Why wouldn't you buy this 45watt Solar System for $149???

[Rbertalotto]

I'm a bit of a newby "things solar"...But for $150....Isn't this a good deal even if it is 'disposable"

http://www.harborfreight.com/solar-panel-kit-45-watt-68751.html

What would it cost to duplicate this system with "good" stuff?




Description
Solar panel kits are a great way to generate plenty of clean, quiet energy, using solar energy from the sun to run TVs, lights, computers, even recharge 12 volt DC batteries. Setting up Chicago Electric solar panel kits is easy. The solar panel kit comes with three 15 watt solar panels - simply connect the solar panels to your own 12 volt DC storage battery, and then use at least a 300 watt power inverter (sold separately) to power your 120 volt AC appliances anywhere.

Three 15 watt solar panels produce clean, quiet energy
Lightweight, weatherproof construction
Amorphous silicon solar cells for maximum output in both bright and cloudy conditions
Voltage regulator has easy-to-read LED display, 12V cigarette lighter socket, 5V USB, 3-6-9V DC outlets and two 12V sockets for the included Light Kit
Includes mounting hardware, 12V Light Kit, battery terminal clamps and universal DC power adapter

Requires 12 volt storage battery and 300 watt power inverter (sold separately).
Specifications
Name Solar Panel Kit, 45 Watt
SKU 68751
Brand THUNDERBOLT MAGNUM SOLAR
Application TVs, Lights, Computers, And Recharging 12v Batteries
Number of Panels 3
Wattage (watts) 45
Product Height 36-21/50 in.
Product Length 12-21/50 in.
Product Width 3/4 in.
Accessories Included Mounting hardware, 12v light kit, battery terminal clamps and universal DC power adapter
Warranty 90 Day

[Almot]

One more thing: panels 100W or larger are meant to be roof-mounted, mostly people just mount it flat, with no provisions for tilt. Life is easier this way. 100W panel is a bit of pain if you want a portable tilted setup like that 45W kit. Doable, few members did this, but you might not like it in the end. Again, flat means less output, that's why I wrote that for your purposes it's better be 120W if you want it flat. You "might" make it with flat 100W if weather cooperates and if you are not running laptop too often.

[CaptRick]

Well I will go the other way and say buy them, I did.
This set up works for my intended purpose, I have a 25 foot TT , all the lights have been switched to LED's, no TV and I dry camp for 3-4 days at a time. I have two 12V batteries and spend 90% of my time outside or away from camp dirt riding. I cut the PVC frame the panels come with in 3 pieces so it all fits into a big duffel bag to transport. I have a battery monitor (cheap plug in) and these panels keep my batteries topped up after a full day in the sun. Northen NM camping so sun is pretty much full on all the time. I also use the panels on the TT when it is stored at home to keep the batteries at full charge.
I am really a low electric use guy, I only use one or two interior LED lights in the evening plus the water pump and the stereo that's about it. I have a Yamaha 2400 gen set if I really want to use the AC or need more power. I BBQ 95% of my meals outside and the frig is switched to propane. For the price I figured I would see if solar worked for me, it does and I will eventually upgrade to panels on the roof of the TT but for now this set up works just fine.

[Almot]

Rbertalotto wrote:

Almot, you mentioned a $200 solution with 80-100 watts. Can you elaborate on this with a source? You also mentioned the need for 12V for the fridge. Is this 12V needed even when used with propane? (I would imagine it would because the ignigter must be electricity dependent and so must the thermostat?)

100W panel $145
8A $52 controller
The panel is - I think - lower end Chinese brand, nothing extraordinary. Controller is fairly decent.
If you are REALLY scared and want a "kit", here is 100W kit $240. Don't know Phocos controllers, nobody is using them, and 20A is an overkill for 100W panel. They are probably dumping unpopular controllers. Also, in this kit you will - most likely - have to discard Z-brackets, as most people make their own L-brackets, they are easier to work with. The kit comes with cables and free S/H - this is important, very seldom panels are shipped for free. But I would hate to get stuck with a controller that I don't like. Jeez, they even include a controller display, nobody needs a display with 100W system. Must be really unpopular controller.

Shop around. There are many solar stores, but panels can be expensive to ship.

Yes, propane frig needs 12V for valves, thermostat etc. If there is any Dc circuit in there, it draws at least 7 AH a day.

[Rbertalotto]

Thanks LoudDog...I recently bought a Honda EU2000i just for that purpose and to run my AC in the hot summer.
But if I didn't have to use it in the cooler months, I'd rather just leave it behind.

JimInDenver...could you tell us what products you are using? You seem to be happy with the results. I wouldn't have any issue with spending $300 for a much better "usable" system.

Thanks!

[Rbertalotto]

Wow! Great education I'm getting!

Almot, you mentioned a $200 solution with 80-100 watts. Can you elaborate on this with a source? You also mentioned the need for 12V for the fridge. Is this 12V needed even when used with propane? (I would imagine it would because the ignigter must be electricity dependent and so must the thermostat?)

Steve, does your 300watt flat system supply what you need based on your post above?

[JiminDenver]

As others have said, to big as a maintainer and too small to be of use for dry camping.

For around twice that you could have a simple set up like ours. A 230w panel, a controller and 25 ft of extension cord between the panel and controller. With it we run the things you mentioned plus the furnace, fans, a small inverter, all using a single grp 27 battery. I hope to get a bigger inverter for running the microwave and such with the bigger battery.

[LoudDog]

Or get a generator and charge your batteries every couple days for a few hours. Or two 6v batteries, led lights, and careful management, maybe once every 4-5 days.

[RJsfishin]

If you need small panels for storage etc, it maybe not be robbery, but you need at least 3 more just like them to have even 90 watts,......@ $300 total.
And for $300 you can have a 200-300 watts system in either a single or double panel.

[Almot]

My answer is "Why would you"? 🙂
45W is not a charging system, it's a maintainer, for preventing slow self-discharge with loads disconnected when rig is in storage. However, for a maintainer this is overkill, 5W-10W system is enough.

LED lights and pumps will need 7-10 AH a day or more, depending on what lights and how often to pump. The smallest laptop needs at least 4 AH per hour, depending on the task, so let's say 8 Ah for 2 hours. Plus, self-discharge, detectors, occasional radio - 20 AH total. In case you forgot about DC circuit of propane fridge - often there is such a circuit - this is another 10-15 AH a day. Total 30 AH or more.

To collect 30 AH in a sunny weather with a tilted panel, you need 80W-100W panel. 120W with flat panel in summer - this is on a sunny day. Plus 10A controller. Total cost around $200 plus cables. For extra piece of mind, even with such a minimalistic approach, without microwave or any other 120V devices, I would increase the system power by at least 1.5, going for 180W panel, this wouldn't cost much more. Wattage higher than 180 would result in either 2 panels, or expensive MPPT controller.

PS: in Rv solar it's customary to measure panels in watts, and energy needs in amp-hours (AH). So don't get confused.

[SteveAE]

You might want to first decide how much energy you use every day by doing an energy audit before buying panels and then having to adjust your usage to meet the panel output. It is surprising many Amp-Hrs. are consumed by just the everyday items, some of which run in the background) in many RV's.

For instance, my mid-size travel trailer uses roughly 30 Amp-Hrs. per day for items like the refrigerator, water pump, CO2 detector, clock radio backlight, bath fan, etc....all before I even turn on any lights (LED) or use the furnace. There are guys who are better at this than I am (whom I am sure will chime in), but to replace that 30 Amp-Hrs. on a daily basis, I would need roughly 75 watts of solar panels (assuming 5 hours/day of peak output) with everything (panels, controllers) operating at 100% efficiency and with no wire losses....all of which are impossible). So a 100 watt panel would not be inappropriate for me. I have 300 watts, flat mounted on the roof, but use the trailer mainly in the winter when sun is at a premium.

Hope this helps,
Steve

[HiTech]

The rule of thumb I have seen suggested is SWAG at 5 hours a day of full output. So if it is say 3 amps peak output you might see 15 amp hours a day back into your battery on sunny days.

LEDs are easy to keep up with if not too many or too long. laptops can be power pigs - just look at the size of the power supply in watts - up to 220 watts for some (vs 45 in solar). If you crank the speed and backlight down they can be manageable. Water pump uses a lot but may not run long.

If what you have is working for you now, this could extend your stay a bit.

One thing I like about this set up is when you outgrow it, it can transform into 3 individual battery maintainers.

There are a lot of options these days in systems for $150, though when you add in shipping costs the options do narrow quickly.

Jim

[MEXICOWANDERER]

It helps to keep in mind at that level of power, the panel will = roughly this gizmo plugged in for four or five hours a day. Hoover Dam, it ain't

[Rbertalotto]

Thanks Jim......Your cogent comment is greatly appreciated...

I would use it when remote camping to keep the battery in the camper charged for laptop use and a few lights (LED) for a few hours every night and to run the waterpump for a shower in the morning. Everything else would be running off Propane.

I know I need to do more research on what these devices are drawing and would 45watts put it back during a typical day.

I have a 10,500 watt roof top unit on my house that SolarCity installed last September. So far I'm $185 ahead of the electric utility! I love opening that bill every month and seeing a credit instead of a $230 invoice!

So I'm no stranger to solar power, but I really don't know anything about it. I see RV systems costing near $1000 and that simply doesn't make sense to me at this stage in my RVing.

Thanks again!

[HiTech]

It's not the worst thing in the world and the cloudy solar production might even be a bit better than other 45w set ups. But no idea what solar controller they are using. They are not all created equal.

If you could buy that locally vs. having to pay extra to ship something else it may not be bad. The flexibility in output voltages is interesting. It is big enough to charge an iPad or 2 at the output of the bigger Apple charger, if the USB is set up to output more than half an amp.

What would you like to do with solar? Just get your feet wet, or maintain some batteries that are not near a charger?

Jim

[MrWizard]

moved from technology corner