enphase monitoring

[silverhorsefarm]

Mystery Solved

It was just a bad modem. The installer delivered a new envoy unit and it synched right up and has worked flawlessly since.

[The Original Mike]

Grit tie with Battery Backup

Legally, you cannot use home built (non-UL approved) panels in/on any insured structure. And, as strange as it sounds, you can't feed non-UL electricity from your own panels, into a micro-inverter, and then legally, feed it into the grid. But hey, I'm not a lawyer.
Grid Tied is about 95% of harvest, into usable power, add batteries and it drops to about 50%.

What a cool forum! I'm going to use this a lot. (especially when I have to sound like I know what I'm doing )

Not to quibble Mike, but I thought a good inverter/charger (like your 6048) is about 92% efficient, and if you have an MPPT solar controller built to handle a 48V battery setup (like an outback FlexMax 60), you lose about 8-12% more efficiency, so a good battery grid tie system, set up correctly with the proper wire gauges will end up being approximately 80-84% efficient, unless I'm missing something.

[trbizwiz]

What a cool forum! I'm going to use this a lot. (especially when I have to sound like I know what I'm doing )

Not to quibble Mike, but I thought a good inverter/charger (like your 6048) is about 92% efficient, and if you have an MPPT solar controller built to handle a 48V battery setup (like an outback FlexMax 60), you lose about 8-12% more efficiency, so a good battery grid tie system, set up correctly with the proper wire gauges will end up being approximately 80-84% efficient, unless I'm missing something.

yes 8 to 12% loss from mppt to batteries, then losses in the batteries, and losses converting back to 240 volts for home use, not to mention battery volume losses over time with each recharge.

You can probably get away with diy panels and micro inverters until your first house fire. But bet your sweet a$$ that your insurer will be licking his chops when he reads in the fire Marshall's report that you used home made solar panels, even if they did not cause the fire. Now that will be an expensive lesson. but what's 10 years of freedom and the cost of paying for your home that you no longer live in and the rent you pay your parents so your family has a place to stay while you are in jail. But hey you saved $50 per panel building them your self, sure they took 12 hours each to build, but time is cheaper than money.

[The Original Mike]

yes 8 to 12% loss from mppt to batteries, then losses in the batteries, and losses converting back to 240 volts for home use."

This is the only part of your post that isn't accurate, trbizwiz. As I understand it, Hybrid battery backup systems first fill the batteries, and then feed directly back to the grid, bypassing the batteries except for occasional "sips" to maintain full charge.

[trbizwiz]

This is the only part of your post that isn't accurate, trbizwiz. As I understand it, Hybrid battery backup systems first fill the batteries, and then feed directly back to the grid, bypassing the batteries except for occasional "sips" to maintain full charge.

I took the percentages from the prior post so I cant verify those. But the energy that goes into the batteries will be greater than the energy that comes out of the batteries, and the amount of energy that comes out of the batteries will only decrease over time. After the energy bypasses the batteries it will resume the higher rate of efficiency, probably some small losses for battery system monitoring. But the hybrid system will be less efficient than a straight grid tie system, and probably a little more efficient than a straight battery system, with a higher initial cost than either.
If you really want a hybrid system, buy a Prius, and buy the conversion kit to make it a plug in. Charge it off of solar, and use it to power your house during short outages. I think the 3rd gen Prius out now has a much larger battery pack, this is why it is bigger and heavier with a larger engine and gets better fuel mileage.
I actually have one, it's a great little car. But I haven't really considered converting it to plug in. But maybe it would work for you guys wanting a battery backup for your house. Either way you will be replacing batteries every so often, but at least this way you'll get 47 mpg in between. Surely that additional 17 mpg over a civic will offset some of the battery cost.
$750 rebate right now or 1.9% finance on 'em right now too. No fed rebates.

By the way we took a family vacation to Florida from Missouri, The round trip was under $160 in fuel. Not bad at $3 per gallon. The Mouse got the savings though, he cost $400 per day if you include food and crap.

[Mike90250]

A grid tie system, is about 95% efficient (after the harvest). You only have inverter losses, and the actual power the PV's put out, which is closer to the PTC rating (if given) or about 20% lower than the STC spec.

Add battery backup (for power fail only) and if set right, so batteries are only float maintained, and not cycled, you likely only loose a couple more %. That would be in wire losses, as battery systems are limited to about 150V, instead of 500V for pure grid tie, lower voltage = higher amps and higher losses.

If you go off grid, losses are roughly 50% of PV nameplate.
MPPT loss
wire loss
battery charge loss
battery leakage loss
battery usage loss (internal resistance)
Inverter losses
more wire loss - amps @ 48V

[pocowok]

Envoy monitoring

Just installed a 11.34 kw PV array with Enphase microinverters and promised monitoring. I plugged the modem (Envoy) in to my router and it found the internet almost immediately, but it cannot find the powerline telemetry from the inverters.

I am going to try a different Envoy unit later today, but was wondering if anyone knows about the transmission distance limitations of the Enphase/Envoy system. The PV array is about 75 meters away from the house and I was thinking that the inverter telemetry is attenuating over that distance such that the Envoy modem can no longer hear the signal.

Any thoughts?

Did you get your Envoy working? If not, try the followings:

1. Make sure the power lines from the micro-invertor to the service panel are away from any other electric power line and other wiring for potential line noise coupling.
2. Add torrid at the micro-invertors if necessary
3. Connect the cat5 cable directly from Envoy device to your access point or router.

Hope this help!

Jack

[russ]

Hi Pocowok - Welcome to Solar Panel Talk!

Russ

[sdold]

I recently had a "no signal" (Zero bars) from my inverters and thought I'd post the solution here since this thread was about that symptom.

I have a 20A double pole breaker in the main panel feeding a sub-panel about 5 feet away. In that sub panel, I have another 20A double pole breaker connected to the solar panels (10AWG in 80 feet of conduit).

I first tried my Envoy everywhere in the house, no signal. Frustrated, I installed a dedicated plug in the garage fed by a 15A single breaker in the sub-panel, to get it as close to the inverters as I could without actually putting it up at the array. Same thing, no communication, zero bars.

I'd read that interference on the power line could be a problem. In my junkbox, I found two ferrite toroids, about an inch deep by an inch diameter. I pulled the two hot wires from the 20A breaker in the main panel (the ones feeding the sub-panel). I put one toroid on each hot wire, wrapped around one turn, and connected them back to the breaker. I didn't do anything to the neutral. I instantly had all five bars and perfect communication. I'm not sure if something was loading down the communication signal, or if noise/RF of some kind was coming from the rest of the house, but isolating the Envoy from the rest of the house RF-wise solved the problem.

I'm not sure how I would have been able to use toroids if I hadn't had the sub-panel, because it allowed me to have the inverters AND the envoy on one side of the toroids, and the rest of the house on the other side. I guess you could put them on the house branch circuits, but it would take a lot of them unless you isolated the interference to one or two circuits. If the problem is interference from some device in the house (on a branch circuit), maybe you switch the circuits off one at a time to isolate the "noisy" one, and put toroids on just that one. But the sub panel made it easy in my case.

I almost didn't try the toroids, but I'm sure glad I did. I didn't expect the results to be so dramatic.

Steve