SolarEdge vs Enphase AC coupling vs Outback

[astraelraen]

We are looking into getting a grid-tied system with a small battery bank for outage purposes to run important loads. I havent mapped out what qualifies as an important load but I suspect our fridge, freezer well pump and a few other 15/20amp circuits probably would be on the list. The well pump is 240v.

I have done some very general research and gotten a few bids. My annual kWh use is about 11,500, which translates to about 950 per month. PVwatts says I need a system size around 7.5 - 8kW. Most of the local vendors seem to prefer Enphase and none have impressed me with battery knowledge.

I was comparing the following systems and wanted some input:
Solaredge Storedge system with 7600 inverter and battery backup addon + small battery bank
Outback Radian system with 8048 inverter and small battery bank
Enphase S system with AC coupled battery bank

Pricewise these systems are mostly comparable in equipment cost (within 2-3k) not including installation labor. The Enphase system is probably the most expensive.

Given the fact that I dont expect many outages, our grid is historically really reliable - I want a great, reliable grid-tied system. However, I want the peace of mind a small battery bank (and the ability to expand) brings. What is the best system choice?

[mblevins]

I can't offer any specific advice, but I do have some general advice:

- Just stating the obvious, your well pump pulls quite a bit more amps than your fridge.

- Might want to look into the battery size and maintenance. I didn't, skimped on battery maintenance, and now have to replace my batteries. At least with my Hybrid system, it won't work properly without a full 440 AH battery bank.

- I originally wanted the hybrid system so I could run the house off of solar if the grid was down. Turns out where I live there's a high correlation of grid outages and snow covering the panels If I had to do it over again, I would have just bought a grid tied system and a generator for backup. Less expensive and less work.

[ButchDeal]

I would stay away from any AC coupled system, they are overly complex and in you case mix brands.
It sounds like you have very limited need for backup power but the back up systems are going to greatly increase costs and complexity.
You really need to decide if that is what you want as it is limiting options and dragging the ROI down.
I have outback for backup but I have regular outages.

[astraelraen]

I have similar feelings regarding the AC coupled systems just from my light research. However, I haven't found a local vendor who wants to install a DC coupled battery backup.

I am considering installing the panels myself and hiring out the AC-side electrician work, which reduces the installation bill considerably. I have priced out the above mentioned systems on various wholesaler/dealers and I think I can get a 7.5-8kW hour system + ~400-500amp hour battery bank for around 20-25k - equipment cost.

A grid-tie solar-only installation seems to go for around 11-15k - equipment cost.

The Solaredge system is on the low end of that equipment cost scale and I have read the installation manuals, it doesn't seem too terribly complicated on the DC side. I feel like this is the best value for the money, however it also is the newest system. The Outback systems seem like they are more proven?

[astraelraen]

I can't offer any specific advice, but I do have some general advice:

- Just stating the obvious, your well pump pulls quite a bit more amps than your fridge.

- Might want to look into the battery size and maintenance. I didn't, skimped on battery maintenance, and now have to replace my batteries. At least with my Hybrid system, it won't work properly without a full 440 AH battery bank.

- I originally wanted the hybrid system so I could run the house off of solar if the grid was down. Turns out where I live there's a high correlation of grid outages and snow covering the panels If I had to do it over again, I would have just bought a grid tied system and a generator for backup. Less expensive and less work.

We have/are considering a generator as well. But my wife (and myself somewhat) have a general "bad feeling" about spending 15k on solar panels and staring at them while they do nothing in the case of an outage. It just kind of rubs me the wrong way

I have done some general battery research (none of the local vendors seem to want to go into this realm) and I think a 850-1000 AH size would be ideal for emergencies. I don't think that is the best idea from a cost perspective right now. A ~400AH size like you have seems a better compromise given the current cost structure of batteries and if we had a long-term outage we would just have to switch to "ultra conserve" mode.

[jflorey2]

Solaredge Storedge system with 7600 inverter and battery backup addon + small battery bank
Outback Radian system with 8048 inverter and small battery bank
Enphase S system with AC coupled battery bank

Given the fact that I dont expect many outages, our grid is historically really reliable - I want a great, reliable grid-tied system. However, I want the peace of mind a small battery bank (and the ability to expand) brings. What is the best system choice?

Well, you have a decision to make then.
If you want the "peace of mind" of a full backup system (and don't want a generator) then you are going to have to bite the bullet of battery maintenance - and that's not cheap or easy. But if you are willing to do the work and pay the money then that's a good option. Note that the GS8048 has a minimum battery size.

If you want simplicity, reliability, low cost and _some_ solar backup then consider an SMA system; that provides 2000 watts of solar when the grid is down (and the sun is out.)

If you want simplicity, reliability, low cost and more of a full-time backup then I'd go with one of the two grid tie systems you list and a small generator.

[bcroe]

Decades ago I wanted some backup for stuff like the well and the furnace, so I took $500 and bought an electric
start 8hp generator. In 20 years it has been used 4 times. Maintenance is start it once in a while, keep a maintainer
on the cranking battery, which I have replaced a couple of times. It could be jumped to the car.

There are automatic full house generators, which may run on your natural gas, propane, or diesel; a luxury I certainly
don't need. A battery backup is EXTREMELY expensive (initial and long term), VERY limited in capability, HIGH in
maintenance, quite unforgiving, and it mandates a generator ANYWAY.

I would feel pretty bad always looking at a battery backup system that is so costly and troublesome, so limited, and
practically never gets used.

Recently I installed a PV grid tie system to cover a lot of my home energy needs. Output is erratic, weather
dependent, and puts out the least energy when I need energy the most (winter). The rare times the grid quits,
seem to be the same as when the PV is least effective. But the PV has nothing to do with my backup power.
Bruce Roe

[SunEagle]

Decades ago I wanted some backup for stuff like the well and the furnace, so I took $500 and bought an electric
start 8hp generator. In 20 years it has been used 4 times. Maintenance is start it once in a while, keep a maintainer
on the cranking battery, which I have replaced a couple of times. It could be jumped to the car.

There are automatic full house generators, which may run on your natural gas, propane, or diesel; a luxury I certainly
don't need. A battery backup is EXTREMELY expensive (initial and long term), VERY limited in capability, HIGH in
maintenance, quite unforgiving, and it mandates a generator ANYWAY.

I would feel pretty bad always looking at a battery backup system that is so costly and troublesome, so limited, and
practically never gets used.

Recently I installed a PV grid tie system to cover a lot of my home energy needs. Output is erratic, weather
dependent, and puts out the least energy when I need energy the most (winter). The rare times the grid quits,
seem to be the same as when the PV is least effective. But the PV has nothing to do with my backup power.
Bruce Roe

It is kind of funny that people hate to spend money on something that just doesn't seem to give them anything now because it just sits there and does nothing. Like a generator in case the grid goes down.

Yet people spend thousands of dollars over the years on a term life insurance policy without giving any thought that they get noting for it unless they die. Seems ironical to me.

As far as I am concerned a generator is like an insurance policy. Both cost money that really doesn't get you anything now but both can provide support in case something bad happens.

[astraelraen]

I understand a battery backup system is not the best value at this time. However, if the increased cost is "only" (I use that lightly ha ha) 10k or so, which based on equipment cost alone that is what I'm looking at - I am more than willing to consider it.

I was doing a little more research on the Outback Radian. It appears as if the panels are connected to the charge controller/battery and then the inverter does it's magic from there. If you do not have an appropriately sized battery bank (ie not large enough to absorb the energy generated at peak generation), wouldn't that mean some solar power is lost since the panels can't feed the grid directly?

I also did a little more research on the SolarEdge product and called a few vendors.... there are competing reports the product only works with "specified" battery backup solutions and will not work with all battery backup solutions. I don't know if this is true, but if so is probably a deal breaker for me.

Electricity is complicated.

[SunEagle]

I understand a battery backup system is not the best value at this time. However, if the increased cost is "only" (I use that lightly ha ha) 10k or so, which based on equipment cost alone that is what I'm looking at - I am more than willing to consider it.

I was doing a little more research on the Outback Radian. It appears as if the panels are connected to the charge controller/battery and then the inverter does it's magic from there. If you do not have an appropriately sized battery bank (ie not large enough to absorb the energy generated at peak generation), wouldn't that mean some solar power is lost since the panels can't feed the grid directly?

I also did a little more research on the SolarEdge product and called a few vendors.... there are competing reports the product only works with "specified" battery backup solutions and will not work with all battery backup solutions. I don't know if this is true, but if so is probably a deal breaker for me.

Electricity is complicated.

At this point Solaredge had plans to have their inverters work with Teslas' Powerwall battery system. While there may be a few of those being "tested" in the US and Australia they aren't being sold yet or even for the near future.

There are Hybrid systems available that use the Outback hardware and most use FLA type batteries. There are also other battery manufacturers that make Lithium type systems that will are similar to Tesla and will be competing with them but as of yet none of them are close to being economical to purchase as a energy storage system.

So the question is, do you install hardware now for a possible future battery that matches up to your solar inverter or wait to install a more cost effective solar / battery hybrid system or just install a solar pv grid tie system along with an emergency generator for electrical power backup. Your money, your choice.

[huge]

Get the solaredge and a generator now. Wait patiently until a better solution comes about for battery backup for the solaredge. Technology is advancing too fast right now for you to waste so much money on something you might use in a few years. Would you feel worse if you wasted so much money on something you used to literally save you a few dollars when the grid goes down? Or to deal with the fact that you lost a few cents of electricity generation from your panels when they're sitting there doing nothing?

Imagine how you would feel in 2 years when a better and cheaper solution is produced and you haven't even used your battery back up once

[AustinTreehouse]

Solaredge has their Storedge 7600 available that works with the Tesla Powerwall. If you already have a 7600 there will be a retrofit (not yet available) to turn it into Storedge 7600. Solaredge is hoping for it in Q4 2016 but they aren't holding their breath.

Good video showing the differences between the solaredge 7600 and storedge 7600

https://www.altestore.com/store/inverters/hybrid-inverters/solaredge-storedge-76kw-inverter-p40444/

[jflorey2]

I was doing a little more research on the Outback Radian. It appears as if the panels are connected to the charge controller/battery and then the inverter does it's magic from there. If you do not have an appropriately sized battery bank (ie not large enough to absorb the energy generated at peak generation), wouldn't that mean some solar power is lost since the panels can't feed the grid directly?

No. The panels feed the charge controller, the charge controller feeds the inverter and the inverter feeds the grid. During normal (grid tied) operation the battery is almost never used; it functions like a big capacitor and that's it. Only when the grid goes down do you draw from the battery.

If the grid is down and the batteries are full and your loads are not using all the solar power available - THEN you lose power.