[PA_Robert]

Solar has piqued my interest as well as another redundant power source. Like Robert said, W PA is a bit gloomy to rely solely on solar power but as a stop gap it has its place. I do not want to spend $20k or anywhere near and do not want all the panel gear on my roof in the event we move in the next few years. I've found the brand in the link below. Looks good for stop gap or for camping etc . Any comments on this line ?

Jackery Explorer 500 Portable Power Station

Jackery Carrying Case is a premium EVA bag designed to fit and protect the Explorer 500 Portable Power Station from damage. Stylish, practical, and durable.

www.jackery.com

For a point of power consumption, that size jackery would run a typical freezer/fridge using 300 watts for about 1.75 hours...but the motor start will probably exceed the limit of the built in inverter.

 

[ColoradoMinuteMan]

For a point of power consumption, that size jackery would run a typical freezer/fridge using 300 watts for about 1.75 hours...but the motor start will probably exceed the limit of the built in inverter.

(Running Watts x Hours) x ( 1 / inverter efficiency) = Required Battery Watts Hours
(300W x 1.75H) x (1 / .90) = 583 WH

You’ll have to look at the specs on the storage device because some battery types can’t be depleted below 50% (cycle depth) of total capacity so if you require 600 WH you’ll need a capacity of 1200 WH, so you need to read the specs of a specific unit to see the recommended cycle depth. You’ll also want to determine the starting W required and ensure that you size the inverter to match. Some inverters will list a peak power rating that they can maintain for a few seconds (usually 200% of running). It really depends on how long the starting W of the freezer is maintained to know if you will exceed the peak rating. Another consideration is that inverters also suck energy the entire time they are powered on, even if there is no or little draw from the appliance, so you also need to understand what the idle inverter draw is and add that to the necessary AH required in stored energy.

 

[hoplite59]

Pardon my ignorance but as I understand solar, it will store the energy it collects on a sunny day and be ready for use after the fact ?

 

[John Galt 1]

@PA_Robert

TexasHomesteader's numbers are fairly realistic. I've been running a 6000 watt system for about 7 years and my numbers are similar. Keep in mind that different people have slightly different definitions of "cloudy weather"

Yes, I've seen close to 6000 watts out of my 6000 watts in panels but 4400 watts is probably closer to the norm on a sunny day and the batteries are low enough to pull hard.

 

[PA_Robert]

(Running Watts x Hours) x ( 1 / inverter efficiency) = Required Battery Watts Hours
(300W x 1.75H) x (1 / .90) = 583 WH

You’ll have to look at the specs on the storage device because some battery types can’t be depleted below 50% (cycle depth) of total capacity so if you require 600 WH you’ll need a capacity of 1200 WH, so you need to read the specs of a specific unit to see the recommended cycle depth. You’ll also want to determine the starting W required and ensure that you size the inverter to match. Some inverters will list a peak power rating that they can maintain for a few seconds (usually 200% of running). It really depends on how long the starting W of the freezer is maintained to know if you will exceed the peak rating. Another consideration is that inverters also suck energy the entire time they are powered on, even if there is no or little draw from the appliance, so you also need to understand what the idle inverter draw is and add that to the necessary AH required in stored energy.

Yes. True. I was just trying to keep it simple.

We can dive into efficiency of inverters/converters and such and depth of discharge for different types of batteries at a later date with some folks.

We really need to create an electrical 101 sticky.

Actually we need a few. One for electrical basics. One for estimating your power needs for what you want to power. One for solar panel electrical generation and storage. One for those "solar generators" (aka battery /inverter packs). And battery types and characteristics.

 

[PA_Robert]

Pardon my ignorance but as I understand solar, it will store the energy it collects on a sunny day and be ready for use after the fact ?

Not really. the term "solar" is a very broad brush stroke. There are different types of solar systems.

Solar panels themselves can not store it. They only convert available light to DC (direct current) electricity. No sunlight..no power.

Batteries store it.

The basic three types of solar systems are:

Grid Tied - usually bigger solar panel array that makes DC power. The DC power goes to an inverter. The inverter changes DC to AC (alternating current) and connects to your home's electrical system, which is connected to the grid. This is a "two part" system. Panels and Inverter. Obviously it only makes power when there's sunlight. When it's dark you still have grid power. If grid goes down...you have no power. (there's can be more but this is the most simple explanation)

Off Grid - Typically this type of system is for us "preppers". We want to be able to power things when the grid goes down. The amount of panels and the amount of batteries depends on what you want to power. It's a "four part system". You have solar panels which make DC power. The DC power goes to a charge controller. The charge controller "controls " the voltage/power, which will charge the batteries. The batteries supply DC power to an inverter. The inverter changes DC power to AC power. Once inverted we can use it with our "normal" 120VAC things that we plug into our home outlets. The four parts are solar panels, charge controller, batteries and inverter.

Hybrid - combination of the two.

What is a hybrid solar system?

A hybrid solar system connects to the grid and has a solar battery to store energy. They are more reliable than off-grid or grid-tied-only solar systems.

www.solarreviews.com

 

[TexasHomesteader]

Today at peak time 1230, my 23 kw solar system is making about 1300 watts or 1.3 kw
its totally cloudy
yesterday was sunny, at this time I was making about 17 kw

clouds suck

Todays number at almost noon is that the 23 kw system is making 2.7 kw
again totally overcast, just a little brighter than yesterday

 

[hoplite59]

Todays number at almost noon is that the 23 kw system is making 2.7 kw
again totally overcast, just a little brighter than yesterday

what will that level of KWs power.

 

[MyPrepperLife]

I just want to comment about the cloudy weather.

I live 100% off grid, full time. This winter here in northern Maine we've had much less sun than we normally have in winter. So far this winter I've had to use my gas generator four or five times to charge the battery bank for my solar-electric system. In contrast, last winter I didn't use the gas generator at all to charge my battery bank.

 

[ColoradoMinuteMan]

Pardon my ignorance but as I understand solar, it will store the energy it collects on a sunny day and be ready for use after the fact ?

Well, the short answer is: some can, some can't.

Generically Solar Power is just a means of capturing solar radiation and converting it to electricity. The simplest system will just convert it to electricity to power a circuit with some sort of load on it. For example, a solar panel the is connected to a pump and the pump will run while the sun is providing enough radiation to power the pump motor. Nothing is stored in that arrangement. Other systems will have a battery bank of some sort and the converted electricity from the panels will charge controller that will charge batteries while there is enough solar radiation (and battery capacity) to do so. The batteries will then be drawn upon to provide electricity when there is not enough solar radiation to power the loads. There are also grid-tied systems that will use the solar energy to power the public utility grid which will provide electricity to anyone on the public grid. There are also all sorts of hybrid options that use a combination of these systems.

what will that level of KWs power.

Well, short answer is that it depends. 23kw is 23,000W. Below you can see some examples of what various appliances can use.

Appliance Energy Use Chart | Silicon Valley Power

 

[hoplite59]

Well, the short answer is: some can, some can't.

Generically Solar Power is just a means of capturing solar radiation and converting it to electricity. The simplest system will just convert it to electricity to power a circuit with some sort of load on it. For example, a solar panel the is connected to a pump and the pump will run while the sun is providing enough radiation to power the pump motor. Nothing is stored in that arrangement. Other systems will have a battery bank of some sort and the converted electricity from the panels will charge controller that will charge batteries while there is enough solar radiation (and battery capacity) to do so. The batteries will then be drawn upon to provide electricity when there is not enough solar radiation to power the loads. There are also grid-tied systems that will use the solar energy to power the public utility grid which will provide electricity to anyone on the public grid. There are also all sorts of hybrid options that use a combination of these systems.



Well, short answer is that it depends. 23kw is 23,000W. Below you can see some examples of what various appliances can use.

Appliance Energy Use Chart | Silicon Valley Power

Thank you, and sorry for slowing down the thread with seemingly dumb questions.

 

[charliemeyer007]

Just a reminder that new things tend to work better than old things. Deteriorated panels produce less, batteries hold less, refrigerators need more power so factor that in to your calculations for the sizing criteria.

 

[Alaskajohn]

Solar has piqued my interest as well as another redundant power source. Like Robert said, W PA is a bit gloomy to rely solely on solar power but as a stop gap it has its place. I do not want to spend $20k or anywhere near and do not want all the panel gear on my roof in the event we move in the next few years. I've found the brand in the link below. Looks good for stop gap or for camping etc . Any comments on this line ?

Jackery Explorer 500 Portable Power Station

Jackery Carrying Case is a premium EVA bag designed to fit and protect the Explorer 500 Portable Power Station from damage. Stylish, practical, and durable.

www.jackery.com

I watch some cabins for a neighbor who lives out of state. We have the 1000w Jackery and we will take it and a solar panel out and spend a few days at each cabin a couple times each summer. I can pick up a cell tower with data and I have done consulting work with a laptop and video while my wide is looking at her iPad doing her thing, we string up lights, etc. With multiple lights, devices, etc, and taking advantage of 18 hour daylight, I don’t think the battery ever got below 85% of charge, if that low. I would think the 500 watt would be good for camping and such as the 1000 watt one is overkill for what I typically use it for recreational purposes.

 

[fordtrucksforever]

I am out at my cabin, and future residence, while the weather is below freezing and full heavy cloud cover. Checking out how well my pot belly stove works for the first time since it was just installed. Yesterday my batteries were fully charged and I had no problems running things as usual.

Saturday was sunny and battery bank was full charged. But without sun yesterday and all today I had to watch things and be careful so not to drain them down. I avoided using much power today since panels were not very productive.

Tonight my battery bank is up but not fully charged. Looks like for most of this week is going to be mostly the same. I have 1800 watts of panels but more than one day with heavy overcast and freezing drizzle, not much happening in the way of output from panels.

I have not run in to this problem before. Usually I can cut back and problem. But the cloud cover, drizzle and almost what looks like fog is not letting any rays thru.

If too heavily overcast tomorrow like today, I will expect my batteries to not charge enough so they wont be getting much use. Will rely of generator in that is the case. Most the time especially when not so cold I dont loose so much like this week.

Must be Al Gores fault

 

[PA_Robert]

I just want to comment about the cloudy weather.

I live 100% off grid, full time. This winter here in northern Maine we've had much less sun than we normally have in winter. So far this winter I've had to use my gas generator four or five times to charge the battery bank for my solar-electric system. In contrast, last winter I didn't use the gas generator at all to charge my battery bank.

What size system (panels and battery)? And what kind of daily loads----peak watt, total watt for day?

All 120 or two leg 240?

I assume no big loads are on solar/battery i.e water heater, clothes dryer, electric stove, baseboard heat, HVAC)

Without reference of size and system, it's hard to quantify your post. I can live 100% off grid and only have power needs for a satellite connection for my internet and my phone. So, I would only only need to generate a few hundreds watt per day.

Not trying to be a ****, just trying to understand peoples' systems.

 

[PA_Robert]

@PA_Robert

TexasHomesteader's numbers are fairly realistic. I've been running a 6000 watt system for about 7 years and my numbers are similar. Keep in mind that different people have slightly different definitions of "cloudy weather"

Yes, I've seen close to 6000 watts out of my 6000 watts in panels but 4400 watts is probably closer to the norm on a sunny day and the batteries are low enough to pull hard.

Thank you.

You have 6K in panels....and generate 4400 normally on a sunny day. That is instantaneous value.

But what was your total generation for a day in watt hours?

And yes, cloudy or overcast is subjective

 

[MyPrepperLife]

What size system (panels and battery)? And what kind of daily loads----peak watt, total watt for day?

All 120 or two leg 240?

I assume no big loads are on solar/battery i.e water heater, clothes dryer, electric stove, baseboard heat, HVAC)

Without reference of size and system, it's hard to quantify your post. I can live 100% off grid and only have power needs for a satellite connection for my internet and my phone. So, I would only only need to generate a few hundreds watt per day.

Not trying to be a ****, just trying to understand peoples' systems.

My system configuration and usage parameters this winter are the same as last winter. Here they are.

• Titan solar generator with 120 V inverter and 16 KWH battery bank
• 10 180W solar panels (two arrays of five panels)
• Daily watt draw is between 2.5 KWH and 3 KWH
• Peak load is maybe 1.2 KW, but that only happens when my submersible well pump is running, which only happens a few times per day for about a minute each time. The rest of the time load is generally between 100 and 250 watts.

RE "I assume no big loads are on solar/battery i.e water heater, clothes dryer, electric stove, baseboard heat, HVAC)"

Correct.

 

[John Galt 1]

Thank you.

You have 6K in panels....and generate 4400 normally on a sunny day. That is instantaneous value.

But what was your total generation for a day in watt hours?

And yes, cloudy or overcast is subjective

Keep in mind that the charge controller will reduce power going into the batteries as it sees the batteries getting close to full.

Also keep in mind that 900 watts of those panels are mostly facing west to extend the "solar day" but receive little sunlight before 3 in the afternoon.. This is because we try to keep the mini-split AC on sunlight power as long as possible to minimize strain on the batteries.

But if the solar controller keeps pushing power into the batteries all day 24+ kwhs during the summer and on an average winter day with a bit of cloud.around 10 kwhs.
I've seen days where I've gotten less than 2 kwhs during a heavy rain/clouds day. With snow on the panels you get nothing.

 

[PA_Robert]

Below is a screen shot from a friend's house. He has 8K of solar panels. It's grid tied (he has no storage). What he makes he uses, and if there's excess it gets fed back to the grid.

This graph is from 28 Jan. The last three days (Jan 29, 30,31) he added another 20 KWH, for a total of 197 KWH for January. He made 226 KWH in December.

I knew the capacity factor of solar was not great, especially in our area (NW PA). I'm a mechanical engineer and I work in power generation. So availability, efficiency, capacity factor are things I am familiar with. But I guess not familiar enough because I'm not a "renewable" guy. I work gas plants.

From the numbers I'm getting from my friend, here on SB, and a colleague, I'm definitely going to need a grid tied charger for batteries. I'm not going to build a solar panel array big enough to keep batteries topped off. Our worst case is 5-7 days with only 25% (avg) being generated of installed capacity.

But again my goal is to use what I can, have back up for power outages lasting a couple/few days and in the event SHTF, I'll have something long after the gas and propane is gone.

I don't plan on having a good return on investment for my system. 1200-1800 watts solar, 15KWH of battery storage and a quality 3k Watt or higher inverter/charge controller. My estimates, based on current cost per KWH, it will break even in 17 years... I'll consider it the same as my food stores, bang stick food, car insurance, life insurance, etc. It's better to have it and not need it, than need it and not have it.

 

[ColoradoMinuteMan]

Keep in mind, most grid connected panel arrangements don't actually feed the house. They feed the grid and the house consumes from the grid. It's subtle, but important difference because when the electricity grid goes down, you will not be able to power the house from the panels. There are systems that integrate a transfer switch to allow this, but it is something specific that you will need to design for to ensure that your house can consume solar power in the case that the grid goes down.

Below is a screen shot from a friend's house. He has 8K of solar panels. It's grid tied (he has no storage). What he makes he uses, and if there's excess it gets fed back to the grid.

This graph is from 28 Jan. The last three days (Jan 29, 30,31) he added another 20 KWH, for a total of 197 KWH for January. He made 226 KWH in December.

I knew the capacity factor of solar was not great, especially in our area (NW PA). I'm a mechanical engineer and I work in power generation. So availability, efficiency, capacity factor are things I am familiar with. But I guess not familiar enough because I'm not a "renewable" guy. I work gas plants.

From the numbers I'm getting from my friend, here on SB, and a colleague, I'm definitely going to need a grid tied charger for batteries. I'm not going to build a solar panel array big enough to keep batteries topped off. Our worst case is 5-7 days with only 25% (avg) being generated of installed capacity.

But again my goal is to use what I can, have back up for power outages lasting a couple/few days and in the event SHTF, I'll have something long after the gas and propane is gone.

I don't plan on having a good return on investment for my system. 1200-1800 watts solar, 15KWH of battery storage and a quality 3k Watt or higher inverter/charge controller. My estimates, based on current cost per KWH, it will break even in 17 years... I'll consider it the same as my food stores, bang stick food, car insurance, life insurance, etc. It's better to have it and not need it, than need it and not have it.

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