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Energy prices - gone nuts.

Calimori

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Calimori
The conspiracy theory is that the WEF have that as an intent. I had to search for it again but Ida Auken was trying to provoke a discussion about how the future was heading. It has some possible positive and lot of negatives about the way we are going. Everything a service, Airbnb house sharing. Food delivery. But the quote is lost to new readers if you don’t read the rest of the piece. It just becomes the title.
I am not sure the original piece but here is a copy: https://www.forbes.com/sites/worlde...ifferently-well-live-in-2030/?sh=285fc8981735
 

AlanJ

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i’m not convinced about tesla power wall. it’s like panels are dc low voltage. inverted to mains to charge a powerwall thst has to turn the 235v ac back to lower v dc, to store in battery. they ti use it has to reverse all tgat to a/c mains. surely better for your panels to pump their ex straight into a dc battery. ??????
 

Calimori

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Totally agree. A dc panels to dc battery charge, which then goes once through an inverter to power your ac house would have a lot less losses.
We can measure them as the PowerWall is very accurate with data. My solar inverter is a SolarEdge system which is also very accurate.
I will get a spreadsheet going.
 

russdx1

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Nice sunny day today :)
Battery charged, hot water heated, now putting excess onto the grid. Gf did all her washing at correct time as well so all good :)

If stays sunny should get close to 30kw generated today.

46F76EDF-B9BF-48D4-9A5D-675D770A4688.jpeg
 
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Fantazia2

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Nov 3, 2015
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Darlington, UK
I know my battery storage uses ac input and converts to dc for the battery and then back to ac again for usage, but ots supposed to be about 97% efficient for conversion.

I'm not sure if direct dc from solar panels to dc for battery is going to be much more efficient as you would still need something that would drop the high voltage DC from the solar panels anything from 90v upto 500v down to the nominal 48v used in most storage batteries, not sure on the Tesla power wall what voltage the battery runs at. Also I think this would add more cost to the system as the ac inverter circuit is already in there and you would still need it if directly dc charging the battery.
 

Calimori

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I have just looked at the data and I can't quite work it out as my battery is being charged from the grid and then discharges back to the grid during peak time. For this, I get to buy and sell units for £0.1124 but there are obviously some losses in the conversion into storage and then back. These get mixed up my own solar that would be being put into the storage and then back.

The Tesla Gateway see's 96.3% of the power the Solaredge solar inverter sees. This might be inaccuracies in measuring but may well be the conversion from DC to AC. Not far off the 97% you mention @Fantazia2

When I try to look at the energy going into the battery and coming out over the day, this might be from solar or from the grid charging, I know how much it has been discharged that day. This seems to be 89% efficient. It fluctuates from 88% to 91% without any correlation to the amount discharged from the battery.
To put this into some perspective, the process of charging and discharging of the battery (controls by Tesla via Octopus) loses on average, 1.2kW of energy a day. Not too bad due to the other benefits such as £0.1124 a kW.
 
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