Non grid tied solar uses?

[DMcCoy]

My interest in solar goes back to being a kid, so I finally bought a small 100w system from HF just for fun. I can't foresee a time when I will be off grid or grid tied.  All my buildings have grid electricity.

My thoughts are toward setting up a portable tool battery charging station, or running a pre-heater to my domestic water heater. I understand the inefficiency in my proposal but leaving it in the box is even worse. 

Has anyone else come up with uses?
Thanks,
Dave

[Southside]

I have a portable chicken tractor with a 100W battery charging system tied to some LED lights.  Does not matter where it is, I have light in it.  

[Nebraska]

Ok...@Southside... I have to ask in case I come across such a thing. What is a chicken tractor? Are you talking a self move able hover/ shed for some sort of free range, layer broiler set up?   Or are you raising a super race of chickens with thumbs preparing to  hatch (pun intended) an evil scheme?

[Southside]

Not self movable, but movable.  I took a hay wagon frame (two axle, kicker style) and stripped it down to the running gear and main beams, then I put one of those bent steel car port kits on top of it which gave me a light, yet bolted together frame, wrapped that with board and batten siding, and voilla, portable chicken coop that follows the cows around for the layers.  Can pull it with a pickup or tractor, the floor is made from hardware cloth so in the warm months there is plenty of air flow up and out the covered windows, door closes at night and no predator issues.  

I will get a photo of it and post it here.  

[Nebraska]

Ok that's what I wondered, there have been a few folks do that up here, but I think we've got too much winter, not enough grass season (it's over we've frosted the last three nights) for that to work well. It's usually tax day in April or shortly after that grazing season begins to start here.

[Southside]

This is the hitch end, nest boxes in the bump out. 

 

[clearcut]

I’m assembling a solar “generator “, lacking a better term. Solar panel (100 watt), charge controller, marine battery, and (when it arrives) an inverter sufficient to run the chest freezer. 

The plan is when the power company shuts off the power for “public safety “ again, we were out for 4 days in our last little adventure, I should be able to keep the frozen food from thawing, and make enough ice to keep the refrigerator cold. 

Oh, and the WiFi. The kids will willingly go without food, but no WiFi? No way!

I hope to go solar, probably grid-tie soon and this rig is my test bed. I’m using this set up to learn more about solar. For example I learned a lot about start up amps. The 5 amp rated refrigerator uses more that 18 amps on startup. I’m not sure how many more than that because my original inverter would fault at 17.9. 

I also learned that the computer’s backup battery does not tolerate modified sine waves - at all. 

[ljohnsaw]

The plan is when the power company shuts off the power for “public safety “ again, we were out for 4 days in our last little adventure, I should be able to keep the frozen food from thawing, and make enough ice to keep the refrigerator cold.

Wasn't that fun? The CPUC is planning to fine them now - we'll see.  Yeah, avoid spending the allocated monies on tree trimming and give the investors a better return.

I was out for only 18 hours.  I have grid-tied solar but that does not work when the grid goes down.  A neighbor called me and was mildly upset that his solar wouldn't work, either  If you try to "trick" your inverter with a generator (220v), you'll likely fry your generator - so I've read on the internet.  The only option is a separate solar system (off-grid battery to inverter) to provide "backup" power for the necessaries.

A single deep cycle battery?  How long do you think it will last running your fridge and wifi?

[DMcCoy]

The great time suction known as the internet has led me to buy a new book.  Boatowners Mechanical and Electrical Manual 4th edition.  @ $21 delivered.
Right?  Sailboats and Sawmills= <---->
When it all comes down sailboats are floating cabins that require dependable self sufficiency.  I'm sure much will not be relevant to anything I may want to do but the reviews of this book have me thinking it might well be a page turner.

[maple flats]

I have both grid tied and battery back up solar. Actually it is two systems, the grid tied is 4840 watts that has been stated, shuts down if the grid goes down, by law, to protect workers working to fix the problem. The second is 1480 watts separate from the 1st part. That has an inverter, Lithium battery bank (LiFePo4) and once the batteries are fully charged the inverter sends excess energy to the grid providing the grid is energized. That portion is used just for 1 critical circuit. I make maple syrup and one expensive piece of equipment (my reverse osmosis or RO) must never freeze. That is kept in a well insulated small room with no windows and all seams are foam sealed. That room has a wall furnace, propane fired that uses no electric, but if the furnace fails and the grid goes down, my batteries power an electric heater to protect the RO At 0 degrees F my batteries can heat that room for 2 days with no sun (or if snow covers the panels). If such a failure were to last longer I'd need to start one of my generators to charge the battery bank. Fortunately this system has only been tested on purpose, the furnace has never failed and in 7 years with this set up the power has been out less than 1 hr. total.
For those looking to "play around" with solar, the HF panels are way over priced, as are Northern Equipment solar. You will get far more for the same money buying panels off most sources on the web. Just do some searching and compare, then buy.
For example, HF sells a 100 watt kit containing the cheapest type of panels, 4@25 watt max that have a 90 day guarantee, the cheapest, lowest efficiency type of charge controller, and some minimal wiring for $190 US. Northern Equipment is no better.
If you buy one good panel try one of these   Most Affordable Solar Panels | LetsGoSolar.com. Then get a good charge controller and a good battery or battery bank. Look into LIFePo4 batteries, cost more up front but they last, if run properly 3000-5000 chargew cycles, or 20+ years, while you will be lucky to get over 2 years on a deep cycle lead/acid battery of the same AH rating (amp Hour).

[Greyman]

I've been thinking about getting one of those kits from HF also.  Eventually I'll have an off-grid system, but I have to design the house, cut trees, mill logs, and build the house first...     In the meantime I was going to use it primarily to get familiar with solar systems, but also to charge batteries, run some lights when needed, and maybe run a little apartment size fridge (I haven't run any numbers on that, I have no idea if it's feasible or not).   Eventually it may become the power source for my spring water pump.  It comes with a 10 amp charge controller, but I would like to get the 30 amp so I could expand it if needed.

[btulloh]

That's a worthwhile endeavor, @Greyman  .  I learned a lot doing a small system like that.

Maple flats has a good point about ala carte vs buying the HF kit though.  After you upgrade to the 30 amp controller and the inverter you're left with a sub-standard solar panel.  There are lot of full-featured 30 amp controllers available and they are inexpensive.

Either way you go, you end up with useful power and learn a lot about the practical side of a solar setup.   

[Nathan4104]

DM, our RC airplane club set up a solar system to charge our batteries.  Simply a bunch of old panels that someone was replacing, a couple cheap charge controllers and as many old dump truck/ loader batteries as we can fit in the shed. I hook up a 1000w inverter when we want 110v for something but we have more capacity than we ever use with all the old batteries. To charge some power tools, it could easily be built in a simple cart and wheeled around.  Not having to run a generator or vehicle and enjoy the quiet while recharging at our site is very nice. 

[marsofold]

I have 1260 watts of solar panels (10ft x 10ft). Currently disassembled for my move to WV. The biggest sell to using it off-grid is that you are selling it to yourself at the retail rate (12 cents/kilowatt-hour for me) vs selling to the grid at the avoided cost of 2 cents/kilowatt-hour. Using a meat freezer to freeze a rotated pair of 2 liter bottles as a freeze-pack for a big cooler is very efficient. Running big loads at noon helps with heavy current draws. If you live in a warm hilly area, another option for storage is to pump water uphill to a holding pond for later draw-down through a hydropower turbine generator. A big initial investment, but cheaper than replacing batteries if you have the land and the climate to avoid the pond freezing.

[JRHill]

My interest in solar goes back to being a kid, so I finally bought a small 100w system from HF just for fun....

I invested a bit for three of the HF kits mainly for topping off/maintaining starting batteries and the 12v lights that come with the kits for use in the winter. The kits were placed in outbuildings too far from the house to run power.. But what I found was that when the days get short and more overcast, the batteries to which they were hooked actually lost charge instead of maintaining them. Why? The charge controller that comes with the kits has enough idle draw that the watts pulled from the batteries over night and on cloudy days is greater than the charge added to the batteries when there is sunlight for generation. The only way to make the kits useful as planned originally would be to walk to each out building to disconnect the batteries before nightfall and then go back each morning to reconnect. No thanks.
There were other disadvantages: the panels are VERY low power and lose life over time much faster than the higher quality panels used for std RE systems. Search "amorphous" vs "mono or poly crystalline" solar panel.
Bottom line is the HF solar kits are good for a starter kit and to learn the basics of a solar experiment. But they are not cost effective over time and end up being more expensive per watt than the higher quality equipment.
BTW, we have lived off grid for 10+ years on a 3000 watt system of 15 panels with Outback products and Trojan L16 batteries. Yes, that system also has an idle draw component but even on a cloudy day will add more to the batteries than is lost to overhead.

[peakbagger]

Harbor Freight PV equipment is expensive crap. Its too bad, folks buy it and end up throwing it away. There is lot of junk equipment on the internet that makes false claims in their literature.

I have a solar hot water system that has been heating my water for hot water totally for 7 to 8 months and is used to preheat my water the rest of the time. It has DC a powered pump that circulates the glycol from the panels on the roof to the storage tank coils. I have a old Siemens 12 volt solar panel wired to the pump with an on off switch and an on off controller that cycles the pump on when the collector temp exceeds my storage temp. The system has been running for 15 plus years with little or no attention. Note there is no battery involved and the pump can take the unregulated DC coming off the panel. Note no batteries in this system and no charge controllers, these add a lot of complication and cost.

I sold a couple of same 12 volt panels to a friend, he has them wired direct to an exhaust fan on his outhouse. When the sun is out the fan runs. I think he has a switch on it, that is it.

Keep in mind that the market is focused on grid connected applications, the typical surplus panel is not 12 volts and will need a quality charge controller. Morningstar makes good ones. Most of the cheap internet charge controllers are Pulse Width Modulated (PWM). They throw away a lot of potential power. Maximum Power Point Tracker (MPPT) type controllers cost more but put out more charge power. Unfortunately a lot of crap controllers on the internet are advertised as MPPT and are actually PWM.  

I think the key to building small solar projects is to keep the first one small and simple until you get enough education to do fancier ones. If you go with battery project, resign yourself to wearing them out quickly. Many off grid folks recommend starting out with golf cart batteries so when they fail too quickly the investment is not as painful. Stick with lead acid, lithium chemistry batteries may sound like the way to go but the learning curve is steep and they can fail dramatically

Builditsolar has a lot of non grid tied solar projects

[beav]

Lots of good advice there peak bagger.
However I think that mppt charge controllers add cost, complexity, and high tare losses to a system. Yes they potentially harvest more electrons. They are good in many situations. Like being able to tailor the output of grid tied panels to a usable voltage.
My 20 yr. Old pwm controller still works fine and is butt-simple.