OK help me verify this. We are in the design phase of a very efficient new home in Central Oregon. The plan was to try to hit net Zero Energy.

The initial figures from beOpt are giving me a Energy cost of $528.00 per year.    That is a consumption of 720 KWH per month. There is no Gas, totally electric, GSHP, 2500 sq.ft. R40 walls, R60 roof, R 20 slab on grade,  high SHGC, on south side, Windows in the mid .1 U value. I actually expect consumption to be lower than that.

The energy Supplier (Midstate Electric Coop) has a residential rate of .06125 / KWH    Current panel prices locally are about $5.50 per watt installed. Solar production is estimated at about 5 hours per day, so I figure I would need about 5 kw to supply all my power. Federal credit of 30%, state credit of $2.10 per watt, but capped at $6K.
No utility rebates.

As I figure that, it is about a 25 year break even on solar panels.

Then there is the Sustainability aspect. The local coop buys all their power from the Bonneville Power Administration. BPA has enough Wind energy to supply over 70% of their total needs at some times. The majority of the rest of their production is Hydro. They do buy power from one small Nuclear facility and a couple of other small private suppliers, un named as to the method of production. I believe their total Wind and Hydro production is like 99%. 

So it seems to me to buy panels that have a certain amount of embodied energy, and install them in this rare case is less sustainable than to buy Hydro and wind energy.

I realize this is an unusual circumstance and a really low energy cost, is there something else I am missing? 

Your numbers look reasonable to me, assuming that you are in an area with high solar insolation. I am assuming that you are on the dry side of the coastal mountains.

From an economic standpoint, your electricity is unusually inexpensive, so hard to compete with. In this sunny area of Colorado, I have estimated costs for solar PV including subsidies comes in about $0.064/kWh to $0.082/kWh for the three systems that I am monitoring (http://www.residentialenergylaboratory.com/comparison_of_pv_systems.html). That cost is similar or higher than what you pay the utility.

I guess the only reason you have to go with solar PV is to meet your goal of net-zero energy, and leave that other clean utility energy to your neighbors. Alternatively, you could argue that it is better to leave those solar subsidies to those who could better benefit from them.

You need 8kw installed, with no shade to give you your 720kwh monthly (annualized)

We don't look at hourly power production based on a panels rated output. That is at standard test conditions and you never know if you have 1300w/m2 falling on the panel or 500 w/m2 (test conditions are at 1000w @25C).

You have to put it through a program knowing your inverter, wiring, roof pitch and orientation to get a real answer but the number I gave you will be pretty close.

One other thing to think about is that if you produce most of the power yourself, the line losses are reduced and that extra renewable (wind/hydro) power can go to another customer without solar.

Posted By MikeSolar on 26 Oct 2012 09:34 PM
You need 8kw installed, with no shade to give you your 720kwh monthly (annualized)

One other thing to think about is that if you produce most of the power yourself, the line losses are reduced and that extra renewable (wind/hydro) power can go to another customer without solar.

Thanks, I guessed there was more to the calculation. But because the state rebate was maxed out and no Utility rebates, this takes my break even point to 46 years! Here again, is the unusual situation, that the majority of this power production is within 100 miles, reducing line loss, as much as practical, and because of the rate of integration of wind energy, the Utility is struggling with the issue of overproduction. During spring runoff period they are producing more than they need. We really wanted to produce our own power, for Sustainability and economic reasons, but It just does not seem to be feasible from either standpoint.

I find the price for the PV array quite high. Here is a material package for a 7KW system for $1.77/watt
http://www.dmsolar.com/6grwi24sopap.html

With a State credit of $2.1/ watt. I see your break even much sooner with little more shopping and negotiation.

No idea how they can sell it that cheap unless some components are seconds. Regardless, wiring and labour MIGHT be $1/w if it is an easy install so I suspect it could be done for under $3.50/w depending on regulatory and permit hassles. If there is a $2.10/w state credit and a Fed credit (I assume there is one)..........where is the problem?

The electric supplier and the state will only allow systems that are certified and installed by Certified installers.
The system Liebler is suggesting would not be allowed. As I mentioned current installed price is $5.50 per watt, as per some aqcuaintences that recently installed as cheaply as they could.

"The system Liebler is suggesting would not be allowed."
WHY???

It meets all building code requirements (UL approved components) ! It would, of course, need to be installed by a 'certified' installer under a proper permit and inspected.

$ 26,110 is really obscene profit for the installation company!

The system has to be approved by the state, and every component of it.
Then it has to be inspected by the local jurisdictions, and then by an inspector certified by the state.
The installer also has to be trained and cerified by the state.

I would suppose if I approched an installer and told him I wanted him to install the system, but I was supplying all the components he would tell me to pound sand.

But regardless, If I were able to put in that system and the end cost ended up $3.50/watt as Mikesolar suggested,
then my net cost after Federal and state rebates, State being capped at $6000, is still $13,600

So if I eliminate a projected $528 per year electric bill that still adds up to a 26 year break even.

You are extremely fortunate in having what may well be the lowest priced electricity in the US. According to one source I found the US average is $0.12/KWH with a range up to $0.36. Enjoy it while it lasts! But I sure wouldn't bet on it lasting much longer.

When I lived in Oregon (near Portland) I was "served" by PG&E
PG&E as of January 2012):

12¢ / kWh - up to the baseline
14¢ / kWh - 101 to 130% of baseline
29¢ / kWh - 131 to 200% of baseline
33¢ / kWh - >200% of baseline

I think the biggest difference is because it is a member owned, not for profit utility, served by a not for profit supplier.

We are in an REA now in Colorado, and pay .0834. Part of the reason PG&E,a and other investor owned utilities Such as Excel here, pay large Efficiency rebates, is becasue they have boosted the rates to everyone to pay for them. It is a huge
Profit center. This came directly from My companies power Rep. But I have to admit I was pretty shocked at the rates.........
I have a plant in CA that pays up to $.39
Then in Georgia.....$.04

Posted By Liebler on 28 Oct 2012 12:34 PM
"The system Liebler is suggesting would not be allowed."
WHY???

It meets all building code requirements (UL approved components) ! It would, of course, need to be installed by a 'certified' installer under a proper permit and inspected.

$ 26,110 is really obscene profit for the installation company!

In the US a large fraction of the installed cost is the permitting & inspection paperwork etc, which in addition to he permitting fees them selves, adds a lot to the sales and processing overhead for the solar contractor.  The difference between the raw hardware costs and the installed price is not all going into the pocket of the installation company as profit.

In places (like Germany) where the process is extremely streamlined systems in the 5-7KW range are running ~$2-2.50/watt.  In most locations in Germany they don't even have to pull a permit ahead of time-  call the contractor for bids, arrange for a time to install it, it gets installed typically in one working day (7.5 hours is the typical amount of installation labor, about a tenth that of the US), and the certified contractor mails the standardized forms off to the permitting bodies. 

In a few parts of the US where some effort has been made to take the regulatory overhead out of it it's much cheaper.  In "Solarize Massachusetts" communities they are currently hitting around $3.50/watt for installed price in competitive bids, and in NJ it's running about $3/watt.  But it's clear there's room for improvement- it's not as if German labor is inherently so much cheaper & more productive than US labor, (even if the related bureaucracies surrounding solar installations are.)

More here.

NJ is the hottest solar pv market in the country although that is about to change: http://insideclimatenews.org/news/20120618/new-jersey-tops-solar-panel-installations-california-srec-prices-new-york-massachusetts-hawaii-seia-gtm-research Seeing as NJ is also a leader in red tape, one suspects its favorable prices owe to a surfeit of contractors who are competitive and know what they are doing. Cross the Ben Franklin bridge into Pa and you find a few contractors who have been certified by the state to do rebate-eligible installs. They are comparatively inexperienced and exhibit some confusion about for whose benefit the state rebate program exists.

Posted By Liebler on 28 Oct 2012 12:34 PM
"The system Liebler is suggesting would not be allowed."
WHY???

It meets all building code requirements (UL approved components) ! It would, of course, need to be installed by a 'certified' installer under a proper permit and inspected.

$ 26,110 is really obscene profit for the installation company!

Some states have some pretty strange requirements as far as UL listing as well. Example, in a couple of states I have installed large Control panels for industrial equipment, comprised of motor starters, fuse blocks, etc.

Even though the panel is UL listed, and every component is UL listed, if the complete "package" is not UL listed, I have had to bring in outside Companies, and have the system listed.

It is crazy, but happens fairly often, so I would not be comfortable buying a system unless I had a local company to back it up.

Whenever I hear of attempts to zero out a single home's energy usage via PV I wonder if we would all be better served by banding together into some form of community PV effort.

Rather than endure the high cost and aggravation of deploying 100 5 kw PV systems on top of 100 homes each with siting, shading, and connection challenges, instead install 500 kw of PV in one central location, such as on top of a Super Walmart or similar building.

Another variant could be covered parking - one of the most precious commodities in my neck of the woods from Tax Day until Halloween is a shading parking spot, thereby avoiding having to climb into a 120*F car and wait for its AC to beat back all that absorbed heat. Parking canopies topped with PV would solve two problems, and it is a darned rare parking lot that presents shading problems to a PV project.

Economies of scale would certainly kick in - instead of spending $25k to put 5 kW PV on my own home, perhaps I could invest $15 kW in a cooperative that deploys 5 kW PV "in my name" on top of or in the parking lot of the local Walmart, Home Depot, grocery store, or similar. I've offset the same amount of home energy use at much lower cost and aggravation.

I like that idea.  Also, if a lot of the parking lot lighting could be incorporated under the panels, it would cut down on a lot of the light pollution these parking lots cause.

Your idea is similar (in a smaller scale) to what is done with wind power in my area.  I chose to "buy" all my electricity as wind power from the company that supplies wind power to our grid.  The 2.5 cents / Kwh more I pay for my electricity to support this renewable source is much less than it would cost me to invest in the amount of solar pv I would need to power my house.  Our electric rates here are relatively cheap.  The wind energy premium takes me from about 10 cents to 12.5 cents /Kwh currently.

I'm not sure why we aren't seeing smaller pv coops around here yet.  I suspect it comes down to dollars and cents and the ability or inability to make a profit, or at least break even, in a reasonable amount of time.  My area isn't the best for sun either, though I'm seeing more and more pv being put on houses regardless of the fact that we don't have an srec program here in NY yet that I'm aware of.

We currently buy "green Power" also, and as this thread started out, will end up doing that with the new home. We were paying like $1 per 100 kWH for green power, then it was dropped to 7.5 centys per KWH! So it cost me like $.50 per month.
There is economy of scale, but also then you are getting back to an additional grid. And it seems finding like minded folks in some areas can be a challenge as well.

There are some big cooperative arrays under construction as we speak, OUR REA is involved in this one:
http://www.tristategt.org/greenpower/cimarron.cfm

Who is installing your Ground Source Heat Pump for you? I don't know how many companies there are in central oregon that specialize in that type of system. Send me a message [email protected] if you need any help with that end of your project from somebody that knows the local area. We are located in Portland Oregon.

Posted By SkyHeating on 30 Nov 2012 04:14 PM
Who is installing your Ground Source Heat Pump for you? I don't know how many companies there are in central oregon that specialize in that type of system. Send me a message [email protected] if you need any help with that end of your project from somebody that knows the local area. We are located in Portland Oregon.

We aren't that far. We are still in the design phase. I have found several GSHP Dealers there, but so far have only talked to Air Tech. They have a pretty good portfolio of projects.

Hmm...I wonder just how green power can be for just 50 cents extra per month. That sounds like just enough to print the bill on green paper and stuff it into a green envelope.