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Rooftop solar power may be flooding the grid

smh.com.au

21–30 of 99 posts

Re: Rooftop solar power may be flooding the grid

#21
"Monitor electricity 3600 times a second" in the video seem wrong, as AC is usually 50 to 60 HZ that would be measuring the consumption 60 to 72 times per period which does not really make sens. It's likely 3600/hour or 1/seconds. Immediately make me doubt the quality of the research.

Edit: DC -> AC. was tired.

Re: Rooftop solar power may be flooding the grid

#22

home appliances should be aware of the home's solar panels somehow. you could fill a washing machine and have it wait a few days and turn on if the solar panels are at full usage. other things could operate at peak hours (dishwasher) you could also pump water into a silo when it's bright outside.

>home appliances should be aware

You mean IoT installed into wallplugs and whitegoods appliances, pool pumps, heaters, washers, heat pumps/air conditioners, hot water systems, etc.

Yeah. If there was only an IoT standard that worked to allow for usage to be monitored and devices to be switched on/off in a standard way ... sure.

There are "appliances" like HomeAssistant.io and OpenHAB and Domoticz out there to micro-manage these peripheral home devices and monitor consumption/excess/PV generation, and rulesets that can trigger responses and excess/egress of energy,

but it's too complex for the Inverter/Solar managers to take care of usually.

Re: Rooftop solar power may be flooding the grid

#23

Interesting. In Australia do people regularly install rooftop solar installations without also installing battery units? What's the logic there? Just selling it to the grid?

Yeah, we had extremely generous feed-in tariffs for a while. It's generally net-metering too so pretty good value, even as the prices have come down. We have no shortage of sun most places, so it's pretty easy to almost wipe out your entire bill (except for the service/distribution fees, which have gone up a lot over the last few years, I guess to combat that).

A very relevant YouTube video from Dave at EEVBlog, where he goes through the numbers for his five year old solar installation, to see whether it has paid for itself. He also does hypothetical modelling of adding a battery, which proves to not be financially compelling at all.

https://youtu.be/aQQE8V9NBXw

Re: Rooftop solar power may be flooding the grid

#24
post #21

"Monitor electricity 3600 times a second" in the video seem wrong, as AC is usually 50 to 60 HZ that would be measuring the consumption 60 to 72 times per period which does not really make sens. It's likely 3600/hour or 1/seconds. Immediately make me doubt the quality of the research. Edit: DC -> AC. was tired.

*AC is 50 to 60Hz (DC does not alternate). Also I can see how it's possible that electrical fluctuations could happen at a higher rate than the utility frequency. 3600 Hz does seem like a lot though.

Re: Rooftop solar power may be flooding the grid

#25

An interesting alternative to battery storage opened in the UK this week - liquified air energy storage. I wonder if this may be helpful. https://www.theguardian.com/business/2018/jun/05/pioneering-...

>liquified air energy storage. I wonder if this may be helpful.

Let me answer this: No, it would not be helpful, because on pretty much all metrics (capital and operating costs, efficiency, flexibility, size etc) this technology is way worse than battery storage.

Unfortunately - today - a lot of money which could be sensibly used deploying cost effective technology such as solar and wind power (and to a lesser extent battery storage) is wasted pursuing fundamentally flawed concepts (such as compressed air energy storage, and now this liquified air), which have no chance of being competitive .

Re: Rooftop solar power may be flooding the grid

#26
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.

There is a company in Australia that have improved flow batteries technology to the point where it can be miniaturised down to the size of a fridge freezer (previously they were the size of shipping containers) ten shipping containers full of them are able to store 3.2 megawatt-hours of energy and discharge a megawatt of power for over three to four hours which is roughly enough to keep 500-600 average homes going for the afternoon during the end of day consumption peak.

They are perfectly suited to be paired with solar/wind/etc where they can store up the days usage and discharge at a regular rate throughout the evening peak when generation is reduced. And as for reliability, unlike lithium-ion, flow batteries can last for 20+ years with unlimited cycles.

Re: Rooftop solar power may be flooding the grid

#27
post #19
post #7

Earlier quoted context omitted.

Australia has some of the most expensive electricity in the world. There are no bitcoin miners of any size here. The electricity problems we are facing are pure corruption and negligence. Solar isn't the problem, its the lack of funding and poorly weighted energy markets that are crippling Australia's grid.

Solar isn't the problem, but the renewables situation is related. We had a Labor government with the Greens holding a balance of power from ~2010 to ~2013. The Labor party had, I believe, been opposed to a carbon tax up until that point. Then, likely because of pressure from the Greens, introduced a carbon tax. The lesson there will not have been lost on big investors. If anyone invests in fossil fuel generation (ie,…

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.

Re: Rooftop solar power may be flooding the grid

#28
post #21

"Monitor electricity 3600 times a second" in the video seem wrong, as AC is usually 50 to 60 HZ that would be measuring the consumption 60 to 72 times per period which does not really make sens. It's likely 3600/hour or 1/seconds. Immediately make me doubt the quality of the research. Edit: DC -> AC. was tired.

> DC is usually 50 to 60 HZ

Immediately make me doubt the quality of the comment

Re: Rooftop solar power may be flooding the grid

#29

So solar power is irregular and has a peak production (mid day) far from peak consumption (start and end of business day)? News at eleven, water is wet and all that... edit: I should have said irregular through the day.

"water is wet and all that..."

...and it's a very good energy store when much of your energy demand is for heating/cooling with target temperatures in the "habitable zone".

The only real challenge (but a big one) is getting the incentive structures right so that they are not "hacked" (e.g. pretending to be a dispatchable consumer at high supply but actually just switching to the conventionally billed socket at times of high demand) and keep inevitable oversteering/pork cycle within a reasonable margin.

Re: Rooftop solar power may be flooding the grid

#30

An interesting alternative to battery storage opened in the UK this week - liquified air energy storage. I wonder if this may be helpful. https://www.theguardian.com/business/2018/jun/05/pioneering-...

There’s also places like Dinorwig: https://www.theregister.co.uk/2016/05/16/geeks_guide_electri...

You may have seen some of these balloons appear here and there, too: https://www.google.com/search?tbm=isch&q=Biogasanlage

Having now read the wikipedia article, I see that my answer to my youngest daughter was much too simple. "Daddy, what's that?" "That white balloon next to the barn? It's full of cow fart. The cows in the barn fart, the farmer keeps the fart in the balloon and then burns it to make electricity when people need lots of electricity". According to Wikpedia it's a little more complex. But I like the simple version better.

Whatever the source, it's gas the farmer can burn whenever the spot price for electricity is high.

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