What is the best battery technology

So, I am about to embark on a rather large solar project,...well, large for me anyway. The more I research on batteries the more confused I become. I was hoping to find some folks who have used different batteries for solar energy storage, and their experiences good and bad.

The new tesla batter looked promising, except for the cost. They have 2 available. The 7 kW battery 3500.00, and 10w 5000.00.

The pros for me personally. Compact design, high effency, no maintenance, 10 year warranty with 10 more optional. The cons- the 10kw battery is not designed for daily use. It's meant to be used like a generator for back up. The 7kw may be too small for what I need, which means I would have to get 2 7kw@ 7000.00 OUCH!

There is the more traditional approach of lead deep cycle batteries. They seem to need a lot of upkeep and monitoring to assure proper functioning, and I think I would need a virtual boat load of them! I'm not sure of the shelf life and I'm afraid if I need quite a lot, I'll just have to replace them maybe a couple of times, I'd rather once and done if possible.

More recently I found the nickel or Edison battery. I've heard some say they will last for 100 years, with a simple top off of electrolyte solution. They are not very efficient after the first 5-7 years, maybe 15% or more loss, but will remain stable after that. That may mean an addition of batteries or solar panels later on. Not sure how to compensate that. They are more expensive than lead less expensive than tesla.

I believe by the end of the year, a researcher from MIT is about to begin production on a salt water battery. Very environmentally safe, very efficient. I would be a little afraid to be a Guinea pig, especially when I feel so ill informed on the topic, and I'm afraid to contact the company, as I don't want to be SOLD a product, I just want the truth and facts so I can make a good decision.

If there's anyone out there that has any real life information, or experience on any option above, or something I haven't heard of yet, I appreciate your input and dialogue.

Oh...a bit of information, I think I'm looking at 10 kW of solar, and I have about 600 sqft of roof space to work with. Hoping to have this project completed by this time next year.

Thank you!

This is where I got the information I'm discussing here.

www.teslamotors.com...

ironedison.com...

www.nanalyze.com...

You have a very interesting project ahead wetpaint72, looks like you're going off-grid completely
btw do you know that when you have solar panels on your roof it makes it untouchable by the fire department in case of fire ?

a reply to: manuelram16fortunately, they are not on the house roof! Thanks for the heads up!

originally posted by: manuelram16

btw do you know that when you have solar panels on your roof it makes it untouchable by the fire department in case of fire ?

Why is that?
Is it because of shock hazard? If so why is it considered more of a risk than the electricity supply already in buildings?

Good luck Wetpaint72 with your project. Although no experience with a house solar system I use LIFEPO4 for electric bicycle for years with good success. They have a life cycles exceeding 2000x but the batteries arn't cheap. If you buy a 10KW LifePO4 and only use 50% of its capacity per day it should last over 10 years with ease. But many recommend its cheaper to first reduce your energy consumption by buying energy efficient appliances (fridge based on 12v danfoss compressor etc) before going solar.

a reply to: glend
I am already reducing on the front end with appliances and lighting. I'm even considering putting most of the house on dc to reduce loss and increase effeciency. I will look into those batteries. Thanks!

The best battery tech is one that does off gas.

Be VERY careful with that.

Wrong kind of battery in an enclosed space = very bad day.

a reply to: Wetpaint72

If you are trying to generate 10KW with solar,I hope you live near the sun-maybe on Venus or Mercury might be near enough.

Or you have a gigantic land mass covered in solar panels here on Earth..

Be VERY careful with any massive lithium ion battery storage-those things can go off without warning-a tiny lithium phone battery can explode with enough force to seriously hurt a person,so make sure you have a proper temperature/humidity controlled environment if you choose giant lithium battery banks like the tesla jobs.

I had a lithium camera battery spontaneously melt and go on fire a couple of months ago-it would have burned my house down if I wasn't luckily in the room at the time.I keep my camera batts in a metal box with a gallon bottle of water on top, out in the garage now.
10KW of tesla lithium battery could probably annihilate a whole city block if it decided to explode..

Man,I would be happy if I could collect 0.5KW with solar panels in where I live (Wales,awful weather mostly).
I would probably need a football field full of panels to do so sadly.

Consider trying to lower your electricity consumption,maybe use LED lights where you can(if you are using lights that is).
Good luck with it all !

a reply to: neo96
Yeah, I've seen pics of fires...not good. I just broke down and emailed the Aquion company. Those salt water batteries seem pretty safe.

a reply to: Silcone Synapse
Lol. Not quite Mercury. It's only 600 sqft of coverage.

a reply to: Silcone Synapse

I agree about the power that lurks within lithium batteries, I use similar in my RC models, and like you I keep them all in a metal box. However, the tech has improved a lot, they are much safer now.
I remember when Sony had a problem with their laptops spontaneously bursting into flames, but when was the last time we heard of such a thing?
There's billions of mobile phones using lipoly's and how often do we hear of those exploding?

If I were OP I think I'd be going with lithium, I'd just make sure they were as far from the house as possible.

ETA: I remember when I first got into RC models I read something that claimed the battery I was using had the same power as a stick of dynamite. It was the size of a Mars Bar.

a reply to: Wetpaint72

dc sounds good. What might help your decision making process is working out the expected cost per KWh over the lifecycle of the solar/battery technologies you're examining. For example this link projects his cost at 16c kWh including panels and LIFEPo4. I also wouldn't rule out using different battery technologies in a system. Perhaps LifePo4 for more frequent loads (lights and fridge) and maintenance free AGM for infrequent loads (washing machine etc). If the AGM batteries are only drained to 50% capacity once a week they should last 10 years as well.

a reply to: glendthank you very much for the link. I had not thought to use separate batteries for different loads! Fantastic idea. Did you happen to check out the aquion batteries. I'd be interested in your opinion on those, if you had the time.

I went off grid about a year ago and use a 48 volt system with a battery made for a forklift. weighs about 2000 pounds and has worked great. Bought from GNB batteries. I have a 12 foot x 36 foot roof completely covered with 18 24 volt panels and get about 4500 watts of power. So far that has been more than enough for us an we haven't had to run the generator yet..

a reply to: Wetpaint72

Never heard of the aquion but just had a quick check, they do look good. Their efficiency is only 85% but I personally value cycles above all else because you can always add a panel or two to make up for that loss of efficiency. I would definitely short list the aquion and the 4 Year Standard Warranty shows they have confidence. Good find.

Edison batteries are very good as they have a 50+ year life time IF PROPERLY MAINTAINED.

The next best are LiFePO4 batteries. that have around a 10 year life span and have a very good storage capacity.

These are the same batteries that are used in the tesla wall but in a form that you can used to build your own custom system.
www.electriccarpartscompany.com...

My RV runs three group 24 12v 85 Ah deep cycle batteries at about $100 each and last about 3 years.
if i replace them with 4 100Ah-3-10C-32V-br-LiFePo4-Lithium-Encased-EV-Batteries it will cost about $500 but last 4 times longer and weight 1/9 the weight of lead deep cycle batteries.

The lead acid deep cycle batteries give a total of 255 Ah where the LiFePo4-Lithium-Encased-EV-Batteries give me 400 AH with room in my RV battery compartment to add 8 more LiFePo4 batteries in series/parallel connection for 12 volt 1200 Ah.

I plan to add 500 watts of solar panels to the roof of my RV to charge these LiFePo4 batteries.

originally posted by: rlrsar
I went off grid about a year ago and use a 48 volt system with a battery made for a forklift. weighs about 2000 pounds and has worked great. Bought from GNB batteries. I have a 12 foot x 36 foot roof completely covered with 18 24 volt panels and get about 4500 watts of power. So far that has been more than enough for us an we haven't had to run the generator yet..

Might I ask, where do you live...or how many hours of sunlight do you get. And how many days can you survive with consecutive gray skies. Thank you

a reply to: VoidHawk
Sometime ago I saw on TV news a building that had PV solar panels on the roof and the fire dept. refused to put water close to it due to shock hazard.

originally posted by: manuelram16
a reply to: VoidHawk
Sometime ago I saw on TV news a building that had PV solar panels on the roof and the fire dept. refused to put water close to it due to shock hazard.

Interesting article on this www.motherjones.com...