The price of solar power just fell 50% in 16 months • Hacker News Board

Re: The price of solar power just fell 50% in 16 months

#441

Post by ssmoot » Thu, May 05, 2016, 3:15 PM UTC

DennisP wrote: post #347

ssmoot wrote: post #294

Earlier quoted context omitted.

It'd take over 1 BILLION Powerwalls to store half the daily usage in the US (using old usage numbers off Wikipedia). I wonder if there's enough raw materials to make that realistic. And how to you manage recycling, repair, replacement, end-of-life concerns for all those batteries on that scale? Not asking a sarcastic hypothetical. Genuinely curious. It's hard to wrap my head around numbers that big. For reference I u…

Raw material supply is a big issue; see Berkeley physicist Tom Murphy's calculations: http://physics.ucsd.edu/do-the-math/2011/08/nation-sized-bat... He's mainly talking about lead but for lithium it's even worse. A lot of things look great until you look at the scaling limits. Hydro storage is another example; Murphy's got a post on that too.

If these numbers are even close to accurate, this should be the top post.

It's no use for everyone to argue over wether a completely implausible idea is financially competitive on a small scale when the implication is we're talking about scaling on a national level.

Re: The price of solar power just fell 50% in 16 months

#442

Post by msellout » Thu, May 05, 2016, 3:29 PM UTC

icanhackit wrote: post #324

msellout wrote: post #291

Earlier quoted context omitted.

Yikes. Yes, of course technology is driven by human preferences. But, No, humans must occasionally accept that certain habits are not sustainable given current and near-future technologies.

I generally agree with your position but in this particular scenario the people with the greatest capacity to adjust their behavior are the people who will be affected the least financially by a hike in peak prices and thus less likely to change or more likely to invest in solar at home, while those with the least flexibility in work arrangements and spending, e.g. lower income earners working in the services sector,…

More variant pricing will better distribute usage. The unfortunate effects on the poor can be negated by a sales tax paid back to all citizens equally as a lump sum.

Re: The price of solar power just fell 50% in 16 months

#443

Post by zeristor » Thu, May 05, 2016, 6:47 PM UTC

fanf2 wrote: post #396

cjensen wrote: post #372

Earlier quoted context omitted.

Pumped storage is routinely used to store energy. It's not theoretical. Has Flywheel storage every been seriously used in large-scale commercial applications? Someone mentions it on every energy-storage thread, and I'd like to know if the people suggesting it are just spinning our wheels.

The JET fusion reactor in Oxfordshire uses flywheels to provide very large pulses of electricity for short periods of time (a minute or two iirc). The reactor requires too much energy to run directly off the National Grid.

As I recall from a tour I went on of jet 30 years ago there are a large bank of flywheels which spin up over several minutes, these are then rapidly discharged to a bank of capacitors which are then used to power the experiment, I believe the duty cycle was 9 minutes. [1][2]

I believe some electric cars used capacitors to store regenerated electricity from breaking.

"More Ampères please Mister Woodbine." - Road to Welville

[1] - http://pia.sagepub.com/content/200/2/95.abstract

[2] - http://www.euro-fusionscipub.org/wp-content/uploads/2014/11/...

Re: The price of solar power just fell 50% in 16 months

#444

Post by lisivka » Thu, May 05, 2016, 7:51 PM UTC

yourapostasy wrote: post #439

lisivka wrote: post #437

Earlier quoted context omitted.

Make container of highly porous material then fill it with a fluid which will avoid that material surface at molecular level. AFAIK, it is invented years ago.

Can you post a link to that please? When I search around starting with the Wikipedia [1] entry, I don't find a description of what you are describing. [1] https://en.wikipedia.org/wiki/Molecular_spring

http://www.google.com/patents/US7767301 http://dergipark.ulakbim.gov.tr/eoguijt/article/view/1034000...

Re: The price of solar power just fell 50% in 16 months

#445

Post by eru » Fri, May 06, 2016, 12:02 AM UTC

pilom wrote: post #431

afarrell wrote: post #341

Earlier quoted context omitted.

Is there a way to coordinate demand without asking thousands of people to give Alice the ability to shut off their appliances?

Yes, industrial plants will turn off production (for instance at an aluminum smelting plant) in relation to the frequency of the grid. Grid frequency decreases slightly when demand starts outpacing "supply."

That frequency change used to be a natural reaction from the generators.

I wonder whether they create that signal artificially with electronics these days, or if it's still a natural consequence of the mechanics of the spinning generators they run in power stations?

Re: The price of solar power just fell 50% in 16 months

#446

Post by dTal » Sat, May 07, 2016, 1:19 PM UTC

amenghra wrote: post #236

S_A_P wrote: post #229

Earlier quoted context omitted.

Can validate. The problem with electricity is that there is no large scale storage like there is for other forms of energy like NG and Crude. Until someone comes along and figures out how to store electricity, this will continue to cause grief to power companies. Power plants are really just options, if the price per kWh is at a certain point then it makes sense to spin up or take down a plant and generate power. Add…

Some countries store energy by pumping water up a dam. Seems efficient.

Better than nothing, but not that efficient. I took the tour of the somewhat mis-named Dinorwig Power Station (really a pumped storage facility) in Snowdonia, Wales. The figures they quoted there put it at about 75% efficiency. It's not really supposed to be for 24-hour power smoothing, more for rapid response to sudden demand; it's a lot faster to open a valve on a turbine than to stoke up a coal plant, and for some spikes (such as the example they quoted on the tour, when everyone puts the kettle on when Coronation Street finishes) you have a 30-second window or so. However, as demand has increased it's being used more and more, and the more it's used the more power we're wasting.

Interestingly, it does not use a dam. There's a natural lake at the bottom of a mountain and a man-made reservoir at the top, and the entire pumping facility is completely inside the mountain; it's not at all obvious that there's anything there at all from the outside. I think about that whenever people moan about the environmental impact, or flooding valleys.

Re: The price of solar power just fell 50% in 16 months

#447

Post by luckydude » Sat, May 07, 2016, 4:04 PM UTC

ChuckMcM wrote: post #103

The aggressiveness of the price drops on solar is pretty amazing. I just lost one of the inverters on my grid-tie system after it had run trouble free for 13 years. So we're looking at the first "major" repair to the system I installed in 2003. And in 2003 my 5.2kW of panels on my roof cost $38,000 before subsidies and $19,000 after. 28 panels, two 2.5kW inverters, net about 4.2kW of generation. I priced out replacin…

Hey Chuck, I've been waiting for solar to come down and it sounds like it has. When you priced it, was it just for parts or was that $7K installed?

And for the do-it-yourselfers, how much of the cost is installation now? Is it practical to do most of the grunt work yourself and then get an electrician in to do the final part?

Re: The price of solar power just fell 50% in 16 months

#448

Post by ChuckMcM » Sat, May 07, 2016, 4:49 PM UTC

luckydude wrote: post #447

ChuckMcM wrote: post #103

The aggressiveness of the price drops on solar is pretty amazing. I just lost one of the inverters on my grid-tie system after it had run trouble free for 13 years. So we're looking at the first "major" repair to the system I installed in 2003. And in 2003 my 5.2kW of panels on my roof cost $38,000 before subsidies and $19,000 after. 28 panels, two 2.5kW inverters, net about 4.2kW of generation. I priced out replacin…

Hey Chuck, I've been waiting for solar to come down and it sounds like it has. When you priced it, was it just for parts or was that $7K installed? And for the do-it-yourselfers, how much of the cost is installation now? Is it practical to do most of the grunt work yourself and then get an electrician in to do the final part?

As mentioned elsewhere it was just parts. Installation of grid tie systems isn't hard but does have a number of building code things you have to follow (at least in California). At the time we did the install my wife took a solar installer's course which went over the current code.

I can recommend that as a plan of action, find a local group offering job training as a solar installer and take it. Then using that knowledge you can design an installation that meets your local code.