I received my proposal summary today (central Florida)

[hodad66]

Small house (765 under air). $100 monthly FPL bill, tree shade in the morning, half
of the pitched roof faces south, low pitch 2/12.

6.62 KW & 1 PW (I asked for 2 PW's)
Solar Power System $17,530
Powerwall & taxes 6,700
PW Installation & hardware 2,750
Gateway 1,100
----------
$27,880

My local installer's price for 6.51kw is $12,360

Tesla's performance assumption is that I would still have a $30 bill to FPL monthly and
I'm guessing that is because of the PW.

I always stayed away from installing solar because I thought that it would never pay
for itself (in my lifetime). The backup possibilities were my main interest & still are.

Comments?

 

[boriszima]

Seems like a good price, $17,530/6.620=$2.65/watt which is Tesla's going rates. Powerwall is $10k after install, which i think reading forums here is the norm. In most location, you have to pay "connection" fee to your Electrical Utility, some small monthly fee as electricity is moving back and worth. If you have many outages powerwall is a good choice. Otherwise if you have some kind of NET metering and good power, might be an economical waste.

 

[hodad66]

Seems like a good price, $17,530/6.620=$2.65/watt which is Tesla's going rates. Powerwall is $10k after install, which i think reading forums here is the norm. In most location, you have to pay "connection" fee to your Electrical Utility, some small monthly fee as electricity is moving back and worth. If you have many outages powerwall is a good choice. Otherwise if you have some kind of NET metering and good power, might be an economical waste.

My wanting Powerwall (2) is as backup for after hurricane situations. The last two were
miserable & hot. The 5K difference will help pay for the 2nd pW.

 

[Dan123]

Will one Powerwall be sufficient to run your AC? Usually it is not, unless you have a small AC with less than 7KW startup load.

 

[TheTalkingMule]

Powerwalls(and most residential battery storage) is still wildly expensive, solar is absurdly cheap. If I were looking for post-hurricane backup I'd just get one Powerwall for now and not plan to run the A/C while the grid is down.

Soon enough you'll get the equivalent of 2 Powerwalls for $6k installed, but it's gonna be another 2-5 years so battery production can ramp in China.

Think about a post-hurricane week.....it's generally sunny since the massive low pressure system is usually followed by a block of high pressure. While everyone's scrambling around for resources, you can have all your lights and computers and TV and refrigerator and laundry functioning off a decent solar array and just one Powerwall. Simply don't run the central A/C and either clothesline your laundry or only run the dryer at mid-day when you know it's going to be sunny for the duration of an outage.

People shouldn't inconvenience themselves as a part of "going solar", if anything it should make you feel better about blasting the A/C. But I do think there's value in making some minor adjustments in advance of and during an extended blackout. For now.

 

[hodad66]

Powerwalls(and most residential battery storage) is still wildly expensive, solar is absurdly cheap. If I were looking for post-hurricane backup I'd just get one Powerwall for now and not plan to run the A/C while the grid is down.

Soon enough you'll get the equivalent of 2 Powerwalls for $6k installed, but it's gonna be another 2-5 years so battery production can ramp in China.

Think about a post-hurricane week.....it's generally sunny since the massive low pressure system is usually followed by a block of high pressure. While everyone's scrambling around for resources, you can have all your lights and computers and TV and refrigerator and laundry functioning off a decent solar array and just one Powerwall. Simply don't run the central A/C and either clothesline your laundry or only run the dryer at mid-day when you know it's going to be sunny for the duration of an outage.

People shouldn't inconvenience themselves as a part of "going solar", if anything it should make you feel better about blasting the A/C. But I do think there's value in making some minor adjustments in advance of and during an extended blackout. For now.

You are quite right about cost factor. As to AC, I have no idea but have heard about adding a "soft start" to assist with ramping up.
My AC is only 2 tons and I keep my house at 81. Even being able to run my ceiling fans, Fridg, etc. would be great.

 

[NinjaVece]

You are quite right about cost factor. As to AC, I have no idea but have heard about adding a "soft start" to assist with ramping up.
My AC is only 2 tons and I keep my house at 81. Even being able to run my ceiling fans, Fridg, etc. would be great.

I also only have one PW2 which runs a sub-panel if the grid power fails. Outside that sub-panel is my AC condenser (the HVAC fan unit is in the sub-panel however), my electric stove/oven and my Tesla wall charger (I have a Model 3). Since even a 2 ton condenser is going to bring your total house usage to over 5 kW, one PW2 is likely not going include it. Let me know if your installer says different.

But you certainly can handle everything else. Fans (even the HVAC fan), lights, appliances (including fridge and micro) and things like computers and TVs should all be fine under a sub-panel with a single PW2.

 

[hodad66]

Soon enough you'll get the equivalent of 2 Powerwalls for $6k installed, but it's gonna be another 2-5 years so battery production can ramp in China.

At 70 I,m not sure how long I can wait!

 

[TheTalkingMule]

You can always build your own if you like.

These Supercharged DIY Powerwalls Are Giving Tesla Some Serious Competition

 

[neroden]

Small house (765 under air). $100 monthly FPL bill, tree shade in the morning, half
of the pitched roof faces south, low pitch 2/12.

6.62 KW & 1 PW (I asked for 2 PW's)

Why are they proposing something other than what you asked for?

You wanted outage security for a hurricane and are willing to pay through the nose for it. Get them to offer you what you wanted!

 

[Shygar]

Are you sure your local installer isn't including the 30% federal tax credit in their quote? Their price is 30% cheaper according to your numbers.

 

[hodad66]

Are you sure your local installer isn't including the 30% federal tax credit in their quote? Their price is 30% cheaper according to your numbers.

No he subtracted the 30% further down. The comment from all other bidders is that he is
operating under cost & may be out of business soon. They mention that I will be left in the cold
with no warranty or service.

 

[hodad66]

Why are they proposing something other than what you asked for?

You wanted outage security for a hurricane and are willing to pay through the nose for it. Get them to offer you what you wanted!

I am in contact with the person that provided the proposal currently but it is goig slowly as I
prefer email over phone conversations due to my hearing loss.

 

[Dan123]

No he subtracted the 30% further down. The comment from all other bidders is that he is
operating under cost & may be out of business soon. They mention that I will be left in the cold
with no warranty or service.

$2 per watt is not an abnormally low price. Yes, it is low, but not too low. He probably is just installing cheaper and larger 72-cell panels, and using a cheaper SMA string inverter.

 

[hodad66]

 

[hodad66]

I'm beginning to think that Tesla's quote might be string system as they estimated that
the system would only provide 76% of my power needs. I don't see micro-inverters or
optimizesrs listed in the quote. My rep called last night & said that she would contact
me today........ 8:45 PM and no call yet........ I wanted to ask her this very question.

 

[boriszima]

No he subtracted the 30% further down. The comment from all other bidders is that he is
operating under cost & may be out of business soon. They mention that I will be left in the cold
with no warranty or service.

Just make sure warranty is good from the Installer and form the actual manufacturer. Yeah it will suck if Installer goes out of business but at least actual physical equipment will be warrantied by actual company. Likely it will cost to ship and you might be out of pocket to replace some, but actual hardware is warrantied.

I'm beginning to think that Tesla's quote might be string system as they estimated that
the system would only provide 76% of my power needs. I don't see micro-inverters or
optimizesrs listed in the quote. My rep called last night & said that she would contact
me today........ 8:45 PM and no call yet........ I wanted to ask her this very question.

I thought Tesla uses "string inverters" such as solarEdge and Delta. If you do not have any shade, then it likely wont make a difference. Plus if you are wanting Powerwall, its cheaper? to installer one big inventor and connected it to Powerwall rather than having many on your roof and need maybe needing another hardware to go from DC to AC.

 

[cwied]

I thought Tesla uses "string inverters" such as solarEdge and Delta. If you do not have any shade, then it likely wont make a difference. Plus if you are wanting Powerwall, its cheaper? to installer one big inventor and connected it to Powerwall rather than having many on your roof and need maybe needing another hardware to go from DC to AC.

A couple of corrections: SolarEdge inverters use power optimizers on each panel to avoid shading issues nearly as effectively as microinverters, so it's only the Delta inverters that might have a significant difference when shaded. Also, the Powerwall 2 (the current generation) is AC coupled, not DC coupled. It is not connected directly to the solar inverter. Each Powerwall unit has its own inverter built in.

 

[hodad66]

View attachment 405808

A couple of corrections: SolarEdge inverters use power optimizers on each panel to avoid shading issues nearly as effectively as microinverters, so it's only the Delta inverters that might have a significant difference when shaded. Also, the Powerwall 2 (the current generation) is AC coupled, not DC coupled. It is not connected directly to the solar inverter. Each Powerwall unit has its own inverter built in.

My quote includes Delta inverters which seems to indicate that it is a string install. For a tech
leading company it is interesting that a house with shade issues gets a proposal for string
installation.

Here is the bid for string install again by my local contractor.

 

[hodad66]

Here is Tesla's assumption as to my usage & production. The drop mid summer has to be due
to my neighbor's oak shading my roof in the morning. Then in winter two of my palms shade
due to the slant of the sun.