Solar power for the home (1 Viewer)

[DaveF]

I was talking with a colleague recently who's thinking about retirement relocation in the coming years. I told them they should take a look at Idaho if they haven't.

 

[DaveF]

I've received the detailed drawings for the solar panel installation. I put together the HOA application for the exterior modification, and got the necessary neighbors' signatures. We'll be submitting for HOA approval in a week. Installation will start mid January.

I have a south-facing roof with no obstructions (vent pipes) in the installation area, which allows for full coverage:


I'm using Hanwha Q CELLS, Q.PEAK DUO BLK-G5 315, 315 Watt Solar Panels. The Panasonic cells that Telsa produces are a bit better, but I had some difficulties with my Tesla sales manager, and didn't want to lose another month or two sorting that out. I'm getting 100% production (predicted) with these cells on my roof, so it should be fine.

This installation is using micro inverters at the solar panels, with Enphase IQ7-60-2-US MICRO INVERTERS. These invert from DC to AC at the panel and send the AC down to the utility meter. Again for comparison, Tesla uses a conventional inverter, sending DC from all the panels to the inverter at the utility meter, where it's converted from DC to AC. There are pros and cons to both. Microinverters are best suited for shaded areas where the panels have different coverage, and have differing production from each other. In that scenario, the conventional inverter limits the total product to be that of the lowest producing panel. In my case, with no shading, I'd have been just as well off with a conventional inverter. But, there's no real downside that I could find with the micro-inverters, and it's what my installer uses. So, that's fine.

The conventional inverter may become the approach of the future, where people want to store power in a battery bank or charge their electric car directly from solar output, avoiding round-trip inverter losses. But for now, for me, for the foreseeable future, those applications aren't available and aren't affordable. So micro-inverters are good for me.

 

[Sam Posten]

@DaveF Battery?

 

[TonyD]

The system we are looking at has a battery that collects too I think.
My wife is doing it all I’ll have to ask her when she gets back from a cruise this week.

 

[DaveF]

Good question. For me, no battery. No point. You get a battery if you’d otherwise have a backup generator, because you’re at risk of extended power outages. I’m not. Buried lines, and all that.

From a home solar sense, the price of a battery backup only worsens the payback. In Virginia, solar panel ROI isn’t great, about 12 years. Battery backup would make it a non-starter.

YMMV based on local incentives, pricing, and utility buy back regulations.

 

[Sam Posten]

@DaveF the point of the battery is not just downed lines but systemic regional outages too. I've lived through a few of those and have plannd for solar with battery to survive the next one. But I get that not everyone is as paranoid about it as me.

 

[John Dirk]

Very interesting thread. I've always been afraid of solar because it's installed on a roof that will eventually need replacing. We just had ours replaced and, if we had solar panels, they would have had to be temporarily removed. Are today's systems designed to reasonably account for this?

I haven't done the economics yet because my wife pays the bills and like @TonyD , she's away on a cruise at the moment.

 

[Sam Posten]

@John Dirk Tesla Sokar Roof dude!

 

[DaveF]

@DaveF the point of the battery is not just downed lines but systemic regional outages too. I've lived through a few of those and have plannd for solar with battery to survive the next one. But I get that not everyone is as paranoid about it as me.

Yep. As I said, if you’d otherwise have a backup generator, then you’d likely want a battery backup (if you can afford it).

But if you don’t have a generator (I don’t), then you’re not spending the $10,000 for a Powerwall and making your Solar take 20 years to pay for itself.

 

[DaveF]

Very interesting thread. I've always been afraid of solar because it's installed on a roof that will eventually need replacing. We just had ours replaced and, if we had solar panels, they would have had to be temporarily removed. Are today's systems designed to reasonably account for this?

I haven't done the economics yet because my wife pays the bills and like @TonyD , she's away on a cruise at the moment.

Install solar when roof is new. In 20-some years when you need a new roof, replace everything.

This is the perfect time for you since you just replaced the roof. Well, better would have been before so you could have had a solar installer certify the roof needed replacing for the solar, and the 30% tax credit would have applied to the roof replacement too!

 

[ManW_TheUncool]

Hmmm... thanks for pointing that out about roof replacement, Dave.

Definitely something to consider as our roof may need work before too long. We've had a local installer swing thru our neighborhood for business here in Brooklyn the past month or so, but we aren't really ready for such a project yet -- we're not even that sure if we'll stay beyond the next couple years at this point...

_Man_

 

[DaveF]

Take a look at the tax credit schedule. I believe they’re reducing or expiring in 2020.

 

[John Sparks]

We were thinking of installing (leasing, we're 65+), so buying was out of the question. When you look at all the variables, i.e. selling; 20/25 year lease. If phones are constantly being updating, but you have panels that are going to be 25 years old when you finally own them...why buy/lease something that is going to be obsolete in such a short time. Hence, we didn't have them installed.

 

[DaveF]

We were thinking of installing (leasing, we're 65+), so buying was out of the question. When you look at all the variables, i.e. selling; 20/25 year lease. If phones are constantly being updating, but you have panels that are going to be 25 years old when you finally own them...why buy/lease something that is going to be obsolete in such a short time. Hence, we didn't have them installed.

They’ll be about 10 years old when I own them. Solar panels aren’t computers with new versions coming out every year, making obsolete models from a couple years prior. They’re an investment — not the best ROI depending on one’s situation — but an actual investment, versus a depreciating purchase of a smartphone.

 

[DaveF]

Now Witness the Firepower of this fully Armed and Operational Battle Station!

 

[DaveF]

The utility company came out Wednesday to install the new metering box, and the solar was turned on Thursday. Naturally, it's been overcast and raining since.

 

[DaveF]

On a sunny day, I actually produce electricity!

 

[DaveF]

Another update for those interested in solar, here's three months of production / consumption data and utility bills. My local rates about about $0.12/ kWh.

 

[LeoA]

Are there solar panels yet that also double as roofing material? Seems like an obvious opportunity to me instead of the way it is today where the solar panels have to be installed over something like an existing metal roof.

Sort of like Formula One and IndyCars back 40 years ago when it dawned on some bright engineer that the engine block didn't have to just be bolted onto structural members of the chassis, but could also double as a structural component itself for weight savings (I believe Lotus with their legendary Lotus 49b in the 1967 F1 season started it).

Seems rather wasteful and unnecessarily expensive how solar panels have been handled so far. But then again I'm no engineer.

 

[DaveF]

Only the Solar City riles, which are too expensive to make economic sense for most.

I don’t think it’s due to lack of imagination but because it’s a difficult problem to make solar cells serve as roofing material, and do so affordably.