What do you mean? I just can't lag-bolt the frames to the decking through the shingles?
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What do you mean? I just can't lag-bolt the frames to the decking through the shingles?
nwdiver
Well-Known Member
Panels are ~$0.70/w (Bulk discount)
SMA 10kW inverter ~$0.30/w
Ironridge racking ~$0.12/w
Misc ~$0.08/w
I don't have an invoice yet since we're still sourcing materials.
Here's the list from a project I helped with last year... purchased from civic solar.
I like to try to get 3 or 4 people that are interested and knock out everything in one go... everyone helps everyone. You can get some killer deals when you order ~$30k in materials.
That's pretty reasonable. Missing are the conduits, fittings, wire, splice box, ground rods, DC disconnect, external AC disconnect, breaker. That's about the price I'm seeing for the mid-range panels (~250W) and for racking. So with that quote, you're at $1.30ish/W, and the electrical stuff would probably drive it up to $1.40/1.50ish.
Better get it done before NEC 2014 is adopted and requires the rapid-disconnect up there.
Thanks for the example!
Better get it done before NEC 2014 is adopted and requires the rapid-disconnect up there.
Thanks for the example!
nwdiver
Well-Known Member
That's one of the few benefits of living in West Texas :wink:
But... what the rapid-disconnect requirement will do is just make DC optimizers mandatory. One of the three projects I'm working on will have a solar edge system that will comply with that requirement. It adds ~$0.20/w to the cost and improves efficiency ~15%.
InTheShadows
Active Member
Those kinds of gains are very unlikely unless you have a poor site to begin with. I like solar edge, however I don't like how they claim the gains they do. Modern well designed systems have a 15% derate factor. 3% of that is uptime (snow cover,thunderstorms, power outages) 2-3% is inverter inefficiencies.
Most modern panels have 0 negative tolerance and modern string inverters are much better at miss matched panels, and have multiple MPPT controllers. (See SMA's optitrac technology.)
We have a solar edge system we installed 4 years ago in a good site and it is producing the expected calculated output just like all of the other systems we have installed. Nothing extra of any significance.
For us the added cost isn't in the materials, they cost just as much as other top quality inverters, they take a little longer to install.
JRP3
Hyperactive Member
Considering the winter we've had in the north east I was wondering about heating elements in panels to keep them clear. A quick Google came up with this http://www.solarpowerworldonline.com/2014/02/snow/ http://blizzardsolar.com/
Not much detail but I assume resistive heating elements are used.
Not much detail but I assume resistive heating elements are used.
@JRP3's question made me think of another:
In Greece, everyone has solar hot water systems. Everyone. Yet I don't see them at all in the US. Is there a good explanation, or is this just a cultural difference?
In Greece, everyone has solar hot water systems. Everyone. Yet I don't see them at all in the US. Is there a good explanation, or is this just a cultural difference?
I suspect cheaper power combined with a less favorable climate in the US. It's easier to plumb in a cheap tank-based water heater that fits nicely in the corner than a larger system that needs to be installed.
What's the climate in the areas with lots of solar hot water?
I've read arguments that in areas that freeze regularly and have net metering it is more cost effective to get solar hot water indirectly by installing extra PV panels and a standard water heater (or especially a heat pump type) - you only need to match the average annual use instead of the winter case, and solar thermal systems lose a lot of efficiency in colder weather anyway.
I was planning to do solar hot water/solar space heating when I bought this house (fin tube baseboard oil heat currently,) but between a shortage of installers and what I've been reading, I'm not sure it makes sense in my mid-Atlantic climate.
Walter
InTheShadows
Active Member
We have installed a few solar hot water systems. In freezing climates you need to use an active glycol based system or a drain back system. Both of which are much more complicated and expensive to install than a direct thermosyphioning system. (Which is awesome if you live in a climate where there is no risk of freezing) They also have more maintenance and sizing a system for winter needs ends up in overheating in the summer or shutting part of the system down. Resulting in waste.
That explains it -- I was staying at a friend's house on a Greek island, and I'm quite certain that below-freezing temps are exceedingly rare there.
cantdecide
Member
Having spent time in Sydney (lots of solar hot water) and the Bay area (few around) I wondered the same thing...
They have the same climate, so what is different?
In the are of Sydney that we lived there was no piped natural gas, so most used electricity. In the Bay area people use natural gas, so presumably that is a cheap option that wasn't available or wasn't cheap in Sydney at the time.
The other factor I found was the form factor... Is Sydney they just put the whole thing including tank on the roof. In the US that would be considered unsightly so they take the more expensive option to put the tank in the attic.
That was all I could find... Perhaps electricity was more expensive in Sydney or there were government rebates as well I wasn't aware of.
Outside of the Bay area of course there are freezing concerns.
I am expecting for my next hot water system (in the Bay area) to oversize my solar electricity and use electric hot water.
They have the same climate, so what is different?
In the are of Sydney that we lived there was no piped natural gas, so most used electricity. In the Bay area people use natural gas, so presumably that is a cheap option that wasn't available or wasn't cheap in Sydney at the time.
The other factor I found was the form factor... Is Sydney they just put the whole thing including tank on the roof. In the US that would be considered unsightly so they take the more expensive option to put the tank in the attic.
That was all I could find... Perhaps electricity was more expensive in Sydney or there were government rebates as well I wasn't aware of.
Outside of the Bay area of course there are freezing concerns.
I am expecting for my next hot water system (in the Bay area) to oversize my solar electricity and use electric hot water.
omgwtfbyobbq
Active Member
I've read China is similar. I think it's due to cultural and economic/political reasons. On one hand, people in other counties aren't as fussy about things being "just right" as people in the US are, and energy interests in the US have much more political/economic sway than they do in Greece/China.
I had a house built in Northern California in 2012 and actively solicited bids for solar hot water. The cheapest active system that I could find was $10,000 installed. By active I mean a system that did not simply have a tank at the top of the collector acting as a passive "pre-heating" system ahead of a conventional water heater. I ended up choosing a Navien condensing tankless water heater for $1,600. The EnergyGuide label said $125/year cost to operate. I could not be happier with my choice. If I had more roof area for solar PV, I probably would have chosen a heat pump electric water heater.
California also has a rebate scheme for solar hot water. However, the vendors are not set up for it and the ones I talked to felt that the required engineering calcs were so onerous that they would have to charge me nearly the whole rebate amount to get someone to do the calcs and submit the paperwork. The rebate scheme also required glycol systems for freeze protection on the basis that circulating the warm water from the tank (the few times it would be needed in N.CA) for freeze protection was wasting energy.
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lolachampcar
Well-Known Member
Chiming in with another data point on PV costs.
Owner/builder 10.4K DC using point inverters => $2.4/watt including contracting major elements (roof ties, assembly, electrical) and all sealed drawings and permitting. The Fed Tax Credit drops my return to under seven years no cost of money.
Owner/builder 10.4K DC using point inverters => $2.4/watt including contracting major elements (roof ties, assembly, electrical) and all sealed drawings and permitting. The Fed Tax Credit drops my return to under seven years no cost of money.
nwdiver
Well-Known Member
WOW... that's pretty good... so ~$2.4/w acting as your own General Contractor? I've had mixed results... my initial electrical quotes varied WILDLY; $500 - $4000 to finish the electrical with everything mounted.
I can do the electric without a problem, it's the roof and racking that I am not comfortable with. Poking holes in the roof just makes me nervous. Yeah, I know, I play with hundreds of amps of power in an open panel and the worry about making a leaky hole in a roof throws me off.
Has this been talked about in here? I think I've read some here don't mind a small demand fee and some don't like the idea at all. It seems this is not good for all those living in Arizona with solar....
SRP board OKs rate hike, new fees for solar customers
SRP board OKs rate hike, new fees for solar customers
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