Powering high loads like dryer

[Traveler004]

Hi everyone. I'm new here but have been watching will's vids for about a year and read the book. I often trip up over doing simple calculation from amps to watt hours. I have to use paper as it just isn't natural in my my head yet. One of the things i really just can't wrap my head around is load voltage.

I have a breaker box with 15amp and 20amp breakers. My 220 volt dryer is on 2x15amps double breaker which would be volia 30 amps. I can do that part, LOL.
but how did someone arrive at that. Some electrician must have said average drier uses 3.3 kwh. so 3300 watts / 220v gives me 15 amps. But its on a 30 amp breaker that's probably just elbow room. Anyhow there is that special plug for your dryer that tells you it's allot of juice.

So when deciding on a 12v or 24v DC system i'm confused because i appear to need 220v AC for my dryer. No one is talking about 220v DC systems and people are definitely hooking up big loads So what i'm i missing as I try to plan a staged conversion from grid only system to solar with automatic grid switch system?

Do i need 2 inverters? One that inverts to 120V for AC lights etc, and one that inverts to 220V for dryer. Can a 12V DC really power a 220V load? should it? what's that calculation? and since I want to put in an automatic switch I need a switch that attaches to my 30 amp breaker and from the solar controller I attach ?what?how much?

See i'm very confused. A long explanation, although appreciated might just add to my confusion as I have read allot to no avail. I'm hoping to just see an example of solar panel to clothes dryer example so that I can map it out in my head.

 

[ghostwriter66]

So do this -- go onto Google and find a AC to DC wattage calculator -- then convert 220VAC 3300watts to DC ... and you will see a number thats going to probably make you rethink a dryer using solar and inverters...

 

[Traveler004]

Enter AC Device Ratings

AC Voltage	220	VAC
AC Amperage	30	Amps AC (enter mAh as .xyz)
Wattage	6600	Watts
DC Voltage		12 V
DC Amperage	607.20 Amps DC

I don't know if i filled that in correctly. but it gave me 6600 wattage. I entered the stuff in bold.

 

[John Frum]

See i'm very confused. A long explanation, although appreciated might just add to my confusion as I have read allot to no avail. I'm hoping to just see an example of solar panel to clothes dryer example so that I can map it out in my head.

Assuming your are in North America.
Residential power is 120/240 volts alternating current at 60 hertz.
The power in the panel is 2 hot legs(L1 and L2) and a neutral.
L1 to neutral is 120 volts
L2 to neutral is 120 volts
L1 to L2 is 240 volts.

Unless you have cash like train smoke running an electric dryer via solar is a non starter.
Just because the dryer is on a 30 amp 240 volt circuit does not mean it draws 7200 watts.
The breaker is sized to protect the wire.
Say your dryer uses 3500 watts while its running and it runs 1 hour per day to dry your clothes.
You need a 120/240 volt inverter rated > than 3500 watts and a battery that can sustain > 3500 watts continous.
The batteries required for just the dryer will be > 3.5 kilowatt hours which would require 4x battleborn batteries at $950.00USD per or equivalent.

 

[SolarRat]

Do i need 2 inverters? One that inverts to 120V for AC lights etc, and one that inverts to 220V for dryer. Can a 12V DC really power a 220V load? should it?

Just one 240v inverter. When correctly hooked to your breaker box it will provide the house with both 240v and 120v.

I'd definitely go with a 48v battery system...12v won't do it with that load.

 

[Supervstech]

Hi everyone. I'm new here but have been watching will's vids for about a year and read the book. I often trip up over doing simple calculation from amps to watt hours. I have to use paper as it just isn't natural in my my head yet. One of the things i really just can't wrap my head around is load voltage.

I have a breaker box with 15amp and 20amp breakers. My 220 volt dryer is on 2x15amps double breaker which would be volia 30 amps. I can do that part, LOL.
but how did someone arrive at that. Some electrician must have said average drier uses 3.3 kwh. so 3300 watts / 220v gives me 15 amps. But its on a 30 amp breaker that's probably just elbow room. Anyhow there is that special plug for your dryer that tells you it's allot of juice.

So when deciding on a 12v or 24v DC system i'm confused because i appear to need 220v AC for my dryer. No one is talking about 220v DC systems and people are definitely hooking up big loads So what i'm i missing as I try to plan a staged conversion from grid only system to solar with automatic grid switch system?

Do i need 2 inverters? One that inverts to 120V for AC lights etc, and one that inverts to 220V for dryer. Can a 12V DC really power a 220V load? should it? what's that calculation? and since I want to put in an automatic switch I need a switch that attaches to my 30 amp breaker and from the solar controller I attach ?what?how much?

See i'm very confused. A long explanation, although appreciated might just add to my confusion as I have read allot to no avail. I'm hoping to just see an example of solar panel to clothes dryer example so that I can map it out in my head.

The dryer shouldn’t be on two 15a Breakers... it should be on two 30amp breakers.

it should be on #10 or larger wire, especially if it has aluminum feeding it.

most full size electric dryers in the us have a 3500W heating element and an 80watt or larger electric motor. We electricians are required to calculate 4500W for the laundry loads, that isn’t the draw, it is the expected load, including washer. Lots of factors go into the calculation.

figure an hour runtime, with sporadic heat, and constantmotor load, likely in the 2.5-3.5 KWh load range... depending on moisture of the clothes...

That is a lot of battery and solar.

 

[Traveler004]

You need a 120/240 volt inverter rated > than 3500 watts and a battery that can sustain > 3500 watts continous.
The batteries required for just the dryer will be > 3.5 kilowatt hours which would require 4x battleborn batteries at $950.00USD per or equivalent.

North american, yes.
I got everything up until here. inverter rated for 3500 watts. Are they rated by watt hour? I had one and i just remember it had a burst rating and a continuous rating. So if I use 3500 watts over the course of 1 hour. That means a continuous rating of 3500 Wh? so like even if I use it for 1 min. 3500 Wh/60(mins) so i only use 58 watts. I still need an inverter thats rated for 3500 continuous (meaning watt hours) Do I understand right?

Now you said i need batteries for 3500 watt hours. 3500w/220v = 15amps. so a 100 amp hour batter should give me 6 hours from one battleborn. So i'm missing something?

By the way thanks for your detailed explanations.

 

[Traveler004]

The dryer shouldn’t be on two 15a Breakers... it should be on two 30amp breakers.

it should be on #10 or larger wire, especially if it has aluminum feeding it.

most full size electric dryers in the us have a 3500W heating element and an 80watt or larger electric motor. We electricians are required to calculate 4500W for the laundry loads, that isn’t the draw, it is the expected load, including washer. Lots of factors go into the calculation.

figure an hour runtime, with sporadic heat, and constantmotor load, likely in the 2.5-3.5 KWh load range... depending on moisture of the clothes...

That is a lot of battery and solar.

thanks
I'll have to check that out. If I find one more problem with this old house i'm going to scream. To be honest it wouldn't surprise me. Part of the benefit of adding the solar is that the grid system will be getting an overhaul at the same time.

 

[Supervstech]

North american, yes.
I got everything up until here. inverter rated for 3500 watts. Are they rated by watt hour? I had one and i just remember it had a burst rating and a continuous rating. So if I use 3500 watts over the course of 1 hour. That means a continuous rating of 3500 Wh? so like even if I use it for 1 min. 3500 Wh/60(mins) so i only use 58 watts. I still need an inverter thats rated for 3500 continuous (meaning watt hours) Do I understand right?

Now you said i need batteries for 3500 watt hours. 3500w/220v = 15amps. so a 100 amp hour batter should give me 6 hours from one battleborn. So i'm missing something?

By the way thanks for your detailed explanations.

No.

inverters are rated in wattage output. 3500 watts is an output capacity.
Batteries are rated in storage capacity, or Wh...

 

[Supervstech]

North american, yes.
I got everything up until here. inverter rated for 3500 watts. Are they rated by watt hour? I had one and i just remember it had a burst rating and a continuous rating. So if I use 3500 watts over the course of 1 hour. That means a continuous rating of 3500 Wh? so like even if I use it for 1 min. 3500 Wh/60(mins) so i only use 58 watts. I still need an inverter thats rated for 3500 continuous (meaning watt hours) Do I understand right?

Now you said i need batteries for 3500 watt hours. 3500w/220v = 15amps. so a 100 amp hour batter should give me 6 hours from one battleborn. So i'm missing something?

By the way thanks for your detailed explanations.

Amps aren’t relevant to the battery discussion yet.

Wh is what you need.

a battleborn 100Ah battery has 1400Wh in it...

 

[BoloMKXXVIII]

Use the original solar dryer...the sun.

 

[Supervstech]

North american, yes.
I got everything up until here. inverter rated for 3500 watts. Are they rated by watt hour? I had one and i just remember it had a burst rating and a continuous rating. So if I use 3500 watts over the course of 1 hour. That means a continuous rating of 3500 Wh? so like even if I use it for 1 min. 3500 Wh/60(mins) so i only use 58 watts. I still need an inverter thats rated for 3500 continuous (meaning watt hours) Do I understand right?

Now you said i need batteries for 3500 watt hours. 3500w/220v = 15amps. so a 100 amp hour batter should give me 6 hours from one battleborn. So i'm missing something?

By the way thanks for your detailed explanations.

You are using 240v amps, and applying it to a 12v battery Ah rating...

can’t do that.

3500W at 240 v is about 15 amps... putting aside you don’t have3500W draw... you have. 4500watt draw or more at times...
3500W at 12 v (really 14v) is 250Amps... and the battleborn max output is 100 amps... so, you need 3 minimum to even turn on a 3500W inverter...

 

[SolarRat]

A 48v 200ah (~10kw) battery would be the minimum I would use to allow some cushion and also power other loads in your house. A 5kw inverter with maybe 8kw peak would be a minimum starting point for an inverter...

Just for comparison, a 48v 200ah battery would be equal to 8 Battleborns! You would be better off getting two (preferably four) of those 24v 200ah batteries everyone is talking about and put them in series for 48v.

 

[JeepHammer]

Basic Solar Power System, No DC (Panels, Charger or Battery) specified,
Showing common US Standard Inverters, DC to AC.



*IF* you panels and battery bank is large enough, you can connect to normal home breaker box, but notice the Inverter produces in 240 Volts AC, the same way power comes off the grid into homes.



SOME systems are 'Grid Intertie', meaning when your panels aren't producing, a power grid connection supplies the power.
Many of these don't have batteries, instead directing excess panel production onto the power grid, turning you meter backwards, but this takes a special meter from the service provider, and you have to live in a state that allows excess daytime production to be put back on the grid. This is NOT a DIY project.

Completely Off Grid,
You have to produce enough from panels to both support the home AND charge the batteries at the same time.
This is a big investment in panels since the sun only shines part time, so 100% of your usage has to be produced in the 'Peak Sun' hours.

Your battery bank and inverter must be up to the job, so many of us off grid run higher voltage than the smaller DIY systems you see advertised.
Your cloths dryer for instance...
240 Volts x 30 Amps = 7,200 Watts per hour.

Coming from 12 Volt Batteries,
7,200 Watts / 12 Volts = 600 Amps/Hour!

Coming from 24 Volt Batteries,
7,200 Watts / 24 Volts = 300 Amps/Hour.

Coming from 48 Volt Batteries,
7,200 Watts / 48 Volts = 150 Amps/Hour.

Look at it this way, with a 200 Amp service line, which is most common in US homes,
240 Volts x 200 Amps/Hour = 48,000 Watts/Hour capacity.
Voltage going UP is most certainly the best way to go if you are going to draw a lot of Watts,
BUT,
Since you have to both produce those Watts in short full sun hours, and store those Watts in batteries, it's neither cheap or easy...

 

[Darkstar]

Use the original solar dryer...the sun.

Would be nice - We have nothing but rain for 6 months out of the year here...

 

[Darkstar]

This heat pump dryer looks interesting.

https://www.greenbuildingadvisor.com/article/heat-pump-clothes-dryers

 

[Steve_S]

Could any of these be an option for you ?

Best 120V Portable Clothes Dryers

Portable Tumble Dryers are only one type of portable dryer. Learn about our options below. The Panda 3.75-cu.ft. Compact Laundry Dryer has a relatively large capacity at 13.2 lbs (about 6 or 7 wet bath

clean4happy.com

Have a gander and see if maybe it's an option.

There are also another type of "Hanging Dryer" that some have talked about (in an off grid cabin site which I belong to) here is a link to one which was mentioned that apparently works quite well.

Robot Check

I've been pondering something like the above one but haven't decided as the power requirements aren't "crazy" but I just don't know how well they work.

 

[Whats-n-Watts]

Basic Solar Power System, No DC (Panels, Charger or Battery) specified,
Showing common US Standard Inverters, DC to AC.

View attachment 5549

*IF* you panels and battery bank is large enough, you can connect to normal home breaker box, but notice the Inverter produces in 240 Volts AC, the same way power comes off the grid into homes.

View attachment 5550

SOME systems are 'Grid Intertie', meaning when your panels aren't producing, a power grid connection supplies the power.
Many of these don't have batteries, instead directing excess panel production onto the power grid, turning you meter backwards, but this takes a special meter from the service provider, and you have to live in a state that allows excess daytime production to be put back on the grid. This is NOT a DIY project.

Completely Off Grid,
You have to produce enough from panels to both support the home AND charge the batteries at the same time.
This is a big investment in panels since the sun only shines part time, so 100% of your usage has to be produced in the 'Peak Sun' hours.

Your battery bank and inverter must be up to the job, so many of us off grid run higher voltage than the smaller DIY systems you see advertised.
Your cloths dryer for instance...
240 Volts x 30 Amps = 7,200 Watts per hour.

Coming from 12 Volt Batteries,
7,200 Watts / 12 Volts = 600 Amps/Hour!

Coming from 24 Volt Batteries,
7,200 Watts / 24 Volts = 300 Amps/Hour.

Coming from 48 Volt Batteries,
7,200 Watts / 48 Volts = 150 Amps/Hour.

Look at it this way, with a 200 Amp service line, which is most common in US homes,
240 Volts x 200 Amps/Hour = 48,000 Watts/Hour capacity.
Voltage going UP is most certainly the best way to go if you are going to draw a lot of Watts,
BUT,
Since you have to both produce those Watts in short full sun hours, and store those Watts in batteries, it's neither cheap or easy...

I have a question that maybe you can answer sir. Say an array faces south and is in full sun 7 hours per day in winter and 4.25 of those are peak hours. Approximately what could one expect for a 305w panel to produce per day? In other words what would off peak production be?

 

[k490]

I have a question that maybe you can answer sir. Say an array faces south and is in full sun 7 hours per day in winter and 4.25 of those are peak hours. Approximately what could one expect for a 305w panel to produce per day? In other words what would off peak production be?

I bought some used JA solar 395-watt panels, and I picked up a panel tester off Amazon back in November. If I tilted the panel just perfectly at the sun the highest reading I got was 388 watts. I noticed adjusting the angle just 10-15 degrees would drop the output down to the 360-watt range quickly. These numbers were taken when the panel was cool when it was in the sun for an hour it dropped into the 350-360 range. The panel was hot enough I had to use gloves to move it around the outside temp was only in the 80's.

 

[Madcodger]

I have a question

PVWatts

Estimates the energy production and cost of energy of grid-connected photovoltaic (PV) energy systems throughout the world. It allows homeowners, small building owners, installers and manufacturers to easily develop estimates of the performance of potential PV installations

pvwatts.nrel.gov

Your tax dollars at work (if you live in the US). May as well get something for all that money we give 'em. Works anywhere in the world, so if a person is somewhere else, yet another gift from the US. Enjoy.