How Can I Take the 30% Federal Tax Credit for Solar If ...

Re: How can I take the 30% Federal Tax Credit for Solar if ...

PostBy: lsayre On: Sun Aug 10, 2014 5:13 pm

Thanks for taking the time to post that Freddie!!! Lots of wisdom there. If I went grid-tie only, with 24 x 250 Watt panels, I would probably break even on the average year. For this area the average sunshine per day is considered to be 4 hours, and we use about 6,200 KWH per year. I've seen where the typical payback for this sort of system is nominally projected to be 12 years.

But if I remain on the grid and have batteries (a system referred to as grid-tie with battery back-up), the inverter will charge the batteries directly from the grid if and when necessary (though the normal means of battery charging will be via the solar panels and a MPPT type charge controller), thus keeping them at a level of 50% or greater charge at all times (sans perhaps a grid outage). I agree that even under this scenario the batteries are only claimed to be good for 7 to 10 years before replacement. But it does offer a means to charge them without a generator, and to get the benefit of battery power when the grid is out.
lsayre
 
Stoker Coal Boiler: AHS S130 Coal Gun
Coal Size/Type: Blaschak Anthracite Pea
Other Heating: Resistance Boiler (13.5 KW)


Re: How can I take the 30% Federal Tax Credit for Solar if ...

PostBy: McGiever On: Sun Aug 10, 2014 9:44 pm

Freddy wrote: Yup, for safety, when the power goes down a grid tie system goes with it. With no batteries you have no power. There is one inverter that will deliver a small amount of power with no batteries, but only for charging cell phones or what not. Think about it.... if you want power directly from panels, you must have zero clouds. One little cloud &your TV shuts off.


Freddy,
Just to be clear, If the grid goes down and one HAS a few batteries AND the grid tie...his PV system goes right on working and charging? No need for Safety shut down referred to above?
McGiever
 
Stoker Coal Boiler: AXEMAN-ANDERSON 130 "1959"
Coal Size/Type: PEA / ANTHRACITE
Other Heating: Ground Source Heat Pump
Stove/Furnace Make: Hydro Heat /Mega Tek

Re: How can I take the 30% Federal Tax Credit for Solar if ...

PostBy: Rob R. On: Mon Aug 11, 2014 5:43 am

lsayre wrote:
I've considered going with LP, but that would mean a propane tank in the yard. My wife is not too keen to that.


But she is ok with the coal bins, solar array's, and bank of batteries? ;)

A 100 gallon propane tank usually isn't hard to "blend in" with the landscaping, and is more than sufficient to run a gas range & dryer...two appliances that when powered via 100% electric use a lot of power. I have two 100 lb tanks with a switchover regulator. each tank holds about 23 gallons and lasts us at least a year for cooking only. We use the burners often, and the oven gets used probably 2-3 times per week. The few times I have needed to run the generator for power, it was nice that the range wasn't competing for generator capacity.
Rob R.
 
Stoker Coal Boiler: EFM DF520
Hand Fed Coal Stove: Hitzer 50-93
Coal Size/Type: Lehigh Rice
Other Heating: Dad's 1953 EFM Highboy

Re: How can I take the 30% Federal Tax Credit for Solar if ...

PostBy: Freddy On: Mon Aug 11, 2014 6:01 am

McGiever wrote:Just to be clear, If the grid goes down and one HAS a few batteries AND the grid tie...his PV system goes right on working and charging? No need for Safety shut down referred to above?


All grid tie systems must automatically disconnect from the grid if/when the power goes out. That being said.... they do make a system that does what you are asking....(http://www.wholesalesolar.com/grid-tie- ... ery_backup) .... it charges batteries and if the power goes out, it will disconnect & seamlessly keep your power on, BUT... you pay for that privilege in more ways than one. First, the upfront cost is more, and second, you must use a central inverter which is not as efficient. For the entire life of the system you will be throwing away credits that could be used on an ongoing basis. We are talking 3.5 to 11% difference. With no batteries you can use micro inverters. Each panel gets it's own inverter. Also... micro inverters do not need special know how to install. If you can install a normal electric panel, you can install micro inverters. With a central inverter you had better understand what to do with 800 volts DC!! If I wanted an automatic back up, instead of batteries, I'd put in a whole house automatic generator. Remember... you need a generator either way.

While we are here.....with central inverters all panels put out as much power as the weakest panel. If ONE panel has snow cover, the entire system is pretty much down. With micro inverters, every panel is it's own separate system. If one panel is covered with snow, all the other panels still make full power. There is a way to make a central inverter work more like micro inverters. You can buy "optimizers" for each panel. They cost a lot! On a 30 panel system you'll spend $2,000 for optimizers.
Freddy
 
Stoker Coal Boiler: Axeman Anderson 130 (pea)
Hot Air Coal Stoker Stove: Reading piece o' junk in the barn (rice)
Coal Size/Type: Pea size, Superior, deep mined

Re: How can I take the 30% Federal Tax Credit for Solar if ...

PostBy: lsayre On: Mon Aug 11, 2014 6:12 am

The legal controversy (gray area) can be avoided if one utilizes an inverter that is both grid tied and battery tied, but does not have the capability to back-feed excess electricity to the grid. The Schneider Conext SW is such an inverter.

An example of full blown grid-tie with grid back-feed and battery back-up is the Schneider Conext XW series of inverters.

In some states or communities you might have difficulty permitting the XW. There should be no issues with the SW, as it has no ability to feed onto the grid, but rather it can only draw from the grid or from batteries.
Last edited by lsayre on Mon Aug 11, 2014 12:24 pm, edited 2 times in total.
lsayre
 
Stoker Coal Boiler: AHS S130 Coal Gun
Coal Size/Type: Blaschak Anthracite Pea
Other Heating: Resistance Boiler (13.5 KW)

Re: How can I take the 30% Federal Tax Credit for Solar if ...

PostBy: McGiever On: Mon Aug 11, 2014 8:44 am

Okay , thanks Freddy. :)
Where I was getting mixed signals was between the system being shut down vs being disconnected from grid...two different events.
Your explanation cleared that up for me, Thanks.

I can see there can be different approaches to going solar PV, such as, save bottom line electical cost throughout the year by put and take w/ the grid or be totally self sufficient off grid or some combination of both.

Then it's just a matter of what one needs/wants and the economics to build and operate it all. :)
McGiever
 
Stoker Coal Boiler: AXEMAN-ANDERSON 130 "1959"
Coal Size/Type: PEA / ANTHRACITE
Other Heating: Ground Source Heat Pump
Stove/Furnace Make: Hydro Heat /Mega Tek

Re: How can I take the 30% Federal Tax Credit for Solar if ...

PostBy: titleist1 On: Mon Aug 11, 2014 9:31 am

Just a couple thoughts as I was reading this thread and looked around at all the electricity sucking stuff within view.....

If someone is going completely off grid I thought they used DC powered as needed appliances and such to avoid having an inverter?

Anyway, Lights would be an easy replacement to 12VDC LED's. Buy a few reels of LED strips and glue them around something round, pop on a shade and your good to go!

From our experience a 1000 gal propane tank would last a few years for cooking & hot water & dryer use (ours is buried in the back yard so it doesn't hurt the view). Hand fed coal stove for heat & cooking on in winter. The well pump we have would take some thought but I did see a you tube video recently showing how to make your own hand pump from some PVC pipe and a inner tube, not sure if I could get the 150' of lift from our water level or not, though. The two sump pumps would have to be replaced with DC versions.

Keep the DSL modem for access to the coal forum....
Get rid of the TV.........oops.....that last thing just got this idea shot down by the others in the house!
titleist1
 
Hot Air Coal Stoker Stove: Harman Mag Stoker (old style) one in basement, one in workshop
Hand Fed Coal Stove: Harman Mark III on standby for long power outages
Coal Size/Type: Rice/Anthracite; Nut/Anthracite

Re: How can I take the 30% Federal Tax Credit for Solar if ...

PostBy: lsayre On: Mon Aug 11, 2014 9:43 am

Most battery based Solar systems are drifting toward 48V DC as the standard. To drive 12V DC and/or 24V DC appliances you then need a transformer. An inverter is essentially a transformer. So either way, you are going through a transformer and suffering losses.

With a 48 V system you can run way more solar panels through a single battery "charge controller" than for 24V, and with 12V you can only get a scant few panels linked to your batteries via a single charge controller. The other advantage is that a 24V system uses half the wire gage of 12V, and a 48V system uses half the wire gage of 24V. With copper prices as they are, 48V is pretty much the best way to go. Less line losses also, so you can run longer wires with 48V.
lsayre
 
Stoker Coal Boiler: AHS S130 Coal Gun
Coal Size/Type: Blaschak Anthracite Pea
Other Heating: Resistance Boiler (13.5 KW)


Re: How can I take the 30% Federal Tax Credit for Solar if ...

PostBy: McGiever On: Mon Aug 11, 2014 10:20 am

With Freddy's simple grid tied system and a break even [zero cost] with annual credits , running a generator [1800 rpm not 3600 rpm] [on diesel, NG or LP fuel not gasoline] the few times really needed is not a bad way to go. :) Buy used and save a bundle. ;)
McGiever
 
Stoker Coal Boiler: AXEMAN-ANDERSON 130 "1959"
Coal Size/Type: PEA / ANTHRACITE
Other Heating: Ground Source Heat Pump
Stove/Furnace Make: Hydro Heat /Mega Tek

Re: How can I take the 30% Federal Tax Credit for Solar if ...

PostBy: lsayre On: Mon Aug 11, 2014 10:33 am

And to think that Nicola Tesla wanted the world to adopt DC current, but the world listened to Thomas Edison and went with AC. Now we know that the future is DC and eventually AC will fade into oblivion. Yet another example of Tesla being ahead of his time.
lsayre
 
Stoker Coal Boiler: AHS S130 Coal Gun
Coal Size/Type: Blaschak Anthracite Pea
Other Heating: Resistance Boiler (13.5 KW)

Re: How can I take the 30% Federal Tax Credit for Solar if ...

PostBy: Rob R. On: Mon Aug 11, 2014 11:15 am

Larry, I think you have that backwards.
Rob R.
 
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Re: How can I take the 30% Federal Tax Credit for Solar if ...

PostBy: jpete On: Mon Aug 11, 2014 11:42 am

Rob R. wrote:Larry, I think you have that backwards.


X2

The alternating current generators at Niagara power station still have plaques with Tesla's name and patent number on them. :)
jpete
 
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Re: How can I take the 30% Federal Tax Credit for Solar if ...

PostBy: lsayre On: Mon Aug 11, 2014 11:57 am

Guess I flubbed that one! In many cases Tesla's ideas lost out to the ideas of others. I just figured this to be one more. I believe he died a poor man. Though perhaps that is wrong also.
lsayre
 
Stoker Coal Boiler: AHS S130 Coal Gun
Coal Size/Type: Blaschak Anthracite Pea
Other Heating: Resistance Boiler (13.5 KW)

Re: How can I take the 30% Federal Tax Credit for Solar if ...

PostBy: jpete On: Mon Aug 11, 2014 6:06 pm

You're right about Tesla dying penniless in 1943. He signed away rights to many of his patents during his life in order to generate cash for his pet project, wireless electricity.

Within hours of his death, the government scooped up all his papers from his apartment and most of them remain classified to this day.

An interesting tidbit I came across in a 1951 issue of "Mechanix Illustrated" my father had save was about the Army running a project which was successful in "broadcasting electricity" and had been able to illuminate a light bulb from 15 miles away. The ultimate goal was to power vehicles on the battlefield from a central power station.

Coincidence?
jpete
 
Hand Fed Coal Stove: Harman Mk II
Coal Size/Type: Stove, Nut, Pea
Other Heating: Dino juice

Re: How can I take the 30% Federal Tax Credit for Solar if ...

PostBy: lsayre On: Sun Aug 24, 2014 3:47 pm

I've worked up a handy spreadsheet that computes the average Watts you can expect to generate daily on a per month basis (depending upon your number of solar panels installed), and it also calculates the total annual KWH output you can expect to achieve from your solar panels. The spreadsheet is attached here.

The spreadsheet has only 6 required (and possible) user data input areas. It is required that you do the following to make it work for you specifically:

1) Enter the Square Meters of your solar panels overall total outside edge to edge surface area. This area includes the frame.
2) Enter your panels rated efficiency percentage.
3) Enter your panels PTC rating as a percentage of its STC (standard test conditions) rating. If this percentage is unknown, then choose and enter here the value of 89.5 (as this seems to work for most commonly available panels).
4) Enter your battery bank locations temperature factor (1.19 is the factor for batteries stored where they can experience 50 degrees F). If you don't have any batteries, then simply enter 1.00 here.
5) Enter your inverter(s) efficiency.
6) Enter your locations average monthly solar insolation (the amount of average sunshine given as KWH/m^2/day) for each of the 12 months of the year.

The spreadsheet as seen here is set up for Kyocera 250 Watt panels. They are rated at 250 watts STC and 223.7 watts PTC (more of a real world rating).

If you know only the STC Watt rating for your panels, any you know nothing else, leave everything where I have it now and simply change the Panel Efficiency rating in percent until the Calculated Panel Watts agrees with your panels STC rating.

The hardest part of all is finding the nominal monthly solar insolation values for your locale. The spreadsheet as written has these values adjusted for panels which are fixed at an angle that matches my local "latitude" and match the sunshine figures for my local region of Ohio. Your figures and your panels tilt angle will vary from mine, and these figures will need to be adjusted to match your conditions accordingly.

As for all of my spreadsheets this one was generated in Linux and saved as a conversion to the XLS format so it can function in Microsoft Office. I hope it works in translation. Most all of them do fine, but I don't have Excel, so I can't verify it.
Attachments
Watt Potential For Solar Panels.xls
(23.5 KiB) Downloaded 7 times
Select:BBcode: [nepafile=52893]Watt Potential For Solar Panels.xls[/nepafile]
lsayre
 
Stoker Coal Boiler: AHS S130 Coal Gun
Coal Size/Type: Blaschak Anthracite Pea
Other Heating: Resistance Boiler (13.5 KW)