's growing at double-digit rates each year.
Is solar ready to take over the world?
According to a provocative recent essay in Nature Energy, not yet. Two solar analysts, Varun Sivaram and Shayle Kann, argues that solar still has some hard economic obstacles to overcome before it can become a major energy source and provide, for example, one-third of our power. Overcoming these hurdles could mean the difference between solar leveling off as a niche technology and solar taking over the world.

http://www.vox.com/2016/4/18/11415510/solar-power-costs-innovation

Paper: Link

 

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India is on track to soar past a goal to deploy more than 100 gigawatts of solar power by 2022, the country’s energy minister Piyush Goyal said on Monday.
Speaking at the release of a 15-point action plan for the country’s renewable sector, Goyal said he was now considering looking at "something more" for the fast growing solar sector. According to him, solar may be viable option, because is now probably cheaper than coal.
Solar energy prices hit a new record low in January with the auction of 420 megawatts in Rajasthan at 4.34 rupees a kilowatt-hour. In comparison coal tariffs range between 3-5 rupees/kWh.

http://www.climatechangenews.com/20...cheaper-than-coal-says-india-energy-minister/

 

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I have used solar power for twenty years.
With no grid power they offer a viable power supply.
You need a battery bank and a back up generator (only a small one as it charges batteries and is not used for appliances etc).
Once you learn to calculate useage and adapt it is great not having an electricity as you do in a city.

Alex

 

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. . . . and then you realize that it gets dark at night!

 

Exactly. That is what the paper says, basically (Durrh!), although this is obscured by fancy terms, like "value deflation" which, so far as I can tell, they seem to use wrongly*. The paper points out that, as solar capacity increases, the price of daytime electricity drops, relative to that generated at night and that, without some system for storage, this will limit the economic value of adding more solar capacity.

What strikes me though is that this provides a market opportunity for operators of electricity storage to innovate and invest, so that they can buy cheap during the day and sell dear at night.

I suppose one may need the guiding hand of government policy here, to ensure you have a virtuous circle of development and installation of both, rather a chicken-and-egg blockage of development, in which each side waits for the other to make the first move!

*From what I have been able to research, value deflation is actually the marketing technique of keeping price per sales unit constant while making the size of the sales units smaller, i.e. an alternative to a retail price increase: http://www.investopedia.com/terms/v/value-deflation.asp
(In Europe we see this most flagrantly at the moment with toothpaste - just about all the manufacturers seem to have gone from 100ml tubes to 75ml ones, while maintaining prices. F*** the lot of them!)

 

Agreed. The bad news there is that to provide that market opportunity, power prices have to go up dramatically. For example, you might have to price daytime power as it is priced now, but increase nighttime power by $1 a kilowatt-hour. (Most BESS implementations cost between 25 cents and $1 a kilowatt-hour over their lifetime - and then they still need to make a profit.)

 

If you're caught in a suboptimal stable market equilibrium, only government or disaster can extricate you. Your choice.

On abstract grounds: In places and times where the primary demand for electricity is during the day - which is everywhere there is, for example, air conditioning in homes and office buildings - the only necessary "storage" would be that provided by ordinary thermal solar setups almost automatically.

In private homes etc, where LED lights and similar innovations coupled with things like that new cheap battery tech Plasma Inferno linked (and a reasonable use of gizmos like Stirling cycle generators run off the furnace for backup) would cover anything short of an electric oven cooking a turkey, storage is one of those problems mass production handles really well.

If it's down to storage, it's solved. In theory.

 

The environmental disaster that would result from so many storage systems out there would make us long for the days of coal power. A good example of the cure being worse than the disease.

 

Don't be silly. Every car in the US is carrying not just one but two of least efficient and most poisonous storage systems around, every rural house has a propane tank or something of the kind sitting next to it - and a septic system the size of a garage hooked up. Not to mention air conditioners, water softeners, machinery supplies - c'mon.

For all you know it'll be an air pressure tank. Or a flywheel.

This is one of those problems that was made to order for industrial economies. Check out Plasma Inferno's battery link in "Chemistry".

 

Apparenlty, the US solar market is now 1 million installations strong.
"It took us 40 years to get to 1 million installations, and it will take us only two years to get to 2 million,” said Dan Whitten, vice president of communications at the Solar Energy Industries Association (SEIA). “This is a time to mark when the solar industry started to accelerate at warp speed."

At the end of 2015, the U.S. solar market hit a total capacity of 27 gigawatts. That represents just 1 percent of the current U.S. electricity mix, but it could triple to 3 percent by 2020. This year alone, the U.S. solar market is projected to grow 119 percent, which represents an additional 16 gigawatts of new installed capacity and more than double the record-breaking 7.3 gigawatts added in 2015.

http://www.greentechmedia.com/artic...r-Market-Now-One-Million-Installations-Strong

 

That's an optimistic way of saying solar's growth rate is slowing!

 

A car battery has about 20 pounds of lead in it. A system capable of running a house for a day has 600. That's an increase in lead of 30 times if you do it across the country.

Would you rather have an ounce of propane dissolved in the water you drink, or an ounce of lead?

Could be. Both have been talked about for decades. I hope some major discovery comes along that enables one or both to be practical.

But until then, solar is best used to offset daily peaks, rather than being a source of energy to be stored in lead-acid (or even lithium ion) batteries for home consumption.

 

Yes but wasn't the flaw in that not recognising that the human population will stabilise, all by itself, at around 11 bn?

 

It is far from trivial. It may be doable, but it would take significant advances in technology to accomplish such a plan.

 

It doesn't have to run it for a day. It has to run it for a night. Why are you using car batteries for solar storage? Is there some reason that manganese setup Plasma Inferno linked in "Chemistry" is unavailable to you?

And if you are going to insist on that, why not use better ones: https://en.wikipedia.org/wiki/Tesla_Powerwall

The houses around me have more than 100 pounds of very poorly controlled and unplanned lead acid battery storage sitting around, and hundreds of gallons of propane in tanks perched in their yards, and no such problems. It's routine.

I think you are overestimating the practicality of what we have now, and underestimating the effort involved in getting us here.

So explosive growth is anticipated by all, up to at least a third of the electrical power consumption of the US - the daily peaks.

The mode of "stabilization" of the global human population is the matter of primary concern. Of course it will stabilize. The question is how.

 

I guess in areas that never experience weather, that would make sense.

People don't. They use deep cycle lead acid batteries, not car batteries. Different design, same lead.

The same reason they are unavailable to you. There are basically two chemistries available today for residential power storage - lead acid and lithium. There are very few other chemistries; some nickel-iron, some nickel-cadmium and that's about it. They are so rare that it is, in general, very difficult to configure charge controllers to work with them.

Now IN THEORY there are plenty of other chemistries available. Flow batteries could make a big dent in storage. There are aluminum chemistries and silver chemistries that have promise. All have their pluses and minuses, and it would be wise to consider them BEFORE we declare the problem solved and potentially create a bigger problem than the one we are trying to solve.

And I think you are underestimating them. Have you ever constructed an off-grid power system, or an on-grid power system that uses batteries to do peak shaving? Ever tried to get a system that balances solar generation and dispatchable loads? I think your opinion might change if you did.

We'll hit some pretty fundamental limits at about the 25% level. (Which is still a good thing; moving 25% of US generation to solar would be great.)

 

Or in areas in which "weather" is a considerable factor and expense in the current setup already, or ones in which "run a house" is a flexible term with some tradeoffs available.

Aside from the market being no help in such an approach, are we at least in agreement regarding the problem: storage?

Which a thermal solar central plant provides as a direct expansion of its basic construction.

? Misread?

I think you have made some odd assumptions about my opinion. Also: Back a couple, the advantage of peak shaving via solar was that it didn't require that kind of storage.

And not designed, but lived (houseguest) off grid - it worked fine. Windmill. They had computers, electric lights. Their furnace and plumbing and phone (including the barn well and stock tank) worked all winter long, even after ice storms and blizzards - which was not true of their neighbor's. They had a backup gas powered generator and a backup kerosene space heater, like their more prosperous neighbors, but hadn't started either one (for the house) in years.
Sacrifices? Laundry - unable to machine wash without hassle unless the wind was blowing. Which they regarded as no sacrifice at all - they hand washed using modern gear, and line dried, by preference anyway (cleaner and longer lasting clothes).

And of course all the hassle of jury-rigging their own setup, a series of problems of a kind normally handled by professional engineers and designers and marketed turn-key. In a modern industrial economy.

No, I haven't done any serious engineering. But when I see the people who are trying to sell me nuclear power plants throwing up their hands in the face of storing day-generated power, and then read something like Plasma Inferno's link (and that's not the first such encounter with this pattern) in which we find that the mechanism of a well-known battery configuration had never actually been investigated until last year:

it looks to me like the major hurdles here are probably not engineering ones.

 

The problem lies in matching unreliable generation with unpredictable load. If the two match (and the remaining baseline is sufficient to run the grid when the unreliable sources are unavailable) then there's no need for storage. If the two do not match and cannot be made to match, then you need a lot of storage.

In general we will make the most progress with dispatchable/aggregated load and large scale storage (i.e. pumped storage.) Economics and environmental considerations do not favor battery based storage for large scale implementations outside of specific grid-stability applications (frequency stabilization, voltage stabilization, VAR compensation.)

I know of several such systems as well. They are, in general, run by people who have become experts in renewable energy of the sort they are using - and are often not good showcases for environmentally benign living. Every person I know who is truly off-grid, for example, has a gas/propane/diesel generator that they run pretty regularly, and small engines of that sort are the dirtiest types of power we have.

Such systems, if installed in a typical person's house, would be dead within a month.

Those are two different things. Nuclear power plants are base load generators, and are not suited for peaking purposes (which is basically what storage is pitched for.) Fast startup combined cycle NG plants are far better at providing peaking power - and they exist, and they work today.

Any sane, ecologically responsible future system will combine base load generation (nuclear, large hydro) with renewables (wind, solar) and peakers (NG primarily.) As renewables proliferate, the additional reliable capacity will come from construction of new peakers and aggregated load resources. It will be decades before we see chemical storage (i.e. batteries) making a significant change in that power breakdown.

I've been in the power engineering field since the 1990's, and during that time I have seen perhaps 500 announcements of new batteries in trade journals. Lithium ion chemistries that increase energy storage by a factor of 10 - and reduce cost by a factor of 2. Lithium-metal batteries and silicon anodes are two of the latest big hopes there. I have seen molten sodium chemistries that will be very safe; the author is certain of it. Fuel cells that will convert natural gas to electricity so efficiently and cheaply that all homes will soon have one. It has gotten to the point where we won't talk to new companies unless they have engineering samples we can test in our labs.

So it's great that people are working on zinc-manganese batteries. They join the ranks of the thousands of researchers making similar claims. Still battery technology chugs along with an average improvement of about 5% a year in energy storage density and about 2% a year improvement in life. The smart money would be on a similar rate of improvement in the future.

 

I think you miss the point. The mechanism of the zinc manganese battery had never been investigated, until last year. That pattern is frequently encountered in this arena. I recall reading - a few months ago - that of the 700 or so likely molten and phase changing salts that looked promising on paper for thermal solar storage, five had been thoroughly investigated, and two others looked into. And so forth.

It's possible the smart money would notice that when solar generation capability hits 25%, the market for storage innovations will suddenly become larger than the market for - say - nuclear power innovations. Imagine equivalent research efforts. Just a thought.

So do most of my neighbors who are on-grid. Because grid power needs backup, too - when your furnace and plumbing don't work without it, say. Remember "weather"?

Storage is not being "pitched" - in this thread - for peaking purposes. It's being "pitched" for replacing non-solar base load generation at night and in bad weather.

Or as I put it: the people throwing up their hands at the prospect of substantial storage improvements, banging on and on about the complexity of the problem and the impossibility of substantial near term progress and the expensive nature of solar and the amount of research already devoted to it with indifferent results, are the same ones selling me nuclear reactors.