Solar’s Future is Insanely Cheap • Hacker News Board

Re: Solar’s Future is Insanely Cheap

#101

Post by maallooc » Thu, May 14, 2020, 11:49 PM UTC

Scoundreller wrote: post #77

maallooc wrote: post #68

Earlier quoted context omitted.

>I don't mind if my hot water tank super-heats water in the middle of the day for the rest of the day. Water does not have the capability to store much energy. >If electricity is really cheap, my freezer can jump into overdrive. Your freezer can't if it's not a ammonia refrigerant. You will actually be wasting energy. >I don't care if my fridge/freezer takes a break Your fridge actually does not use electricity const…

It's common here to have 150L+ water tanks. Can take it from 50C to 75C and then let the anti-scald valve temper the output when drawing. OK on the freezer. Could still take the fridge down to 2C. The concept of the fridge taking a break while running other loads is to reduce peak draw current. If everyone did that, it would make the grid more stable.

No it won't. Actually, the grid doesn't give a f about your fridge. Residential electricity usage is only 37% and fridges use about 9% of that.

Re: Solar’s Future is Insanely Cheap

#102

Post by woodandsteel » Thu, May 14, 2020, 11:49 PM UTC

Barrin92 wrote: post #9

undershirt wrote: post #4

Is solar just a stopgap tech? Like, do they still require fossil fuel energy to create, not to mention maintain and rebuild? And I know we’re now strip mining the ocean for battery metals. I don’t yet sense the sustainability in this amid all this economic hand-waving of “it’s getting cheaper”. (forgive my tone, i have a hard time of making sense of the big picture of renewables, hoping to eventually see how it actua…

I'm not sure about the resource costs of solar in particular but the question is a very salient one. Vaclav Smil has a great piece on this. "What I see when I see a wind turbine" "the quest for renewable electricity generation. And yet, although they exploit the wind, which is as free and as green as energy can be, the machines themselves are pure embodiments of fossil fuels. • Large trucks bring steel and other raw…

Vaclav Smil is looking at this all wrong. There are three phases here

1) power is produced by plants that take fossil fuels to build and fossil fuels to run

2) power is produce by plants that take fossil fuels to build and no fossil fuels to run

3) power is produced by plants that were built using renewable energy and run off of it too.

Most of the people who focus on phase 2 basically want us to stay on fossil fuels forever, but they don't want to come out and say it.

Re: Solar’s Future is Insanely Cheap

#103

Post by maallooc » Thu, May 14, 2020, 11:50 PM UTC

lifeisstillgood wrote: post #100

Scoundreller wrote: post #77

Earlier quoted context omitted.

It's common here to have 150L+ water tanks. Can take it from 50C to 75C and then let the anti-scald valve temper the output when drawing. OK on the freezer. Could still take the fridge down to 2C. The concept of the fridge taking a break while running other loads is to reduce peak draw current. If everyone did that, it would make the grid more stable.

The general point made here is really interesting though - a large number of our appliances (domestic and small business) can easily be time-agnostic if built for it. It may take a decade or two to replace the fleet but boy, just think of the opportunities replacing every appliance globally presents - this is on the order of a new Tesla (the disruptive company) for each appliance. Scheduling exchanges, where your loc…

Actually lights consumes more than fridges in terms of residential electricity.

Re: Solar’s Future is Insanely Cheap

#104

Post by clairity » Thu, May 14, 2020, 11:51 PM UTC

sephamorr wrote: post #28

Power markets are more complicated than most people realize. One thing to note is that solar power can be cheaper than gas, but still not be economic. The fact of the matter is that an intermittent kWh is not as valuable as an on-demand reliable kWh to a utility who's number 1 priority is reliability. Even as solar is acquired at lower and lower prices, if evening power is generated by expensive and inefficient gas t…

> "Solar is clearly economic in many markets, but we'll never get grid emissions in a place like California down much more without storage."

even before reliable utility-scale storage, there is a lot of low hanging fruit from covering the southwest US in solar and wind. but yes, the costs of intermittent power like wind and solar doesn't by itself end with installation.

Re: Solar’s Future is Insanely Cheap

#105

Post by somewhereoutth » Thu, May 14, 2020, 11:51 PM UTC

Scoundreller wrote: post #69

3fe9a03ccd14ca5 wrote: post #8

I'm actually quite shocked at how much energy is produced by solar, especially when compared to residential wind turbines. Panels are efficient, and when it's sunny, you're juicing. The real challenge is of course bringing down cost of storage, which is the key to make solar systems efficient (not just cheap).

> residential wind turbines Wind has a scalability problem. Residentially, it's only a good sell as a backup supply for when solar isn't cutting it to hopefully prevent generator use. And even that's a tough economic argument. Towers have huge economies of scale, both in total size and height. So the turbines just keep getting bigger and bigger because it's more and more cost effective.

If my understanding is correct there is curious difference in perceived scale with kinetic vs thermal energy. Based on a a rowing machine's advertised metrics, I calculated you could row across the English channel on half a packet of chocolate biscuits.

Re: Solar’s Future is Insanely Cheap

#106

Post by Barrin92 » Thu, May 14, 2020, 11:53 PM UTC

woodandsteel wrote: post #55

Barrin92 wrote: post #9

Earlier quoted context omitted.

I'm not sure about the resource costs of solar in particular but the question is a very salient one. Vaclav Smil has a great piece on this. "What I see when I see a wind turbine" "the quest for renewable electricity generation. And yet, although they exploit the wind, which is as free and as green as energy can be, the machines themselves are pure embodiments of fossil fuels. • Large trucks bring steel and other raw…

So are you saying that we should abandon renewables, and stick with fossil fuels until a truly green energy technology is invented, sometime in the future? And if that is not what you are saying, then what exactly do you think we should be doing today?

Cut down on the energy we expend, minimize the amounts of materials we use, focus on technology that consumes less energy rather than just attempting to make more of it in marginally less dirty fashion and so on.

Instead of promoting electrical cars which consume vast amounts of materials and still run on a dirty energy mix cut down on the car reliance altogether, for a trivial example.

Re: Solar’s Future is Insanely Cheap

#107

Post by mistermann » Thu, May 14, 2020, 11:57 PM UTC

avmich wrote: post #34

Barrin92 wrote: post #30

Earlier quoted context omitted.

I don't understand your comparison at all. Given that the primary problem that a wind turbine seeks to solve is environmental, the environmental costs in making the turbine have to be considered. There's no relationship to computers here, it's not a question of philosophical purity, but of correct evaluation of the costs and benefits of a technology.

> the environmental costs in making the turbine have to be considered. Of course it is considered, and few short decades ago that was a valid counterargument. Not anymore - and not later, given the pace of development in efficiencies and breadth of applications.

> Of course it is considered...

One would certainly hope so, but lots of weird things happen on this planet.

Where could someone who is interested to learn about the degree to which this is true go to read about what is really happening on the ground? Where did you learn about it?

Re: Solar’s Future is Insanely Cheap

#108

Post by mistermann » Thu, May 14, 2020, 11:58 PM UTC

woodandsteel wrote: post #102

Barrin92 wrote: post #9

Earlier quoted context omitted.

I'm not sure about the resource costs of solar in particular but the question is a very salient one. Vaclav Smil has a great piece on this. "What I see when I see a wind turbine" "the quest for renewable electricity generation. And yet, although they exploit the wind, which is as free and as green as energy can be, the machines themselves are pure embodiments of fossil fuels. • Large trucks bring steel and other raw…

Vaclav Smil is looking at this all wrong. There are three phases here 1) power is produced by plants that take fossil fuels to build and fossil fuels to run 2) power is produce by plants that take fossil fuels to build and no fossil fuels to run 3) power is produced by plants that were built using renewable energy and run off of it too. Most of the people who focus on phase 2 basically want us to stay on fossil fuels…

> Most of the people who focus on phase 2 basically want us to stay on fossil fuels forever, but they don't want to come out and say it.

How do you know this? Serious question.

Re: Solar’s Future is Insanely Cheap

#109

Post by bbeekley » Fri, May 15, 2020, 12:00 AM UTC

TheGrim-888 wrote: post #47

Retric wrote: post #6

Another aspect of this is the cost of the physical solar cells have dropped low enough that other costs have become significant. This is pushing companies to increase efficiency which opens the door for other applications. A hypothetical cheap ~30% efficient solar panel could add something like 40 miles of range per day to a car in ideal conditions. That starts to look actually useful vs a simple gimmick.

Correct me if I'm wrong, and I quite possible could be, but from a quick Google search, I'm seeing numbers of anywhere 200Wh/mile to 350Wh/mile for a Tesla. If we're generous and assume only 200Wh/mile, then 40 miles of range translates to an energy consumption of 8,000Wh. A 100 watt solar panel, producing the full 100 watts, would take 80 hours of perfect sunlight to produce enough power for an extra 40 miles of ran…

Doing some calculations from another direction:

The maximum daily energy density of sunlight in sunny Los Angeles is about 6.4 kWh / m2 [1] (assuming perfect, moving angle of panels to sun).

If we can turn the entire footprint of a Model X into solar panels, that gives us about 10 m2 (big car!).

The US DoE reports the Model X gets 100 mi / 31 kWh [2]. Or 12.4 kWh for 40 mi.

So those panels would need to get 1.2 kWh / m2 of solar power. Which is about 18% efficiency and pretty reasonable for good consumer panels [3].

But it assumes the car is in sunlight all day at the perfect angle, there is no loss (eg due to weight), in a locale as sunny as LA (eg Seattle gets half of the sunlight as LA), and can be completely coated in efficient panels (the model S solar roof is [1] https://globalsolaratlas.info/detail?c=34.270738,-116.929301...

[2] https://www.fueleconomy.gov/feg/Find.do?action=sbs&id=41196

[3] https://news.energysage.com/what-are-the-most-efficient-sola...

Re: Solar’s Future is Insanely Cheap

#110

Post by robotbikes » Fri, May 15, 2020, 12:01 AM UTC

ravedev wrote: post #82

TheGrim-888 wrote: post #47

Earlier quoted context omitted.

Correct me if I'm wrong, and I quite possible could be, but from a quick Google search, I'm seeing numbers of anywhere 200Wh/mile to 350Wh/mile for a Tesla. If we're generous and assume only 200Wh/mile, then 40 miles of range translates to an energy consumption of 8,000Wh. A 100 watt solar panel, producing the full 100 watts, would take 80 hours of perfect sunlight to produce enough power for an extra 40 miles of ran…

But you could have a few 100w (or 200w) solar panels installed on the roof of your house which either charge your home battery or offload that to the grid. And just charge your car when you want. It is true that you lose some energy every time you store or transfer it, but if we install solar panels on every roof (so we get excess energy from solar) and also find a way to store energy cheaply for a long time, that sh…

Yeah I think I did some back of the napkin calculations that this would be feasible if we put solar panels on every roof. One challenge is that installation is still pretty expensive from a labor point of view because roofs are all unique to one degree or another (age, orientation, composition) and the parts and knowledge to DiY aren't yet commonly available at the local big box hardware store. Plus you have to interact and interconnect with the power company so its another layer of complexity and specialization. Adoption could be greatly accelerated if we had something that made installation of panels on houses a priority especially for lower income households in both the developed and developing world as they would in theory benefit the most from really cheap electricity or at least lower electrical bills. As it stands now it can pay for itself over time but typically on the scale of decades and there are a lot of middle men who will install them and then own the panels and try to profit off of the price differential.