With self-install solar panels, and a €150 plug-in adapter that feeds power directly into electricity sockets; a DIY home power system is becoming popular in Europe. : futurology

[–] [email protected] 43 points 5 months ago (2 children)

It's still early days for this tech. Right now its maximum output is 800W, which is not a lot. OP mentions this delivering 3kWh on a typical day, about 10% of a typical US household's consumption.

But it's the direction of travel that is interesting here. This will get better, and cheaper. Then systems like it will be able to deliver 25% of daily consumption, then half. All with affordable systems you can install and set up yourself.

Many people have nightmares about dystopian and apocalyptic futures. I would feel safer in a world where electricity production was decentralized and could survive major disasters.

[–] [email protected] 7 points 5 months ago* (last edited 5 months ago) (3 children)

OP mentions this delivering 3kWh on a typical day, about 10% of a typical US household's consumption.

Wow, this is much. If you are correct, a typical US household consumes two times the energy than a typical german household.

The last numbers I found where from 2021 with 5411 kWh for a household with 3 or more people.

[–] [email protected] 3 points 5 months ago* (last edited 5 months ago)

a typical US household consumes two times the energy than a typical german household.

Can't even use a bit more powerful drill without blowing the fuses in some older european houses, because the old wiring is too weak.

[–] [email protected] 2 points 5 months ago

Yeah that one made me whiplash as well. Jesus, we thought we blew out the meter at 17kwh in a shitty aussie rental during a brutal winter with oil heaters

[–] [email protected] 2 points 5 months ago

I didn't know if it's correct, but consider that nanny (most?) use natural gas for heating, cooling, cooking, and got water, so those aren't Even counted!

[–] [email protected] 3 points 5 months ago

I am very interested in this for hot summer days with peak demand or power-hungry appliances. I hope they come up with north american versions!

[–] [email protected] 21 points 5 months ago (1 children)

This is several layers of illegal where I live

[–] ThePantser 5 points 5 months ago (1 children)

Except it self terminates the backflow once mains is powered off so it is it's own backflow prevention breaker. It already does what is legal. Just needs approval.

[–] [email protected] 4 points 5 months ago* (last edited 5 months ago) (1 children)

Do you know where I live? That isn't legal here. It doesn't just need approval, it needs to be installed by the power company and they're not going to do that because they have massive tax incentives to only install systems that backflow into the grid during overproduction. Just to be clear: You are not allowed to have a closed system with panels over a certain combined size. You are not allowed to connect anything that backflows into your walls (for safety reasons, regardless of if the thing claims to turn itself off in a power outage). If you go all in and do it properly, the power company (monopoly, you have no choice) will simply tax you what they lost or, incase of backflow, tax you 'transmission fees' for whatever you would have earned.

The only people who have solar panels here are rich yuppies who want to virtue signal because it makes zero financial sense to have them. Right wing lobby groups have made sure that consumers and municipalities are disincentivized from running solar panels anywhere for any reason and illegal in any niches where it might've still made sense.

e: your downvotes do nothing; this is law, not opinion

[–] [email protected] 1 points 5 months ago* (last edited 5 months ago)

My mom is a boomer who was fortunate to inherit her mom’s house when both my dad and her mom died within months of each other.

She’s on a fixed income, but was able to get rebates and sincerely Solar relatively early, 2015 I think. Her medium sized northern US house was previously heated with wood pellets, but now has a dual zone heat pump, and the solar has paid for itself in electricity savings in the first 4 years.

She’s lost a panel and inverter since then (inverter was under warranty), but the replacement inverter is less than half the size, and leaves room in the garage for a battery someday.

It’s worked out very well financially for her. I’m jealous because I don’t have the cash or sunny roof space to make it work at my house.

[–] Dabundis 20 points 5 months ago (4 children)

This particular type of home solar implementation runs into a scalability issue where each piece is hard-limited by the ampacity of the outlet its plugged into, so at a certain point it can only scale out to be plugged into more outlets and take up more space.

Also, having a system thay feeds into an outlet is quite scary, since the male side of the plug is energized. I get the convenience of this "plug and play" sort of device, but I'd much prefer to see something hardwired and enclosed.

[–] [email protected] 8 points 5 months ago

Safety wise it's perfectly safe. The male end is only energized if it detects that it's actually connected to the grid, then it matches the sine wave of the grid. It can't just electrocute you if you unplug it and touch the exposed pins.

[–] Hugin 6 points 5 months ago

NEC allows for 20% of the main breaker for solar backfeded. Higher then that and you have to go for a line side tap and bypass the breaker box completely.

[–] [email protected] 3 points 5 months ago* (last edited 5 months ago) (1 children)

Huh, I wonder what the safety features are. From a skim of the article, it's detects power demand somehow, so maybe that helps.

Also, I'm concerned for linesmen, because somebody is going to buy this and not tell their company that they are energising the local grid, rather than just consuming. Europe apparently has some kind of solution, but nothing stops you from using it elsewhere.

[–] [email protected] 6 points 5 months ago (2 children)

From the article, it says it automatically shuts down if it detects a full power outage for exactly that reason

[–] Dabundis 5 points 5 months ago (1 children)

Yeah, legally that's what it needs to do at that point in the system. if you want a solar system to be energized during an outage, you have to have what's called a "Grid-forming" inverter (as opposed to grid-following) and it would likely need to connect up at the utility connection point

[–] Hugin 5 points 5 months ago

Grid forming inverters are for solar generating plants. They are allowed to start up an unenergized grid. At that level they are a part of the utility grid.

For homes to run of of solar when the grid is down you need to do islanding. This is a seperate beaker box feed directly by the solar and battery. This allows the house or a portion of it to stayed powered without putting power back to the grid and endangering any linemen working on the grid.

[–] [email protected] 1 points 5 months ago

I'm really curious how it can tell what's being drawn in a fool-proof way, without actually putting energy out.

[–] [email protected] 2 points 5 months ago (1 children)

“Ampacity” — I don’t know if that’s an actual word but you perfectly described what the bottle neck is. I like it!

[–] Dabundis 6 points 5 months ago (1 children)

It is! Here in the US, that's the word used by the National Electric Code to talk about current carrying capacity

[–] [email protected] 1 points 5 months ago (1 children)

Do "ampacity" and "amperage" mean the same thing?

[–] Dabundis 3 points 5 months ago (1 children)

Not exactly. Amperage is "amount of current", ampacity is "ability to carry current"

[–] techMayhem 4 points 5 months ago (2 children)

So ampacity is fusion of amperage and capacity?

[–] Dabundis 2 points 5 months ago

you got it 👍

[–] [email protected] 1 points 5 months ago

Also called a portmanteau, like internet, malware, or genome.

[–] A_A 12 points 5 months ago

Thanks for rewriting the title and make it straightforward ...as the original headline from "The Verge" was confusing and useless (for me).

[–] [email protected] 6 points 5 months ago (2 children)

These micro inverters are a cool near-term portable solution for those looking to dip their toes into home energy storage. Ultimately, I hope we see residential DC electrical become more commonplace soon. That will make the grid integration that this tackles a non-issue for most (i.e. those who aren’t selling their excess solar capacity) but will ultimately be simpler and more efficient for the grid as a whole.

The average home has only a few devices left that still use AC internally (mostly large or old appliances) and home storage systems lose energy to power conversion overhead in both directions at multiple stages. Since each conversion represents a loss of up to 20%, the AC standard introduces an increasing amount of unnecessary friction close to the point of delivery.

Illustration: if your home charges from the grid, that’s one conversion AC —> DC. If you then use that power to charge an electric vehicle, that’s two additional conversions AC —> DC —> AC —> DC (currently few EVs support DC charging unfortunately). If you then charge your laptop in the car using the official charger, that’s two more conversions AC —> DC —> AC —> DC —> AC —> DC. Altogether this requires about 3x as much power than necessary with residential DC electrical, since then the power can go from solar to storage to car to laptop without the need for power inverters.

[–] Juvyn00b 6 points 5 months ago (2 children)

What voltage of DC would you propose for the common household? Keep in mind that one good reason for alternating current is for safety. Higher voltage AC will allow your muscles to release if contacted. Higher voltage DC does not. Additionally, using higher voltage with either type reduces actual wiring cost in the walls to deliver similar wattage. I don't have the math on me for sure, but delivering 12vdc to every outlet would require much larger in wall cables... And that doesn't even touch the subject of voltage drop (with the exception that larger cables can mitigate this somewhat).

[–] [email protected] 4 points 5 months ago (2 children)

Well it’s not standardized yet to my knowledge, but for example if we used something like the USB-PD protocol it could be a baseline 5 volts, with device negotiated step up to 9, 12, 15, 24, 28, 36, and 48. Higher voltage isn’t out of the question; EV systems safely run closer to 400 and a number of home batteries range up to 600, but I’d be iffy on the idea of the average contractor putting that voltage in the walls of the average home.

It’s true the copper for longer, higher current, or lower voltage DC runs could get very expensive, but even without HV for distance, thoughtful distribution of storage to expected points of delivery would limit the number of heavy lines needed for current spikes.

Long short, I’m not talking about switching entirely from AC, or pumping DC power through existing residential circuits. I’m talking about adding a secondary system that’s a more integrated version of the ubiquitous portable power station / “solar generator” batteries. It would be a home modernization upgrade, similar to running Ethernet to PoE enabled jacks in each room, installing a fancy intercom system, or what have you.

[–] Juvyn00b 3 points 5 months ago (1 children)

I dig that solution for sure. I know I've seen others in the past only suggest the low voltage DC piece and not have the solution to run 100 foot or more in the wall - but essentially you could load up highly efficient power transformation as well as built in batteries for each device to request the power it needs.

Only real problem next would be the added cost. Not only for the edge devices (which may save money) but for the home transformation itself. 110vac outlets are around a buck or so; pretty hard to beat. My guess is that this would be something better served with early adopters and then attrition.

[–] [email protected] 2 points 5 months ago* (last edited 5 months ago)

I would prefer 48 V, because it is as high as possible while still being safe and leaving some margin (note that 60 V DC is considered maximum safe voltage).

Note that 48 V is 80% of 60 V. So the margin is 20%.

I am against negotiating the voltage dynamically, because I fear that it makes every device drastically more complex, and therefore drastically more expensive. (and drastically more prone to errors)

[–] [email protected] 1 points 5 months ago

DC voltage is considered safe (cannot penetrate human skin) up to 60 V.

So I would propose 80% of that, to leave some safety margin. That would be 48 V, which btw is also a multiple of 12 V, which is commonly used today.

[–] [email protected] 0 points 5 months ago

I agree, all of this AC power was introduced to facilitate conventional power grid, but does not longer make sense in the context of solar power. An update would improve efficiency, and probably some other advantages, such as:

safety (from lower voltage)
probably cheaper (less dangerous means less certification required)
fewer conversions might mean less complex, therefore simpler

[–] BradleyUffner 2 points 5 months ago

Back powering your house through an electrical outlet is hella risky. It's outright illegal in a lot of places too.

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