The cheapest you can go with solar?

[freeEnergy4me]

The main reason I'm doing solar is to save money in the long run and also be independent of the electric companies.

I'm actually in the city, so I already have relatively cheap electricity (heating is another story).  So to get payback for going solar is really difficult going against 9 cents per KWh.

So right now I'm going very cheap. 180W of solar power that charge 3 75aH deep cycle marine batteries and I have a couple inverters all less than $100 apiece.

So total spent so far is about $1600. Unfortunately with all my efficiencies, my electric bill has gone down by almost 50% over last year. So we're talking a $20 bill before solar. So $240/year. So it would take the solar panels more than 6 years to pay for themselves.

UGH!

Problem: I want to get another panel to put me over 300W. I want to replace the batteries with AGM to avoid the potential of explosions. I want a new, better charger....and most of all, I want to have the power distributed through a nice inverter that can handle up to 2000W.  Total cost: $700+$900+$600+$1200 = $3400

Where can I save money?? I think 300W would get me through the summer months. The only big energy consuming item I have is a furnace fan that is like 3-4KWh per day. Grrrr! Aside from that I only consume about 2Kwhr per day max.

[richhagen]

If your current batteries are still functional, get the most use out of them that you can.  Given the type, I doubt they will last that long though.

I did notice that Sun Electric Miami has "Sun" branded panels for $3.34 per watt plus shipping.  I am pretty sure that these are Evergreen cosmetic blemished panels based upon the description and photo.  

A nice Outback or Xantrex inverter will set you back a bit though.  I have a bit of experience with each.  I also have an Exeltech 1100 watt sinewave inverter.  I like it a lot, but it has problems with motor starting that the other two larger inverters do not exhibit.  Also, having played around with a couple of salvaged UPS inverters I have found that they tend to have very high idle currents comparatively.  

You will probably learn that the grid power is still a bargain economically compared with generating your own power.  They have the economy of scale on their side.  Rich

[jzeveney]

Keep your current batteries until they don't work.

How high up are you in the city?  Is a wind generator an option?  I'm on the ground in FL.  Florida is not know for it's wind, however my 400 watt wind generator has been keeping up to date.  at $450 for 400 watt it's a bargen.  If you in an apartment complex with room access for your solar panels then a wind generator is a perfect solution for you.

Z

[ghurd]

First.  Do Not go with AGMs.  They don't seem to last very well for me.  

Not sure the potential of explosions is reduced, but they don't leak on the carpet.

Try golf cart batteries (google the board for T-105s or Sam's).

Maybe L16s or L16HCs if the wallet will do it.  Interstate is fine and cheaper than many others.

Second.  It's often better to bite the bullet now.  Catch 22.

Get more panels (500W?) and an MPPT tracker.  It kind of saves more, depending on how you look at it.  More panels means more power.  MPPT means more power.

More panels now and MPPT later means wasted money until them.  

MPPT now means less power than more panels now.

UGH!  You only pay 9 cents per KWh!

G-

[freeEnergy4me]

Did you buy the wind generator or make it yourself? That seems like a pretty good deal for 400W. I have property so I can go 20ft based on the city's building inspector. How big is your wind turbine?

[VisualMonster]

I'm at $0.15/kwh in California, also with a goal of getting them to pay for themselves.  Going green, saving money, and a hobby all in one... =)

I agree, get as much life out of your current batteries.  I started out with batteries that were supposedly dead and managed to squeeze out almost two more yaers out of them.  I finally gave in and bought 8 new golf cart batteries which set me back on my "pay for themselves" goal, but I'm still on track for about 10-12 year payback.  

It's funny, I actually calculated I can get them to pay for themselves quicker by adding additional panels since I've already payed for the battery/inverter/cable overhead.  You'll probably be in that same category.

[ZooT]

I really don't care how much electricity costs versus making my own....

The upfront costs of being your own powerhouse will eat you alive......but once paid for, you don't have to hand money over to someone else that could be better spent by you........

There's other rewards for doing the RE thing, that aren't monetary......and those rewards are not something to be easilly ignored......

Not to start a political rant......but there's a certain sense of freedom via being independant of the utility companies.....and even if you're not.....looking forward to that day is enough to keep one grinning during dark times....and not to mention a sense of pride that comes from doing something for yourself by yourself

[jzeveney]

I bought my first on to get things going.   I'm working on building one also.  I'm using the project from here as well as this site as a reference.

http://www.topgreen.co.uk/windpower1/pmg_alternator_const1.html

I purchased the 400watt from amazon with the purpose of reverse engineering it for a few things I was uncertain about.  Cool thing is it's keeping my battery bank topped off.  While I play.

I hope to post a few pic today.

Z

[angelanthony777]

5 watt flourescent light bulbs from Walmart will last seven years, $9.88 I have a system which charges while I drive my car to work, or as I write this,every 5 days when I go to town to check my e-mail at the library. I use the car alternater to charge my batteries in the trunk of my car, I have blocking diodes/rectifyer I bought @ radioshack for $2.79 for four, then constructed cables to attach them so the batteries are separate, and won't affect/drain the car battery which starts the vehicle. then plug in a 100 watt inverter, which I purchased at Walmart for $17.88, I have a gravity fed system for my water tanks in the loft of my cabin.The pump is actually a submersible in tank carter weber fuel pump for automobiles,which pulls very little power at all@ 12 volts, no more that a couple of amps, to top off my tanks. I use a float switch with a bosch relay to activate the switch, I purchased for $6.99 @ aquahub.com. I heat with a wood stove, and soon will make a stainless heating coil to install inside the stove to heat our water. The crowning glory will hopefully be a good practical solar water heater/ pv panel. all of Much of the material I used was salvage, or discarded materials. So Solar on the cheap is really what I want to see proven. especially on cloudy winter days. Mine has already paid for itself, and driven by a 1990 honda civic which i bought for $500 dlls. I like to kill two birds, or if I have to more thatn one with one stone.

[scottsAI]

Hello freeEnergy4me,

Don't do it, will save the most $.

As mentioned put the batteries outside and keep existing batteries.

Flooded are much cheaper and longer lasting than AGM. 1/3 the price.

Add an automatic watering system to fix the second most common reason of battery failure, low water.

Solar MPPT and tracking add about 29% each here in MI.

180w * 1.29 * 1.29 = 299w, almost equal to your 300w target.

Summer - cool the panels to improve output by 10-30% (depends on how much cooled)

Check Panels data sheet see how the output power drops over temperature.

Winter add mirrors, cooled panels can handle more than one sun.

If you have the grid connected (and paying the $10/mo.) you may as well us it for storage, not batteries. Grid tied inverter will back feed power until you needed it, keep existing batteries as back up. Over all this will be the lowest cost solution. Ability to expand system to 2kw of panels.

Smallest grid tie inverter I have seen is around 1.8kw, some have MPPT.

Have fun,

Scott.

[ghurd]

"Don't do it, will save the most $".  Agreed.  Agreed Cubed!

"grid connected... Over all this will be the lowest cost solution".  I don't see it that way, at least for this.

You and I are in about the same boat with about 3.5~4.2H insolation average? Say 4.2H.

Say a $2,000 grid tie cost for a small one?  Then he doubles the PV power (more PVs, tracker, MPPT, whatever).  No losses, etc.  1500WH average per day.

Saves 13.5 cents a day.  $40 a year.  50 years to payback for just the inverter.

Cheaper to double the PV watts (however), and use the $2K (inverter money not spent) interest to buy $300 batteries (2 pair of Sam's golf cart ) every 10 years.

Maybe I'm too cheap?

G-

[scottsAI]

Ghurd,

The thinking is the AGM batteries and inverter cost $2k.

The AMG batteries only last 3-5 years

Saw a grid tie inverter with MPPT built in, offering a savings.

Above cost was $3400, $2k is less. Lots of growing room.

Currently Grid tied so paying the $10/mo may as well use it and save cost of batteries.

I have 8 golf cart batteries, cost $500 hard to run my home on these for more than a day.

With local city power, this will not have a payback.

My choice would be to skip the big inverter, only collecting 800whr a day. Run some small loads. Use grid for the larger loads. Experiment with MPPT and build DIY tracker.

Have fun,

Scott.

[freeEnergy4me]

Yeah, that's kind of what I'm doing now. My panels pretty much cover my TV, computer and lighting. THings like fridge, microwave and washing machines are grid tied.

I bought a lower watt Microwave, 800W (altho my Kill-A-Watt says 1200W!!) But being smaller it takes less time to heat. I'm maybe doing 1/2 KWhr a day for heating food. 1.2KwH for the fridge. And I'm now cycling doing the wash on longer runs and when winter comes I'll just air dry my clothes!

So my electric is way down now. I'd love to move up in power, but the inverter, the charger and the batteries...not to mention the panels will kill me. At $1600 I am covering about 1/3-1/2 of my bases.

The funny thing is, the more efficient you become so you don't have to buy so many panels etc., the less your electric bill is. So it makes solar seem even more expensive.

I agree with the "other reasons". If not for them, I'd just have done efficiency over power replacement. The idea of being self-sufficient is very gratifying.

[scottsAI]

Very good freeEnergy4me, you have the right of it.

My batteries are backup only.

Once I put the backup in only had two short power outages! Bummer!

Add couple inches of insulation around your Fridge. Increasing thickness ratio should be the ratio of power saved (couple other factors involved like how often opened, compressor efficiency etc). Also be careful of the heat exchanger, not to cover them. Some new fridges use the coils beneath the skin... cant add insulation.

The idea of being self-sufficient is very gratifying.

Since I have not achieved this I do not know, but expect it would be!

Have designed an off grid hunting camp, might get to build it this summer.

Have fun,

Scott.

[Simple serf]

Well,

I have been running those cheap 15w panels from Northern for about 4 years, and I am currently expanding to all of the area I can use. I am replacing my relay type charge controller with a Xantrex C35, I am installing a Trimetric 2020, a xantrex 700W inverter, and I am going from 150AH to 500AH. With all of the fuses, wiring, and parts, it will come to about $1100 for the new work and I have a total of about $1300 into the system now. With all of the new stuff and the extra panels, I will be able to run all of my electrical loads except for refrigeration, and I am currently looking at a Sunfrost fridge and a older propane fridge. Just depends on what you want to run. My effiency is pretty high, so I can use the 700W inverter without any problems.

My work with solar is because I have always enjoyed working with wind and solar power, and because I am a bit of a survivalist.

Paul

[freeEnergy4me]

That sounds like me. I also bought those Northern panels. Although the idea of having one 150W panel instead of 10 15W is very appealing!  At this point I think they are about the same price, maybe a little more for something like a Kyocera.

I am also a bit of a survivalist. More in the vane of "if I get fired and can't find a job" than "if the Russians invade".  It's good to know the electric company can't turn my power off...or that it won't matter if they do.

[freeEnergy4me]

At this point, I'm just using the SunForce chargers that came with the panels! So they are probably not that efficient, but my batteries at this point are the limiting factor. The PVs charge them up fine, I just need more batteries.

[scottsAI]

FreeEnergy4me,

Golf cart, cost/energy cant be beat.

Costco or sams have the 225ahr 6v. Beware of the smaller lessor batteries they carry, for the price I would get the full 225ahr.

Are you up for a tracker?

Have fun,

Scott,

[freeEnergy4me]

But where? I can't find anything that cheap. For a pair, the cheapest golf car batteries I find are over $300. No where near $100 or less per battery.  That would be a great bargain.

My deep cycle marine batteries aren't doing too badly so far. I just need to string them together and keep the solar on them all the time and I will be ok.

For 225aH of marine deep cycle, it's $240. Not terribly bad.

[ghurd]

Where?  Maybe try CostCo or Sam's Club?  220AH at 12V is $140 for 2 golf cart batteries.

"For 225aH of marine deep cycle, it's $240. Not terribly bad."

Yes it is, when you have to buy them every other year.

Gosh.  $240 should get a pair of golf cart batteries at retail from a golf cart shop.  And they'll last longer than marine batteries.

[scottsAI]

FreeEnergy4me,

Like ghurd said; Costco or Sam's club would be my first choice.

Costco caries the real golf cart batteries in spring/summer only. (at least mine does)

225ahr at 6v, Last summer they were $57 each + 7.50 "core" charge.

Should weight near 70lb each. My costco never had more than two on the rack.

You must pre-buy them if you want more, they will not order then, just don't sell enough in case you don't pick them up, part of the reason I bought mine else where.

Beware of other batteries, deep cycle marine batteries are not the same nor will they last as long.

Sam's had a 189ahr battery, its not a golf cart, saves a few bucks. Much lighter than the golf cart.

I do not have a Sam's near me, checked one out when looking for my battery, they did have a real golf cart battery. Wanted to buy the battery near home.

I seriously looked at 110ah at 12v "golf cart batteries" takes half as many to hit 48v I needed. I went with 6v real golf cart for the higher capacity.

A near by battery store had a crown after market battery for $57, bought 8 couple years ago, working great. That price got delivery to my house with it! This store supplied batteries to most auto shops in a large area.

You live in the greater Detroit area, should NOT be a problem to find a golf cart battery for much more than $60, I only say that because the cost of lead has gone up and I have not been watching their cost.

Have fun,

Scott.

[freeEnergy4me]

yeah. I found two 6v 220aH for $190. The Sams and Costco near me don't carry golf cart batteries.

[beweez]

I am very new to this but have decided totake the plunge and  find a power source that makes more sense. Where did you find a wind generator. You mention 400 watts for 450. we have VERY realiable winds in our neck of the woods and are looking at a windmill  to provide our electricity

[jzeveney]

Here you go:

http://www.amazon.com/Sunforce-44444-12Volt-400Watt-Generator/dp/B000C1Z2VE/ref=pd_bbs_sr_7?ie=UTF8&
amp;s=sporting-goods&qid=1209342498&sr=8-7

I'm pleased with this for the most part.  However you really need 15mph+ for any real current.  Less that that and you under 3 amps or non at all.

Good Luck.

Z

[Jeff]

Dang! I wish I had that 180W of Solar! I'd be so close to being totally off-grid, I'd be extremely happy (I'm trying to curb the language here). I'm getting by with 45W Solar, but 500Amp/hours storage. Last electric bill was 69KwH and $20 for the month. I definitely would advise getting more storage (you mentioned 3 75Ah, I think). Besides the obvious extra storage, it would extend the life of your batteries by discharging each one less. That also has the effect of recovering charge much easier. You would think the numbers would be the same, (considering you use the same amount and charge at the same rate) but when I added just one battery about every 6 months, the quicker recovery was amazing!