Hacker News Reader

Comment by brrt | Hacker News Reader

Actually, renewable energy is, when you actually run the numbers in a sensible way, pretty cost effective: http://www.sciencedirect.com/science/article/pii/S0378775312... - this finds that with 90% solar/wind and modest amounts of storage, electricity would be cheaper in 2030 than it is today, and that the cheapest option is actually a vast overcapacity. There are plenty of flaws with that article, but still less than this post.

View on HN

Just to be clear, the article is saying that using solar power technology from 2030 would be more cost effective 90% of the time, not that using 90% solar energy today would be cheaper by the time we reach 2030.

They assumed electrochemical storage which is really expensive and invalidates there findings, renewables would be significantly cheaper than there suggesting.

They also assume a wide grid and overcapacity, which balances it out. And their storage capacity is minor, and they assume relatively cheap backup power. Like I said, there are plenty of things wrong with it, but it's nothing like what is wrong with the OP.

Battery cost are projected to drop significantly over the next 5 - 10 years.

Battery costs have been dropping radically for the past decade, and there's both aggressive startups (Tesla) and established giants investing heavily in the technology, which will continue to drive prices down.

Hydro is ~1/30th of battery costs. Nobody is prediction price swings on that scale.

It doesn't invalidate their findings, it means they understated their case - thought I think that is what you are saying too.

(Also, http://www.theretheyretheir.com/. Not usually a grammar Nazi, but that's pretty hard to read)

Just a reminder that energy use and electricity use are not the same thing --- about 2/3 of all energy is used for heating and transport, and electricity can't be used for that. (Because it's too hard to store, and because the electrical grid simply can't transport that much.)

Sure, solving renewable energy is a really valuable thing to do, but it's still only solving 1/3 of the problem.

The electrical grid will be upgraded, it's not static. Heat is easy to switch to electric. Short transport will move to electric. Longer haul transport is more difficult, but liquid fuels can be generated from CO2 in the air or water (at somewhat large expense). However, if there is large amounts of overcapacity, then liquid fuel generation via electricity might become economical.

Isn’t the solution to long haul transport electrification of the rail network? An alternative would be a swap and go battery network for the road system. The nice thing about a swap and go battery network is we have storage to even out demand and production.

> 2/3 of all energy is used for heating and transport, and electricity can't be used for that

Well, here in the Netherlands, the majority of the trains will soon (2018) be powered by 100% wind energy. 50% since this year.

So it's categorically (and I would think obviously) incorrect to say "you can't use electricity for transport".

http://www.ns.nl/over-ns/campagnes/maatschappelijk-betrokken...

Heating is another question entirely. You have more of a point there -- it's hard to find an alternative to natural gas for heating.

> Heating is another question entirely.

It's actually a comparatively easy problem to solve. Have a large boiler, heat that with electricity while you have an abundance of energy and keep it moderately well insulated. Drawing the heat off that is simple.

Storing electricity for usage as electricity is the primary problem.

Apparently, most nuclear power plants even produce less energy than if their area was instead covered by solar panels. Says Musk: https://www.youtube.com/watch?v=c-n6xJOFbvA

I seriously doubt that claim.

it's true. somewhat. I mean the energy of the nuclear station stays constant. however the peak power of the solar panels will be higher. but I doubt that the solar panels will still be creating less energy over a longer period of time. unless you build both inside a desert and there you would have other problems like the sand which affects the lifetime of your panels, etc..

btw. i'm against nuclear and non renewable energy, however I think its hard to actually replace ever "bad" energy in the next 10-20 years. we will need a longer time for that. especially since building renewable energy plants fast isn't good for our environment either.

The peak power of solar panels is not higher today.

The highest capacity US nuclear power plant can out-produce the best utility scale solar installation by 10 fold, with both at max capacity, on an equal amount of land.

no with peak power i mean. full sun no cloud the whole day, etc. perfect things wheater for solar energy. However this barely (never) happens. so the energy of the panel changes throughout the day. however highest (possible) peak of solar could definitly be higher than a nuclear power plant (anywhere in the world) on an equal amount of land.

nothing to do with today. just a "what would happen on a perfect day". peak vs peak. also peak of a nuclear power plant could be raised by human and solar panel peak is barely measurable, since there are a hugh amount of factors that could change it.

How can you be against nuclear when you don't even understand the level of output of a nuclear plant? You also suggest that nuclear is mature, but that doesn't mean there aren't new reactor designs being developed.

Solar is also mature by your lame definition of just being around for a long time. In fact, solar has been around longer than nuclear in that regard so it must be more mature then. /s

What's wrong with non-renewable? That simply means it won't last forever. Is it really important that whatever energy generation we use can be repeatedly maintained and operated forever? I don't see any problem in making the most of the Earth's uranium resources while it's cheap enough. In the worst case, we'll just have to stop doing that later rather than sooner.

Run the numbers on it. What's a reasonable expected area for a real-world nuclear power plant? (not the fantasy of the OP, but what real plants usually cover) Reasonable peak and median output long-term for that much solar panel? Throw in some batteries for storage to stabilize the output, and the numbers are pretty compelling.

Then throw in the cost of covering, say, a square mile of land with solar panels versus the cost of building and operating a nuclear plant, even the ridiculous fantasy numbers of the OP. Solar looks pretty good.

A sibling commenter already did run the numbers on it, and found nuclear ahead by a factor of 10: https://news.ycombinator.com/item?id=10503382

I should add, that's just for the largest US plant.

The Kashiwazaki-Kariwa monster in Japan, with seven reactors, was capable of producing nearly 8,000 MW on just ~1,000 acres. Or upwards of 50 to 80 times what the best utility solar installations today can produce at max output on the same amount of land.

https://en.wikipedia.org/wiki/Kashiwazaki-Kariwa_Nuclear_Pow...

The Solar Star installation could end up being the best solar comparison right now (completed in June). At max capacity, it might narrow the ratio such that the Japanese plant is capable of producing 50 to 60 times the power on the same land.

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

Solar star is theoretically capable of about a terawatt on about 4k acres, so that makes the reactor about 15-20 times as efficient. Still a huge difference, but don't hype the numbers too much.

I can't find any source suggesting the Solar Star is capable of 1 TW output with 4000 acres. SunPower's own fact sheet† gives about 1/1500 that capacity for the 3200-acre installation. Where did you hear this?

† http://us.sunpower.com/sites/sunpower/files/media-library/fa...

Gigawatts, not terawatts. My bad.

579mwh ~= .6gwh, on 3200 acres. Assuming a larger 4000 acre site and some efficiency gains on this immature tech, a gigawatt seems reachable.

The Ivanpah plant isn't a great example. The tech is already going obsolete, and it's producing far below theoretical effectiveness. It should be able to produce a terawatt. Fundamentally, it's because solar is immature technology, and nuclear is mature. So what would the efficiency and cost be for a mature solar plant? And how do we get to maturity?

If a solar plant could hit 50% of the energy efficiency on the same land (and the poor-performing Ivanpah plant reveals that it's possible), that raises a question of why we need the cost and complexity of nuclear.

Solar Star (see adventured's comment parallel to yours) may be the current state of the art. It claims 747 MW on 3200 acres. That still doesn't put it in the same league as nuclear.

True, but does it have to be? We can throw more land at the problem. I live in the midwest, where we're starting to see the countryside dotted with windmills. If you can generate a terawatt per square mile, how many do you need?

As a followup, I did some calculations and figure the US averages about 534twh of electricity - say it peaks at 1000twh, which seems reasonable. Both solar and wind appear to be capable of about 1twh per square mile these days, based on existing installations. So 1000 square miles of wind/solar, plus some battery caching, could provide 100% of our typical energy needs. This seems pretty feasible to me.

Considering that no one will want to live near it, and not allow it to be farmed either, such plants aren't as space efficient as they might seen.

Then cover that "unwelcoming" area with solar panels. Win-win.

It would be on right ballpark in Sahara. Assuming that we use current kilometer scale safety zones around power stations.

That's not even close to being true.

Ivanpah has the capability of producing about 400 MW. It produces no energy at night, and doesn't max out the rest of the time. It rests on 4,000 acres of land. [1]

The Palo Verde nuclear plant can produce 3,939 MW from three reactors (currently operating at 3,875 MW). It's located on 4,000 acres of land. It can actually generate 3,875 MW, and can do it all day long if necessary. Most nuclear plants don't run at max capacity often, but it's irrelevant given the extreme difference, reduce it by 75% and it stomps Ivanpah. [2]

[1] https://en.wikipedia.org/wiki/Ivanpah_Solar_Power_Facility

[2] https://en.wikipedia.org/wiki/Palo_Verde_Nuclear_Generating_...

I guess you'd have to count the Palo Verde 10 mile inner emergency zone (200,000 acres). Then you'd be down to 0.02MW/acre, well below Ivanpah's 0.1MW/acre. That's a bit unfair though, since that area does have a small population, so it's not entirely cut off.

Reply on news.ycombinator.com