# Small system recommendations?



## Silvercreek Farmer (Oct 13, 2005)

Any recommendations for a complete small solar power system? We are looking for a system that can power a fence charger and, occasionally, power tools like a circular saw, table saw, small compressor, and possibly a small water pump. An off the shelf system would be great.


----------



## ET1 SS (Oct 22, 2005)

Silvercreek Farmer said:


> Any recommendations for a complete small solar power system? We are looking for a system that can power a fence charger and, occasionally, power tools like a circular saw, table saw, small compressor, and possibly a small water pump. An off the shelf system would be great.


Powering an electric fence is very easy.

Power tools are hard.

I have seen people who wanted to setup solar power for a cabin that was only going to be occupied one weekend each month. So they wanted to have a battery-bank charging all month long, to be used on that one weekend. the problem with that idea is the batteries need to be kept warm at all times. So the heating system is far more complicated than the solar system.


----------



## wy_white_wolf (Oct 14, 2004)

You are better off using a generator for occasional loads like the tools and such you have listed. They have to varied and great of a power requirement for a small solar setup.

WWW


----------



## Steve_S (Feb 25, 2015)

Silvercreek Farmer said:


> table saw, small compressor,


 maybe a problem for a small system, the rest no problem but:

A Tablesaw @ 15A = 1800w running + 50% Watts power surge on start. If the system and inverter is big enough to deal with it ok. It will drain battery bank fast if not right sized. 

Compressor's vary a LOT from small oil less hobby to much bigger, so it all depends on what you have. Anything larger than a little hobby one that blows up tires and balls, maybe an airbrush, wouldn't worry about it but like a 3HP-20Gal well that will draw a LOT like the Tablesaw, the bigger the motor, the more start surge it has which is hard on inverters & batteries.

Well pumps on solar can be tricky too, depends on the well (deep well pump or jet pump etc). Water Pump have a massive start surge because it takes a lot of oomph to pull up & push water out at pressure, once going not so bad. IF you have a deep well pump then the only solution is a Soft Start pump, better is a soft start multi-stage pump which really keep power drain low while giving good constant pressure. Some may tell you, you "have to have" a 240V pump too... HOGWASH, my well is 280' deep, pump has to push 350' total run from well into cabin @ 50psi, a Grundfos SQ5, Soft Start 120V pump does the job perfectly and the hit on the inverter is surprisingly minimal (that means inverter & battery bank are not stressed, longer lifespan - less potential for bad things).

To properly make suggestions a bit more info is needed. Look at your compressor, saw etc and get the amps... shorthand math: 120volts X 10amps = 1200 watts. or 1200watts ÷ 120volts = 10A. and account that your start surge for a motorized device (includes fridge compressor too) will be roughly 50% more than base... so a 1200watt saw will likely draw 1800w on start. *Some newer tools have more efficient motors now with less surge on start, more common in fridges actually. These are basic guideline math which is usually good enough. Also try to add up the "most" power you may likely draw at any given time (that will help size the Inverter you'll need to supply the power and guide battery sizing somewhat too).

Inverters, ok many folks trip on this... I'm not going to get techie on this. Simply put, a Pure Sine Wave inverter is really the only choice in the 21st century because electronics (including many power tools) and motorized devices like a fridge (compressor) are sensitive to the wave form. You can easily fry electronics (including LED lights) and reduce efficiency & life span of motors as they work harder & create more heat. Mod Sine & Square Sine Inverters are cheaper BUT not good for modern electronics and you'll be burning stuff up and replacing things. ** *Most generators are Mod Sine *which is better than Square Sine and can run compressors, saws, mig welders but NOT good for "fine electronics", these can be used as backup to solar systems which feed 120V to a proper charger that conditions the power and charges the batteries. *Inverter gennies* excluded, they are Pure Sine and have no bad effects but are more expensive but also much more fuel efficient as well). Note, it's been quite some time since I have seen a Square Sine generator being sold, I really don't think anyone bothers with that tech anymore. 

Good Summary here, applies to generators as well. *Pure Sine Wave vs. Modified Sine Wave Inverters – What’s the Difference? * https://www.altestore.com/blog/2015/10/pure-sine-wave-vs-modified-sine-wave-whats-the-difference/

The Solar "Kit". Are you looking for a portable setup on a cart or similar, that you can drag out when there and lockup in shed when gone ? Do you want to mount panels on a roof and setup a "solar closet" with your gear (controller, inverter, circuit panel, batteries) installed in it ? There are a few folks who put together some rather good DIY Solar Carts and how/what they did can be found on YouTube and they did it far cheaper than buying an assembled manufactured unit. There are many "roof" kits and of course you can ground mount (potential security / theft issue) which does have it's benefits to (adjustable and such). So knowing what kind of "kit" your aiming for will also improve recommendations.

Now a NON-PC word... and if someone wants to Crusade, do it somewhere else.
Many people bash Chinese products... In some instances that is warranted but chuck the emotional & rhetoric arguments aside for a minute. They did not jump off a boat and take your factories & jobs away, that was the company presidents, CEO's and Board of Directors / Stockholders (and the Gov that permitted it) who sent those jobs there for more profit margins and as such the Chinese are just subcontracting and making whatever the spec is as specified by the designers & engineers developing the product. If Black & Decker designs and specs a crap tool with inferior materials, that's what they make and that's what delivered to B&D... simple enough, just like any other subcontracting manufacturers in the world. The Chinese Companies proper are working very hard at putting out decent product @ decent pricing and reasonable margins (not maximum market bares pricing). They are establishing their "brand" as it were and really stepping up... (I can just feel the angry naysayer's chomping at the bit - see what being emotional over something does) Bottom Line is some is CRAP but more & more is Good to Great and well priced to boot. To that end, do not discount quality Offshore products as they work and perform as well as others and usually at much better price points, _ultimately YOUR WALLET is the one taking the hit for whatever you buy_, So if you want to be "emotional or anti-China rhetoric supporting" OK no problem, you can buy US, UK, German or whatever and pay accordingly, but if, like most people, you have a tight budget and want best value for your hard earned buck then don't limit / handicap yourself and be smart about your researching and looking at products out there.

Just a side note... My Midnite Classic Controller is a Top Brand made in USA, my Batteries - Rolls Surette made in Canada, my racking systems made in Germany, my wiring & circuit panels etc North American Made, my "Canadian Solar" panels made just outside of Toronto, my "Marine Grade" Pure Sine Inverter/Charger Combo is APC made in China and 95% efficient (which is very good btw). The mix / combo saved me a pile and no compromise on quality either. I like to think of my wallet and it's long term health too !

Lastly, are you looking to buy a "kit" off the internet and install yourself ? 
OR have enough knowledge & list to be able to go to a local solar dealer and buy your parts and DIY or have them install it ? 
Do you want to walk into Homedepot and buy a ready made system ?
*HD is an example, you pay way to much anything solar there, for example their Grape Solar stuff is good but nut$ on pricing, "plug & play no fuss" but still way overpriced. Also not the most recent tech either because of how the package their kits and do production cycles. 

Hope this is helpful and helps you collect the info you need to get the best suggestions / thoughts on what kind of system would likely suit your needs. One last thought, whatever you buy, keep in mind that your needs may likely change over time and you'll probably will want to add on later for more capacity as prices continue to drop, so don't get stuck with a fixed / locked kit you won't be able to expand and grow with down the road. Also having that kind of non-expandable product makes it much harder to resell down the road if you do a big upgrade and replace more of the stuff. Just a thought to consider as well so you don't lock yourself into a "disposable" situation (I hate chucking good money out, I'm sure you do as well).

I did not touch batteries as that's a crazy place to furtle around in, better dealing with that once you have a better idea on what will be needed etc... The batteries are a wildcard on pricing and changing a LOT and fast....


----------



## big rockpile (Feb 24, 2003)

Power Tools, take Gas Motor and fill a Compressor use Air Powered Saws. Use Air to Pump Water.

big rockpile


----------



## Silvercreek Farmer (Oct 13, 2005)

Thanks for the responses so far! The compressor would likely be a small pancake compressor (rarely used to run an air nailer), and the water pump would be a small (7 amp?) pump to push creek water up a 20 ft or so hill. A friend of mine has 4-70 watt panels, 4-90 amp hour batteries and a 2500 watt pure sine inverter. He spent $3800 on the system back in 2010 and hasn't ran many tools off of it, but uses it to power a rainwater pump similar to the one I'd need and a cooling fan on his greenhouse. How would this work? Any ideas on what this would cost today?


----------



## Steve_S (Feb 25, 2015)

For that kind of coin, you could likely double what capacity he has. The cost of low watt panels in nuts compared to current 260w+ panels cost. Batteries are expensive but dropping slowly, some types like LiIon faster but still $. 

Here is a "kit" from the dealer I bought my stuff from, it's in Ontario Canada so you likely can get cheaper but identical in the states (unless that duty thing screws it up). https://www.solacity.com/product/3-panel-cottage-kit/
*Specifications:*
*Solar power* 915 Watt
*Controller type* MPPT (EP Solar Tracer-3215BN, 30A MPPT) *
specs here: http://www.epsolarpv.com/en/index.php/Product/pro_content/id/573/am_id/136
*Max. current* 30 Amp
*Battery Voltage* 24 Volt (4x Trojan L16RE-B-6V 6V battery, RE series, 370Ah/20h) included 
*Amp-hours (20-hour)* 370 Ah
*Output power* 2,000 Watt
*AC Voltage* 120 Volt
and that's for $3889 CAD / $3090 USD (at current exchange)
Your friends system is 280w and low Ahr comparatively speaking.

* = I would upgrade that to the 40A model and that gives room for more expansion later if needed.

Hope that Helps.


----------



## Silvercreek Farmer (Oct 13, 2005)

Thanks for the link Steve! Those are kits are exactly what I was looking for. After reviewing the options, I think a smaller system may actually suffice given that the need to run tools will be pretty infrequent. Would a 1500 watt inverter run a circular saw?


----------



## Steve_S (Feb 25, 2015)

IF it's a 10A saw, that's 1200 watts running and likely 1500 watts on surge (when you pull trigger) or when loaded (cutting thick heavy wood). 15A saw might be pushing it as that would likely strain the inverter a touch (they do take momentary surges, typically 20% over rated capacity but not good for them). Your pancake compressor and everything else would be ok though. ** I used DeWalt 20V Cordless to build my home, powerhouse & pumphouse and much more and it's a peach charging the batteries and not tangling with cords. Tablesaw (15a), Compressor (20A) and 120V MIG (too many Amps) I Ran off my big Generator. I can say that the DeWalt kit was one of the best purchases I ever made and no complains except one, Circular Saw is 6-1/2" blade and not cheap for good ones.

The two expensive & important parts are the Inverter (always go Pure Sine) and batteries, cheapo's or non-deep cycle are wasting money as you'll be chucking them (some will vehemently argue against that, remember some folks still think the planet is flat, so).

The "kits" also do not include circuit panels & such usually, that can add some dollar figures. DC Fuses & breakers, isolation cutoff switch etc... so look carefully at the kits to know what is offered and what extras you'll need to complete your system. Smaller systems are pretty straight forward, once you go big, then it get's more complex.

BTW always remember, it's not the Voltage that kills you, it is the Amperage behind it, be aware of it & respect that...


----------

