One item that is rarely talked about is the battery black start problem for micro inverter based systems. Because the panels are in effect producing AC power directly with micro inverters, the power is generally brought straight down to the main breaker panel and then on to the battery for charging. Now let’s suppose you’ve had a particularly bad power outage and for whatever reason (day 4 or not paying attention) you’ve allowed the battery to drain pretty much completely. If you’ve installed this system for your nontechnical mother in law, it’s going to happen pretty much every time the power is out for a day. Now it’s morning and time to recharge the battery with the panels. (The grid is still down, so no help there!) The sun comes up. You are producing a little power, maybe 1kW. The sun is low yet. This means the battery should try producing a AC signal for the panels to sync with so it can generate power to recharge the battery. The battery has to give in order to take. The problem here for the micro inverter system is if the two exchange energy through the main circuit panel, then the rest of the house gets a crack at the energy too. Recall the battery has been down potentially overnight. The freezers are warm. The house is cold. Every light switch in the house is still on. This cold house is primed to draw its maximum load for the month as everything comes on at once. However, we already stated that the battery is pretty much out of energy and the solar isn’t producing much, so what happens is the demand overwhelms the supply, the battery drains lower and is forced to give up. An hour goes by. It tries and fails again and has drained itself further. Now it is a race. Either the sun gets high enough in the sky to deliver its full 10 kW or whatever the size of your system is (fat chance in the winter!) and finally it overwhelms the load and manages to charge the battery and your system is saved to run again another day, or the battery becomes so depleted it can’t try again, and it will stay dark until the grid finally comes back on the following Tuesday. So much for battery backup keeping the lights on! Black start is not very reliable. If you have direct dc charging of the battery (powerwall 3 and not powerwall 2), this can’t happen because the energy goes to the battery system first then the inverter and then the house. The battery can totally decide to let the house stay dark a while longer until it feels it is charged enough to support that morning restart load and get everything running again. It doesn’t have this option if the solar and battery connect through the main panel. Does Tesla actually do this? I don’t own a powerwall 3, but they would be dumb not to, so I’m going to assume they do. If you are running on an older ac micro inverter system and do have the black start issue, you can rescue yourself turning nearly everything off in your breaker panel, wait until the sun is high and the battery mostly charged, then gradually turn the load back on, but this only works if you are home, you are willing to open your breaker and start flipping switches and you’ve taken the time to actually label what is what. So, it isn’t going to work for the rental property you bought, your house sitter or maybe your elderly parents. It also only works if you haven’t let the battery get so depleted the system has given up completely and it refuses to even try. So, now you will be closely monitoring your battery state of charge every time the power is out for more than a day to try to keep it to not drop below 10%. This may mean you shut everything down at 10 pm with state of charge 20% because you know that if you leave it on, y morning you’ll have burned it down to below 10%. Tropical fish? Pet lizard? Sorry guys. Your time is up. If the battery goes dark for days you are surely doomed. Maybe you will survive the night? Ours didn’t. The cats and people were fine though. It’s a lot of micromanagement, and might involve some difficult decisions. It isn’t quite what you signed up for when you thought you were getting battery backup for a power outage. With a DC coupled system, the fish can still die, but at least the battery is more likely to be up and doings its job at least some part of every day in a prolonged outage without a lot of intervention. You need more solar, not more battery if you want the fish to live.
Thank you for the side by side comparison of these two options. I am building a new home in a community with only 2 quality solar installers available. They unfortunately both strongly encourage using Enphase micro inverters, even though I am also wanting a backup battery installed. I have a hard time ignoring the efficiency loss of the DC-AC and AC-DC conversions, especially since it looks like the only roofs available for panels will be east and west facing. I think their resistance to using the DC optimizers is most likely related to brand loyalty, comfort with the Enphase products and services provided to them. I am trying to decide what I am going to do. I may choose to install my solar panels in a few years from now after I see how the new Tesla Power Wall battery plays in the market place. I also wouldn’t be surprised to see Enphase add solutions with DC optimizers in order to cater to customers with my preferences and to compete more effectively with Tesla.
I think Tesla powerwall 3 would have been the best choice for me. Unfortunately it wasn't available until about 3 months after I already installed my system. String inverters are the way to go and my gut tells me Tesla is going to be around for a while. Smart money with just spend a little extra and have a spare string inverter card sitting on a shelf. Way more efficient solution than having multiple microinverters creating multiple failure points under every damn panel.
I have both a string inverter on the SW roof and Enphase micro inverters on the NE roof. So far the Enphase micro inverters clearly beat the string inverter in low light conditions and when shade hits any of the panels. Also the string inverter is likely to need replacing after about 10 years while the Enphase micro inverters are likely to last their 25 year warranty. The string inverter is almost 5 years old now and I had a lot of problems with chimney shade. I chose the Enohase system to avoid any shade headaches and to save space in the home. With only 8 panels on the NE roof the cost difference is negligable and if your panels are not between SE and SW a lower peak output is not really an issue. For a lot of panels without any shade issues I would go with a hybrid inverter just to save money. But with trees, multiple roof orientations or dormer shade the Enphase system is truly great. In my case putting a battery somewhere is already a challenge, so I may go for an AC battery that gives me some freedom of placement. Just my two cents.
i was in a similar situation when we did our install this autumn. one contractor offering enphase, the other offering powerwall 3. i struggled for a month over the decision, flip flopping back and forth between the lower cost and more elegant design of the tesla system, but the robust redundancy and flexibility of the enphase system (being able to hook up to a gas generator was a nice option to have). in the end we decided on enphase. mostly because we live in a rural area, and the enphase installer was much closer to us for support. and if we do need support, we know that likely our whole system isn't going to be down, only a portion of it - which will keep us with power when we most need it. i also really like that enphase has a native web app, my eyes are really bad and reading my phone is hard lol! though i must say, thank goodness for these bad eyes because boy are all those enphase boxes on the outside of my garage a real eye sore... if i lived in the city, i think i probably would have just gone with a powerwall (well powerwall-esque type solution, honestly elon gives me the creeps...) i think the dc optimizers are performant enough to make them a viable option, but the fact that they still create a single point of failure at the inverter level was just more risk than we were comfortable with. hope you're able to figure out which system best meets your needs.
Well, there are three ways. Micro-inverters, DC Optimizers, or simple RSDs (solid state switches to meet firefighter safety codes). Well, four ways: Nothing at all has the least actual fire hazard and is now encompassed in NEC 690.12 and UL 3741. But city codes still typically require the RSDs... unfortunate since RSDs (or micro-inverters, or optimizers) have 3x the fire hazard as having nothing. I'm dealing with city permit requirements right now in fact. In anycase, the output of the entire string is not reduced by that much. Panels have had bypass diodes for over 20 years now. Mostly shading a single panel only cuts-out that panel, with a minor penalty for the other panels. 50%? No, that's not the case and never has been the case. Usually not much more than just the loss of the shaded panel. This is true with micro-inverters and optimizers as well. A shaded panel can only produce so much electricity. The only time micro-inverters and optmiizers make any sort of sense is when most of the array is going to have shading issues. THEN they make sense. But otherwise they're just an extra expense that installers like to have because it is easier for them to monitor the system. At the expense of the home-owner buying the system. Also, modern bifacial + half-cut panels handle shading a whole lot better, which makes it even less of an issue. I get nearly twice the output from a modern residential panel in partial shading than I do from a traditional mono / non-bifacial / full-cut panel in shading. Its like night and day. -Matt
I could not agree more. Most people intuitively understand that electronics typically age like milk not fine wine. Eventually they will fail. Both DC optimizers and microinverters literally add an additional failure point under each panel.
The triple conversion 'penalty' of an AC coupled system (micro inverters) vs a DC coupled system (string inverter) is about 5%. This is because the DC-DC conversion in a string system also has losses. To say that its 30% without further explanation makes me wonder if you are partial.. Also, with far more efficient GAN based electronics appearing in more modern inverters, the 'penalty' is about to be further reduced.
DC coupled ground mount systems require neither of the devices. Assuming everyone puts panels on the roof is a bad assumption. Removing snow from my panels is easy since they are ground mount.
I understand bifacial panels are more likely to be self clearing because the meager backside production will warm the panel and encourage the snow to slide off. I certainly know that with normal panels, if they are covered with snow, you are going to produce absolutely nothing.
I think micro inverters are probably going to lose favor given the more flexibility of keeping it DC. With more batteries and EVs with bidirectional chargers, there may much more efficiency to be had by going DC to DC for those components
Maybe some architecture like dual smaller parallel inverters able to handle 1/2 load each might provide more resiliency in case of an inverter failure. Maybe a little more expensive but you know you’ll at least maintain 50% power even when inverter down
I agree as well, for two reasons. First, because large integrated battery solutions like the Tesla PW3 have MPPTs built-in (six of them per unit, in fact), basically for free. And second because regulations are slowly moving away from requiring junk up on the roof which is what tripped-up string inverter companies like SMA in the first place. No micro-inverters, optimizers, or RSDs needed. aka UL 3741.
@@marcppparis Yes. Most regulatory bodies, including the NEC, have regulations that are more or less formed by the companies that make the equipment. If they can find a way to sell more gear, they will. It isn't through any nefarious reasons... its only because the code-making bodies and conferences just aren't that interesting for neutral third parties to attend. They get top-loaded with parties that have a financial interest in the regulation. In the case of RSDs, fire fighter unions formed a concern over dealing with live solar equipment and micro-inverter and optimizer companies pounced on that to more or less push-through mandatory per-panel devices, since they could optimize the equipment they were already selling to also perform the RSD function. Despite that, most regulations do make sense. Just that in the case of solar, they don't. Putting the equipment and extra connectors up on the roof vastly increases fire risk up on the roof. This got lost in the pile. The actual risk to fire-fighters is extremely low, and with like 10 minutes worth of training to either not muck around in the panel footprint or just clip the cables (zero current flow)... disappears entirely. It's a non-issue that has been blown all out of proportion. This mechanism is also why the GFCI regulations have gotten so messy in the U.S., by thet way... makers of circuit breakers saw an opportunity to sell more expensive gear and it got to the point where GFCI main breakers are being mandated even for dedicated circuits for devices like EVSEs that already have internal GFCI monitoring. -Matt
Haven’t solar panel bypass diodes. I think that’s what they’re called pretty much alleviated the need for module level devices ( at least where shading is concerned)
I haven't seen any significant benefit from bypass diodes on my string array of 400w residential panels. One panel gets shaded and I lose most of the power production.
They do and they do work. I have a string of 8 residential panels and 2 get shaded in the late afternoon. The string drops to roughly 7/8ths, and then 6/8ths of its production when that happens. Jasonoid, if you are losing the whole string then make sure that the string voltage is not dropping out of the MPPT range due to there being too few panels after discounting the shaded panel. If the Vmp of the shaded configurations drops too low, the string will stop producing because it will be running closer to the Voc. -Matt
Oooo Um 30% more efficient for a DC optimized system is absolutely False!! I would say 2 systems exactly the same one DC Optimized and One Enphase Micros, you may see 3 to 5% more Production with the Solar Edge DC Optimized System. If there are multiple pitches, azimuths, and shading in my experience the Enphase system will out preform the Solar Edge all day long!!
Seems like microinverters are old school technology. If we have a limited amount of roof space, we can’t afford the ten to thirty percent energy loss that comes with microinverters. And, the average homeowner will want at least 50 kWh of storage, both for topping the change off in our cars and keeping the lights on through long outages or dark winter days. So Enphase is a lose/lose with their microinverters and their tiny batteries.
Skipping all of them and operating at the lowest number of panels per string possible is always the most cost effective. I really wish they would bring back lower voltage mppts/inverters depending on your setup because it reduces complexity, yes extra wire is needed but frankly PV wire is stupidly cheap and less complicated. Microinverters are just a bad idea and always have really been for long term. Stepping voltage up or down generally is not that big of a deal its the conversion from AC to DC or DC to AC...not changing the voltage.
You can get those types of MPPTs. Look at Victron gear. My favorite is the 150/35 (150 Voc max, 35A output @ battery voltage). Its perfect for strings of 2 or 3 residential panels, or a greater number of smaller panels. That said, if you are only doing 3-panel strings you will wind up back-hauling a huge number of relatively thick solar PV cables. Just back-hauling 3 strings with 10 AWG solar cabling is 6 cables + ground and needs 1" conduit due to the thickness of the double-insulated solar cabling. -Matt
@@junkerzn7312 You can do a 3 if that works out for ideal shading. I ended up doing two because I have two arrays of 10 panels and my first MPPT is matched to output and my second is over paneled. It also worked out better for me for shading. Frankly the cost and complexity for me was minor vs the cost of a optimizer which adds a lot more cost. Even the 6awg wire I used was only about ~50 bucks for the two runs I have each again the cost of like a solar optimizer but PV wire is frankly dirt cheap the labor if you are already there is minor. Anywho I just think people are being over sold on extra stuff with a carefully designed system can save a lot of money and complexity.
@@darrenorange2982 The rule of thumb is that the string needs to produce sufficient voltage with 2 panels shaded and in bypass. Meaning the MPPT still needs to be able to operate well with 2 panels dropped from the string. Of course if you only have 3 panels in the string, you can drop the rule to just dropping 1 panel. Generally speaking, this is fairly easy for grid-tie string inverters where string voltages are in the 350VDC+ range when the string inverter only needs to produce a 120VAC waveform (for 240VAC split-phase or 120VAC output). The string needs to produce roughly 170VDC to remain optimal, so there is a lot of room for dropped panels. For Smaller battery MPPTs, the battery voltage is going to be (up to) 14.6V, 29.2V, or 58.4V depending on the battery topology, so the DC string with panels dropped must still be able to produce at least that much voltage plus around 5VDC. Vmp (operating, not open circuit). Call it 20VDC, 35VDC, or 65VDC depending on the battery bus voltage, to continue to operate optimally. Also fairly easy to achieve with a limited number of panels though you have be a bit more careful with 48V battery systems on a 150Voc MPPT where you can only afford to drop one residential panel due to shade in a 3-panel series. -Matt
@@darrenorange2982 Yup, I agree. I vastly prefer more cabling than more electronics. 6 AWG is a bit thick tho. 10 AWG ought to be plenty for single-string runs that aren't paralleled.
Microinverters also convert to AC at the panel, making the transmission of current over distances much more efficient. (Less loss, and much less cost of wiring). I'd also be a little concerned about the statement "up to 30%" loss on the triple conversion. Most conversions are easily under 5%, so at worst you are looking at more like 15%, and no matter what you will have to convert at least once, so now the difference is likely less than 10%. Both are good options, but if your run from PV to the inverter is more than 20'-25', please do your homework on the efficiency of the wiring needed to carry DC. (and remember the distance is not as the bird flies, its the length of the wire, so all the bends and curves add up quickly).
The shading issue has been largly solved for decades, there are tons of videos doing tests of panels... Even one where they used a cricket bat and smashed one of the panels... The rest of the string was largely unaffected. Panel level monitoring is neat, but optimizer or micro inverter systems are expensive and much more difficult to repair. Since the likely failure point ia the inverter over a panel it means a call out to your house and access to a roof which may need scaffolding... These seem like way more hassle than they are worth. Hoymiles, NEP, or AP systems seem to make more sense since they have the 4-1 micro inverters which brings the cost per panel way down. Just as an example, a single Enphase IQ8A for a 400W panel in Canda is around 330 bucks, the panel itself will be around 300 bucks. But if you do the 4-1 unit that is sized for the same panel it will cost around 450 bucks or about 112.50 per panel, reducing the overall cost which makes the payoff period of the system more resonable. Enphase in my area just makes the whole system not viable.
My system uses Enphase microinverters but I will never use or recommend them again. The insanity of these people to adopt the latest cliche thing being talked about is too much. Enphase, without warning customers, pushed an update to require a "key" to use their systems. It broke many, perhaps all, installations that rely on external controls, mine included. We now have a hard dependency on renewing this key from Enphase. This is entirely unnecessary as my system, and I suspect the majority of others, are secured. And even if they aren't, it's not up to Enphase to dictate how I run my system. Many installers and developers of Enphase systems complained but the company refused to revert their boneheaded decision.
With the battery it will be fast 5hrs, DC electricity into the battery and slow 24hr AC draw out of your battery. Smaller cheaper inverter. 😊😊😊😊 If charging the EV battery DC is faster and simpler. If EV v2g into the home battery DC is faster and simpler.
How do you get up to 30% better round-trip efficiency with solar edge than Enphase? Let’s do the math: Enphase efficiency = 97% for IQ7A CEC Weighted Efficiency X 90% for Tesla Power Wall 2 round trip efficiency = 87.3 % efficiency. Solar Edge Efficiency = 99% CEC Weighted Efficiency for solar edge inverter SE7600H-US X 94.5% Peak Roundtrip Efficiency for solar Edge Energy Bank BAT-10K1P X 98.8% Weighted Efficiency for P505 solar edge optimizer= 92.4% efficiency. Where are my math wrong?
One item that is rarely talked about is the battery black start problem for micro inverter based systems. Because the panels are in effect producing AC power directly with micro inverters, the power is generally brought straight down to the main breaker panel and then on to the battery for charging. Now let’s suppose you’ve had a particularly bad power outage and for whatever reason (day 4 or not paying attention) you’ve allowed the battery to drain pretty much completely. If you’ve installed this system for your nontechnical mother in law, it’s going to happen pretty much every time the power is out for a day. Now it’s morning and time to recharge the battery with the panels. (The grid is still down, so no help there!) The sun comes up. You are producing a little power, maybe 1kW. The sun is low yet. This means the battery should try producing a AC signal for the panels to sync with so it can generate power to recharge the battery. The battery has to give in order to take. The problem here for the micro inverter system is if the two exchange energy through the main circuit panel, then the rest of the house gets a crack at the energy too. Recall the battery has been down potentially overnight. The freezers are warm. The house is cold. Every light switch in the house is still on. This cold house is primed to draw its maximum load for the month as everything comes on at once. However, we already stated that the battery is pretty much out of energy and the solar isn’t producing much, so what happens is the demand overwhelms the supply, the battery drains lower and is forced to give up. An hour goes by. It tries and fails again and has drained itself further. Now it is a race. Either the sun gets high enough in the sky to deliver its full 10 kW or whatever the size of your system is (fat chance in the winter!) and finally it overwhelms the load and manages to charge the battery and your system is saved to run again another day, or the battery becomes so depleted it can’t try again, and it will stay dark until the grid finally comes back on the following Tuesday. So much for battery backup keeping the lights on! Black start is not very reliable.
If you have direct dc charging of the battery (powerwall 3 and not powerwall 2), this can’t happen because the energy goes to the battery system first then the inverter and then the house. The battery can totally decide to let the house stay dark a while longer until it feels it is charged enough to support that morning restart load and get everything running again. It doesn’t have this option if the solar and battery connect through the main panel. Does Tesla actually do this? I don’t own a powerwall 3, but they would be dumb not to, so I’m going to assume they do.
If you are running on an older ac micro inverter system and do have the black start issue, you can rescue yourself turning nearly everything off in your breaker panel, wait until the sun is high and the battery mostly charged, then gradually turn the load back on, but this only works if you are home, you are willing to open your breaker and start flipping switches and you’ve taken the time to actually label what is what. So, it isn’t going to work for the rental property you bought, your house sitter or maybe your elderly parents. It also only works if you haven’t let the battery get so depleted the system has given up completely and it refuses to even try. So, now you will be closely monitoring your battery state of charge every time the power is out for more than a day to try to keep it to not drop below 10%. This may mean you shut everything down at 10 pm with state of charge 20% because you know that if you leave it on, y morning you’ll have burned it down to below 10%. Tropical fish? Pet lizard? Sorry guys. Your time is up. If the battery goes dark for days you are surely doomed. Maybe you will survive the night? Ours didn’t. The cats and people were fine though. It’s a lot of micromanagement, and might involve some difficult decisions. It isn’t quite what you signed up for when you thought you were getting battery backup for a power outage.
With a DC coupled system, the fish can still die, but at least the battery is more likely to be up and doings its job at least some part of every day in a prolonged outage without a lot of intervention. You need more solar, not more battery if you want the fish to live.
I vote for Enphase between these two as it will not go bankrupt as Solaredge.
I hope not ENPH stock has tank many problems.
Thank you for the side by side comparison of these two options. I am building a new home in a community with only 2 quality solar installers available. They unfortunately both strongly encourage using Enphase micro inverters, even though I am also wanting a backup battery installed. I have a hard time ignoring the efficiency loss of the DC-AC and AC-DC conversions, especially since it looks like the only roofs available for panels will be east and west facing. I think their resistance to using the DC optimizers is most likely related to brand loyalty, comfort with the Enphase products and services provided to them. I am trying to decide what I am going to do. I may choose to install my solar panels in a few years from now after I see how the new Tesla Power Wall battery plays in the market place. I also wouldn’t be surprised to see Enphase add solutions with DC optimizers in order to cater to customers with my preferences and to compete more effectively with Tesla.
I think Tesla powerwall 3 would have been the best choice for me. Unfortunately it wasn't available until about 3 months after I already installed my system. String inverters are the way to go and my gut tells me Tesla is going to be around for a while. Smart money with just spend a little extra and have a spare string inverter card sitting on a shelf. Way more efficient solution than having multiple microinverters creating multiple failure points under every damn panel.
I have both a string inverter on the SW roof and Enphase micro inverters on the NE roof.
So far the Enphase micro inverters clearly beat the string inverter in low light conditions and when shade hits any of the panels.
Also the string inverter is likely to need replacing after about 10 years while the Enphase micro inverters are likely to last their 25 year warranty.
The string inverter is almost 5 years old now and I had a lot of problems with chimney shade.
I chose the Enohase system to avoid any shade headaches and to save space in the home. With only 8 panels on the NE roof the cost difference is negligable and if your panels are not between SE and SW a lower peak output is not really an issue.
For a lot of panels without any shade issues I would go with a hybrid inverter just to save money. But with trees, multiple roof orientations or dormer shade the Enphase system is truly great. In my case putting a battery somewhere is already a challenge, so I may go for an AC battery that gives me some freedom of placement.
Just my two cents.
i was in a similar situation when we did our install this autumn. one contractor offering enphase, the other offering powerwall 3. i struggled for a month over the decision, flip flopping back and forth between the lower cost and more elegant design of the tesla system, but the robust redundancy and flexibility of the enphase system (being able to hook up to a gas generator was a nice option to have).
in the end we decided on enphase. mostly because we live in a rural area, and the enphase installer was much closer to us for support. and if we do need support, we know that likely our whole system isn't going to be down, only a portion of it - which will keep us with power when we most need it. i also really like that enphase has a native web app, my eyes are really bad and reading my phone is hard lol! though i must say, thank goodness for these bad eyes because boy are all those enphase boxes on the outside of my garage a real eye sore...
if i lived in the city, i think i probably would have just gone with a powerwall (well powerwall-esque type solution, honestly elon gives me the creeps...) i think the dc optimizers are performant enough to make them a viable option, but the fact that they still create a single point of failure at the inverter level was just more risk than we were comfortable with.
hope you're able to figure out which system best meets your needs.
Well, there are three ways. Micro-inverters, DC Optimizers, or simple RSDs (solid state switches to meet firefighter safety codes). Well, four ways: Nothing at all has the least actual fire hazard and is now encompassed in NEC 690.12 and UL 3741. But city codes still typically require the RSDs... unfortunate since RSDs (or micro-inverters, or optimizers) have 3x the fire hazard as having nothing.
I'm dealing with city permit requirements right now in fact.
In anycase, the output of the entire string is not reduced by that much. Panels have had bypass diodes for over 20 years now. Mostly shading a single panel only cuts-out that panel, with a minor penalty for the other panels. 50%? No, that's not the case and never has been the case. Usually not much more than just the loss of the shaded panel.
This is true with micro-inverters and optimizers as well. A shaded panel can only produce so much electricity. The only time micro-inverters and optmiizers make any sort of sense is when most of the array is going to have shading issues. THEN they make sense. But otherwise they're just an extra expense that installers like to have because it is easier for them to monitor the system. At the expense of the home-owner buying the system.
Also, modern bifacial + half-cut panels handle shading a whole lot better, which makes it even less of an issue. I get nearly twice the output from a modern residential panel in partial shading than I do from a traditional mono / non-bifacial / full-cut panel in shading. Its like night and day.
-Matt
I could not agree more. Most people intuitively understand that electronics typically age like milk not fine wine. Eventually they will fail. Both DC optimizers and microinverters literally add an additional failure point under each panel.
What half-cut panels panels are you using?
@@robert5 The particular ones I just got are the Hyundai 410W's. HiS-S410YH(BK). But there are many choices.
-Matt
The triple conversion 'penalty' of an AC coupled system (micro inverters) vs a DC coupled system (string inverter) is about 5%. This is because the DC-DC conversion in a string system also has losses.
To say that its 30% without further explanation makes me wonder if you are partial..
Also, with far more efficient GAN based electronics appearing in more modern inverters, the 'penalty' is about to be further reduced.
What is GAN?
No it's just common sense. Do the math.
I have Solar Edge system. The inverter was replaced after 4 years. But optimizers have not. So far so good. ☀️☀️☀️☀️☀️
Cheaper to have neather if you don't have shade
... even if there's some shade. Bypass diodes are in every solar panel for a reason.
DC coupled ground mount systems require neither of the devices. Assuming everyone puts panels on the roof is a bad assumption. Removing snow from my panels is easy since they are ground mount.
I understand bifacial panels are more likely to be self clearing because the meager backside production will warm the panel and encourage the snow to slide off. I certainly know that with normal panels, if they are covered with snow, you are going to produce absolutely nothing.
I think micro inverters are probably going to lose favor given the more flexibility of keeping it DC. With more batteries and EVs with bidirectional chargers, there may much more efficiency to be had by going DC to DC for those components
Good observation. If the DC-coupled offerings can match Enphase's reliability and after-install support then I think you are correct.
Maybe some architecture like dual smaller parallel inverters able to handle 1/2 load each might provide more resiliency in case of an inverter failure. Maybe a little more expensive but you know you’ll at least maintain 50% power even when inverter down
I agree as well, for two reasons. First, because large integrated battery solutions like the Tesla PW3 have MPPTs built-in (six of them per unit, in fact), basically for free. And second because regulations are slowly moving away from requiring junk up on the roof which is what tripped-up string inverter companies like SMA in the first place. No micro-inverters, optimizers, or RSDs needed. aka UL 3741.
@@junkerzn7312 I’m sure microinverter companies lobbied for current regulations
@@marcppparis Yes. Most regulatory bodies, including the NEC, have regulations that are more or less formed by the companies that make the equipment. If they can find a way to sell more gear, they will. It isn't through any nefarious reasons... its only because the code-making bodies and conferences just aren't that interesting for neutral third parties to attend. They get top-loaded with parties that have a financial interest in the regulation.
In the case of RSDs, fire fighter unions formed a concern over dealing with live solar equipment and micro-inverter and optimizer companies pounced on that to more or less push-through mandatory per-panel devices, since they could optimize the equipment they were already selling to also perform the RSD function.
Despite that, most regulations do make sense. Just that in the case of solar, they don't. Putting the equipment and extra connectors up on the roof vastly increases fire risk up on the roof. This got lost in the pile.
The actual risk to fire-fighters is extremely low, and with like 10 minutes worth of training to either not muck around in the panel footprint or just clip the cables (zero current flow)... disappears entirely. It's a non-issue that has been blown all out of proportion.
This mechanism is also why the GFCI regulations have gotten so messy in the U.S., by thet way... makers of circuit breakers saw an opportunity to sell more expensive gear and it got to the point where GFCI main breakers are being mandated even for dedicated circuits for devices like EVSEs that already have internal GFCI monitoring.
-Matt
Haven’t solar panel bypass diodes. I think that’s what they’re called pretty much alleviated the need for module level devices ( at least where shading is concerned)
I haven't seen any significant benefit from bypass diodes on my string array of 400w residential panels. One panel gets shaded and I lose most of the power production.
They do and they do work. I have a string of 8 residential panels and 2 get shaded in the late afternoon. The string drops to roughly 7/8ths, and then 6/8ths of its production when that happens.
Jasonoid, if you are losing the whole string then make sure that the string voltage is not dropping out of the MPPT range due to there being too few panels after discounting the shaded panel. If the Vmp of the shaded configurations drops too low, the string will stop producing because it will be running closer to the Voc.
-Matt
Oooo Um 30% more efficient for a DC optimized system is absolutely False!!
I would say 2 systems exactly the same one DC Optimized and One Enphase Micros, you may see 3 to 5% more Production with the Solar Edge DC Optimized System.
If there are multiple pitches, azimuths, and shading in my experience the Enphase system will out preform the Solar Edge all day long!!
Can solar surge Ai work outside US. (Nigeria)?
I’m afraid not yet but perhaps in the future. Right now we are limited to major US urban areas.
Seems like microinverters are old school technology. If we have a limited amount of roof space, we can’t afford the ten to thirty percent energy loss that comes with microinverters. And, the average homeowner will want at least 50 kWh of storage, both for topping the change off in our cars and keeping the lights on through long outages or dark winter days. So Enphase is a lose/lose with their microinverters and their tiny batteries.
Skipping all of them and operating at the lowest number of panels per string possible is always the most cost effective. I really wish they would bring back lower voltage mppts/inverters depending on your setup because it reduces complexity, yes extra wire is needed but frankly PV wire is stupidly cheap and less complicated. Microinverters are just a bad idea and always have really been for long term. Stepping voltage up or down generally is not that big of a deal its the conversion from AC to DC or DC to AC...not changing the voltage.
You can get those types of MPPTs. Look at Victron gear. My favorite is the 150/35 (150 Voc max, 35A output @ battery voltage). Its perfect for strings of 2 or 3 residential panels, or a greater number of smaller panels.
That said, if you are only doing 3-panel strings you will wind up back-hauling a huge number of relatively thick solar PV cables. Just back-hauling 3 strings with 10 AWG solar cabling is 6 cables + ground and needs 1" conduit due to the thickness of the double-insulated solar cabling.
-Matt
@@junkerzn7312 You can do a 3 if that works out for ideal shading. I ended up doing two because I have two arrays of 10 panels and my first MPPT is matched to output and my second is over paneled. It also worked out better for me for shading. Frankly the cost and complexity for me was minor vs the cost of a optimizer which adds a lot more cost. Even the 6awg wire I used was only about ~50 bucks for the two runs I have each again the cost of like a solar optimizer but PV wire is frankly dirt cheap the labor if you are already there is minor. Anywho I just think people are being over sold on extra stuff with a carefully designed system can save a lot of money and complexity.
@@darrenorange2982 The rule of thumb is that the string needs to produce sufficient voltage with 2 panels shaded and in bypass. Meaning the MPPT still needs to be able to operate well with 2 panels dropped from the string. Of course if you only have 3 panels in the string, you can drop the rule to just dropping 1 panel.
Generally speaking, this is fairly easy for grid-tie string inverters where string voltages are in the 350VDC+ range when the string inverter only needs to produce a 120VAC waveform (for 240VAC split-phase or 120VAC output). The string needs to produce roughly 170VDC to remain optimal, so there is a lot of room for dropped panels.
For Smaller battery MPPTs, the battery voltage is going to be (up to) 14.6V, 29.2V, or 58.4V depending on the battery topology, so the DC string with panels dropped must still be able to produce at least that much voltage plus around 5VDC. Vmp (operating, not open circuit).
Call it 20VDC, 35VDC, or 65VDC depending on the battery bus voltage, to continue to operate optimally. Also fairly easy to achieve with a limited number of panels though you have be a bit more careful with 48V battery systems on a 150Voc MPPT where you can only afford to drop one residential panel due to shade in a 3-panel series.
-Matt
@@darrenorange2982 Yup, I agree. I vastly prefer more cabling than more electronics. 6 AWG is a bit thick tho. 10 AWG ought to be plenty for single-string runs that aren't paralleled.
Microinverters also convert to AC at the panel, making the transmission of current over distances much more efficient. (Less loss, and much less cost of wiring). I'd also be a little concerned about the statement "up to 30%" loss on the triple conversion. Most conversions are easily under 5%, so at worst you are looking at more like 15%, and no matter what you will have to convert at least once, so now the difference is likely less than 10%. Both are good options, but if your run from PV to the inverter is more than 20'-25', please do your homework on the efficiency of the wiring needed to carry DC. (and remember the distance is not as the bird flies, its the length of the wire, so all the bends and curves add up quickly).
Microinverters convert DC to AC at the panel. MICROINVERTERS ARE LITERALLY CONVERTING DC TO AC AT THE OUTPUT OF THE MICRO INVERTER.
It is now clear to me. You are a salesman.😅
Why? I didn't see any bias
Also, "Salesman" usually don't make any more $$$ regardless of which one you chose.
The shading issue has been largly solved for decades, there are tons of videos doing tests of panels... Even one where they used a cricket bat and smashed one of the panels... The rest of the string was largely unaffected.
Panel level monitoring is neat, but optimizer or micro inverter systems are expensive and much more difficult to repair. Since the likely failure point ia the inverter over a panel it means a call out to your house and access to a roof which may need scaffolding... These seem like way more hassle than they are worth.
Hoymiles, NEP, or AP systems seem to make more sense since they have the 4-1 micro inverters which brings the cost per panel way down.
Just as an example, a single Enphase IQ8A for a 400W panel in Canda is around 330 bucks, the panel itself will be around 300 bucks. But if you do the 4-1 unit that is sized for the same panel it will cost around 450 bucks or about 112.50 per panel, reducing the overall cost which makes the payoff period of the system more resonable.
Enphase in my area just makes the whole system not viable.
Can I use the solaredge DC converters with EG4 12KPV?
Solaredge announced last week it’s getting out of battery game. Just giving you a heads up.
*Sigh* why do you keep repeating this shading lie? What do you think bypass diodes do?
Efficiently does not matter to me.
I want to know $/kWh over life.
In this case, Solar Edge definitely wins as long as the equipment stays functional.
My system uses Enphase microinverters but I will never use or recommend them again. The insanity of these people to adopt the latest cliche thing being talked about is too much.
Enphase, without warning customers, pushed an update to require a "key" to use their systems. It broke many, perhaps all, installations that rely on external controls, mine included. We now have a hard dependency on renewing this key from Enphase. This is entirely unnecessary as my system, and I suspect the majority of others, are secured. And even if they aren't, it's not up to Enphase to dictate how I run my system. Many installers and developers of Enphase systems complained but the company refused to revert their boneheaded decision.
With the battery it will be fast 5hrs, DC electricity into the battery and slow 24hr AC draw out of your battery.
Smaller cheaper inverter. 😊😊😊😊
If charging the EV battery DC is faster and simpler.
If EV v2g into the home battery DC is faster and simpler.
How do you get up to 30% better round-trip efficiency with solar edge than Enphase? Let’s do the math:
Enphase efficiency = 97% for IQ7A CEC Weighted Efficiency X 90% for Tesla Power Wall 2 round trip efficiency = 87.3 % efficiency.
Solar Edge Efficiency = 99% CEC Weighted Efficiency for solar edge inverter SE7600H-US X 94.5% Peak Roundtrip Efficiency for solar Edge Energy Bank BAT-10K1P X 98.8% Weighted Efficiency for P505 solar edge optimizer= 92.4% efficiency.
Where are my math wrong?
You are right, He added, nor multiplied.
You math is correct!
30% is a bold claim and false in my opinion. In my experience it is closer to 3 to 5%