Anyone running solar powered stuff at home?

[MannDude]

Update time: Am going to make arrangements to power my at-home work station via solar. Crunched the numbers and it should be doable without too much additional cost to the existing system. Going to need to buy another 100watt pannel as well as re-arrange some things so I can start powering stuff upstairs instead of just down in the basement.

2X100watt panels and about 200aH of battery storage should suffice I believe. I'll check my math again before I proceed further but since the 'light' workstations (laptop+second monitor+speakers and sub) use about 35watts of power, I do believe it'll be easy to power off solar.

35watts times 10hours of run time per day = 350 watt hours.

Panels should produce about 800 watts of power per day, give or take.   (2X100watt panel = 200 watts X 4 hours of good sun = 800 watts)

0.35Kw X 3 X 2 = 2.1 Kw battery bank storage (.35kw is daily workstation energy use, 3 is the max days I want to be able to run on the batteries with no charge, 2 is to double it so the batteries never get below 50% used)

2100watts / 12v = 175aH (2100watts = the 2.1Kw from the above example. 12v system so am dividing by 12 to get amp hours.)

Then just replacing the old and potentially dangerous 400watt inverter with a new one.

I may start replacing the existing batteries with some new sealed gel ones. They're much more expensive but they're maintenance free, can be stored indoors (Which is why I want them) and should last a long time... ideally wouldn't need to even think about replacing them for 5 or 6 years. Still researching what my battery options are though. Right now the existing setup will accommodate what I want to do as soon as I get a new panel in the mix and new inverter.

 

[drmike]

 so the batteries never get below 50% used)

70%+ is recommended low discharge level by most folks.

 

... and you insist on running an inverter.  I've mentioned the inefficiencies of that prior and the hazards of running el cheapo AC inverters (i.e. square sine wave that ruins power supplies).

 

From you list "laptop+second monitor+speakers and sub"...  

 

Laptop is DC at the plug.  Just pick up a car power supply for your laptop. 

 

Monitor may not be DC before the plug, they make DC models, but many have power transformers inside the monitor.  If you have inline block or wall wart, it's almost certainly DC and that's a simple pig tail usually.

 

Speakers - computer ones at least are always DC power.

 

I am wagering 2 out of three items mentioned are DC and no reason to park them on DC-AC inverter.

 

Cost out a decent DC-AC inverter - pure / true sine wave.  They aren't cheap.

 

[gordonrp]

Nice @MannDude, addictive hobby. I just ordered 2x 100ft lengths of 2/0 XHHW-2 copper cable to support adding more panels. I also grabbed this midnite solar combiner box to combine the panels in the attic (4x24v strings of 2x100w 12v panels), and if when it shows up it seems good quality I'll grab a second one to put on the inverter side of the 100ft length. 

I keep thinking about switching the battery bank from 12v to 24v or 48v, but I have too much money invested in 12v inverters for me to want to do it right now.

Still deciding on a new charge controller, probably going with the midnite classic 150 as it will take almost any VOC up to 150v and convert it down to 12/24/48v battery banks. 

 

[raindog308]

Personally, I'm waiting for this:

 

[drmike]

I keep thinking about switching the battery bank from 12v to 24v or 48v, but I have too much money invested in 12v inverters for me to want to do it right now.

Still deciding on a new charge controller, probably going with the midnite classic 150 as it will take almost any VOC up to 150v and convert it down to 12/24/48v battery banks. 

24v would probably be optimal.   Those better controllers allow mix and match voltages - like solar input at one voltage and batteries at another.

There are DC-DC converters of all sorts - like 24v to 12V and 48V to 24/12V.  Might be best approach for you since invested in good / costly inverters.  Do 24V battery then on power draw side tether DC-DC step converter and then into the DC to AC inverter.

Reason why I say avoid AC when you can, it gets more complicated and a lot more costly.

That Midnite Classic 150 looks so familiar.... What is the company that uses the same / similar housing for their controllers?  Evading my memory.

 

[MannDude]

 so the batteries never get below 50% used)
70%+ is recommended low discharge level by most folks.

 

... and you insist on running an inverter.  I've mentioned the inefficiencies of that prior and the hazards of running el cheapo AC inverters (i.e. square sine wave that ruins power supplies).

 

From you list "laptop+second monitor+speakers and sub"...  

 

Laptop is DC at the plug.  Just pick up a car power supply for your laptop. 

 

Monitor may not be DC before the plug, they make DC models, but many have power transformers inside the monitor.  If you have inline block or wall wart, it's almost certainly DC and that's a simple pig tail usually.

 

Speakers - computer ones at least are always DC power.

 

I am wagering 2 out of three items mentioned are DC and no reason to park them on DC-AC inverter.

 

Cost out a decent DC-AC inverter - pure / true sine wave.  They aren't cheap.

It'd only get to "50%" after 3 days of 10 hour use, assuming there was no charging of the batteries during those 3 days. So even under normal use, with the sun rising and setting each day (god I hope) it shouldn't even hit 70%.

I know it's inefficient but I'm trying to keep it simple. I want things to run from the same inverter and dont' want to have an adapter for this device, have one for this one, and then have this other thing plugged into the inverter. Easier to just have it all run on the same stuff and build accordingly. 12v is recommended for systems under 1Kw anyhow.

True sine waive inverters aren't too bad. Lots of options for high output ones for $200 or less. Many of which will include USB chargers which I could use for things like my phone and Raspberry Pi.

 

[MartinD]

The inverters make it more complicated!

Everything you've mentioned so far runs off 12vdc (as drmike mentioned) so to be pulling that up to 120/240vac and back down to 12vdc is hugely inefficient and complicates things a lot more than they have to be. Then there's the safety aspect of both yourself and the equipment - there's just no need.

Create a 12vdc powerbank rail that you can plug in to instead. A little bit of modification of some cables/plugs and you'll be up and running the most efficient and safest way possible.

 

[MannDude]

Okay, if I don't use an inverter how do I actually power my devices then? If I can't plug them into something as I do now, how am I connecting them to power? I can't even visualize what it is you're referring to.

 

[MartinD]

You connect directly to the battery (or a powerbank connected to the battery).

The adapter for your laptop is just a transformer and inverter to go from ac down to 12vdc (or 9, or whatever). If you get a car adapter for your laptop it'll be the same thing so you just snip off the cigarette lighter plug and take the 2 wires directly to the battery.

Everything should be done via fuses though, of course!

 

[rmlhhd]

Okay, if I don't use an inverter how do I actually power my devices then? If I can't plug them into something as I do now, how am I connecting them to power? I can't even visualize what it is you're referring to.

Something like these should do fine - http://www.amazon.com/s/ref=nb_sb_ss_c_0_7?url=search-alias%3Delectronics&field-keywords=12v+bus+bar&sprefix=12v+bus%2Caps%2C218&rh=n%3A172282%2Ck%3A12v+bus+bar

As @MartinD said use fuses.

 

[JahAGR]

True sine waive inverters aren't too bad. Lots of options for high output ones for $200 or less. Many of which will include USB chargers which I could use for things like my phone and Raspberry Pi.

Not sure how high output you're looking at but beware of anything that seems too good to be true for the price.

Here's a page about a guy who got a cheap high power true sine inverter, had it blow up under very little load, and ended up having to redesign it to make it usable...

http://ludens.cl/Electron/chinverter/chinverter.html

(This guy has a really cool custom hydroelectric setup too if you check out the rest of his site. Highly recommended)

Power electronics are expensive and the cheapo manufacturers will cut every corner they possibly can. Try to go DC-DC wherever possible.

 

[gordonrp]

That Midnite Classic 150 looks so familiar.... What is the company that uses the same / similar housing for their controllers?  Evading my memory.

Maybe the outback flexmax80 (fm80) http://www.amazon.com/Outback-Flexmax-Solar-Charge-Controller/dp/B008MOITL8 which is also my other choice, but probably going midnite solar classic 150 for a few reasons, including their "mostly made/assembled in the usa" per their video; 

 

[Neo]

Yeah better let everything run at DC, you can get for example Notebook chargers that gives you 16-22Volt enought for running a small Notebook or bigger Netbook on 12volt. I do the same, because converting voltage from 12Volt DC to 230Volt for example has about 15-20% loss, depending on the inverter. Same for PC's / small desktops you can get 12/24Volt chargers also to run them on your solargrid without big loss.

Other Bonus what he also said: 12Volt dosent kill you, 120/230Volt does, so its safer.

 

[PureVoltage]

Just picked up a little panel the other day going to play around with it before spending more money on a larger scale.

 

[drmike]

True sine waive inverters aren't too bad. Lots of options for high output ones for $200 or less. Many of which will include USB chargers which I could use for things like my phone and Raspberry Pi.

USB power = $10 step / buck converter.  12V to 5V @ 1-3A depending.  That's simple and cheap... and easy to keep stock spare (another point with solar - must be your own inventory control for when things break and they do).


Inverters - pure sine are pricey.  $200 is a big chunk.  Talking 200 watts or more of panels for $200, so it's significant.

Something like these should do fine - http://www.amazon.com/s/ref=nb_sb_ss_c_0_7?url=search-alias%3Delectronics&field-keywords=12v+bus+bar&sprefix=12v+bus%2Caps%2C218&rh=n%3A172282%2Ck%3A12v+bus+bar


As @MartinD said use fuses.

I have multiple bus bars.  The simplest set for my very small outbuilding setup uses steel twisted/braided wire up off pieces of wood screwed in with metal screws with nylon grommets. 


I have a positive bar and a negative and they are about umm a foot apart to avoid any contact errors.  


It is a simple alligator clamp setup. Made for active use (plugging and unplugging and within a few feet active zone the use, batteries, etc.)


Those small screw terminal bus bars I am meh about.... never had wonderful experience with them and screwed down stuff can work, but probably not for most folks.  More of a hardwired permanent project install.


I have large bus bars for my old big system and they are solid copper and 4-5 ft each and we have industrial screw terminals on those.  Cause they were intended to be hooked up to a big fat battery stack where amps really could be flowing. (like 10Kw in battery and multiple Kw in panels).

Okay, if I don't use an inverter how do I actually power my devices then? If I can't plug them into something as I do now, how am I connecting them to power? I can't even visualize what it is you're referring to.

Solar kind of fails in this way.  There is no plug standard outside of say automotive lighter plug style stuff (which is prone to failing from bad connections, loose connectors).  The automotive plugs however are dirt cheap and abundant.  I use automotive plugs often since I can buy a female end and then select from MANY prebuilt useful DC things for a relative bargain.  For instances a 3 plug female bar with USB power plug can be had for $5 via Ebay or Amazon.  Power adapters to run notebooks are are abundant in this format and what I have often powered.


There are some more refined sockets and distribution panels in the RV and boating world.  However once you start messing with that, you get so much cash into so little of anything that's it's a joke.


My solution and what I still do is this --- I run multiple wire runs from the controller or battery (prefer a controller with power handling integrated) to where I am using the power.  Everything I have run and continue to is low draw.  So 14g speaker wire is more than adequate for up to 50ft runs (pulling 1-3A tops @ 12V).  Powering computing devices, LED lights, maybe a DC fan array, etc.


On the plug in side (where using the power) you take the wire and strip the end and connect to it a barrel connector (female).  This is much like what you find on many consumer computing devices (circle inlet with a center pin).  Depending on what I am plugging in (I like DIY wiring vs. dealing with manufacturer wonky connectors) I wire in matching sized barrel male connector.


So literally:


battery bank --> 14g wire run --> female barrel adapter --> male barrel adapter --> end thing being poweredDC Pigtails:


http://www.amazon.com/s/ref=nb_sb_noss_1?url=search-alias%3Daps&field-keywords=dc+pigtail

 

[drmike]

Maybe the outback flexmax80 (fm80) http://www.amazon.com/Outback-Flexmax-Solar-Charge-Controller/dp/B008MOITL8 which is also my other choice, but probably going midnite solar classic 150 for a few reasons, including their "mostly made/assembled in the usa" per their video; 

Outback, BINGO... Good company, long recommended as leader on the pro builds of bigger systems for residential market.

I need to watch video on Midnite folks.. Anything built in the USA peaks my interest.  We need more of that and more buying of such.

 

[drmike]

Other Bonus what he also said: 12Volt dosent kill you, 120/230Volt does, so its safer.

I'll be the first idiot to say this true.

DC is capable of injury so don't discount and get sloppy.  Cross connecting bus bars or battery terminals is mighty ugly instant discharge.

Normally in leaky situation where you are grabbing positive and negative leads it's kind of like a nerve burn feeling.  Nothing to let go of it.  120/230V in contrasts hurts like hell and getting free of it is a big problem with a lot of folks.

There is much about safety and mixed environments (moisture) as you note outdoor landscape lighting continues to be in a big way DC power for sanity sake.  Just been historically expensive for what they sell you.

Mann's pursuit of AC (okay misunderstanding about tethering to DC) keeps me looking at my 4ft power strips loaded with wall warts and looking at tags on other stuff.  Honestly, computing side, damn near everything is DC natively at the point where the device is getting power.

Strip in front of me has 12 plugs and 8 are stepping down to DC.  Remaining 4 are umm probably all DC too though.  Like one I know is DC post-plug  has a power conversion board other side of the plug on unit... Can see it since it's uncased....  Monitors have straight 120V power from wall to unit, they have power conversion inside units.

If one shops smartly and buys gear with wall warts and gets power conversion outside of units, pigtailing everything is a cinch for DC setup.

I've had solar setups for ummm a decade.  I've used an AC inverter twice for testing... 

 

[Eirbyte]

Nice to see people getting into renewable energy.

Miriam and myself  have been living off-grid (no mains connection) since 2002. Our system at the moment is 1kW of PV and a 3 meter diameter wind turbine around 2kW charging a 800AH bank of led acid batteries @ 24VDC

All lights in our house are LED 24VDC and power points are AC from an inverter. We built our own wind turbine to Hugh Piggotts design and we teach workshops on how to build them this is one we did in Portugal in 2012 vimeo.com/50145242

It would have made more economic sense to get the grid in the first place but sense was never one of my strong points. Over the years we had a lot of fun and met some interesting people and traveled to interesting places all thanks to renewable energy.

Hosted some sites in the past with the only offgrid datacenter that I know of Aiso.net but the support was not the best and the prices are high.

Good sites for info are:

Hugh Piggott

OtherPower

Paul Gipe

The Back Shed

 

[drmike]

It would have made more economic sense to get the grid in the first place but sense was never one of my strong points. Over the years we had a lot of fun and met some interesting people and traveled to interesting places all thanks to renewable energy.

Welcome to the forum @Eirbyte!

Have you established the break even point for your own system?  Grid is cheap where the lines are already in place and just need connected mainly.  Still a lot of places where chunks of mile or miles necessary to get power to you, and that's insanely expensive.

ROI on solar isn't bad and happens...  so long as one lives to see that day (i.e. decade or more).

Good piece on batteries ---> http://otherpower.com/off-grid-battery-guide

The Edison batteries are the must haves, but they aren't cheap and few manufacturers.

 

[Eirbyte]

Have you established the break even point for your own system?  Grid is cheap where the lines are already in place and just need connected mainly.  Still a lot of places where chunks of mile or miles necessary to get power to you, and that's insanely expensive.

ROI on solar isn't bad and happens...  so long as one lives to see that day (i.e. decade or more).

ROI or payback was never an issue for us we bought some land and started with a 60w panel some old batteries and a petrol generator. We built our system and house oner the years.

Our system now is:

German solar panels 195w x6

Batteries Hoppecke 2v 800ah @24vdc

Outback MX60 that also controls the dump load for the turbine

And our turbine you can see here http://www.eirbyte.ie/blog/wind-turbine-maintenance/