EcoRenovator  

Go Back   EcoRenovator > Improvements > Solar Power
Advanced Search
 


Blog Register 60+ Home Energy Saving Tips Recent Posts Search Today's Posts Mark Forums Read


Reply
 
LinkBack Thread Tools Display Modes
Old 10-13-16, 11:21 PM   #1
EcoLearner
 
Join Date: Oct 2015
Location: Rocky Mtns
Posts: 113
Thanks: 105
Thanked 26 Times in 19 Posts
Question DIY solar/worth the cost?

Due to some unforeseen good fortune this past year we have found ourselves faced with 2 things: 1. larger than expected income for '16 and 2. Much larger than expected tax bill coming in April!!

I'm really wrestling with doing a DIY solar, as it is the only viable deduction at our new income level (which will be a 1 year thing, next year its back to normal).

Facts: We have 2 EVs in our household. We use about 25kWh per day for the vehicles alone. On our power plan this bumps us up into tier 3 (14.5c) every month.

We have had 2 large national and 1 local solar company bid the job. All have estimated that we "need" about 10kWh system. Bids range from 32k to 36k. Not going to happen. If we do this project we want to pay cash and that is just beyond our range at the moment.

By browsing the live data from actual installs in my area of similar size I have calculated that 10kWh systems nearby return about $135 per month on a one year average. Our power company does annual reset on net metering with no monetary credits, so it does no good to over-generate.

I've found a quality system (Mitsubishi MLE280W panels and Solaredge power optimizers and Inverter, mounts, wiring, support) for exactly $18170 delivered.

With Federal and State tax credits calculated ($8300) in it's about 8 years to break-even.

This still seems like an unacceptably long time. Especially if you look at other investments that you might miss (opportunity cost).

Would we be better off waiting and just paying the extra $8300 to the gubbermint??

Would a smaller system make sense?

The synergy of having electric vehicles with solar really appeals, but something is holding me back from pulling the trigger. Any insight from the wise eco minded renovators?? Comments?


Roostre is offline  
Digg this Post!Add Post to del.icio.usBookmark Post in TechnoratiTweet this Post!
Reply With Quote
The Following User Says Thank You to Roostre For This Useful Post:
wilsonsmith (11-27-16)
Old 10-13-16, 11:46 PM   #2
Helper EcoRenovator
 
Join Date: Mar 2010
Location: South Jersey
Posts: 57
Thanks: 42
Thanked 17 Times in 11 Posts
Default

Well as I see it if you pay $8300 to the gov the break even is never you lose $8300. Or take the credit and in 8 years your even. I've been in my house 24 years, so wish I could have done solar way back when, now I'm disabled so lose out on the tax credits and can't physically do a self install, so I leased a system. Still saves me after the lease fee. So I'm happy
celblazer is offline  
Digg this Post!Add Post to del.icio.usBookmark Post in TechnoratiTweet this Post!
Reply With Quote
The Following User Says Thank You to celblazer For This Useful Post:
Roostre (10-14-16)
Old 10-14-16, 06:33 AM   #3
Steve Hull
 
Join Date: Dec 2012
Location: hilly, tree covered Arcadia, OK USA
Posts: 809
Thanks: 238
Thanked 164 Times in 122 Posts
Default

Roostre,

There is more to the equation than you have written - and when you see it you will be quite pleased.

Like you, I put in a similar sized system. Mine is 12.9 kW and I looked hard at the "return on investment".

First, go to Renvu.com (link below) and look at Enphase systems. I just installed a 10 kW system of Hanwa 265 W panels and Enphase M215 microinverters (with roof racking) for a delivered materials price at $1.02 per watt. This is an ideal system for a self install.

Secondly, the two estimates you got ($32K and $36 K for a 10 kW system) are in line with what I charge ($3/watt; materials and labor). Assume you do a 10 kW self install system with materials cost of $10K. Your true value in the home is double that ($20 k labor "fee") as you have improved your home value by $30 k ($10k+$20k). There is a lot of data out there showing that homes with PV sell for more than the installed cost of the system. You cannot deduct your labor or get the tax credit for it, but in reality, you have substantially improved your home value. But for now, let's assume your home is improved by some 200% more than your materials cost.

Thirdly, your self installed system ($10K materials cost) will get you an immediate 30% residential tax credit. On a $10K materials purchase, this will be $3K from the Feds. Looks like you have an additional state credit of 15% so that will be another $1.5k for a total of 4.5 K. Your actual basis is now $5.5 k looking forward (not $10K).

Now it gets interesting. You utility structure has you in a bind being in the expensive high tier ($0.14/kWhr).

The savings of $135/month you see from neighbors may or may not be correct. You can go to PVWATTS and find out how many yearly kWhrs you should expect. Beware that the assumptions in this program (defaults) are VERY conservative and are out of date. For example, PVWATTS assumes a system efficiency of 86% where the Enphase inverter efficiency is 97%. But with good inputs it will get you close. I have found that even with good inputs, my Enphase systems produce about 10-12% more monthly/yearly kWhrs than PVWATTS predicts.

Let's assume you save what you have seen - $135 a month ($1620/year). On the simplest of return calculations your basis is $5.5 k and you save $1.62 K per year. This is a 3.4 year return on investment (ROI). Using the rule of 72, this is a 21% ROI.

But it actually gets better . . . . In reality the $1620 you save per year go to other financial perspectives and this "saves" you some 2% per year (lost opportunity cost). The 2% figure is conservative, but it gets you there. Then assume the cost of electricity will increase significantly above inflation for many years. Choose your percentage (let's use 5%). Adding 2 and 5% together give you a 7% figure on savings per year. You can now do a reverse amortization to figure your ROI, but lets use the "rule of 72".

This gives you the time to double an investment given a percent return. 72/7 = about 10 years. So just the savings on your system give you a doubling of investment (basis) in 10 years.

The bottom line of all this is that the internal rate of return on a self installed solar system is on the order of 20-30%. And doing it yourself only adds to the savings.

Another way to look at it is to add the tax credit ROI (21%) with production situation (7%) for a total of 28%. Again the rule of 72 gives you a payback of ~ 2.6 years. But you are also saving on electricity, so the actual ROI is even better.

No - the return is NOT 8 years but certainly less than 3, maybe 2 or so.

The negatives . . . . Climbing on the roof is not easy, but on a self install, you are "making a lot of $", so it is well worth your time (~ $500 per hour). A self installed system of 10 kW (~ 40 265 W panels) is about 40 or so total one person hours ($20,000 divided by 40 hours = $500 per hour). Maybe it takes you 80 hours - heck that is still a lot of cash you are saving.

You may need some basic tools. Socket wrench, cordless drill, measuring tape, ladder, etc. Nothing out of the ordinary.

You may (or may not) need a electrical permit to do the final hookup. I am an engineer, not an electrician, but you can hire an electrician to help or to go over everything at the end.

My prices are current as I just ordered from Renvu this week (Hanwa 265 w panels at $0.51/watt and Enphase microinverters at $90 each). To get prices, you need to register, but that is easy.

renvu.com | Search By

Hope this gets the wheels turning . . . . . .


Steve
__________________
consulting on geothermal heating/cooling & rational energy use since 1990

Last edited by stevehull; 10-14-16 at 09:07 AM..
stevehull is offline  
Digg this Post!Add Post to del.icio.usBookmark Post in TechnoratiTweet this Post!
Reply With Quote
The Following 8 Users Say Thank You to stevehull For This Useful Post:
Geo NR Gee (10-15-16), jeff5may (10-14-16), jimmerjammer (10-15-16), kenora (02-05-17), Mobile Master Tech (11-26-16), pinballlooking (10-14-16), Roostre (10-14-16), WisJim (01-06-17)
Old 10-14-16, 08:59 AM   #4
Supreme EcoRenovator
 
Join Date: Jan 2010
Location: elizabethtown, ky, USA
Posts: 2,227
Thanks: 324
Thanked 558 Times in 467 Posts
Send a message via Yahoo to jeff5may
Default

Oh, the virtues of sweat equity... With nearly all of these ecorenovations, the return on your own labor pays back in tangible dollars quicker than estimated (if you do it right the first time). Besides saving the prevailing wages charged by skilled tradesmen, another adventure is added to your life story and skill set. If and when something goes awry, be it the system, the economy, the power utility, or whatever, you will be in a better position to deal with the change. Having commissioned the rig, the cause and effect relationship will be known without having to call on "the guy". Later, if you want to expand, the process will be much easier than the first time through.

Plus, you can share pics with all of us. Everyone wins!

Good luck making your decision. Everyone I know (especially those with electric cars) that has commissioned a PV system like you are contemplating had no regrets after the fact, except that they didn't go bigger earlier.
jeff5may is offline  
Digg this Post!Add Post to del.icio.usBookmark Post in TechnoratiTweet this Post!
Reply With Quote
The Following User Says Thank You to jeff5may For This Useful Post:
Roostre (10-14-16)
Old 10-14-16, 09:27 AM   #5
Steve Hull
 
Join Date: Dec 2012
Location: hilly, tree covered Arcadia, OK USA
Posts: 809
Thanks: 238
Thanked 164 Times in 122 Posts
Default

Roostre,

Renvu is a superb place to get advice for first time DIYer such as yourself. I do strongly advise against central inverter units and power optimizers.

Several people on this site have installed Enphase microinverters and it is really simple. Maybe they will chime in.

Lastly, avoid the perspective to "just wait, the price will come down". The solar industry will have further declines in modules and inverters, but at $1/watt for materials, we are getting close to basic manufacturing costs. For example, racking costs are fixed and are about $25 per panel. The basic cost of aluminum rails, nuts/bolts/screws is right there. The further price declines (next couple years) will only be a tiny fraction of the declines we have seen in the last ten years.

Waiting just reduces your ROI and you need to do something now considering your 2016 impending tax situation.

I agree with Jeff that putting in a too small system is a waste of time. Do it right the first time. The best way to do this is to design your system size correctly. I gather you have an annual metering so that you can "store" or bank kWhrs in the summer for winter use. Is that correct?

If it is, then you are very lucky.

Might be helpful to show us your month by month kWhr use as well as the charges per kWhr throughout the year. That way, we can assist you on designing the "right" size in kW and panel number. You are exactly correct that too large a system is a waste.

An intermediate install plan would be to hire a handyman that is not afraid to work on the roof. Let's say, you pay him $25/hour and the job requires some 40 hours. You are out some additional $1000 for labor, but then you still get some 45% back of this $1000 (fed and your state credits). Beats paying a solar installer some $20,000 + to put in $10,000 worth of solar materials (panels, microinverters, racking, wiring).

The last thought I wish to leave you with is that Enphase has a 25 year non-prorated guarantee. This is through Siemens. I have had to only replace one Enphase microinverter (of many hundreds) and it was here in four days with pre-paid shipping of the bad unit back.

Let us know how to help. Even though it is just a "nuts and bolts" install, this is a major project, let's be realistic. But it is one that will have incredible financial and satisfaction perspectives.


Steve







Steve
__________________
consulting on geothermal heating/cooling & rational energy use since 1990
stevehull is offline  
Digg this Post!Add Post to del.icio.usBookmark Post in TechnoratiTweet this Post!
Reply With Quote
The Following User Says Thank You to stevehull For This Useful Post:
Roostre (10-14-16)
Old 10-14-16, 09:55 AM   #6
Super Moderator
 
pinballlooking's Avatar
 
Join Date: Jun 2013
Location: SC
Posts: 2,427
Thanks: 124
Thanked 440 Times in 356 Posts
Default

@Stevehull
We want pictures and a solar post on its own about your project. Please share your story to help others.
It is a good story that others can reproduce.

I was going to post to this but Steve has done a great job.
Here is my story.
http://ecorenovator.org/forum/solar-...lar-array.html
I even installed mini splits so I could heat with solar power.
I personally think it is really worth it. No regrets at all.
Our Chevy Volt just hit 59,587 solar powered miles. We have had two years with covering everything with solar.

you said.
"Facts: We have 2 EVs in our household. We use about 25kWh per day for the vehicles alone. "
We charge our Volt from empty 2 - 3 times a day so we have 25+ kWh a day charging also.


I also installed enphase and there is a lot of info out there to do a by the book install.
I think this is the simplest install for a DIY person. The per panel monitoring is so good at a glance I can tell every panel/ microinverter is doing what it designed to do.


My return on investment is greater than the stock market and I am helping the environment at the same time. Win Win in my book.
__________________
Current project Aquaponics system , Passive Solar Greenhouse build

To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.

Solar Install 12.5 Kwh-
To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.

Mini Split installs -
To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.

EV Chevy Volt -
To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.
pinballlooking is offline  
Digg this Post!Add Post to del.icio.usBookmark Post in TechnoratiTweet this Post!
Reply With Quote
The Following 2 Users Say Thank You to pinballlooking For This Useful Post:
Mobile Master Tech (11-26-16), Roostre (10-14-16)
Old 10-14-16, 12:15 PM   #7
EcoLearner
 
Join Date: Oct 2015
Location: Rocky Mtns
Posts: 113
Thanks: 105
Thanked 26 Times in 19 Posts
Default

Quote:
Originally Posted by stevehull View Post

The best way to do this is to design your system size correctly. I gather you have an annual metering so that you can "store" or bank kWhrs in the summer for winter use. Is that correct?

If it is, then you are very lucky.








Steve
Steve,

Thanks for the information, links, and enthusiasm!

Our power company will not pay for spinning the meter backwards, but in reading the "Net metering service" agreement they credit any generation forward to the next month. All unused credits accumulated expire with the regularly scheduled meter reading in March each year.
Roostre is offline  
Digg this Post!Add Post to del.icio.usBookmark Post in TechnoratiTweet this Post!
Reply With Quote
Old 10-14-16, 12:19 PM   #8
EcoLearner
 
Join Date: Oct 2015
Location: Rocky Mtns
Posts: 113
Thanks: 105
Thanked 26 Times in 19 Posts
Default

Quote:
Originally Posted by pinballlooking View Post
Here is my story.
http://ecorenovator.org/forum/solar-...lar-array.html



My return on investment is greater than the stock market and I am helping the environment at the same time. Win Win in my book.
I have been following your thread for quite some time and it is an inspiration to make the leap!

Many of my skeptical friends say that the system maintenance costs will erase any benefit. Have you experienced any issues? How often do you need to clean them?
Roostre is offline  
Digg this Post!Add Post to del.icio.usBookmark Post in TechnoratiTweet this Post!
Reply With Quote
Old 10-14-16, 12:57 PM   #9
Apprentice EcoRenovator
 
Join Date: Apr 2011
Location: PNW
Posts: 194
Thanks: 0
Thanked 45 Times in 30 Posts
Default

Was going to reply also, but like Pinball, realized that Steve has just about said all you need.
Go for it if physically able. You will learn a lot also.

You did not say what your age is or your physical capabilities. I'm over 70 an would DIY solar in a moment if I lived in a good solar area (In western WA, not enough sun esp. since I would not want to cut down my 170 ft trees!)

Since you are in Utah, back in the 1980s, when solar was more than 5X as expensive in inflation adjusted dollars as now (ain't tech advances GREAT!) we did a study of using solar power for a missile base in S. Utah/Nevada and saw areas where the LONGEST stretch without sun was 3 day during the previous 40 years! So, you may be in a great area if in the South of Utah.

Even back then, the solar would have been lower cost (including then state of art hydrogen/bromine fuel cell storage) than building a dedicated new power plant plus distribution lines.
mejunkhound is offline  
Digg this Post!Add Post to del.icio.usBookmark Post in TechnoratiTweet this Post!
Reply With Quote
The Following User Says Thank You to mejunkhound For This Useful Post:
Roostre (10-14-16)
Old 10-14-16, 01:03 PM   #10
Apprentice EcoRenovator
 
Join Date: Apr 2011
Location: PNW
Posts: 194
Thanks: 0
Thanked 45 Times in 30 Posts
Default

How often do you need to clean them?

Posted before I say your question. The study from the early 80's I mentioned looked at the maintenance costs, specifically cleaning.

With the exception of cleaning after severe dust storms, never. The penalty was a 4 to 5% reduction in electrical output.

You can do your own trade on value of your cleaning time vs. say a 500 W loss of output on a 10kW array.

mejunkhound is offline  
Digg this Post!Add Post to del.icio.usBookmark Post in TechnoratiTweet this Post!
Reply With Quote
The Following User Says Thank You to mejunkhound For This Useful Post:
Roostre (10-16-16)
Reply


Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On



All times are GMT -5. The time now is 11:55 AM.


Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2018, vBulletin Solutions Inc.
Content Relevant URLs by vBSEO
Ad Management by RedTyger
Inactive Reminders By Icora Web Design