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Rooftop solar power may be flooding the grid

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Re: Rooftop solar power may be flooding the grid

#91

Post by majewsky »

stephen_g wrote: post #72
majewsky wrote: post #55

Earlier quoted context omitted.

> solar gives you cancer Is that hyperbole or are they seriously saying that?

Hyperbole in that specific case, but they did have an enquiry into wind turbines partly examining alleged health effects...

Okay, that's not as outlandish as health hazards from solar. We have a lot of wind turbines in Northern Germany, and some people complain that they emit low-frequency sounds and thus cause noise pollution. I don't know about the research on this topic, though; I never noticed any adverse effects when staying near wind turbines.

Re: Rooftop solar power may be flooding the grid

#92

Post by Dylan16807 »

pjc50 wrote: post #86
js8 wrote: post #76

Earlier quoted context omitted.

By decentralization I mean something different, decentralization of energy production. The fact that, say, a village can decide to install a solar panel array to satisfy some of their energy demands, and they don't have to rely on powerful (and often global) energy companies who mine coal or process oil, is an important game changer in terms of power relations between people.

You just have to buy the solar panels from a global megacorp instead. Don't get me wrong, this kind of decentralisation can be very effective in small isolated communities such as the Scottish islands, but for most places doing it locally is both more difficult and more expensive.

> You just have to buy the solar panels from a global megacorp instead.

That's still a massive improvement in competition. But I'm pretty sure it's also not true and tons of companies make solar panels.

Re: Rooftop solar power may be flooding the grid

#93

Post by D_Alex »

Angostura wrote: post #78
blkhawk wrote: post #49

Earlier quoted context omitted.

I think there a physics problem there. The efficiency is way worse than charging almost any type of battery. So unless material for any type of battery becomes completely unavailable (including say Iron and sulfur or lead), the power free and you manage to build your Air Liquifier with less resources than batteries it will always be a stupid way to spend resources.

They are claiming efficiencies of 60-70% compared with batteries of nearly 90%

OK, I have thought about this a bit (I have worked on gas liquefaction plant design), and I do not believe this claim.

70% is about the maximum thermodynamic efficiency of any heat engine operating between -190 degrees and ambient. And the best efficiency you can expect in liquefaction, in a very complex and large plant, is circa 50% (1). Combined with storage losses, I think the overall cycle efficiency cannot be more than 25% or so.

Happy to review and comment on any back-up to their claim.

(1) see eg here: https://search.informit.com.au/documentSummary;dn=8933572137...

Re: Rooftop solar power may be flooding the grid

#94

Post by TYPE_FASTER »

slavik81 wrote: post #47
llukas wrote: post #41

Earlier quoted context omitted.

We're trying to fit square peg into round hole - after 50 years of centralized grid with one type of predictable demand curve now we got all those people that dare to install their own solar. I'd wish that utilities would stop fighting and accept inevitable.

What's the inevitable?

The service utilities provide changes from energy production to energy storage, distribution, and management.

Re: Rooftop solar power may be flooding the grid

#95

Post by antisthenes »

tappaseater wrote: post #88

I am in my 5th year of a 9.8MW system. I have generated about 45MW of power and approximately 1/3 stays in my home and the rest is sold to local power company. A couple of years after installation I started to see negative press for solar and eventually some action by my local power company. "Solar is no use to me", to quote the manager. Their actions finally killed new solar in our town. They used arguments like thi…

> I am in my 5th year of a 9.8MW system

Do you run a power plant?

Re: Rooftop solar power may be flooding the grid

#96

Post by aligibbs »

baud147258 wrote: post #13
aligibbs wrote: post #9

Earlier quoted context omitted.

Solar power is not irregular at all, and is entirely predictable with a weather forecast. Unless Australia has an entirely different usage pattern to the rest of the developed world- businesses are perfectly aligned to use the solar power generated during the peak.

From the article: "the growing peak demand that comes at the end of the day, as the sun sets.". So the solar production of electricity peaks earlier than the end-of-day consumption peak.

Sure, there is an evening peak when people get home and start cooking/turning on their homes etc- which can't really be offset with solar (without using storage, battery/hydro). Doesn't negate the fact that solar generation pretty much perfectly matches business usage.

Re: Rooftop solar power may be flooding the grid

#97

Post by henearkr »

ludston wrote: post #50
henearkr wrote: post #27

Earlier quoted context omitted.

Following your reasonning, there is no reason why investors should shy away from renewables. The Greens would not harm any project of additional large scale batteries, for example.

I think there are two main reasons whu investors would shy away from renewables in Australia: 1) Firstly there are no large well-known actors, so there is uncertainty around renewable energy companies are going to "win". 2) Secondly, Australia currently has a government that is hostile towards renewables. It could at any time introduce legislation that would make renewables economically untennable.

Even with the evilest scheme, it seems unlikely to come up with something harming the rentability of renewables, or of solar in particular. It's basically free electricity from sun, which is plenty in Australian deserts. You pay only the installation, which price is determined by the tech market.

Re: Rooftop solar power may be flooding the grid

#98

Post by John_KZ »

stephen_g wrote: post #64
John_KZ wrote: post #53

Why don't Australians use Solar water heaters? It's the best ROI you can get from solar, Mediterranean countries and the sunny parts of China have absolutely massive capacities installed. It's direct thermal, so it's not a cool high-tech gadget, but if you're worried about the environment, it's "better" than solar panels when applicable. It also essentially includes on-site thermal storage, so no grid instabilities.

Lots of them around (especially in my state, Queensland, which has hot summers and mostly fairly warm days in winter), but you need to use a gas or electric booster to have hot water all the time. So in a lot of places it actually turns out to be fairly similar energy use to put in a high-efficiency heat-pump hot water heater. I've just evaluated this because I want to replace the hot water system at my house, and I…

Solar panels mix well with heat pumps in hot and dry climates indeed, because of the happy coincidence that peak solar radiation=peak demand for cooling. In that case it's not a bad combo, especially if you have mild winters without temps deep in the freezing (which ruins the COP for heat pumps, assuming you use them for heating too).

Re: Rooftop solar power may be flooding the grid

#99

Post by Angostura »

D_Alex wrote: post #93
Angostura wrote: post #78

Earlier quoted context omitted.

They are claiming efficiencies of 60-70% compared with batteries of nearly 90%

OK, I have thought about this a bit (I have worked on gas liquefaction plant design), and I do not believe this claim. 70% is about the maximum thermodynamic efficiency of any heat engine operating between -190 degrees and ambient. And the best efficiency you can expect in liquefaction, in a very complex and large plant, is circa 50% (1). Combined with storage losses, I think the overall cycle efficiency cannot be mo…

Thank you for that thoughtful and informative reply.
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