Future Solar Install (DIY Possible?)

[nwdiver]

You provide great information -- Thanks!

So other than the downsides of using parts from one company, the DC optimizers have the advantages of micro, and can still be used for a direct DC path in the future if that turns out to be useful. Right ?

No... the optimizers do provide ~350v DC to the string inverter but the string inverter has to 'activate' them... without the string inverter the optimizers don't work. They talk to each other... it's complicated and I don't fully understand how. This is one of the advantages touted by Solaredge and to be fair is also an advantage of micros. What's called 'safe shutdown'. Removing AC power de-energizes DC power. But this is really only a benefit if your house were to catch fire and firefighters were concerned about accessing your roof with an axe... during the day.

 

[Sharkbait]

Yes, it is possible to install solar PV yourself. I helped a friend put up 35 panels on his workshop. Some caveats: Go with micro-inverters.

At the beginning, I was leaning toward Enphase micro-inverters. In the end, I decided to go with SolarEdge optimizers, a single SolarEdge inverter and LG Mono X panels. It was a good decision. Comparatively, my system is one of the best performing ones in the high desert. I have no 'clipping' typical with overproducing panels and lower spec'd micro-inverters. You get it on some days. I will admit the panels are facing due south.

Not to say Enphase is a bad choice. Just saying to do your homework.

 

[strider]

More fuel for the micro vs string inverter...

What if a panel die 10-15 years down the line (heck at the rate things are changing, even 5)? Thinking hail damage or something (or even if the panel just dies under warranty); they probably won't be making the same panels then. Aren't there issues with subbing in a different panel in a string?

I want one of the SB inverters that has the SPS outlet so I can run my fridge and charge flashlight batteries if the power goes out but I was doing some reading and the above was mentioned as a pitfall (the person was pro micro inverter obviously).

 

[Sharkbait]

What if a panel die 10-15 years down the line (heck at the rate things are changing, even 5)? Thinking hail damage or something (or even if the panel just dies under warranty); they probably won't be making the same panels then. Aren't there issues with subbing in a different panel in a string?

If the panel dies under warranty, the company that installed it should replace it for free. If it dies outside warranty, you replace it. Sixty and seventy-two cell panels are very common. This has nothing to do with the micro-inverter or string inverter. If the micro-inverter fails, you replace it. If the string inverter fails, you replace it. Not a big deal.

 

[nwdiver]

If the panel dies under warranty, the company that installed it should replace it for free. If it dies outside warranty, you replace it. Sixty and seventy-two cell panels are very common. This has nothing to do with the micro-inverter or string inverter. If the micro-inverter fails, you replace it. If the string inverter fails, you replace it. Not a big deal.

Yep... panel specs are close enough these days that replacing it with a panel that's 'close enough' would work. You would probably install a 300w panel and only get 270w out of it but it would work just fine.

 

[strider]

If the panel dies under warranty, the company that installed it should replace it for free. If it dies outside warranty, you replace it. Sixty and seventy-two cell panels are very common. This has nothing to do with the micro-inverter or string inverter. If the micro-inverter fails, you replace it. If the string inverter fails, you replace it. Not a big deal.

Inverter failures sure, but I'm talking panels in 15-20 years. Will 60-cell panels still be around? Also, if one dies the company may not make those any more and will replace it with a "better" one that they are making then.

My question then is are we fairly comfortable that the parameters of the panels (voltage ranges, output ranges, physical size, etc) will hold constant for 20 years? That's a crazy long time in a field that's undergoing constant innovation like this. The challenge is that I may be looking at a 15-year payback (hopefully not with a DIY but where I'm moving power prices are crazy cheap) and if I have to make changes prior to or just after payback it destroys the economics.

I don't expect anyone to have a crystal ball, just more fodder for the discussion.

 

[Sharkbait]

My question then is are we fairly comfortable that the parameters of the panels (voltage ranges, output ranges, physical size, etc) will hold constant for 20 years?

The better solar panels are warranted to produce 90% of their original specs from years 1-10 and 80% for years 11-20. If I'm still living at 86, they will still be under warranty. After that, I'll probably not much care. I can still get parts for my 97 Camry; I suspect I'll still be able to replace 60-cell panels in 18 years. When you consider the size of these panels are meant to lay on the roof of a house (although mine are mounted on a ground-mount system), the form factor will probably not change but output power will continue to increase as new panels evolve.

 

[strider]

The better solar panels are warranted to produce 90% of their original specs from years 1-10 and 80% for years 11-20. If I'm still living at 86, they will still be under warranty. After that, I'll probably not much care. I can still get parts for my 97 Camry; I suspect I'll still be able to replace 60-cell panels in 18 years. When you consider the size of these panels are meant to lay on the roof of a house (although mine are mounted on a ground-mount system), the form factor will probably not change but output power will continue to increase as new panels evolve.

I agree with everything you said. My question was will you be able to just stick these newer panels in a string with older panels hooked up to a string inverter?

 

[nwdiver]

I agree with everything you said. My question was will you be able to just stick these newer panels in a string with older panels hooked up to a string inverter?

Yes.

 

[Sharkbait]

I agree with everything you said. My question was will you be able to just stick these newer panels in a string with older panels hooked up to a string inverter?

All things being equal - yes. However, I use both SolarEdge optimizers along with a SolarEdge string inverter. Like micro-inverters, optimizers should be scaled to the size of the panels to take advantage of the higher output offered by newer panels. So you need to be aware of what your micro-inverters or optimizers are best able to handle with consideration to panel power output. Consider reading a SolarEdge tutorial on the subject. I'm sure one exists.

 

[wcfinvader]

All things being equal - yes. However, I use both SolarEdge optimizers along with a SolarEdge string inverter. Like micro-inverters, optimizers should be scaled to the size of the panels to take advantage of the higher output offered by newer panels. So you need to be aware of what your micro-inverters or optimizers are best able to handle with consideration to panel power output. Consider reading a SolarEdge tutorial on the subject. I'm sure one exists.

I'm planning on using Micro-Inverters mainly because I want to stay away from High-Voltage DC where possible. I also was thinking about Micro-Inverters to get full power out of each panel. I've read a couple diy solar guides but as you may have noticed there aren't many. Whenever Tesla starts delivering their powerwalls is when we will know more about how soon we will get solar. Sure wish they could pump DC into our Tesla to negate the loss from converting to AC and back but oh well I kinda understand why they have it set up that way.

 

[SageBrush]

Sure wish they could pump DC into our Tesla to negate the loss from converting to AC and back but oh well I kinda understand why they have it set up that way

Then please explain -- I've wished for the same.

 

[wcfinvader]

Then please explain -- I've wished for the same.

This is me purely speculating here so take it with a grain of salt but I believe it's because there would need to be more hardware (maybe not much) and also (maybe more importantly) because the output is limited (3kwh?) there wouldn't be much significance to pump direct to DC and the vast majority of presumptive customers wouldn't have a need for DC power.

 

[Sharkbait]

"Each Powerwall has a 6.4 kWh energy storage capacity, sufficient to power most homes during the evening using electricity generated by solar panels during the day."

Source: Powerwall | The Tesla Home Battery

As I see it, the Powerwall is meant to supply your residential power needs after you stop collecting insolation or sunshine beating down on your panels. At only 6.4 kWh storage, it's not going to begin to recharge the batteries on your Tesla if they are depleted. The target for this product is really your residence. On a typical evening, until daylight the next morning, my residence consumes just about 6 kWh, which is perfect for a Powerwall installation.

At my average electric rates, and after all installation costs, it will take about 75 months to recoup the cost of the Powerwall. However, my installation might require additional solar panels, a larger string inverter and other costs to support my total daily residential needs AND charge the EV batteries.

One really needs to do the math before buying, especially if your solar system is tied to Time of Use (TOU) rather than Net Energy Metering (NEM). I'm on NEM, which means my cost for charging the EV is the same at night as it would be during the day. If you're on TOU, your electric rates are cheaper to buy at night, when one would most likely be charging his EV batteries.

 

[strider]

Yes.

Thank you!