Solar power. My first foray into it.

[Brent S]

like I said under another general thread, I’m going to put in a system on my own house. I’ve considered it for a few years now, but economics kept the project at a low priority. I am just starting to learn and source materials now, and plan to post what I discover and show my progress as I go through the process.
So far I have just started skimming the internet for some of the materials. I did contact two companies that plan, design and install systems. One of them was a very young girl reading from her script, but not really having any knowledge of any of it. She had a great speal about how their system pays for itself in just seven years, and is the best thing around. Sure.... The other company, Iron Edison, had a woman that was pretty knowledgeable and helpful. She sent me a survey to determine what my needs actually are and some more info on products they have. I haven’t opened the email yet, but will post what I learn.
The batteries are my focus right now. From what I’ve learned so far, the four main options ar lead acid, lithium, salt water and nickel iron. Lead acid batteries are the most economical but also have the shortest lifespan, of about 5yrs. The lithium is pricey, but has a ten yr life span. The nickel iron battery lasts 30yrs, but I haven’t gotten a real price on it yet. It has some drawbacks, like producing hydrogen gas, (so ventilation is needed), and they need water added often, (maintenance). The nifi battery also needs the electrolyte changed every 8yrs. I am getting the impression that its costs are comparable to the lithium, but will post when I learn more. The salt water batteries are new to me, but I learned the biggest manufacturer of them went bankrupt recently, so I’m more wary of them for now.
I hope this wasn’t too boring talking about batteries for this long! I am the first to admit I’m a novice at this topic, but hope I can learn and share the experience as I put in a system.

 

[Proud Prepper]

How many Kw hours do you need? I would recommend a offgrid battery backup and grid tie-in system, to use to save money and to use if you lose grid power. Add a generator to it for bad weather and your good to go.

 

[Brent S]

How many Kw hours do you need? I would recommend a offgrid battery backup and grid tie-in system, to use to save money and to use if you lose grid power. Add a generator to it for bad weather and your good to go.

I have a 10kw generator that I converted to propane a while back, and got a 500lb tank installed. It is a great backup for storms and power interruptions, but I want something long term. Quiet is good too. If things go bad for any length of time I would prefer not to make others aware that I have a good thing going here... I haven’t added up the Watts I need yet, but will this weekend. My plan is to put certain circuits on a sub panel and run that purely with solar while still being connected to the grid. Primarily I want the fridge, (1200watts), freezer, lights and some general outlets on this first part. My plan is to have two seperate solar systems, but am just tackling this one for a start. The two seperate systems is more about redundancy, but also is so I can do this without going into debt. The AC is going to be the holy grail here. It takes a lot to run one on batteries all night. Before I consider that I will replace my 11yr old system with a more energy efficient unit and will then consider trying to go off grid entirely one day. Baby steps....

 

[Proud Prepper]

Go ahead and max out your tax rebate with the grid tie system and then you can add the battery backups in banks over time.

 

[Squirtgunsquirter]

Great subject I will be following.

 

[SheilaT.]

Me too. I want to get my son secure for the furture and this is one thing I can do for him. I'm dabbling in solar now and what I use does what I ask of it ut it's more an education tool for me to learn with. I enjoyed your root cellar thread, looking forward to this too.

 

[Brent S]

Go ahead and max out your tax rebate with the grid tie system and then you can add the battery backups in banks over time.

From what I’ve read, at least here in Ga., anything you buy for the system qualifies for the credit. That’s batteries, hardware, labor, even the landscaping involved (tree removal, etc).
No doubt, splitting the project up into sections can help with the initial costs. One thing I have already learned is for anyone having the illusion of going solar to save money by getting rid of their electric bill, forget it. It is still cheaper to buy your electricity from the power company. By the time your system can pay for itself it is old and obsolete and needs to be replaced. Long term, if your really lucky you could possibly break even, but not likely. I want this for energy independence and security for if the grid goes down.

 

[SheilaT.]

That's exactly the reason we're looking in to solar too. It's not very economic over here either, although there are government schemes that help but you have to be grid tied, which in all honesty defeats the object because your panels will automatically be shut off if there is a grid down situation (Irish I know!) But not so long ago the government over here has been looking into battery systems to be eligible for the feed in tariff.

 

[DrHenley]

there are government schemes that help but you have to be grid tied, which in all honesty defeats the object because your panels will automatically be shut off if there is a grid down situation (Irish I know!)

That's just insane Sally. What stops you from disconnecting from the grid and running off grid? Is just a regulation thing?

 

[SheilaT.]

That's just insane Sally. What stops you from disconnecting from the grid and running off grid? Is just a regulation thing?

These rules only apply to government incentive schemes. If they help pay, or you accept the feed-in tariff your system has to be grid tied and if the grid goes down, so does your solar system. You also have to use government approved systems and installers. I've added a link for more information.

https://www.ofgem.gov.uk/environmental-programmes/fit

There was talk of the feed in tariff being available if you had a system that has batteries as well, ut I'm not sure when that is being phased in. There at least you can make the most of your system and have back up supply, but if you accept the feed in tariff you also have to accept that they can help themselves to your stored electricity or turn your electricals on and off at their convenience.

http://www.bbc.co.uk/news/business-40699986

Needless to say, I'm sceptical.

 

[Mountain trapper]

I agree that if you are close to power lines then utility power per kw hour is cheaper. At least for the first 10 years or so. But what price does one put on energy independence and self sufficiency? In my situation utility power is over 6 miles away. So solar is a huge bargain for me.
I'm actually going with 3 separate solar systems; house and shop, chicken coop and bee house and the main barn. Also have solar at the pump house for charging batteries, plus we have several solar motion sensor lights on the buildings.

 

[Brent S]

I like the idea Arctic has with seperate systems for a few reasons. First off, I’m not rich, so splitting it into smaller systems makes the initial step a little less daunting. Second, if one system has a failure of some kind then at least your whole place isn’t in the dark. Lastly, since I am learning as I build this, I may find one component isn’t as effective or good as I thought it was going to be at least the whole system won’t be stuck with it.
Another thing I really liked that he mentioned, the part about the peace of mind of energy independence and self sufficiency. I am initially shooting to ensure that my refrigerator, freezer , a few small circuits and the lights stay on.
I will tackle the larger appliances later on.
One thing I find most people don’t consider here is that going solar isn’t just about going and getting panels and batteries. It also needs to combine cutting power usage, switching to more efficient appliances, and lifestyle changes.

 

[SheilaT.]

This is one reason I have this little portable system. It has given me the opportunity to discover what amps and watt hours is all about and what I can and won't do without. At the moment that is all I really want from a system, enough energy to help out a bit and educate me.
And yes, I like the idea of splitting the build into several parts, it's something I hadn't thought of.

 

[Maverick]

Watching the thread

 

[Brent S]

Well, I’ve been reading a lot and am learning there are huge differences in pricing. Some of it is differences in quality of parts, some is just branding. Either way, it really is wise to thoroughly compare products. I am pretty sure I am going to do my initial system with 800watts of panel, 2000amp hours of batteries (10x200AH each). There are lots of websites that can help you figure your specific needs and the math is pretty straight forward. In addition to the panels and batteries there is also a charge controller so you don’t cook your batteries, an inverter to turn your battery power into AC power for your appliances, wiring and racking to mount your panels. All this is fairly reasonable until you get to the batteries. I found 100w panels for 120.00 each. They are monocrystaline 12v. That seems to be the least expensive per watt out there, but still had good reviews. The charge controller I picked is the newer technology type MPPT with a 60amp rating. It is actually better than I need but is a pretty important part of the system and will accommodate some growth if I decide later. The inverter is 5000w pure sine wave with 20k peak (for the extra momentary push to start a motor). Sorry, I’m trying to not bore everyone with too much detail here, but most of this is stuff I figured was important from the research I’ve done so far.
So here is the breakdown;
Solar panels 1000
Charge controller 215
Inverter. 400
Wiring and racking 700 (approximation)
Everything is looking really good here at about $2300.00. Oh wait, we’re not done.... remember earlier I said everything was fairly reasonable until you get to the batteries? Well, we’re here.
Of the four battery types; lead acid, salt water, lithium and NIFI or nickel iron, the only one I had a chance of affording was the lead acid. They last 3 to 5yrs. Lithium 10 to 15yrs, and NIFI 25 to 30yrs. Even with the lower longevity, it is still cheaper to replace the lead acid multiple times than go with the other types, by a lot. I am hoping that in the 4yrs or so when they begin to die the other types will be more common and come down in price by then.
So even with lead acid, at 360.00 each, x10, I’m still looking at 3600.00 for batteries. Total for the system is right at 6000.00. With me doing all the install. Still a chunk of change but doesn’t sound too bad for energy independence.
Oh, wait a minute, this isn’t even close to being independent of the grid. I am working on just running my fridge, freezer, lights and general receptacles for the electronics. None of the big stuff, oven, AC, water heater, dishwasher, or even microwave is included here.
I’m not trying to scare anyone off here, just pointing out the reality that it is still cheaper to buy power than produce it.
So, I just ordered a device called Kill A Watt from amazon. You plug it in and get an accurate reading of exactly what your appliances use during whatever time period you set it for. (Daily average in this case). I want true calculations before buying any of this setup. For instance, your fridge should run about one third of the time over 24hrs, so I calculated the wattage based off that average. I will see what my particular load is exactly. With the knowledge of the amount of power you need, then you multiply that by 3 days to gauge for stormy days and battery storage. Then you multiply that figure by 2 as you don’t want to drain a battery by more than 50%. So to run your really important appliances with little risk of loosing power you need ALOT of extra battery storage.
All the stuff I sourced was on amazon, but there are loads of other sites out there too. I just like amazon for a good variety of products to choose from and the free shipping (with prime, which I have for the business already).
I will post product info after I do my load tests as that may possibly change them.
Sorry for the long winded post here, but I’m a little fried from reading for a few hours on all this.....

 

[Proud Prepper]

Great update. There are lead acid battery brands that can be drained down to 30% and not lose any charge integrity.

 

[DrHenley]

AGMs charge faster, have a higher max discharge rate*, are less prone to sulfation, can be safely charged indoors, and have a lot less self discharge than other lead acid batteries. They are a bit more pricey but I think they are worth it. The indoor charging was really the deciding factor for me.

* Due to the fact that AGMs have a higher max discharge rate, even though they are deep cycle batteries, they can be used as automotive starting batteries. I was informed by an auto shop that the main reason people buy them for their cars is just because of the higher cold cranking amps than flooded lead acid batteries of the same size.

 

[Brent S]

AGMs charge faster, have a higher max discharge rate*, are less prone to sulfation, can be safely charged indoors, and have a lot less self discharge than other lead acid batteries. They are a bit more pricey but I think they are worth it. The indoor charging was really the deciding factor for me.

* Due to the fact that AGMs have a higher max discharge rate, even though they are deep cycle batteries, they can be used as automotive starting batteries. I was informed by an auto shop that the main reason people buy them for their cars is just because of the higher cold cranking amps than flooded lead acid batteries of the same size.

I saw a lot of AGM batteries listed, and may go back to compare before committing. Most of what I read was very pro on them as they can handle being stored on their side or upright, and handle vibration well. Seems like that would be ideal in an auto.

 

[DrHenley]

My first two AGMs were VMax brand that I bought on Amazon. Because they are completely sealed and and vibration resistant, they are cheaper to ship.

I started looking into automotive AGMs when my car battery died. I found a really great price on a DieHard Advanced Gold at Sears and bought a couple of those to power my 2000 watt Pure Sine Wave inverter. I sometimes carry one of these in my truck as a backup battery. Strangely, reviews of this particular battery were really good (EP-65), but not so good for other sizes.

Unfortunately, Sears closed down here, and their price is significantly higher now for that battery anyhow I'd have to drive to Morrow GA to buy one now.
Amazon has some DieHard Advanced Gold batteries, but not that one.

 

[Dani]

I'm watching this thread too. . . its something I would love for an additional backup besides the propane generator. Hunny has been looking into it, but out of our price range right now.

 

[Proud Prepper]

The AGMs can be hard to recondition and may not last very long for solor power system, unless you convert them to a hybrid AGM/LAB device. How you maintain, discharge and charge your AGM makes a big difference. I do think some are good to have just for there cold cranking power as backups.

• #1 Fully charge after each discharge. Estimated life: 6-9 Years

• #2 Fully Recharge at least once a week and equalize once a month. Estimated life: 4-6 Years..

• #3 Only recharge to 85% and equalize once a month. Estimated life: 2-4 years.

• #4 Only charge to 85% and never equalize. Estimated life: 1 year.

How to turn AGM batts into a hybrid AGM/LAB device. if your AGM is dead you can try the following:

DO THIS AT YOUR OWN RISK, BE CAREFUL USE THE PROPER SAFETY PRECAUTIONS

1- pop the caps to expose the cells
2- go down to the local auto parts store and get some battery acid, they sell it in bulk sometimes.
3- take a small syringe and add 10 CC of acid to each cell.
4- wait a day for it to absorb the acid, then do it again.
5- do this each day until the mat does not absorb any more acid
6- drill a very small hole in the top of each cap to allow it to vent and replace the caps. make sure the battery is at zero volts.
7- REVERSE CHARGE THE BATTERY !!! yes that is what he said REVERSE CHARGE. this changes the lead plates. 10 minutes is a good estimate.
8- now drain it to zero with a load such as a resistor or dc bulb.
9- charge it with a regular charger that has a variable supply for current in the correct direction.

The fully charged resting voltage will be between 12.2 and 12.6 and it will behave like a standard LAB. water will have to be added peiodically as it will begin to offgass like a normal battery.

The AGM batteries may be converted, but what if the battery is Sulfated, your in trouble.
The only way I ever found to help the battery is make sure the battery voltage is zero. To do this you must use a supply you can dial in for current. The first thing is to test the battery to make sure it is at zero volts. By reversing the charge you can move the lead in the reverse direction, and you only want to do this for a very short time as the battery may heat and you want to keep this at a minimum, say 10 minutes. Then drain the battery to zero and charge again with a variable supply for current in the correct direction. Now we are talking about AGM cells here and not anything else. Be very careful when doing this, as this is done at your own risk.

You should be able to recover at least 55% of those useless batteries. This type of battery dries out and you cant do a thing with it. You can get it to work as we have done this at the shop. Make sure you drill a small hole in the caps that you pop off for the gases to escape.

A Sulfated Battery

How many times have you heard the expression, "The Battery Won't Take A Charge" or "The Battery Won't Hold A Charge?" More often than not, the culprit is hardened sulfate on the battery plates. Below we will attempt to explain what that means, what the causes are, and some measures to prevent the sulfate from permanently damaging your battery.

Let's look inside a battery cell. Basically, there are the positive plates, the negative plates, separators (to keep the plates apart), and electrolyte (sulfuric acid and water).

In normal use, battery plates are getting sulfated all the time. When a battery is being discharged the lead active material on the plates will react with the sulfate from the electrolyte forming a lead sulfate on the plates. When there is no lead active material and or sulfate from the electrolyte remaining the battery then is completely discharged. After a battery reaches this state, it must be recharged. During recharge, the lead sulfate is reconverted into lead active material and the sulfate returned to the electrolyte.

When the sulfate is removed from the electrolyte the specific gravity is reduced and the reverse takes place when the sulfate is returned to the electrolyte. This is why the state of charge can be determined with the use of a hydrometer.

If a battery is left standing in a discharged condition the lead sulfate will become hard and have a high electrical resistance. This is what is normally called a sulfated battery. The lead sulfate may become so hard that normal recharging will not break it down. Most charging sources, engine alternators and battery chargers, are voltage regulated. Their charging current is controlled by the battery's state of charge. During charging, battery voltage rises until it meets the charger's regulated voltage, lowering the current output along the way.

When hard sulfate is present, the battery shows a false voltage, higher than it's true voltage, fooling the voltage regulator into thinking that the battery is fully charged. This causes the charger to prematurely lower it's current output, leaving the battery discharged. Charging at a higher than normal voltage and low current may be necessary to break down the hardened sulfate.

Hardened sulfate also forms in a battery that is constantly being cycled in the middle of its capacity range (somewhere between 80% charged and 80% discharged), and is never recharged to 100%. Over time, a portion of the plate's active materials turns into hard sulfate. If the battery is continually cycled in this manner, it will lose more and more of its capacity until it no longer has enough capacity to perform the task for which it was intended. An equalizing charge, applied routinely every three to four weeks, should prevent the sulfate from hardening.

In both cases, the fact that the battery "won't take a charge" is a result of improper charging procedures which allowed the sulfate to harden. In most instances, it is possible to salvage a battery with hardened sulfate. The battery should be charged from an outside source at 2.6 to 2.7 - volts per cell and a low

current rate (approximately 5 Amps for small batteries and 10-Amps for larger ones) until the specific gravity of the electrolyte starts to rise. (This indicates that the sulfate is breaking down.) Be careful not to let the internal temperature of the battery rise above 125° F. If it does, turn the charger off and let the battery cool. Then, continue charging until each cell in the battery is brought up to full charge (nominal 1.265 specific gravity or higher).This time needed to complete this recharge depends on how long the battery has been discharged and how hard the sulfate has become.

The next time your batteries don't seem to be taking or holding a charge, check the specific gravity with a hydrometer. If all cells are low even after a long time on charge, chances are you've got some hardened sulfate that has accumulated on the plates. By following the instructions outlined above, the problem may be corrected.

 

[DrHenley]

AGMs are best maintained at a float voltage of around 13.5 volts (depending on the temperature). I have expensive smart chargers that keep the AGMs right at 13.5. I've been through a number of less expensive smart chargers that will not maintain the correct float voltage.

1- pop the caps to expose the cells

Pop the caps???

 

[Proud Prepper]

AGMs are best maintained at a float voltage of around 13.5 volts (depending on the temperature). I have expensive smart chargers that keep the AGMs right at 13.5. I've been through a number of less expensive smart chargers that will not maintain the correct float voltage.

Pop the caps???

Yeah, most all are sealed, dont have caps, you have to drill holes and put in caps to convert them. The float voltage is important or they wont last long, unless you completly discharge, then fully recharge.

 

[Brent S]

AGMs charge faster, have a higher max discharge rate*, are less prone to sulfation, can be safely charged indoors, and have a lot less self discharge than other lead acid batteries. They are a bit more pricey but I think they are worth it. The indoor charging was really the deciding factor for me.

* Due to the fact that AGMs have a higher max discharge rate, even though they are deep cycle batteries, they can be used as automotive starting batteries. I was informed by an auto shop that the main reason people buy them for their cars is just because of the higher cold cranking amps than flooded lead acid batteries of the same size.

Thanks for the info Doc. I read about them a couple years ago but had kind of forgotten them. They were just barely more than the lead acid cost wise and with the no maintenance it is definitely a better battery. Longevity is comparable. Either way I already switched to them in my shopping cart on amazon. Thanks again, I’m always open to good ideas and input.

 

[DrHenley]

According to DieHard, their Advanced Gold AGM batteries last twice as long as their Gold flooded batteries.

I suppose it could vary with brand, And I suppose it's how you use it. They will take most kinds of abuse better than flooded. They don't like excessive heat or over voltage. But they handle cold, deep cycling, vibration, different orientations (upside down for instance) and sitting unused better than flooded batteries.

 

[Brent S]

I got my Kill A Watt meter today. Amazon is awesome, two day free shipping.... anyways, it was only 21.00 and now I will see exactly what my specific appliances are actually pulling power wise. You can get a snap shot instantly, and it also records for whatever length of time you like. I am doing a twenty four hour period for the fridge and freezer each.
Right now with the compressor running I’m using 73watts. In between cycles it drops down to 12watts. The lights are LED inside the fridge and on the door so it pulls a little more each time you open it up. On average the compressor runs about 25% of the time, but that’s why I want a 24hr real time measurement for what I’m actually using so I can size the system for our needs. This thing is a neat little tool. You just plug it in and then plug your appliance into it. Really easy to use.

 

[Mountain trapper]

Here's a couple picture of my setup and building to house everything.

. Its not completed yet.

 

[Brent S]

Here's a couple picture of my setup and building to house everything. View attachment 8567 . Its not completed yet.View attachment 8568 View attachment 8566

Holy crap 5at looks cold! Can’t wait for some summertime Picts though!
How many amp hours are your 6v batteries? Looks like a good setup.

 

[Brent S]

Well, my needs for the fridge are 1.2kwh and the freezer is .45kwh. I am going to at least double that amount and then triple it for no sun days, and then double that for not discharging the batteries more than fifty percent.
So, the math is; I need 1.57kwh just for the fridge and freezer. Double that to run lights and misc. other stuff, making 3.14kwh. Then multiply x3 for rainy days, making 9.42kwh. Then times 2 for not draining the batteries more than 50%. That makes 18.84kwh needed for a 24 hr period. This is a good bit more than is needed but I want to plan for the worse case. I will plug this into real products and the cost shortly and post it. I’m kinda scared for the battery costs already!

 

[Brent S]

Looks like I will do fine with 2000AH artery storage. 10 200Amp Hour deep cell AGM batteries. Roughly $4000. Just for batteries. I should still be able to keep the whole system below 8,000. Once I finalize all the parts I will post them with actual costs and pictures. The regular power bill is looking better all the time! Other than the self sufficiency part I don’t see this as economical at all. As soon as the accountant gives us a final tally for last years taxes I will pull the trigger, but still have a little design work to do.