A near 100% renewables grid is well within reach, and with little storage • Hacker News Board

Re: A near 100% renewables grid is well within reach, and with little storage

#181

Post by qqqwerty » Wed, Aug 24, 2022, 7:27 PM UTC

zdragnar wrote: post #6

WalterBright wrote: post #4

5 hours of grid-scale storage seems like a lot.

On its own, it does seem like a lot. Thinking about the nature of renewables where I live, it seems so small as to be not worth mentioning; January will often have a week to several weeks of heavy cloud cover and little wind. A mere 5 hours of capacity is a pittance. Australia, on the other hand, could easily make more sense, as I imagine the outback to be sunnier year round and maybe windier.

What percentage of the population lives in climates like yours? If I had to guess, maybe something like 10-20% of the worlds population?

My gut tells me the vast majority of the worlds population lives in locations that are more similar to Australia's climate than in climates like yours. So we start there, and overtime things get cheaper, we find better solutions to long duration storage, and then we start tackling the harder climates/geographies.

Re: A near 100% renewables grid is well within reach, and with little storage

#182

Post by bcrosby95 » Wed, Aug 24, 2022, 7:28 PM UTC

onlyrealcuzzo wrote: post #28

cm2187 wrote: post #10

The averages don’t tell me much. We need to look at percentiles with intermittent sources of energy. 99% still means 3 full days of blackout every year. So it needs to be sufficient to cover an even higher percentile (in fact I don’t even think there is an acceptable number of hours of blackout in a year). I would be curious how they get to that with energies that pretty much go to zero the week there is no wind.

> 99% still means 3 full days of blackout every year. Presumably the entire grid isn't going down. Brown outs in small parts of the country is what I'd expect. This sounds like the current state of California.

I grew up in California, and brown outs have been a problem here for at least the last 30 years.

I don't know if renewables had much of an affect one way or another.

Re: A near 100% renewables grid is well within reach, and with little storage

#183

Post by adgjlsfhk1 » Wed, Aug 24, 2022, 7:29 PM UTC

idiotsecant wrote: post #172

Retric wrote: post #115

Earlier quoted context omitted.

Swapping hydro from 24/7 power to a backup for wind and solar goes a long way to eliminate the need for storage. We don’t need more total kWh per year of hydro we need to be able to more flexibility get those kWh.

I am an engineer that works on hydro control systems - It's worth noting that a hydro turbine, depending on it's construction, has a certain turndown ratio - That ratio of it's full scale output to it's minimum output. At the turn of the century designers of these turbines did not particularly care about operating at a lot of different power output levels, they cared about maximizing power output at a particular poin…

Can't you get around this by turning on x% of your hydro capacity to 100% rather than turning 100% of your hydro capacity to x%? Also, batteries are really good as a short term storage, so hydro only needs to work on the hours to months time-scale.

Re: A near 100% renewables grid is well within reach, and with little storage

#184

Post by theluketaylor » Wed, Aug 24, 2022, 7:30 PM UTC

5d8767c68926 wrote: post #52

mikeyouse wrote: post #39

Earlier quoted context omitted.

This is pretty outdated.. HVDC has solved most of the transmission problem. Even the typical "3.5% per 1,000km" assumption that shows up on Wikipedia is pretty out of date. Modern projects are built with much lower losses (since they're running much higher voltage) and central Australia with massive solar potential is no more than 2,000KM from anywhere else in the country so generation transmission losses would be mo…

Even if losses were something absurd like 15%, I don't see how that would meaningfully change the numbers. Location offsetting sunlight seems like a huge win.

Indeed. Solar is so cheap (and the price keeps falling) needing to build an extra 15% bigger solar farms is a total non-issue. By the time some projects go from planning to ground-breaking that extra 15% might be free due to costs plummeting.

Re: A near 100% renewables grid is well within reach, and with little storage

#185

Post by inglor_cz » Wed, Aug 24, 2022, 7:34 PM UTC

plantain wrote: post #21

WalterBright wrote: post #4

5 hours of grid-scale storage seems like a lot.

The "Victorian Big Battery" cost about 100 million to build and provides 450MWh, so at those prices the 120GWh they calculate for 5 hours would cost about 25 billion. Not outrageous in the scale of nation building projects.

For 25 billion, you could have two Olkiluoto-like nuclear blocks that actually produce energy and not just store it. For several decades.

(Olkiluoto is considered notoriously over budget.)

Re: A near 100% renewables grid is well within reach, and with little storage

#186

Post by Schroedingersat » Wed, Aug 24, 2022, 7:42 PM UTC

s1artibartfast wrote: post #160

Schroedingersat wrote: post #103

Earlier quoted context omitted.

For the cost of 5kW nameplate of new western nuclear (>$10/W) you can get, right now, at retail, as an individual: 50kW nameplate of solar, and 8kW nameplate of wind, and 75kWh of storage and a 5kW generator (which will almost never need turning on) and a biogas digester. And it will produce enough excess power to replace itself (with a cheaper version) or just triple the batteries if you can get 2-3c/kWh for the sur…

I'm not all in on nuclear, but nameplate comparison is meaningless. Solar might hit the name plate for a few hours a day with suitable weather while nuclear can run 24/7 or on demand.

Good thing we weren't comparing nameplate then but instead comparing ability to meet baseload on a cost basis (that thing that's supposed to be most strongly in favour of nuclear) and finding the result insanely in favour of renewables

5kW nameplate nuclear is 3-4.5kW net with 10-40% of the time needing total backup and zero ability to meet higher peak demand.

The system I described needs 2.4 hours of peak sunlight spread throughout a day or 15 hours of wind in a day or 30kg of biofuel (not doable for very many days) or 30kg of imported fuel or any combination with the battery averaging 1-5(ie. you meet ~85% of load with wind/biofuel and draw ~20% of battery) days to meet the 5kW target. It also has a massive peak capacity which dwarfs the nuclear system during half of the year. You might need to tilt the panels two or three times a year in parts of Canada or similar, and maybe import a few days worth of ethanol (or any other stable hydrocarbon you can run your generator on) each year, but this is still less backup than a fission plant needs.

Couple it to an uncorrelated system or trade some solar for an electrolyzer and fuel cells and you can reduce reliance on imported fuel even more. Solar cells and batteries will also better than halve in price well before your plant is finished -- likely making it impossible to even run, let alone recoup your costs. Additionally perovskites work better with partial shade and are quite likely to hit cost parity with solar so the nameplate value can be reduced (or reliability on a still, cloudy, winter, northern morning will increase).

Re: A near 100% renewables grid is well within reach, and with little storage

#187

Post by geraneum » Wed, Aug 24, 2022, 7:49 PM UTC

ZeroGravitas wrote: post #176

erie wrote: post #170

Earlier quoted context omitted.

And the big elephant in the room? getting the US military on board is going to be tough. Every year, US armed forces consume more than 100 million barrels of oil to power ships, vehicles, aircraft, and ground operations

The US military spends more on renewables each year than most countries. They were on board long before the wider US Government felt it was politically safe. https://www.reuters.com/article/us-usa-military-green-energy... > The military’s push into alternative energy started under Republican President George W. Bush in 2007, when he signed a law requiring the Pentagon to get 25 percent of the electricity for its buil…

Who knows, maybe one day, all of the tensions (wars, etc.) between countries that is rooted in access to oil reserves disappear because of this.

One can dream…

Re: A near 100% renewables grid is well within reach, and with little storage

#188

Post by coryrc » Wed, Aug 24, 2022, 7:52 PM UTC

plantain wrote: post #116

zdragnar wrote: post #102

Earlier quoted context omitted.

We get about nine and a half hours of sun in January, assuming no clouds. That leaves around 14-15 hours of no production, assuming there isn't sufficient wind (also often the case in January). Panels operating at 30% capacity for 9 hours cannot be offset by 5 hours worth of storage. It simply isn't enough storage, even if the panels were operating at 100% capacity. Adding more storage really isn't a great solution e…

You can also over-provision solar and wind to factors well above 100%, and still be more economical than burning fossil fuels.

The US can't even provision 100% capacity because of BANANA, let alone over-provision.

Re: A near 100% renewables grid is well within reach, and with little storage

#189

Post by fulafel » Wed, Aug 24, 2022, 7:54 PM UTC

fallingknife wrote: post #177

fulafel wrote: post #171

Earlier quoted context omitted.

Demand can be regulated to meet supply using various ways (eg pricing, quotas, etc).

Pricing is a poor tool as the signal doesn't propagate quickly enough. Quotas just means blackouts, and that isn't ever going to fly politically.

Disagreed on both:

Demonstrably pricing already technically works in many hourly priced markets in face of difficult conditions - the swings are not that fast and the time quantum can technically be made much smaller still, there is no fundamental signal propagation speed bottleneck in sight.

Quotas yield cutoffs only if you exceed your quota, so you would still get power constantly for light loads unless you err by blowing your quota. This is far better than getting blackouts.

Re: A near 100% renewables grid is well within reach, and with little storage

#190

Post by anonporridge » Wed, Aug 24, 2022, 7:56 PM UTC

theluketaylor wrote: post #180

anonporridge wrote: post #130

Earlier quoted context omitted.

It's not a technical issue, but an economic one. If you have so much wind and solar generation that they spend too much of their lifespans sitting idle and not generating income, they potentially never even pay for their initial build cost and basic maintenance, let alone be a better investment than just buying a treasury note yielding 1%. That's a recipe for long term stagnation and depression.

If whole solar or wind farms find themselves sitting idle someone will drop off some containers nearby to split water into hydrogen or run a data center or something else that drinks power and skip the grid middle-man. Over-idle is not going to be a real issue; someone will always find a way to use of excess power.

Yeah, that's demand response.

Bitcoin miners are the key players innovating in that space right now. It's something that can very easily be packaged up in portable containers. I believe Chinese miners for years had a yearly migration to soak up massive amounts of excess hydro power during the rainy season that would have been otherwise wasted.

There might be a place for more generic computation datacenters, but they would have to find a relatively unique customer that has compute loads that can be turned off and on at a moment's notice, and potentially be down for days, weeks, and even months. There's probably a startup to be founded here, if you can figure out how to severely undercut equivalent AWS services to justify the lack of uptime guarantees.

I don't know enough about hydrogen production to know if it can be quickly spun up/down to suck up variable load. I imagine gas transport infrastructure is going to be the biggest blocker.