SolarCity PPA or DIY and a few questions...

nadeaup

I am trying to make my final decision a 9.6kw system from Solar City for around $17k pre-paid. -- I won't own anything and if I generate more power than I use, solarcity get's it, not me. I do not even get the Fed tax Rebate credit of 30%
OR
Install the system myself (a 10.56k system) for around $20k-22k -- I will OWN it all and it will be $14k when done (federal Tax Credit). I will also get the money for any excess power I generate ( although it won't be much and only in the winter)
enphase m215
Astroenergy 240 watt panels (44)
I'll build my own fixed rack probably use unirac rails...
240 Volts, 44A mps, 200' run to the house (*4 conductors) - Copper(is so expensive!) or Aluminum (Copper 4 awg, Aluminum 2 awg) <-- does this seem right?

As you can see below..
Attachment not found.

Any opinions?

BB.

Re: SolarCity PPA or DIY and a few questions...

Personally--I like to own what I "buy". But--The current leasing costs seem to favor leasing (low costs, low buyout at the end, vendor takes care of maintenance, etc.) because the vendor can take advantages of federal and state credits and other business/leasing deductions that home owners typically cannot.

Some leases appear to have yearly increases in costs--Which may or may not be true 10 years out. Make sure you understand the assumptions and what happens in the out years/residual costs (some leases have a fixed price, others just say market value). One poster was kind enough to upload his lease:

BB. wrote: »

One of our members has posted a sample SolarCity lease here:

Residential Leasing -- Post 114+

Thank you "Jburgess".

-Bill

I suggest that buying a GT solar system is not really an investment. It is unclear how much of return on your money you would get from a sale of the home--Or even if it may depress the price of a home (some buyers will not like solar panels on the home).

So--towards that end--I suggest "extreme conservation" first--Insulation, energy start appliances, new heat pump/Air Conditioning system, heat pump water heater (if electric), double pane windows, more insulation around ducting, etc.... Generally will add to the value of your home and make it more comfortable/quieter.

Have you read about GT installs here--Such as this one:

Illustration of 8 KW (DC) GT Solar PV System Install for Residence in Urban Area

Have you reviews the billing plan from your utility? There are many net metering/billing/payment methods--Some are very favorable to customers, others are not. A few (such as California) can actually cost you more money than not having solar at all (undersized system, Time of Use Billing, if we have high costs in summer afternoons such as A/C, the Time of Use costs can raise the monthly power bill.

-Bill

nadeaup

Re: SolarCity PPA or DIY and a few questions...

Any thoughts on Aluminum v.s. Copper - If sized properly there should be no difference. My only concern I think, will be the connections since aluminum is more prone to shrinking and expansion which could equal loose connections over time... The price difference is huge! Thoughts?

BB.

Re: SolarCity PPA or DIY and a few questions...

It can be done--but you need to get the appropriate aluminum to copper transition connectors (very commonly used by utility companies) and, usually, have access to the crimping tools need to make the connection correctly. Use the copper pigtails to connect into the balance of your (most likely) copper only connections in your system.

Anything less, and you will be fighting intermittent connections into the future.

-Bill

a0128958

Re: SolarCity PPA or DIY and a few questions...

nadeaup wrote: »

I am trying to make my final decision a 9.6kw system from Solar City ...

OR Install the system myself (a 10.56k system) ...

Astroenergy 240 watt panels (44) ...

probably use unirac rails...

... Copper ... or Aluminum ...

Here's alternative leasing terms to consider as part of your lease vs buy deliberations: I lease my 8.1 kW DC grid-tie batteryless system from Infinergy Wind & Solar. Was zero installation cost to me as the leassee. I'm required to purchase all of the harvest @ 70% of whatever my prevailing retail grid utility price is.

With load shifting, I'm actually able to use about 70% of the output, at a grid utility bill savings of 9.9 ¢/kWh (avg for 2011). The remaining 30% I export at an income rate of 7.5 ¢/kWh. Net annual balance is about $250/yr. Lifetime savings to date is about $600, over 29 months, for a zero dollar investment.

The lease is perpetual. I don't own any any of the equipment. Leassor is responsible for all repair costs (including inverter replacement at 10+ years). I am required to insure via homeowners' policy.

I have 36 Astronergy panels just like yours - 225 W each, CHSM 6620 monocrystlline.

My system uses Unirac rail system.

Performance details are here. Lots of pictures and installation details of the panels and BOS is here (same reference as above).

In the 80's there were a number of high profile apartment fires here in the Dallas area, all due to having used aluminum wire (incorrectly). I think aluminum, done exactly per code, is just as safe as copper, but, it has to be done perfectly. Otherwise, use copper, where less than perfect installation can still be forgiving, and view it as an insurance policy.

Good luck!

Best regards,

Bill

ggunn

Re: SolarCity PPA or DIY and a few questions...

BB. wrote: »

It can be done--but you need to get the appropriate aluminum to copper transition connectors (very commonly used by utility companies) and, usually, have access to the crimping tools need to make the connection correctly. Use the copper pigtails to connect into the balance of your (most likely) copper only connections in your system.

Anything less, and you will be fighting intermittent connections into the future.

-Bill

I would assume that one could use Polaris blocks to make the transition from copper to aluminum wiring. Is that not the case? They are stainless steel and don't require any special tools other than an Allen wrench.