[Nords]

Quote:

Originally Posted by TromboneAl How much of the cost of a PV system is the electronics to convert the DC from the panels into AC? I wonder if there would be significant savings if you skipped that, and just had the electronics that took the DC and handled the car charging with that.

Not much. We paid $2500 (retail!) for a 3 KW inverter in 2005. A homeowner buying a complete 3 KW system from an installer would probably pay a total bill of about $30K.

My biggest regret today is not buying an even bigger inverter-- at least 5 KW. I think the latest inverters are probably even cheaper, have more capacity, and are more reliable today. Not Moore's law but not far off.

Quote:

Originally Posted by SecondCor521 I looked into a home system about a year or so ago and found that it really didn't make sense economically for me to do one. I didn't run a sensitivity analysis, but IIRC the key reasons it didn't work for me were: * Cheap electricity. I think I pay around 5 cents per KWH here in Idaho, and that's before the $21 in credits I get for letting the local power company slap a choke on my AC unit in the summer. * Not enough sun. Which corresponds to not enough power generated. * Too high usage. I'm fairly careful with my energy usage, and even with being careful I still use enough electricity to require about $15K - $20K in panels. * Crummy tax breaks on the state level. I think the situation is better in CA and HI, and maybe elsewhere as well.

Yup. No one's willing to pay $10K/KW for a payback that's a minimum of two decades away, and most paybacks are about 25 years. No homebuyer will pay for a PV system, either, so sellers don't get any benefit if they move at the national median of once every seven years.

It's not impossible. With our scrounging, DIY, 20.5 cents/KWHr rates, and tax credits we'll manage to get our money back by 2010 and to pull ahead by 2020 (15 years)-- and that's even if rates don't go up.

Federal/state subsidies ease the pain a little, and most people fail to pay attention to the inflation cost of utilities. I don't think an installer can sell a system on its payback without subsidies, and it's only in times of rapidly rising oil prices that they can get away with scary inflation stories.

A couple years ago I participated in a focus group of 20 homeowners with grid-tied systems, and 19 of them were doing it for the green lifestyle (two of them taught courses on the subject). I was the only one motivated by a different kind of green.

Quote:

Originally Posted by SecondCor521 Also, I wasn't willing to scrounge for panels the way Nords was. I poked around on the Internet and found some reasonably cheap panels, but I priced things out based on buying new panels from the manufacturer.

A local Craigslist seller just unloaded 10,000 watts (50 panels) at $4/watt. I was going nuts-- I had no need for even 1000 watts, let alone 10,000, but it was just too good a "fell-off-the-truck" deal to pass up. Luckily someone finally put me out of my misery by buying them.