This system is working good in a 4000 sq ft shop & house combo, but could use more storage for peace of mind & will likely upgrade next year.
The Aquion Energy Saltwater Storage Battery
David Ewing Branson | Consultant
The Aquion Energy Saltwater energy storage battery has gotten some press in the last couple of years for it's unique technology, but it deserves a lot more I think. I'm just your normal homeowner myself, but I've been following solar technology for years wondering when it would be viable for the general public to start making our own power vs buying it from the grid.
I went OG years ago using lead acid batteries on multiple strings which is NOT viable for most people. If you know what you're doing & maintain your system to a high standard it's still a lot to know & do to keep things working well.
And it's not cheap in any sense. But I've been sharing my knowledge with others in the area & have friends who have their own systems now that we share info on together.
For the sake of terminology, I'll use the word member & relate the following story about one of the newest OG members in our group who wants to remain un-named as most OG owners do:
A few years back I decided to go off-grid (OG) in my garage at home & then maybe in the future, at my house as well. I wanted to find out for myself if I thought I could live with an OG system long term, & starting in my garage was a good way to gain experience. My garage at 2000 sqft is slightly larger than my home, but my power usage is much less & more sporadic.
Being retired, I'm home most days and basically manage a small homestead growing a lot of my own food, we have fruit & nut trees, multiple types of berries, we have chickens, etc. Enough to keep you busy everyday & I'm in my garage doing something all the time. I've also owned a Polaris Ranger EV since 2010 & we use it daily working around the property.
We both love the fact that we just charge it as needed & it has required almost no maintenance to this day. Just turn the key & go - summer or winter. We now have multiple OG friends with these EV's & everyone loves them. So later on I decided that charging it off of solar would be nice & that branched into an upgrade to my OG garage idea.
Another aggravation in the garage was that it had a separate meter which we paid a $28 monthly fee whether we used power from the grid or not. Not a lot, but that money stays in our pocket now. The first thing I found out about trying to go OG was not what I expected.
There's not a lot of solar companies close to me & I figured it would be an issue finding one to just come out here. But the real problem was getting a company to install an OG system period. They all advertise off-grid on their website, but that's really just a search term to get hits to their website. When you call them to come design a system for you, they only seem interested in doing cookie cutter grid-tie systems.
The people that CAN actually do OG systems are apparently the bigger commercial installers & they don't want to be bothered with small residential installs. It took me 3 months to find someone willing to come do my 'garage' install.
So I started with 3.5 kwh of Canadian Solar panels feeding an Outback Flexmax80 Charge Controller which is charging eight Model:L16H-AC 6volt Trojan batteries in series to power up a 48volt system. Inverter was a Magnum Model MS4448PAE 4400 watt, 220vac true sine wave off-grid style capable of bumping up to 8000 watts for short periods.
My only backup was a Generac 11kwh Generator, but because my garage use was not a priority, I rarely had to use the generator to finish something I was working on. Usually I only needed it in the winter when there was no sun for days, and maybe once during summer rains with overcast skies for days on end.
I lived with that for 3 years knowing my main issue was that my batteries were getting charged up early in the day, and I was wasting a lot of power because I couldn't store it for later use. And that is the one frustrating thing about OG systems. If you don't either use the power coming in or you can't store it because your batteries are full, then you have power being wasted.
I could now power my neighbors house with extra energy I would be storing if I had enough battery to store everything I could potentially collect from my panels on a daily basis.
And storing energy has always been the downfall either for an OG system, or commercial customers doing a larger Nano-Grids, Micro-Grids, etc.
There have been options available commercially in the form of Flow Battery technology. Even today, this type of storage is still ramping up to supply the energy storage boom that's really been taking off just in the last couple of years.
There's been limited products available for a residential customer, & everything I found on the web was being installed by commercial solar installers.
If you had a multi-million dollar house, then you could probably get someone to do a system for you fairly easy. But even then, maintenance is another issue. The buy in cost for a flow battery is another consideration. There are a few competing technologies, but when I looked at these around
2015 I was seeing $1-2 per kwh of storage. But also there's an issue with which inverters and charge controllers are compatible.
You could get something very plug & play if you had $100,000 or more to spend. I had heard about saltwater battery technology being developed back around 2011 or so, & after a few months of follow up searching all the flow battery products I could find, by chance I did a youtube search for "saltwater battery".
That's when I found the Aquion product & realized it was currently available for order through Alt-E Solar Products.
Around the first quarter of 2016 I heard they were switching to a slightly larger capacity module called a M110 with 30.6 kwh capacity that would be selling for $15,000. I had really been anxious to expand my system if I could just find the right storage medium for a decent price & now that dream fell into place.
The battery was still a few months from rolling off the assembly line, but I bought one & secured my place in line for what they've named now - the Aspen Module 48M. So I had the battery coming & I just needed a company to design the rest of the system & plan the install.
Did I mention that solar companies really don't want to do OG systems? I called everybody back that I had contacted before & even sent them an email link to go look at the battery in case they were skeptical. None of them would do my job & the one commercial installer I had talked to who could do it, was too involved with other big projects to do such a small system as mine. He was intrigued with the technology, but couldn't justify the time away from his other commitments to do mine.
So I started looking at the new battery specs & of my current system. Then I laid out my own design for what I thought would be adequate. I was going to do it myself & just hire an electrician to connect the parts. It's just not that hard in reality, but the wiring needs the right person.
So I start calling around to electricians hoping to find someone who has done some solar before. I knew I couldn't install the panels myself & it's a 2 story roof!
By providence & the grace of Yahweh, I was in town one day & saw a truck go by with the name of a solar company on the side. I looked him up on the web & this was a local solar company I had not run into yet. Again, he wasn't impressed with the idea of doing an OG system, but was really intrigued when he saw the battery!
So I link to his video of my system & everything eventually installed without much extra effort. The wiring for the solar components are pretty straightforward. An OG system is even a little easier than Grid-tie in some aspects.
Connecting the power from my garage over to the house was really the hardest part of the whole job. But each home will be different depending on where your panels will go & where the inverters & battery will be placed vs where your house breaker panel is.
The one thing unique to my install is that I designed it as a dual hybrid system. I kept my home meter from the grid which I can use basically as a backup on demand as needed.
There's no connection from the grid to the solar system at all & I don't sell my excess power to them. Rather I installed a huge commercial transfer switch because I needed something to handle 200amp service from the grid.
Basically it's a LARGE manually operated double pole - double throw switch I can switch the input power feed to my breaker panel with. It stays on the solar side unless my battery voltage gets too low & the inverters shut off from the low battery cut-off (LBCO) which I have at the lowest setting of 36vdc. I could power on my generator at that point if I choose to, or I can switch to grid power until the sun comes up or whatever the issue is.
But I decide. Because it's not a big issue if the power shuts off for a few hours in the morning before the sun comes up. It's rare, but that's the most likely time I would run out. One thing you have to think about with OG systems is that it's three times more expensive to buy more batteries or to pay to enlarge your system to use more power to run appliances that are not efficient, than it is to spend the money to buy the most efficient equipment.
We're all electric with electric stove & water heater being our biggest drain. I looked into a heat pump style water heater & there's some positives with that, but for the money vs potential savings I haven't seen anything yet that's a no-brainer. Magnetic induction water heating might be the best thing for efficiency, but it's not in the USA yet that I can find.
What is available & works well is replacing central A/C units with mini-splits. I put 3 single head units in 3 different rooms which are each 27 Seer! The great thing is that 90% of the time during the year I only need to run one unit to get whatever heating or cooling I need at that moment. Each unit only pulls 7amps even on high cool, or high heat! So that's 7amps 220vac which shows up as a 14amp dc draw at my battery.
The Aquion prefers low amp drains over long periods of time vs high amp draws for shorter periods. That can be problematic for an all electric home where I can possibly 'over-amp' my battery if for example, the stove is in use & the hot water tank cuts on. Then it may be in the 140 amp dc draw range on my battery & the max you should pull is 140.
Though the technical max before you blow fuses is 200.
So I have to be careful about having both on at the same time. For the battery though, it drops quite a bit of voltage as the amps go up. I've noticed as much as even 8 volts. So this can manifest as a problem especially early morning if I need to kick the water heater on. I have it on a timer so it comes on between 11:30am-3:30pm every day when I'm at the highest charging current.
This is the time when I usually have excess energy because my battery has already charged by 11:30 some days & I may not be doing much during those hours to use the 120amps or so of charge current coming into the battery. But early morning, say 6am if we need showers, if the battery is down to around 44 volts & I cut the heater on, it can drop enough to hit the LBCO at 36v & the inverters shut off.
I could switch the whole house over to grid, but I anticipated this problem up front & designed in a second set of transfer switches just for the water heater & stove.
Since these didn't have to handle 200amps, they're a lot smaller than the main switch. I knew that my system would probably work a lot better with 2 or even 3 modules charging in parallel, but I wanted to get my system going & try it for a year or so & then upgrade once I was satisfied how everything might work.
In the future, with 3 modules & 90kwh of battery storage, or 4 at 120kwh; whatever I want to run would be no problem. On only one battery, I might squeeze 2 days of use out of our system if there's no sun, but only if we cut back on our daily power use. I've got my 2 backups, the gen & the grid.
But most of the year, with the 7kwh of panels I have now, I could eventually fill up as many modules as I could connect to my system.
If I had 3 or 4 modules, I would never need the generator. 4 modules would probably get us through 8 days without even cutting back on our use. When would we have a week with no sun at all? Once you get sun, the panels will charge at full output & 4 batteries will probably fill up in about 2 days of good sun.
So there's a number of things to talk about as far as cutting power consumption as well. We went with 2 of the 8cuft Sundanzer 12vdc Freezers & thanks to some new friends who are also OG to advise me, I have installed quite a bit of LED lighting in my garage. So I have 2 separate 48vdc to 12vdc Converters running those & the lights now.
The bottom line is being OG is not a technology problem.
Look up the Aquion battery. What can you compare it to across the board? I'm also OG for a lot less money than others in the group & I have a better battery than the old lead acid technology. I now have 2 Magnum 4400 watt inverters & 2 Outback Flexmax80 charge controllers connected to the Aquion.
It doesn't care about partial states of charge. You can drain it to 0% state of charge (SOC) & it can sit like that for weeks or months with no problem. No loss in charge cycles or capacity. It doesn't care about partial charging or even the way it's charged. It doesn't have to have a specific charge profile as long as you don't overcharge it.
It's pretty much a plug & play solution for whatever 48vdc inverters or charge controllers you may be using now as long as they can be programmed to stay withing the 30vdc minimum discharge voltage & 59.5vdc high. If they find something the battery doesn't work with I'm sure they'll have that info on their site. Few things are so advanced that they are called disruptive technology. I think the Aquion fits in that definition!
So this system is working good in his 4000 sq ft shop & house combo, but he could use more storage for peace of mind & will likely upgrade next year. Then he wouldn't have to watch over it as much. It has no connected electronic controls or monitoring, though they may opt for that later.
At $15k for the Aquion module plus $1000 for shipping @ 3300lbs! 2 Magnum PAE's of the 4400 watt variety are about $5k with the E-Panels on ebay. The Magnum Router for master/slave operation is $500 approx. The Outback Flexmax80's are about $600 each. Solar panels are $1 a watt or less these days - so $7k for 7000 watt to duplicate this system example.
So that's right at $30k before you pay for wiring, or realistically about $40k installed. They didn't buy it for a payback. Based on what they were paying it would take 15 years or more to break even. The point is we should all be making & sharing power locally with systems we actually own & connecting every few homes into nano-grids.
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