Electrician please comment solar off grid

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HippieDudeRon

Well-Known Member
Grower202085 said:
So the inverters that plug straight into the wall are illegal ? Why do they sell them openly on eBay?
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No they are not illegal.
But adding something to the grid in many places is. So it is not the Inverter, but the act of modifying/interacting with the public grid that is illegal. The inverters are legal and safe. Can own, buy sell all they/you want. To employ them without paying the local government it's cut, is illegal. Though some would argue(founding father being some of them) their attempt to regulate is also illegal.

So again, not advising you on what to do. Just speaking aloud about concepts behind what is going on.

As for safety, no issue with these grid ties. Reliability...another topic. They will not last years, but at the price what can you say. Some better one on the market, but priced accordingly.
 
Roy O'Bannon

Roy O'Bannon

Well-Known Member
You might invest in enough solar to actually sell a meaningful amount back to the elec co and use mains at night. It would take a while to recoup the investment though.

I haven't worked on a place like that in a while, but I did some unrelated work and the owner was really proud of it, showed me the whole set-up. He had a wind set up, same principle.
 
Rocket Soul

Rocket Soul

Well-Known Member
We looked at this but in regards to having extra power as our amp limit is real low. Never went trhu with it though. The way id do this would be building a strip light with separate circuits and strips for mains power and solar power. Hitting maybe fifteen watts a foot on mains and solar makes up for the rest.
solar dc to led dc is a given, why lose power on dc to ac to dc conversions?
If you make your solar and mains connected driver the same voltage you can design your light so that you have the flexibility to connect up strips to any power source; this means you could try out with just a few or one panel, to get a hang off wether this is actually worth it from real numbers from your unique solar situation. id love to see this done but i suspect it wont be worth it in a personal stash-save cash on electric bill.
 
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1212ham

Well-Known Member
HippieDudeRon said:
As for safety, no issue with these grid ties.
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Grower202085 said:
So the inverters that plug straight into the wall are illegal ? Why do they sell them openly on eBay?
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Plugging a grid tie inverter straight into the wall is dangerous and a serious violation, they must be connected with a power transfer switch. Imagine an electrician or lineman disconnecting power and going to work..... then somebody plugs in that grid tie inverter, back-feeds the grid and the electrician or lineman gets electrocuted.........

But enough of that, lets address your goal of saving some money. Solar isn't cheap and the return on investment is normally many years. What's your electric rate per kilowatt hour?
 
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rkymtnman

rkymtnman

Well-Known Member
Grower202085 said:
Take ya smart arse comments and fuck right off.
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sorry you took my comments that way.

but when one of your replies is "finally an educated response" to others in this thread, you get what you deserve. maybe a bit more research on your part, and a little less yapping, no?
 
rkymtnman

rkymtnman

Well-Known Member
1212ham said:
Plugging a grid tie inverter straight into the wall is dangerous and a serious violation, they must be connected with a power transfer switch.
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bingo. backfeeding his array back to the grid during an outage is gonna kill people.
 
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HippieDudeRon

Well-Known Member
1212ham said:
Plugging a grid tie inverter straight into the wall is dangerous and a serious violation, they must be connected with a power transfer switch. Imagine an electrician or lineman disconnecting power and going to work..... then somebody plugs in that grid tie inverter, back-feeds the grid and the electrician or lineman gets electrocuted.........

But enough of that, lets address your goal of saving some money. Solar isn't cheap and the return on investment is normally many years. What's your electric rate per kilowatt hour?
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Yep, called rule 21 in California. And why grid ties have to be smart inverters and sense power In order to shut off if no grid activity.

For CA, at .31-.36/KwH...savings add up quick. And possibly a more obtainable benefit is getting pushed down a usage tier and having lower rates.
 
SnoopyDoo

SnoopyDoo

Well-Known Member
Grower202085 said:
So the inverters that plug straight into the wall are illegal ? Why do they sell them openly on eBay?
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Very illegal. You're pumping power onto the grid. If there should be a power outage in your area and they're working on the line you're pumping out power and could kill somebody working on the line.

BTW, if this is about saving a buck, unless you pay outrageous electrical rates, solar will (usually) cost more than it saves you.

I agree with everybody else on the BlackDog light - overpriced at best and not really that efficient. Meijui, umol technology and Kingbrite on Alibaba are all cheaper and more efficient than a BlackDog light. I replaced a 1kw DE HPS with ~500watts of umol technology LED.
 
Humble_Budlings

Humble_Budlings

Well-Known Member
goofy81 said:
Don't have time to read the entire thread, but has anyone suggested DC to DC converter for LEDs?
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So, most LEDs want 12v dc (correct?). Regular mppt charge controllers come in 12v output, depends on what your batteries need. So any of those products will work, as the power supply for the fixture. It's just a few solder points away...

Ps thread is only on the 2nd page lol
 
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MidnightSun72

MidnightSun72

Well-Known Member
Humble_Budlings said:
So, most LEDs want 12v dc (correct?). Regular mppt charge controllers come in 12v output, depends on what your batteries need. So any of those products will work, as the power supply for the fixture. It's just a few solder points away...

Ps thread is only on the 2nd page lol
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Most led strips and COBs want anywhere from 10V to 60V.

I'd definitely run higher voltage minimum 48V.

I think losses on 12V would be crazy without running really big wires right up to the fixtures.
 
Humble_Budlings

Humble_Budlings

Well-Known Member
MidnightSun72 said:
Most led strips and COBs want anywhere from 10V to 60V.

I'd definitely run higher voltage minimum 48V.

I think losses on 12V would be crazy without running really big wires right up to the fixtures.
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Ah, you're right. I wasn't familiar with what voltage they expected. The good quality Samsung strips are 48v. Fortunately, most mppt controllers have 6, 12, 24 and 48v out.

I was kindof imagining the mppt mounted directly to the frame of the fixture... Could produce a lot of heat
 
MidnightSun72

MidnightSun72

Well-Known Member
Humble_Budlings said:
Ah, you're right. I wasn't familiar with what voltage they expected. The good quality Samsung strips are 48v. Fortunately, most mppt controllers have 6, 12, 24 and 48v out.

I was kindof imagining the mppt mounted directly to the frame of the fixture... Could produce a lot of heat
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No you don't want it in the room at all IMO. Just an extra heat source. Which would bring down your over all system efficiency. Since you'll spend more watts to cool the place. Better leave it out of the grow, run a higher voltage so you can get a decent run before losses.
 
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1212ham

Well-Known Member
I've got some ideas rolling around to drive LED strips directly from a solar panel, as supplementary power. When the sun is week an AC powered driver will pickup the slack. When this grow is done I'll do some testing. I have a 150w panel and my light can take that so it's just a matter of testing the performance. They are a good match at full sun, but I have little idea how well the panel will be loaded with less sun, it may be a sort of passive mppt.
I wish I had voltage/current data for the panel at some different sun levels.
 
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Rocket Soul

Rocket Soul

Well-Known Member
1212ham said:
I've got some ideas rolling around to drive LED strips directly from a solar panel, as supplementary power. When the sun is week an AC powered driver will pickup the slack. When this grow is done I'll do some testing. I have a 150w panel and my light can take that so it's just a matter of testing the performance. They are a good match at full sun, but I have little idea how well the panel will be loaded with less sun, it may be a sort of passive mppt.
I wish I had voltage/current data for the panel at some different sun levels.
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I think you'll end up needing some voltage regulation after the panel, seems like there's a wide variance on the ones I checked.
 
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HippieDudeRon

Well-Known Member
Could use DC to DC drivers(cheap meanwell ldd's come to mind) and run your strips, boards, fixture on those(scale as needed). Solar panels can power then in their range no issue.
Then use a transfer switch or relay to change from solar to a 12v or 24v AC to DC LED driver to power those LDDs off the grid as if they are the solar panels while sun is down/weak. HLGxxx-12 or whatever.
Or swap to a correct AC to DC driver on the switch/relay. Depends on how perfect and efficient you're trying to make it.

I have a low wattage veg light that runs off a 18650 battery bank with DCtoAC inverter. Solar charges the battery all day. Then at night drains the battery. Light is just plugged into the converter and doesn't know if solar or battery. Not the most efficient, but works for my application. Definitely better ways to go.
 
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