Hacker News Board Hacker News, browsed like a classic message board
Live data from Hacker News

Solar Is Cheapest Electricity in History, U.S. DOE Aims to Cut Costs 60% by 2030

cleantechnica.com

Post reply on HN
Print view View original

121–130 of 257 posts

Re: Solar Is Cheapest Electricity in History, U.S. DOE Aims to Cut Costs 60% by 2030

#121

Post by zizee »

flgb wrote: post #61
zizee wrote: post #41

I think the future will be robust national/international grids, with a mixture of storage options (batteries/pumped hydro) to smooth out the intermittent nature of wind and solar. Cynics always talk about the amount of energy storage required for solar as if you need to store 24 hours of energy for solar/wind to be viable. I'd like to see numbers on having 1 hour of storage for peak demand, a robust national grid, an…

I suspect most of the intermittency of wind and solar will be addressed through super-capacity (500% of peak demand, not 100%) and geographic diversity. Batteries will be used for very short-term local balancing and power regulation ... then for those occasional times when hydro, wind and solar don’t cut it, we’ll still burn a little gas but it will be bio gas or green hydrogen, rather than fossil gas. This gas will…

I agree entirely. I chose the 1 hour of storage as a number because I had to say something, and I didn't want to go to low as it would undoubtedly knee jerk responses of "that's not enough, you need X hours".

The main point I was going for is that we shouldn't think of a national network in the same way as we think of a off grid house with solar, where you have to deal with many hours without sunlight, and have storage capacity for several days of rain.

In a similar vein, the intermittency of solar and wind look bad when you look at isolated generation instances, but when you have a continent spanning network, the intermittency is reduced as the wind is always blowing somewhere, and the sun is shining for many more hours than when you look at any single point on map.

Again, I would love to see the numbers if you were plan out a realistic build out of this ideal network. It would probably be a pretty big number, but how would it compare to building out with nuclear, or even just lots of coal power plants from scratch.

Re: Solar Is Cheapest Electricity in History, U.S. DOE Aims to Cut Costs 60% by 2030

#122

Post by Hypx »

Manfredo_1 wrote: post #106
pfdietz wrote: post #103

Earlier quoted context omitted.

All the components of hydrogen, with the possible exception of low cost electrolyzers, don't need to be prototyped. It's existing technology. It's not like (say) molten salt reactors, in which fundamental development remains to be done.

Right, and what company can I call right now to install 50GWh of hydrogen storage? It's existing technology, but it's a novel application of that technology. We haven't used hydrogen electrolysis as a form of grid storage before. And we certainly haven't used it for grid storage at the Terawatt hour scale. And that the scale we'll need to make wind and solar viable. 1 TWh isn't even 30 minutes of global electricity c…

https://www.pv-magazine.com/2020/06/16/hydrogen-storage-in-s...

We could easily have Petawatt-hour scale hydrogen energy storage.

Re: Solar Is Cheapest Electricity in History, U.S. DOE Aims to Cut Costs 60% by 2030

#123

Post by philipkglass »

dukeofdoom wrote: post #93
zizee wrote: post #41

I think the future will be robust national/international grids, with a mixture of storage options (batteries/pumped hydro) to smooth out the intermittent nature of wind and solar. Cynics always talk about the amount of energy storage required for solar as if you need to store 24 hours of energy for solar/wind to be viable. I'd like to see numbers on having 1 hour of storage for peak demand, a robust national grid, an…

So I've been watching these Van build outs into full time living vans for travel. Most of them have solor panels on the roof, and 3 two hundred watt batteries. One guy said it would take him 23 days to fully charge these batteries off of solar vs just a few hours to charged them from the alternator when he is driving. It just doesn't seem very practical at this point. They all seem to have 2 or 3 thousand watt panels…

I think that your recollection is incomplete or garbled. Modern solar panels are about 20% efficient. They can generate about 200 watts per square meter in midday sun with clear skies. 2000 to 3000 watts of panels would be about 10-15 square meters (107-161 square feet). Do these vans actually have roofs that large, completely covered with panels?

You might expect roof top panels with sub-optimal orientation to generate about 12.5% of their peak rating when averaged over a year. That would be 375 watts, annualized, from a system with a peak capacity of 3000 watts. There is no van-portable battery system currently on the market that can store 375 * 24 * 23 = 207,000 watt-hours. (For comparison, the Tesla Model S battery stores 100,000 watt-hours.)

My guess is that you are not correctly recalling how much solar capacity these vans have installed. When I Google for van life solar I get guides and kits referencing much less power.

For example, this guide:

https://www.genericvan.life/2018/04/30/complete-vanlife-sola...

uses a single 150 watt panel. Based on the photo the article includes, I don't think that the van rooftop has room for more than 3 panels of this type.

Re: Solar Is Cheapest Electricity in History, U.S. DOE Aims to Cut Costs 60% by 2030

#124

Post by Manfredo_1 »

Hypx wrote: post #122
Manfredo_1 wrote: post #106

Earlier quoted context omitted.

Right, and what company can I call right now to install 50GWh of hydrogen storage? It's existing technology, but it's a novel application of that technology. We haven't used hydrogen electrolysis as a form of grid storage before. And we certainly haven't used it for grid storage at the Terawatt hour scale. And that the scale we'll need to make wind and solar viable. 1 TWh isn't even 30 minutes of global electricity c…

https://www.pv-magazine.com/2020/06/16/hydrogen-storage-in-s... We could easily have Petawatt-hour scale hydrogen energy storage.

No, you have salt caverns with a volume sufficient to accommodate a lot of hydrogen. Actually implementing such a solution involves massive scale electrolysis, and either massive scales of oxidation cells or gas turbines designed to burn hydrogen. Neither of these things have been done at anything remotely close to the scale required to make renewables feasible.

Back in the 1950s people thought that nuclear power would be effectively free. But actually building it at scale exposed challenges of implementation that weren't foreseen. The cost of a system on paper and the cost after overcoming the challenges of actually building it are two very different things. For hydrogen storage, you only have the former.

Re: Solar Is Cheapest Electricity in History, U.S. DOE Aims to Cut Costs 60% by 2030

#125

Post by panarky »

Manfredo_1 wrote: post #117
crummy wrote: post #115

Earlier quoted context omitted.

Isn't demand shaping things like discounts during certain periods? My electricity provider lets me set a 'free hour of power' every day, as long as that hour is off peak.

Yes, those incentives exist to try and shape demand. But in practice, people rarely take advantage of them. And some things really can't be shaped. The pumps that deliver your water cannot have their demand shaped, unless you're willing to go without running water for some hours of the day.

If we paid the true cost of peak power, it might be worth pumping water with off-peak power and storing it locally.

Re: Solar Is Cheapest Electricity in History, U.S. DOE Aims to Cut Costs 60% by 2030

#126

Post by Hypx »

Manfredo_1 wrote: post #124
Hypx wrote: post #122

Earlier quoted context omitted.

https://www.pv-magazine.com/2020/06/16/hydrogen-storage-in-s... We could easily have Petawatt-hour scale hydrogen energy storage.

No, you have salt caverns with a volume sufficient to accommodate a lot of hydrogen. Actually implementing such a solution involves massive scale electrolysis, and either massive scales of oxidation cells or gas turbines designed to burn hydrogen. Neither of these things have been done at anything remotely close to the scale required to make renewables feasible. Back in the 1950s people thought that nuclear power wou…

Those gas turbines you're referring to can simply be modified natural gas gas turbines. The only limiting factor would be electrolysis, but that is already something people are planning to build a lot of.

Nuclear's problem are fundamentally political in nature. If we really cared about green energy, nuclear power could easily be built out at scale.

Re: Solar Is Cheapest Electricity in History, U.S. DOE Aims to Cut Costs 60% by 2030

#127

Post by Hypx »

flgb wrote: post #61
zizee wrote: post #41

I think the future will be robust national/international grids, with a mixture of storage options (batteries/pumped hydro) to smooth out the intermittent nature of wind and solar. Cynics always talk about the amount of energy storage required for solar as if you need to store 24 hours of energy for solar/wind to be viable. I'd like to see numbers on having 1 hour of storage for peak demand, a robust national grid, an…

I suspect most of the intermittency of wind and solar will be addressed through super-capacity (500% of peak demand, not 100%) and geographic diversity. Batteries will be used for very short-term local balancing and power regulation ... then for those occasional times when hydro, wind and solar don’t cut it, we’ll still burn a little gas but it will be bio gas or green hydrogen, rather than fossil gas. This gas will…

Super-capacity is going to be a major driver for the build-out of water electrolysis for the production of hydrogen. You can turn what will basically be a waste product into a highly useful fuel. I've seen people contend that this will be expensive, but given the very cheap input costs I believe this will be a very cheap process.

Re: Solar Is Cheapest Electricity in History, U.S. DOE Aims to Cut Costs 60% by 2030

#128

Post by Manfredo_1 »

Hypx wrote: post #126
Manfredo_1 wrote: post #124

Earlier quoted context omitted.

No, you have salt caverns with a volume sufficient to accommodate a lot of hydrogen. Actually implementing such a solution involves massive scale electrolysis, and either massive scales of oxidation cells or gas turbines designed to burn hydrogen. Neither of these things have been done at anything remotely close to the scale required to make renewables feasible. Back in the 1950s people thought that nuclear power wou…

Those gas turbines you're referring to can simply be modified natural gas gas turbines. The only limiting factor would be electrolysis, but that is already something people are planning to build a lot of. Nuclear's problem are fundamentally political in nature. If we really cared about green energy, nuclear power could easily be built out at scale.

No, hydrogen rapidly corrodes any metals that it comes into contact with. If they are interchangeable, expect drastically smaller service intervals.

Re: Solar Is Cheapest Electricity in History, U.S. DOE Aims to Cut Costs 60% by 2030

#129

Post by mlyle »

pfdietz wrote: post #102
Manfredo_1 wrote: post #101

Earlier quoted context omitted.

None of those other battery chemistries are seeing the massive growth that lithium ion batteries have experienced. The nuclear "stans" are just pointing out that these are potential solutions, not actual solutions. If iron oxide batteries, or some other chemistry, suddenly becomes cheap and easily deployed at the TWh scale, great. But until then they're not a solution.

Yes, you all are engaging in the "nothing can be invented" argument. It's profoundly reactionary, and also hypocritical, because nuclear itself is dead without great improvement. Uranium quickly runs out if the world is powered by burner reactors and known uranium resources, so either massive seawater uranium extraction or breeding cycles would be needed. Batteries have the advantage of being explorable at a small sc…

> Yes, you all are engaging in the "nothing can be invented" argument.

No, we're engaging in the "this has been resistant to being invented so far, so let's not bet everything on it showing up tomorrow" argument.

> Uranium quickly runs out if the world is powered by burner reactors and known uranium resources

You could quadruple the present rate of uranium use, representing in a major contribution to mankind's energy use, and have 35 years of supply, just using known reserves and no breeding.

And if you were using that much uranium, more reserves would be quickly proven. Do you think we've found all the uranium we'll ever find, even if market prices go up significantly?

And breeding is possible, and understood. Yes, there's proliferation concerns, but that's not the end of the world.

And seawater extraction is practical without much increase in cost.

No one is saying "no renewables" or "no battery storage" or "no pumped storage". Or "no power to gas to power". We need all of these things. And we need the diversity of having nuclear in the mix, too.

Re: Solar Is Cheapest Electricity in History, U.S. DOE Aims to Cut Costs 60% by 2030

#130

Post by yazaddaruvala »

flavius29663 wrote: post #104
yazaddaruvala wrote: post #39

Earlier quoted context omitted.

Here is a commercial installation of solar + storage at $0.04/kWh[1]. And it’s not unique, that article links to the cheapest solar + storage in the US at $0.025/kWh. Additionally, these are today’s prices, as per this article the price for renewables is dropping exponentially every year. And if Elon Musk is to be believed (which I do) the price for storage is also dropping exponentially. [1] https://pv-magazine-usa.…

storage alone will almost never be enough. The electricity is just too important for the modern societies to leave it to chance. You will have events where there will be no wind or sun for weeks. In order to have that many batteries it would require monumental investments. And those batteries would sit unused for years. You need a diverse and distributed generation network, backed by gas burning plants.

I mean, gas definitely doesn't *need to* be involved. At that point you're better off with fission.

For example, the US is connected north to south in 2 electric grids (TX excludes itself, but is huge). Making all three of those grids large enough that the sun definitely isn't obscured for weeks.

Additionally, places like India are talking about building a "world gird" to be the solar power generator for the world.

Post reply on HN