Goal: Net Zero - Companies Suggesting Widely Varying kW Systems

[J.P.M.]

Download and read : Solar Power Your Home for Dummies". You will benefit from the education.

A 100 % off set of your bill may not be the most long term cost effective way to go.

After the book, run PVWatts. Read the help/info screens a couple of times and use 10% system losses instead off the 14 % default. With some better information and a more informed idea of how much of your bill you want to replace, you'll be better able to make a more informed decision.

Do not buy anything until you understand what you're doing and what vendors are telling you. They make money by putting equipment on your property, not getting you the most cost effective way to reduce your electric bill.

[SunEagle]

Have you looked at the pvwatts.nrel.gov website to see what a system would generate in your neck of the woods?

You can enter in a number of different multipliers based on which compass point the panels are facing as well as an efficiency value.

You could then use the yearly kWh value from that calculator and compare it to the Vendor's estimate to see if they are under or over sizing their system.

[adoublee]

What does net zero mean to you? Net zero electric energy across a year? Net zero electric energy each month of the year? Net-zero energy all-in (all-electric house)?

Are you expecting zero dollar or less bill every month?

Would you expect to hold the contractor liable if they missed a month or year of net-zero? Would you rather be conservative and over-generate or be more economic in your decision making (net zero not usually the quickest payback).

I'm not really looking for an answer to all these questions, but when you take it all into account the difference between 8.3kW and 9.7kW isn't all that great if these weren't well defined.

[Nethers]

After living in Central Florida all my life, I've decided to attempt to Net-Zero my power bill with solar installed by a company, by this I mean offset all the expenses of my bill to zero from ($155/mo avg w/ taxes and fees). What I've found strange is that after supplying my power bills, and last 12 months of energy usage, the various solar companies have given me a wide range of suggested builds - anywhere from 8.3 kW to 9.7 kW. In Florida it's either buy or loan, so there is no PPA.

Here are my remaining contenders and what they suggest to Net Zero my bill:

Vendor GuS , 8.960 kW , $23,385 , Solar Edge Inverter with Optimizers and Axitech 280W , est'd 15,124 kWh
Vendor ESA , 9.690 kW , $20,552 , Solar Edge Inverter with Optimizers and Hyundai HiS-S285RG , est'd 14,122 kWh
Vendor Sup , 8.120 kW , $28,444 , Solar Edge Inverter with Optimizers and REC Twinkpeak 2 290W Panels
Vendor SCi , 8.450 kW , $27,462 , String
Vendor Gol , 9.240 kW . $24,474 , Solar Edge Inverter with Optimizers and Hanwa Q 280W Panels , est'd 13,760 kWh

My average monthly power usage is 1186 kWh or 14,232 kWh annually. Do any of these stand out to stay away from? Obviously the two smallest systems that cost the most were probably not going to win. The prices listed are before tax credit.