Help me understand: Delegating devices to remain online when the grid goes down

[mateusz1945]

2 hours ago, UWEB said:

Where you have got this prices from?

facebook group  โซล่าเซลล์ รับงานติดตั้ง และหาช่างราคากันเอง that's where wholesellers advertise to installers. Price not always include VAT tho

[UWEB]

50 minutes ago, mateusz1945 said:

facebook group  โซล่าเซลล์ รับงานติดตั้ง และหาช่างราคากันเอง that's where wholesellers advertise to installers. Price not always include VAT tho

Thanks, just have found their Homepage

https://www.thaisolarsystem.com/category/176/lithium/lifepo4-lvtopsun

[Brock]

The whole system depends, on how many panels you have, and that can depend on the battery and inverter you are using. 

The are trying to get you to work out what is essential to keep running, so those will be powered in the event of a power outage. Remember solar panels dont work at night so no charging. 

The more appliances you want to run will mean more panels, more batteries and bigger inverter. Could they hook up the house to the inverter?? Yes they could, but it may be at the inverter limit, and it will drain the batteries quickly.

Aircon at night will be a big load.

 

[LukKrueng]

On 9/15/2024 at 5:41 PM, KhunLA said:

Unless the sun is not out, very overcast/raining, 10kW inverter w/14kWh battery (if reading right) should keep the house going with no problem.   Depending how long you need it for, ease up in the AC use.

 

If that overcast and or raining, consider you won't really be needing the ACs.

 

We have 8kW inverter w/20kWh of battery, and we use about 8kWh overnight (14 hours), that's only using one 13BTU AC in the bedroom, 2 frigs (sm/med), 65" TV as monitor to my laptop, and wife is on her laptop.

 

Our usage can range from <15-50kWh a day (24 hr period) depending on sun, how little or abusive with ACs, & charging the EVs.

 

<15kWh a day (24 hrs) on our very conservative use days.   We've been basically off grid for 2 years now.  Most produced/consumed ~50kWh.

I have 2 meters on my property. 1 is a 15\45 for house use and between February 23 to August 24 the highest usage I had was 240 units (only one month. Most months it was under 200 units.

The other meter is 5\15 and is only powering 1 small structure and a gate to the property. The highest rating for the same period was 20 units.

With such low usage I can't see how a solar system will be worthwhile. However, since we do have an unstable electric supply with many short blackouts (mostly just off\on, sometimes an hour, but sometimes it can last few hours) and changes in current I would like to install a backup battery for the whole house and maybe even include the other structure.

We don't have a\c. The highest power consumers are the water heater (2x max of 6kw), an oven (max about 3.5kw), fridge (not sure how many KW). We also have a pressure water pump that starts every time we open a water tap and a deep well pump that kicks in every few days in rainy season and could be more often in the dry season (irrigation).

If I were to install a backup battery I'd want ALL to be connected.

Whomever I asked about such a system tells me I should go full solar, or that it can't be done without the solar panel so I can't get a straight answer as to the type\size of the inverter\batteries I would need.

Would appreciate any info, specs and price for such a backup system.

[KhunLA]

38 minutes ago, LukKrueng said:

I have 2 meters on my property. 1 is a 15\45 for house use and between February 23 to August 24 the highest usage I had was 240 units (only one month. Most months it was under 200 units.

The other meter is 5\15 and is only powering 1 small structure and a gate to the property. The highest rating for the same period was 20 units.

With such low usage I can't see how a solar system will be worthwhile. However, since we do have an unstable electric supply with many short blackouts (mostly just off\on, sometimes an hour, but sometimes it can last few hours) and changes in current I would like to install a backup battery for the whole house and maybe even include the other structure.

We don't have a\c. The highest power consumers are the water heater (2x max of 6kw), an oven (max about 3.5kw), fridge (not sure how many KW). We also have a pressure water pump that starts every time we open a water tap and a deep well pump that kicks in every few days in rainy season and could be more often in the dry season (irrigation).

If I were to install a backup battery I'd want ALL to be connected.

Whomever I asked about such a system tells me I should go full solar, or that it can't be done without the solar panel so I can't get a straight answer as to the type\size of the inverter\batteries I would need.

Would appreciate any info, specs and price for such a backup system.

Without solar panels ... only leaves a couple options, and none really practical or economical.   The battery is the most expensive part of any system.   You'll need an inverter anyway, so wee bit more, it would pay to add the panels.

 

Any back up battery you'll need for an hour or more is going to be pricey.  Options would be a full solar system, small 3 or 5kW inverter w/5kWh back up, if conservative.

 

Then they have the solar generators, but they aren't cheap, and already mentions, the ECOFLOW type.

 

edit; not mentioned this thread by ... here

 

Then the ol' gas generators, not a fan of myself.  All depends how much you want to spend, how much you'll really need, or if you want to be bothered with being a bit of hands on & maintenance/gas generator.

 

Agree with the advice, just go all in, 3kW or 5kW solar system, with thought of expanding in future.

Edited yesterday at 03:18 AM by KhunLA

[BritManToo]

46 minutes ago, LukKrueng said:

We don't have a\c. The highest power consumers are the water heater (2x max of 6kw), an oven (max about 3.5kw), fridge (not sure how many KW). We also have a pressure water pump that starts every time we open a water tap and a deep well pump that kicks in every few days in rainy season and could be more often in the dry season (irrigation).

If I were to install a backup battery I'd want ALL to be connected.

Whomever I asked about such a system tells me I should go full solar, or that it can't be done without the solar panel so I can't get a straight answer as to the type\size of the inverter\batteries I would need.

Would appreciate any info, specs and price for such a backup system.

Not worthwhile to have ALL connected as that would mean costs x3, and lets face it you can have a cold shower or wait until the grid's back without that much effort. Leave pump, water heaters, oven on the grid.

 

Have sockets and lights on the solar inverter, no need for solar panels.

6K MrPower hybrid inverter (12kbht) + 48v100ah battery (25kbht) should do it.

Little bit of rewiring in the fuse panel and a couple of extra breakers and you're good for up to 12hrs of grid loss. If you're happy with 3hrs backup you could use a 48v45ah battery (8kbht) using 31240 Lifepo4 cells. 

Really easy to install, 2-4hrs work at most, any electrician that can't do it is an idiot.

 

Around 40kbht inc. (or 20kbht with a 45ah battery)

Then you can add solar panels later if you feel like it.

 

I did the same for my house, but with solar panels, works brilliantly (2.5 years now), no more dark nights, internet router loss or computer switching off. We did have a few knocks on the door from neighbours at the start ...... "Why are your lights still working?"