Posted By NRT.Rob on 16 Jul 2012 05:56 PM
installed cost for PV here in maine is about $3.50-$3.75/watt.

And at that price heat pumps are significantly more cost effective ways of meeting BTU needs with PV.

Roof mount, or ground mount?

roof. no idea what ground mount is.

Funny or not, that's the reality,

Exactly. Anyone who has sat there with paper and pencil in hand (or mouse) trying to make a Net-Zero work with PV sees the dry humor in it. Not impossible, but it represents yet another consideration that has to be juggled during the design phase.

Posted By NRT.Rob on 16 Jul 2012 06:03 PM
roof. no idea what ground mount is.

They're sprouting like mushrooms after a rain on VT Rt 100 just south of Stowe, if you're ever out that way.

I've yet to see a quote come in under $4/w  (pre-incentives) in MA yet, but I would expect to before 2015 after PV heats up a bit more in this (now highly subsidized) market.

I mean I have no idea what ground mount costs are

the $3.50/watt is pre-incentive as well. little less than $50k on a 14kw array here and other quotes around aren't far off. We had a clear roof and covered it though... optimal install, commercial building, no aesthetic trades to make. would have been 15-16 year simple payback with no credits whatsoever.

so,
4,500 watts of PV occupy s about 450 square feet,
Ok, it is not going to drive the house at night, in a storm, rain.....
What it will do is off set your electrical, when it can, in a simple way, for a long time and pay for its self in about 7 years. You get a clean 30% credit on taxes. If you buy it through a business (home office perhaps) the expense can be depreciated over 7 years.
After it has been paid for it is still working for a couple decades to come.
Not bad,
Dan

PV + mini-split sounds great unless you don't have net metering. Then you want some way to pump heat while the sun shines and store it for later (like air->water). Not an all bad idea anyway - it's warmer while the sun shines so efficiency is higher. Non-glazed hot water solar panels might even be useful when used with a heat pump.

Jonr is right. You have to have a tank to make most solar applications work if at all.

Perfect, this is exactly the conversation I was hoping for! Thanks everyone for your input and opinions. I want to consider all sides of this and the conversation goes a long way towards doing that. Regardless of the system I install, I will put pipes in the slab, as well as garage and workshop slabs. I had not thought of north south orientation but that makes sense. Then if necessary I can play with them at a later date. PV in that area is estimated at $5.50 installed. Another factor not yet explored is the power companies net metering program. By law they have to have it but they have the options of just buying back at wholesale and selling at retail, or handling the net on an annuual or bi monthly basis. It is a local REA so that still has to be reasearched.

We will, of course, build the best and tightest envelope we can, High R low U, meticulous air sealing, blower door tests prior to drywall, and then again at the end. My architect is quite schooled in Net Zero, and lives in one, and between us, and all the assistance here, I see it happening.

Thanks again for all the input.

Shop it around- as I understand it OR has a fairly substantial subsidy for residential-scale PV, something like 50% of system cost up to a total benefit of $6K. (So at $5.5K/watt the first couple kilowatts are essentially half-price.)

OR is definitely a net-metering-at-retail state. As the PV market heats up in OR I'd expect to see installed prices to fall a bit, but estimating it at $5.5/watt is probably prudent from a budgeting point of view until you have some hard quotes in front of you.

Posted By Dana1 on 01 Aug 2012 05:55 PM
Shop it around- as I understand it OR has a fairly substantial subsidy for residential-scale PV, something like 50% of system cost up to a total benefit of $6K. (So at $5.5K/watt the first couple kilowatts are essentially half-price.)

OR is definitely a net-metering-at-retail state. As the PV market heats up in OR I'd expect to see installed prices to fall a bit, but estimating it at $5.5/watt is probably prudent from a budgeting point of view until you have some hard quotes in front of you.

The Tax credit in Oregon is $2.10 per watt, with a maximum of $6000 or 50% of net cost.

Actually the net metering is not consistant, It depends on the supplier and whether they are a Public owned utility or a Cooperative. The Oregon laws allow the cooperatives a lot of latitude to design their own program.

Still definitely worth a look.
Thanks

Posted By NRT.Rob on 16 Jul 2012 05:56 PM
installed cost for PV here in maine is about $3.50-$3.75/watt.

And at that price heat pumps are significantly more cost effective ways of meeting BTU needs with PV.

Not that it's really relevant to central OR, but there's recent data indicating the current installed cost of PV in CT is about $5/watt , (maybe I wasn't crazy to consider budgeting $5-6/w and crossing my fingers for less.)

I wonder what is it about the markets in Maine &  Connecticut that PV in ME get's a ~25-30% discount from CT pricing !? Seems like a substantial delta. But as volatile and downward-price trending as the US PV market has been over the past 2 years we should expect a lot of statistical noise on cost data.