Electrician please comment solar off grid

Grower202085

Active Member
If I want to run an 840 watt draw Led grow light from solar directly to an inverter without battery banks to save money on elec what would be the basic slightly overkill setup I would need . Brand of inverter or panels I'm not fussed on just the specs of inverter and how many panels I would need and whether to rig it in series or parallel. Thanks in advance
Will an AC not DC light work on the inverter without battery? Just straight from solar panel to inverter to light ? Will be daytime use only . Then I will plug the light into the grid at night for a few hrs to get the 18hrs up for the day.
Thanks in advance
pic of light i want to run.
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HippieDudeRon

Well-Known Member
Couple ways it could be done. But first thing I would say is look at another light. BD is below average at best. You could get the same PPF output from a different light only drawing 500w. To take it a step further, would DIY a light rather than buy one, but still can buy a much better fixture than that BD.
A better light could nearly cut your solar needs in half right there. That is $$ saved real quick.

Back to the solar,

You'll need probably 1200-1500w of panels to run it off grid. Most of the day they will be luck to get 60% of their rated output. Especially if going DC to AC. DC to DC saves some in efficiency losses.
Using an inverter without a battery bank is not ideal. You would be better off using a grid tie inverter and just feeding the grid all day and keeping your meter still, then let thegrid power at night when no solar activity.

If you DIY a light you could use a DC to DC power supply, and then a rely/transfer switch to time a switch back to grid power late in the day.

There are ways to do it, but if just trying to save some $$ or power...just get a grid tie inverter and some solar panels and feed the grid during the day. Anythign plugged into your house will eat your produced power before it makes it to the grid so in essence is a wash while the sun is up.
 

Grower202085

Active Member
No battery banks but you intend to extend light hours ???

I don't know the cost but it has to be devastating or everyone would roll like that
Yes I will extend light hrs because like I said I will use the off grid during daylight hrs and then plug into the main grid when the sun goes down for 4 or 5 hrs . So I'm saving 14 or 15hrs of elec use by having the off grid setup. Makes perfect sense to me. And it doesn't raise alarm bells having higher than average elec bills that way .
 

Grower202085

Active Member
Couple ways it could be done. But first thing I would say is look at another light. BD is below average at best. You could get the same PPF output from a different light only drawing 500w. To take it a step further, would DIY a light rather than buy one, but still can buy a much better fixture than that BD.
A better light could nearly cut your solar needs in half right there. That is $$ saved real quick.

Back to the solar,

You'll need probably 1200-1500w of panels to run it off grid. Most of the day they will be luck to get 60% of their rated output. Especially if going DC to AC. DC to DC saves some in efficiency losses.
Using an inverter without a battery bank is not ideal. You would be better off using a grid tie inverter and just feeding the grid all day and keeping your meter still, then let thegrid power at night when no solar activity.

If you DIY a light you could use a DC to DC power supply, and then a rely/transfer switch to time a switch back to grid power late in the day.

There are ways to do it, but if just trying to save some $$ or power...just get a grid tie inverter and some solar panels and feed the grid during the day. Anythign plugged into your house will eat your produced power before it makes it to the grid so in essence is a wash while the sun is up.
Awesome , finally an educated response . Sounds great . I think I will just feed the grid and do it that way . Very good idea thank you
 

Grower202085

Active Member
Couple ways it could be done. But first thing I would say is look at another light. BD is below average at best. You could get the same PPF output from a different light only drawing 500w. To take it a step further, would DIY a light rather than buy one, but still can buy a much better fixture than that BD.
A better light could nearly cut your solar needs in half right there. That is $$ saved real quick.

Back to the solar,

You'll need probably 1200-1500w of panels to run it off grid. Most of the day they will be luck to get 60% of their rated output. Especially if going DC to AC. DC to DC saves some in efficiency losses.
Using an inverter without a battery bank is not ideal. You would be better off using a grid tie inverter and just feeding the grid all day and keeping your meter still, then let thegrid power at night when no solar activity.

If you DIY a light you could use a DC to DC power supply, and then a rely/transfer switch to time a switch back to grid power late in the day.

There are ways to do it, but if just trying to save some $$ or power...just get a grid tie inverter and some solar panels and feed the grid during the day. Anythign plugged into your house will eat your produced power before it makes it to the grid so in essence is a wash while the sun is up.
I'll have to get an electrician to Install the inverter to the grid right ?
 

HippieDudeRon

Well-Known Member
I'll have to get an electrician to Install the inverter to the grid right ?
IDK what you "have to do" based on where you live, regulations...yada yada. That's a liability I have no business advising you on...and am not.

But from a what is actually going on there... the grid ties plug right into the wall outlets with a normal 120v plug and a child could do it. Same with connecting 10 24v panels in parallel and connecting to the grid tie inverter.

But based on what overreaching government agency your enslaved to, they may want a cut or to have you pay an absurdly amount to some "business" to do it for you "legally".

Again, I am not advising on any aspect of installation here.
 

1212ham

Well-Known Member
IDK what you "have to do" based on where you live, regulations...yada yada. That's a liability I have no business advising you on...and am not.

But from a what is actually going on there... the grid ties plug right into the wall outlets with a normal 120v plug and a child could do it. Same with connecting 10 24v panels in parallel and connecting to the grid tie inverter.

But based on what overreaching government agency your enslaved to, they may want a cut or to have you pay an absurdly amount to some "business" to do it for you "legally".

Again, I am not advising on any aspect of installation here.
Plugging in that grid tie inverter is very illegal, it could kill some one. It's also a worthless pos. Sometimes there's good reason for regulation. Btw, I have some experiance with solar.
 

Grower202085

Active Member
you missed the point. so you'll have to be home for roughly 100 days in a row and physically disconnect from your array and hook up to line voltage every time it rains or is cloudy. and then vice versa when the array is producing?

great plan.
Dude I'm disabled and always home . Single father trying to save a dollar or two. C'mon I'm here for ideas and guidance not to have the piss taken. Take ya smart arse comments and fuck right off.
 

Grower202085

Active Member
Plugging in that grid tie inverter is very illegal, it could kill some one. It's also a worthless pos. Sometimes there's good reason for regulation. Btw, I have some experiance with solar.
So the inverters that plug straight into the wall are illegal ? Why do they sell them openly on eBay?
 

ilovereggae

Well-Known Member
Dude I'm disabled and always home . Single father trying to save a dollar or two. C'mon I'm here for ideas and guidance not to have the piss taken. Take ya smart arse comments and fuck right off.
You ask questions in a public forum, we give you honest answers. Lots of us have thought about this and/or tried it. Especially if you are disabled (my son has serious health issues and I've been thru all of this) that it's literally impossible to be able to manually switch lights on and off, switch between solar and grid, and not miss any cycles, or be a few hrs off etc. Emergency room trips aside, I have to assume that there are just some days when your gonna be feeling like shit.

Setting up any continuous operation system you need to account for redundancy, and unless you have a trustworthy neighbor you can count on to help you in rough times, it just isn't realistic to do it manually.

Here is my advice if you are really serious about this. I have looked into a similar solar setup. All of the above advice is 100% spot on. You either need a battery system, or to be living somewhere in the US where feeding the grid is still legal (I know in Hawaii it was until just a few yrs ago). Also not sure if she is still around but @sarahJane211 was doing something like this (but does not live in the US), maybe look at some of her threads on the subject.

Without that, here's my idea. No idea if it will work or not, but I am going to try something similar when I finally am able to purchase a home.

Setup your space with 50-75% solar powered lights. Run directly off your panels, skipping inverter and going straight into your solar circuit (not an electrician, but a good friend is a solar installer, and they now wire some residential lighting this way to save on losses. think u will need some type of DC>DC driver to regulate the voltage). On sunny days you are at 100%. On rainy days, you just have a little less light. Just like in nature. Note that I would only use this for a veg space. Flower space I would still run off mains as I don't want to affect my yield. In veg I feel like that variance is acceptable.
 

Lordhooha

Well-Known Member
If I want to run an 840 watt draw Led grow light from solar directly to an inverter without battery banks to save money on elec what would be the basic slightly overkill setup I would need . Brand of inverter or panels I'm not fussed on just the specs of inverter and how many panels I would need and whether to rig it in series or parallel. Thanks in advance
Will an AC not DC light work on the inverter without battery? Just straight from solar panel to inverter to light ? Will be daytime use only . Then I will plug the light into the grid at night for a few hrs to get the 18hrs up for the day.
Thanks in advance
pic of light i want to run.
\/
You want to do all this to run a black dog led? Skip the black dog get something bettEd for the money. If you’re going to do solar just have it done properly but a solar company and have your whole house done so it’ll take most of the load during the day and switch over to the grid on its own at night. Most solar companies have financing available and and they pull all the permits and ensure everything is up to code this way no one gets hurt or killed.
 

ilovereggae

Well-Known Member
You want to do all this to run a black dog led? Skip the black dog get something bettEd for the money. If you’re going to do solar just have it done properly but a solar company and have your whole house done so it’ll take most of the load during the day and switch over to the grid on its own at night. Most solar companies have financing available and and they pull all the permits and ensure everything is up to code this way no one gets hurt or killed.
i totally missed both the Black Dog and the 840W part. Black Dog is 15 yr old technology. Don't waste your money or electricity. We can help you DIY something if you want up to date tech for the cheapest $.

If this is for a personal grow, how much do you need on a monthly basis? You can grow plenty of herb off a modern 240W LED fixture. A gram a watt is easily achievable, over time you could even push that to 2 grams per watt. That's a 1/2 lb every 10 weeks if you setup a seperate veg space (which you could power with 120W) so that you are running perpetually. Using 60% less power than you initially planned on. This would be a blip on your electricity bill, and not even noticeable if you are worried about stealth. If you need more than that, even going to 480W is still going to be considerably less electricity.
 
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