# One year of roof top solar



## georgepds (Apr 28, 2014)

I put up 4.6 kw of grid tied solar panels last on  the roof last year , roughly half in Dec 2012, and the rest in June of 2013. Since installation I’ve been building up a credit with national grid. Eventually I intend to use those credits to heat the house with a Fujitsu heat pump, but, so far,  I find it difficult to wean myself off the woodstove ( a progress hybrid) .

I generated about 6 MWH last year, and got SREC payments of  ~$1500 ( Massachusetts) .For those of you interested in numbers the ROI is ~15% , helped in large part by the reduction in capital outlay (due to Federal tax credit and state rebates)

That said, the biggest kick I get is the electric bill which shows a dollar credit from month to month .


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## firebroad (Apr 28, 2014)

That's impressive!  And a great encouragement for others.


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## lostDuck (Apr 29, 2014)

Is your roof north/south or east/west. Looking in to solar and having trouble calculating the ROI. I have been told North/South in our area (Northeast)  produce much more kWH.

Thanks.


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## Slow1 (Apr 29, 2014)

Sounds like a successful project to me, congrats.  

LostDuck - in our area a south facing roof face is considered optimal (ideal is actually a degree or two off from direct south, but close enough).  Panel installations just have not yet gotten cheap enough to justify installing on east/west faces and only producing for 1/2 the day on each panel.... Although I do wonder as prices fall if such a configuration may become viable in the next few years.

As to calculating your own potential - you can get this done for you largely by having someone (PV company) do a "sun eye" check and give your "solar access" %.  This, along with knowing the face direction and angle can be used to estimate production from whatever size array you want to check.  Look at PVwatts (http://www.nrel.gov/rredc/pvwatts/) as a good starting point.


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## georgepds (Apr 29, 2014)

lostDuck said:


> Is your roof north/south or east/west. Looking in to solar and having trouble calculating the ROI. I have been told North/South in our area (Northeast)  produce much more kWH.
> 
> Thanks.



My roof faces south ( actually SSE ) and gets sun without obstruction. The slope is 30 degrees, a bit shy of the optimum value for net production in the Northeast.

I put up my first grid tied system around the year 00. It cost a lot more and did a lot less. When  I overproduced (which was rare) they paid me back at the net wholesale rate  that the big Nukes got.. gee thanks. When I heard about SRECS and net metering I knew the regulatory environment had changed ( thank you governor Patrick). Problem was , to get in on the benefits, you had to install new panels. When I heard of the federal and state capital incentives, that made it easier to change

What I did is put in half the new system and compare it to the production of the old. For same nameplate wattage my old system was producing far less power.. so that made it easier still to allocate the rare resource (roof space) to the new system.. that's when the other half went in


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## valley ranch (May 8, 2014)

Sounds good, would like to install some at our lower ranch in the high desert.


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## peakbagger (May 13, 2014)

Mass has very generous SREC payments compared to many states. The same system in NH would get $300.Anyone considering solar has to take into account the incentives in place that apply to their home and that the incentives may not be forever. Its still a good investment given the short payback with incentives but the subsidies are bound to change.


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## Where2 (May 13, 2014)

peakbagger said:


> Mass has very generous SREC payments compared to many states. The same system in NH would get $300.Anyone considering solar has to take into account the incentives in place that apply to their home and that the incentives may not be forever. Its still a good investment given the short payback with incentives but the subsidies are bound to change.


"The Sunshine State"=no SREC system and subsidies?? Good luck with those, the legislature hasn't funded that program in years...

Despite having to "pay my own way", I've generated 4.6MWh in 8.5 months and 262kWh already this month.


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## begreen (May 13, 2014)

Kudos for doing this. Time to elect a legislature that get the job done.


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## WoodNotOil (Jun 9, 2014)

For those guys who have done self installs, any ballpark on what your costs were excluding the panels/inverter(s)?  Assuming you were to install all of that yourself and just pay someone to do the grid-tie and inspection (or whatever is required to satisfy state/local/utility).  To clarify, I mean the costs excluding the materials and your own time.


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## Where2 (Jun 9, 2014)

WoodNotOil said:


> For those guys who have done self installs, any ballpark on what your costs were excluding the panels/inverter(s)?  Assuming you were to install all of that yourself and just pay someone to do the grid-tie and inspection (or whatever is required to satisfy state/local/utility).  To clarify, I mean the costs excluding the materials and your own time.


It *really* depends on where you live. In my system, I've got $250 invested in a state certification for my system (only good in my state, and basically an NEC 2011 compliance review of my very thorough three line electrical diagram and system grounding design, both drawn in autocad and printed in full color). Building permits, including the costs for multiple structural and electrical inspection, were $400+ (I live in a small suburban town on the fringe of a metropolis that pays for the building department expenses based primarily on permit fees rather than property taxes). Structural engineering design (because I am in a hurricane prone area) was $500 (I performed most of the drafting necessary for the structural design drawings, the professional engineer provided uplift and down force load calculations based on a 3-second gust of 170mph). There was no interconnect charge, or fee from the utility to bring out a net meter. All my utility wanted to see was a passing final permit inspection document, along with a signed, notarized interconnect agreement. I didn't have to hire an electrician because I have a copy of the NEC and have been deemed by my local AHJ to have the right to make changes to the electrical system on my own personal residence provided I obtain all necessary permits, and provided all modifications I make meet the present version of NEC in use. My AHJ inspectors are quite willing to answer questions during their daily office hours, and staff are willing to provide residents with permitting fee schedules. In my case, the permitting fees are based on a percentage of the total general itemized project cost including materials, as well as reasonable and customary labor expenses, whether you are doing the labor yourself or paying someone else to perform the labor. As part of the permitting process, you must submit an generalized itemization of the project costs, and they will call your bluff if you put down $10 for total labor.

A call to your town office is likely in order to determine the fees in your area.


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## BrotherBart (Jun 9, 2014)

Damn. Over a grand before a watt is generated. That would buy a years worth of juice for this all electric house.


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## peakbagger (Jun 10, 2014)

Instead of ballparking, its a lot easier to work up a cost using a website like AltE or Wind and Sun. In addition to inverters and panels, you need to price up racking and roof mounting brackets, possibly a combiner box (depends on the size of system), special MC4 PV wire for the last run to the combiner or junction box, conduit, wire from the combiner to the inverter, main breaker for the panel assuming its under the 20%bus bar rating, #4 ground wire, revenue meter and in some jurisdictions an outside disconnect.


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## WoodNotOil (Jun 10, 2014)

Yeah, in my case the materials are all part of a kit and already customized to my install by an engineer (peakbagger - this includes all the things you listed).  So the full material cost is known up front.  I just need to figure out what it will cost to have it connected to the net meter and for permitting.  I'll give my town office a call to see about permitting and figure in a few hours of an electrician's time for my estimates at this point.  Where2, interesting the utility doesn't charge to get the net meter to you, I'll have to call mine and see if that is the case here as well.  Thanks guys!


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## mass_burner (Jun 10, 2014)

georgepds said:


> I put up 4.6 kw of grid tied solar panels last on  the roof last year , roughly half in Dec 2012, and the rest in June of 2013. Since installation I’ve been building up a credit with national grid. Eventually I intend to use those credits to heat the house with a Fujitsu heat pump, but, so far,  I find it difficult to wean myself off the woodstove ( a progress hybrid) .
> 
> I generated about 6 MWH last year, and got SREC payments of  ~$1500 ( Massachusetts) .For those of you interested in numbers the ROI is ~15% , helped in large part by the reduction in capital outlay (due to Federal tax credit and state rebates)
> 
> That said, the biggest kick I get is the electric bill which shows a dollar credit from month to month .




Who did your install? I am on the southshore and we are looking to add panels and put in a heat pump for the back part of the house (bedrooms).


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