Utility/recommendations for 100 watt solar panel for home/camping?

tkdguy · Apr 4, 2022

What is your analysis of the above? A real applications that are useful? What accessories are needed? Thanks....

ma96782 · Apr 4, 2022

RE : Enough solar panel

Just from reading a bit and/or watching people who have done it.....
There is a "balance" to be struck.

Huh?
Enough solar panel.
The amount of storage available.
Anticipated need/usage of watts.
Really? You were expecting only Sunny days?
Cost(s)

Anyway.....for smaller applications.....I found that a lot of those full timer RV videos were helpful.

If you're thinking about "Bigger". Yeah, research that too. Hint : YouTube.

Aloha, Mark

PS......back in Hawaii (way back when) my father was the first on the block to have a solar water heater installed. Yeah....it was a game changer back then. BUT, But, but.....around WA? Whatever dude.

RVTECH · Apr 4, 2022

One major consideration you need to answer first - will this be limited to 12 VDC only or do you want to 'invert' to 110 VAC?

This will dramatically influence how you go about this.

tkdguy · Apr 4, 2022

RVTECH said:
One major consideration you need to answer first - will this be limited to 12 VDC only or do you want to 'invert' to 110 VAC?

This will dramatically influence how you go about this.

Do want to invert to 110 V. Ideas?

cigars · Apr 4, 2022

Harbor Freight has a decent 100 watt panel for about $120. They sell the controller too. If you have a battery back up like a Duracell 660 (about $500 at costco) which is also an inverter you can use the panel to charge it in the day time. It's a fairly cheap way to get the job done. Portable solar and portable 110v AC.

RVTECH · Apr 4, 2022

tkdguy said:
Do want to invert to 110 V. Ideas?

Ok - you have a lot to consider such as how much wattage you will be using at any given time, or better yet your average wattage.

This will affect the amp draw which in turn will affect the reserve capacity and how long you can effectively 'run' for.

Inverting to 110 creates a dramatic, additional amperage requirement.

I would HIGHLY recommend you contact a major solar supplier (such as Zamp Solar) and start reading up on it as they will be able to answer your questions in a much more specific manner.

A few years ago I prepared some 'layman' based 'handouts' for customers that answered some of the basic questions about electricity and how it applied to solar and if I can find them I'll PM you a copy!

solv3nt · Apr 4, 2022

What are you trying to power?

Yarome · Apr 4, 2022

ma96782 said:
....for smaller applications.....I found that a lot of those full timer RV videos were helpful.

I dunno if I would say "smaller applications". Mine has 880watts of high effeciency 24V panels. Along with feeding the native 12v it also feeds a 2000W main inverter that will run the microwave, power tools, etc... and/or smaller 300W alt/backup/lower power demand inverter. A nearly full time boondocker and only very rarely have to kick over one of the 2000W portable gensets to top off the battery bank during longer stretches of poor solar production.

(I need two 2k portables to run the A/C. I don't like to suffer.

)

"Smaller"??

For the OP: It all boils down to your expectations, intended use and power requirements.

Before even considering what amount of solar production may be required you would need to determine what size of battery/battery bank would be needed to satisfy your power needs. As previously stated, how much 12v and do you really need 120v? Power consumption and duration of usage would need to be calculated to determine the total amp hours of stored capacity required. From there you would determine what type of battery bank you would need largely based on size, weight, and hugely... cost.

Only then would you consider how to put at least some of that energy back into your battery/battery bank to sustain you over your targetted length of intended use. Solar might be viable. Possibly a portable genset. A combination of the two, or the cheapest... add more capacity to your battery bank and worry about recharging it when you get home.

Doing a "power audit" would be step #1 and as ma96782 stated.... the RV community is a fantastic resource to get an idea of what typical energy eaters consume and how to calculate your Ah (amp hour) needs. I would recommend rvnetwork.com as your best option for extremely knowlegeable solar savy folks... and power usage/consuption in general.

Solar can be a fantastic idea and I know it might seem like a lot of work going down that rabbit hole. It's easy enough to buy a prepackaged "solar kit" and any old battery. Many do that. You'll typically pay at least double what it's really worth with likely half the effective capability it advertises. Typically, the end result being that it won't meet your expectations, you abandon it, and end up a waste of good money you could have used to buy another gun.

Just sayin....

partsed · Apr 4, 2022

RVTECH said:
Ok - you have a lot to consider such as how much wattage you will be using at any given time, or better yet your average wattage.

This will affect the amp draw which in turn will affect the reserve capacity and how long you can effectively 'run' for.

Inverting to 110 creates a dramatic, additional amperage requirement.

I would HIGHLY recommend you contact a major solar supplier (such as Zamp Solar) and start reading up on it as they will be able to answer your questions in a much more specific manner.

A few years ago I prepared some 'layman' based 'handouts' for customers that answered some of the basic questions about electricity and how it applied to solar and if I can find them I'll PM you a copy!

I'd appreciate a copy of the handout if you find it.

Thanks!!

RVTECH · Apr 4, 2022

partsed said:
I'd appreciate a copy of the handout if you find it.

Will do !

I outlined some simple concepts such as ohm's law, watts law etc. along with how 'voltage' works and how it all combines into winding up at the light bulb - or wherever else it is needed!

Yarome · Apr 4, 2022

RVTECH said:
(such as Zamp Solar)

Personally, I would steer clear of Zamp Solar at all costs. They are geared toward the layman end user being able to "plug and play" into solar, however, that comes at EXTREME cost with highly ineffecient packages that can leave you shell shocked and deeply disappointed in performance. Aka: Taking advantage of consumer ignorance.

solv3nt · Apr 4, 2022

Yarome said:
Personally, I would steer clear of Zamp Solar at all costs. They are geared toward the layman end user being able to "plug and play" into solar, however, that comes at EXTREME cost with highly ineffecient packages that can leave you shell shocked and deeply disappointed in performance. Aka: Taking advantage of consumer ignorance.

Anytime you go AC to DC and back again, you lose about 50%.

tkdguy · Apr 4, 2022

i AM THINKING THE NEED IS TO RUN A HOT PLATE, AND OR MICROWAVE. MAYBE SOME OUTDOOR OR INDOOR LIGHTS. IDEAS?

Yarome · Apr 4, 2022

tkdguy said:
i AM THINKING THE NEED IS TO RUN A HOT PLATE, AND OR MICROWAVE. MAYBE SOME OUTDOOR OR INDOOR LIGHTS. IDEAS?

12v LED lighting is simple enough.

A microwave is another matter. Typically around 900watts for a little one so you're looking at a 9-10amp draw. The kicker though is the startup overhead to get the magnetometer to fire. It's doable on a battery with an appropriately sized battery bank and pure sine wave inverter (which isn't the cheap one).

The hot plate is the killer though. Usually something like 1500-1800watts and talking 12-13ish amp draw for a small 7". Some can go intot he 2400-3000+watt range. It's more forgiving in what type of power it likes and doesn't have a huge startup overhead draw.. so a cheaper inverter can be used... however, the run time is typically much longer than a microwave and will likely be a much bigger draw on a battery bank.

In short... I wouldn't plan on using either unless you're willing to sink a large chunk of change into off grid power. Starting range (if you do the leg work and instal/setup yourself)... probably in the $800+ range for a sufficienty sized battery bank and inverter (no solar, yet) to power a microwave or hot plate over a 2-3 day camping trip. 100watts of solar... no possible way for it to keep up with that kind of consumption. Like trying to bottle a unicorn fart.

To do that, minimally, you're looking at somewhere at another $1k+ range at the very MOST conservative estimate and would have limited capability/usage. Unless, supplemented by daily portable genset charging.

For occassional use a few times a year. Your best bet would be to investing in a small portable inverter generator. 2k+ watt should do you. For a "good" one, expect to pay around $900-$1k-ish. On the cheap side you could get away with around $500. You're talking about harbor freight kind of quality level. Might get the job done but likely won't last long, not always reliable, the power provided may be lower than it's rated and a little "dirty". That translates into "wear and tear" on your electronics.

Side note: Contractor type generators are cheaper and might be tempting but they are not allowed in nearly any national or state forest, and are incredibly loud. There are some unwritten generator usage rules that should be learned as well (acceptable hours of operation, etc) so you don't wake up in the morning with sugar in your genset tank... or get shot at!

The small portables are extremely quiet, compact, mobile and easily handled by one person. Which brings up another point. A battery bank big enough to handle that kind of usage will be quite large, very heavy and permanently mounted/installed. Of course, you CAN reduce the size and weight factors significantly by going with lithium, however, expect your wallet to thin out exponentially.

Example: Deep cycle battery bank, on the cheap but still very capable and good quality side (like Costco/Sam's club golf cart batteries), you're talking around $350-$400 for 220ah's "useable" (440ah bank at no more than 50% discharge). Lithium, depending on the type, entry level range for 190ah's 'useable' will be in the $1.2k range... if you're lucky. There are other advantages to lithium, but that's getting pretty steep just to fry an egg on the hotplate or nuke a bowl of soup.

To put companies like Zamp into perpective... they only want to sell you lithium, the battery chemistry is poor, the cell electronics are not all that great, but you can count on $1k per 90ah's "useable". Highway robbery for similar quality lithiums at half the price! (When deep cycle are perfectly fine for the greater majority of people, anyway.) Don't even get me started on the $ per solar watt prices.

Kind of like buying a Ferrari with a Toyota Civic engine under the hood.

Far and wide... head of the class in the portable inverter gensets would be a Honda or Yamaha 2k+ portable inverter generator. Both have subtle pros and cons, but it's a complete 1:1 trade off for most folks. Either one is money very well spent.

Why a genset? For about what it would cost you for the battery bank (which requires regular maintanence) and inverter capable of supplying that amount of power on a limited basis (not counting the research, legwork, then intallation) is about what you would pay for one small package with surplus capability and only limited by how much fuel you take along. Less maintanence and no installation required.

All that said~ A small true deep cycle battery, a 100watt panel and charging system.... that would likely work just fine to feed a string of 12v LED lights and keep your phone charged. You're camping, right? Replace your microwave and your hot plate with a gas/fuel stove/grill and keep the energy needs manageable with a fairly inexpensive and mildly sustainable 12v lighting/charging system.

ENTIRELY too much information, but using it as a bit of a "primer" into main factors to consider when thinking about off-grid energy.

Yarome · Apr 5, 2022

solv3nt said:
Anytime you go AC to DC and back again, you lose about 50%.

Its not quite that bad. With proper equipment, wire type, connections, and gauge sized for the distance on the 12v path the conversion overhead can be minimized. In general, 5%-10% is what I would consider a goal range when you're talking conversion from AC. Although 20% isn't unheard of in some of the setups I've seen.

Modern higher grade equipment these days often only burns 15-20watts in overhead.

Inversion from DC to AC is actually much better with almost no "significant" loss. Or I guess you would say 'ideally".

Yarome · Apr 5, 2022

RVTECH said:
....such as ohm's law....

I need pictures....

tkdguy · Apr 5, 2022

Yarome said:
12v LED lighting is simple enough.

A microwave is another matter. Typically around 900watts for a little one so you're looking at a 9-10amp draw. The kicker though is the startup overhead to get the magnetometer to fire. It's doable on a battery with an appropriately sized battery bank and pure sine wave inverter (which isn't the cheap one).

The hot plate is the killer though. Usually something like 1500-1800watts and talking 12-13ish amp draw for a small 7". Some can go intot he 2400-3000+watt range. It's more forgiving in what type of power it likes and doesn't have a huge startup overhead draw.. so a cheaper inverter can be used... however, the run time is typically much longer than a microwave and will likely be a much bigger draw on a battery bank.

In short... I wouldn't plan on using either unless you're willing to sink a large chunk of change into off grid power. Starting range (if you do the leg work and instal/setup yourself)... probably in the $800+ range for a sufficienty sized battery bank and inverter (no solar, yet) to power a microwave or hot plate over a 2-3 day camping trip. 100watts of solar... no possible way for it to keep up with that kind of consumption. Like trying to bottle a unicorn fart. To do that, minimally, you're looking at somewhere at another $1k+ range at the very MOST conservative estimate and would have limited capability/usage. Unless, supplemented by daily portable genset charging.

For occassional use a few times a year. Your best bet would be to investing in a small portable inverter generator. 2k+ watt should do you. For a "good" one, expect to pay around $900-$1k-ish. On the cheap side you could get away with around $500. You're talking about harbor freight kind of quality level. Might get the job done but likely won't last long, not always reliable, the power provided may be lower than it's rated and a little "dirty". That translates into "wear and tear" on your electronics.

Side note: Contractor type generators are cheaper and might be tempting but they are not allowed in nearly any national or state forest, and are incredibly loud. There are some unwritten generator usage rules that should be learned as well (acceptable hours of operation, etc) so you don't wake up in the morning with sugar in your genset tank... or get shot at!

The small portables are extremely quiet, compact, mobile and easily handled by one person. Which brings up another point. A battery bank big enough to handle that kind of usage will be quite large, very heavy and permanently mounted/installed. Of course, you CAN reduce the size and weight factors significantly by going with lithium, however, expect your wallet to thin out exponentially.

Example: Deep cycle battery bank, on the cheap but still very capable and good quality side (like Costco/Sam's club golf cart batteries), you're talking around $350-$400 for 220ah's "useable" (440ah bank at no more than 50% discharge). Lithium, depending on the type, entry level range for 190ah's 'useable' will be in the $1.2k range... if you're lucky. There are other advantages to lithium, but that's getting pretty steep just to fry an egg on the hotplate or nuke a bowl of soup.

To put companies like Zamp into perpective... they only want to sell you lithium, the battery chemistry is poor, the cell electronics are not all that great, but you can count on $1k per 90ah's "useable". Highway robbery for similar quality lithiums at half the price! (When deep cycle are perfectly fine for the greater majority of people, anyway.) Don't even get me started on the $ per solar watt prices. Kind of like buying a Ferrari with a Toyota Civic engine under the hood.

Far and wide... head of the class in the portable inverter gensets would be a Honda or Yamaha 2k+ portable inverter generator. Both have subtle pros and cons, but it's a complete 1:1 trade off for most folks. Either one is money very well spent.

Why a genset? For about what it would cost you for the battery bank (which requires regular maintanence) and inverter capable of supplying that amount of power on a limited basis (not counting the research, legwork, then intallation) is about what you would pay for one small package with surplus capability and only limited by how much fuel you take along. Less maintanence and no installation required.

All that said~ A small true deep cycle battery, a 100watt panel and charging system.... that would likely work just fine to feed a string of 12v LED lights and keep your phone charged. You're camping, right? Replace your microwave and your hot plate with a gas/fuel stove/grill and keep the energy needs manageable with a fairly inexpensive and mildly sustainable 12v lighting/charging system.

ENTIRELY too much information, but using it as a bit of a "primer" into main factors to consider when thinking about off-grid energy.

very useful. thx

Provincial · Apr 5, 2022

I find it easier for people to understand when I use water to explain electrical flow. It gives them something that they can see, and almost everyone has used a garden hose.

Voltage is like water pressure.
Amperage is like water flow (volume).
Resistance is like size of pipes (or nozzles).

solv3nt · Apr 5, 2022

Provincial said:
I find it easier for people to understand when I use water to explain electrical flow. It gives them something that they can see, and almost everyone has used a garden hose.

Voltage is like water pressure.
Amperage is like water flow (volume).
Resistance is like size of pipes (or nozzles).

I enjoy the mug of beer analogy, gotta love nerds.