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californiamilleghia Reader
1/14/19 10:51 a.m.

What about golf ball size hail stones ?

If the first guy was so far off reality numbers on cost of KW etc I would throw him off my property , 

If it can stand on the facts great , but you get "Time share" salesmen working on commission throwing BS numbers around to make a sale, 

How much to store the extra KWs created in the sunshine to use at night ?  I would want a good battery backup if I needed power at night  when the area power lines are out....

Are you also putting in solar water heating ?


volvoclearinghouse UberDork
1/14/19 11:39 a.m.

Damage to the solar array is covered under home insurance.  

WonkoTheSane GRM+ Memberand Dork
1/14/19 12:00 p.m.
californiamilleghia said:

What about golf ball size hail stones ?

If the first guy was so far off reality numbers on cost of KW etc I would throw him off my property , 

If it can stand on the facts great , but you get "Time share" salesmen working on commission throwing BS numbers around to make a sale, 

How much to store the extra KWs created in the sunshine to use at night ?  I would want a good battery backup if I needed power at night  when the area power lines are out....

Are you also putting in solar water heating ?

Golf ball size hail stones shouldn't be a big problem.  Remember that these panels are designed to be used on remote outposts in the arctic and stuff.  Obviously, one can still be damaged, but my installer said he's never seen one knocked out by a baseball or hail, it took trees.

You really, really don't want to go down the "storing the energy" path, unfortunately.  It's still significantly more expensive than a generator.  See here for WAY more detail than you'd ever really want:



1988RedT2 UltimaDork
1/14/19 12:06 p.m.
jharry3 said:

Do a Net Present Value calculation using the real numbers that you verify yourself.    Other peoples figures lie and liars figure, as the saying goes. 

Walk away from any salesman who lies - because saying 20 years when its 10 is a lie.   Telling you the wrong unit price for electricity is a lie. 

Lying salesmen tell lies and use the lies to sucker you into falling for a "Benjamin Franklin" close - getting you to say "yes" to a series of statements so you say yes to signing on the dotted line.

Almost all alternative energy is subsidized by various federal, state, and/or local tax breaks.  

  Those giant windmills everywhere can't pay for their long term maintenance, for instance, but can make a payout to those who are ninja's at exploiting tax breaks and subsidies.   

Fossil Fuels, nuclear and hydro pay from themselves, the rest are vanity power generation.

Nailed it!

WonkoTheSane GRM+ Memberand Dork
1/14/19 12:12 p.m.

I have a large ground-mount array to cover my needs in CT (11.5 kW, 44 panels).  Luckily, I was spec'd to 110% of my usage the year before we upgraded our woodstove and we had a new baby.  With supplemental electric-heat and additional washing machine cycles, it meant we had a large need to replace.

There's two factors that make it worth it for me: 

1) State & Fed subsidies cut my cost from ~48k to ~25k

b) CT mandates that you're given an even kWh exchange from the electric company.  i.e., if I generate X more kWh than I need on any given day, I have an X kWh credit added to my account to use later.  What this works out to is that I generate a massive surplus from april-september and burn most of it in winter.  It's the worst possible deal for an electric company, and there's no way they'd do it if it wasn't for the law requiring it.  See if your state has similar. 

Because of those two factors, at my place, the break-even point was approximately 5 years, and the ROI really starts adding up @ the 7 year mark.  And my monthly loan payments are less than my average monthly electric bill was, so I really didn't have anything to lose.

Oh, and shop around.  I saved $~4k by using a recommendation instead of one of the three I called "out of the blue."  It is hard to find them.

barefootskater HalfDork
1/14/19 12:35 p.m.

In my little town, depending on where you live, you get either one of the cheapest power companies in the nation or one of the most expensive. No choice, it just depends on location. We also have >300 days of sunshine/year. For about 2/5 of the local populace it can make really good financial sense.

A coworker just had solar installed a few months ago. Had the local "big player" out, did estimates, plans, drawings, financial, etc. Dude was ready to sign and by coincidence a competitor came in and they were just shooting the breeze. Dude ended up saving $10k for an identical system and now pays about $50 less per month to power his house.

Shop around.

oldopelguy UberDork
1/14/19 12:41 p.m.

When you are talking solar the first question is are you in a net metering state? Net metering means that they add up all the power you use, subtract from it the amount you generate and bill you or credit your account with the difference.  There's not a lot of net metering left because it forces the people who don't have solar to pay all the infrastructure costs and pay the prevailing retail rate for a fraction of their power. If you are in a net metering state you may want to take the plunge sooner rather than later because eventually your neighbors are going to want their bills to go down and they are going to quit subsidizing your array.  Generally speaking if you get a contract in place before then you should be grandfathered when the laws change. 

Assuming you are not in a net metering state, like me, then you will be billed at the prevailing retail rate for the power you use and any excess your system pushes back to the grid will earn you payment at the prevailing wholesale rate. The last time I called my CO-OP the retail rate was @$0.12 per kwh and the wholesale rate was @$0.023 per kwh.

So if I use 5 kw every hour of every day and I generate 5kw of power with my array for 12 hours a day then my bill is 12 hours at free and 12 hours at 5x0.12=$0.60 per hour or $7.20 per day.

With the same usage and double the array at 10kw for 12 hours a day my bill is 12 hrs at free plus 5x0.023= $0.115 refund for 12 daylight hours, $1.38, and the same $7.20 at night for a total bill of $5.82 per day.

In addition you can claim for federal subsidies on the solar power you generate, which is currently something like 10% so you could get $0.13 back from the government at tax time with enough paperwork.  My COOP will incentivize me to let them take credit for my solar as part of their mix by upping my wholesale rate to $0.024 per kwh and I don't have to do the paperwork. 

Where I am going with all this is that purely grid connected can be expensive to pay off, and probably not pay for itself all alone.  You can look up your light hours per year online and call your utility and do the same math for your house.

Where you get ahead from a generation standpoint is when you can store your power and reuse it yourself.  Say you installed a Tesla power wall capable of storing the extra 60kwh your array generated.  Now during the day you cover your own usage so no bill for usage, but also no power generated to the grid so no refund either.  At night, though, you can supply your usage from the battery bank so you also have zero billable usage then too. Essentially you are paying for your storage at a rate equivalent to the difference between wholesale and retail power rates.

For me, about a year ago when I did all the math, it made sense to install about 25kw of solar and 8kw of wind at my house, along with a fairly small battery and inverter/charger equivalent to about 8kw for 4 hours.  With the wind and solar resources available at my house that should get me down to @$30/mo for my utility bill, basically just the monthly connection fee.

That setup was roughly $22k at the time, and would have taken @16 years to straight pay off, or closer to 20 if I budgeted for a battery replacement in there. 

frenchyd UltraDork
1/14/19 1:32 p.m.

In reply to volvoclearinghouse :

For A while I was selling Wind generators

sun goes down and you either go back on the grid or switch to backup batteries. Wind generators work any time the wind is blowing fast enough. 

How fast?  Well gear driven wind generators may need 7 mph or more. Direct drive with rare earth magnets might start working as low as 1.5 mph. ( depends on factors like blade design,  diameter, height above obstructions etc. )  good units start above 65 feet, great ones well in excess of 100  

bizarrely smaller cheaper units never will pay for themselves while the really big units that cost a million plus might have a 1-3 year payback depending on a lot of factors.  One I sold went into a truck stop with high electricity usage.  Windy location and the tallest obstruction were semi’s . Hog farmers loved them (Keeping pigs warm through the winter is really expensive)  But there were plenty of snake oil salesmen in the business.  Plus it’s a slow process.  A year is a real fast turnaround and salesmen don’t get paid until the end. 

In General surplus electricity is typically sold at last years rate while electricity you buy may be sold at today’s rates.  While that doesn’t sound that great for the electric company, they are selling something they have no cost in  and in a local area so transmission losses are virtually nonexistent. 

An ideal situation is a combination unit.  Wind, solar, standby, and battery.  However a decent Wind generator can easily cost north of $65,000 ( about a 12 year payback depending on factors such as typical wage nds and terrain )  



bobzilla MegaDork
1/14/19 1:54 p.m.

$20k is a lot less than the last quote we got 6 years ago. it was $75k then. If we could get a solar/wind combo for the house that would cover 70% of our electricity needs for $10k, I think we'd do it. Then find a way to cut back our electric usage. We don't have gas, so we're total electric. Over the last 2 years we've replaced older doors, added insulation and installed a new hvac setup.  I like the idea of being able to function off grid if need be. 

Antihero GRM+ Memberand Dork
1/14/19 2:05 p.m.

I lived totally off grid for about 17 years until I moved into the city for a bit. solar has gotten.....waaaaayyyy cheaper recently and my plan is to upgrade my system as it goes.

My system was way cheaper than what you are talking but I use a generator as well since deep in the woods of the northwest is not a great solar source in the dead of winter. My system is dirt simple a few panels/ battery bank and generator. I use the generator for heavy loads and to charge up the batteries when I use more electricity than I get in solar. For example though, my inverter was $800 but it isn't pure sine wave.


Solar can be a pain, what's your end goal? To be totally suffient or to just have a backup to the grid?

chaparral Dork
1/14/19 4:29 p.m.

If you do it right, you'll have power whenever the grid is powered AND whenever you've got sun - and can even contribute a little bit of resiliency to the grid by allowing the power co. all day to reconnect you

NGTD UberDork
1/14/19 6:18 p.m.

Up here in Ontario, the way it was made viable was to pay ludicrous rates to people to install solar. When they first started, they were giving 20 year contracts that paid in the range of 60 cents/kw. The amount that they pay now is lower but it's still way above the delivered electricity rate. After your contract expires, you get the system rate.

We are now living the legacy of those rates (plus paying for refurbing nukes) with very high electricity rates.

The expected lifespan of most solar panels goes beyond 20 years, most are expected to deliver into the 30 year range. They will degrade, but not to 0 in 20 years. The combination of degradation and the lower payout rate makes the beyond 20 year cash pretty low in any NPV calculation.

vwcorvette GRM+ Memberand SuperDork
1/14/19 8:17 p.m.

Co-worker installed panels himself (physics teacher). Only thing he hired out was connection to the house electric. Super cheap. Got most ofbhis stuff online. Big savings. 

Hoondavan Reader
1/14/19 9:07 p.m.

In a prior life I could recite all the details of Maryland's Renewable Energy Portfolio Standards (RPS) and net metering provisions.  I'm sure lots have changed in the last 10 years...but here are a few key questions to figure out.

Back in the mid-000's New Jersey made their incentives so generous it significantly increased the cost of solar for all customers in the mid-atlantic.

Owners of solar panels own the solar renewable energy credits (RECs) associated w/that generation.  They're sold to the generating companies at auction so they can meet RPS (a certain % of generation must come from solar, and a certain % from other renewable sources).  These credits can significantly reduce the cost of your installation.  I'd make sure you understand what you're being paid for those credits and making sure it's appropriate.  The install company will probably buy them and resell them at auction (and profit).  You should get help from the Maryland Energy Administration if you have any questions. 

Net metering allows you generate excess electricity in sunny months and use that surplus down during winter months, where your heat pump is active and it's not so sunny.  The goal of net metering wasn't to allow homeowners to "sell" electricity, but to send excess generation back to the grid so you can reuse it during periods when you're not generating as much electricity.  This benefits all ratepayers, becasue solar tends to generate the most electricity at times of peak consumption & pricing (hot & sunny).  In reality, electricity price change by the minute...so this is actually a big deal.  Lots of small solar means BG&E doesn't have to fire up a gas plant to cover that peak demand.

It looks like you can carry a credit for up to 12 months.  Anything left and you can get paid supply rate (excludes transmission) for any excess generation credits.  Frankly, if you're carrying a credit for 12-months you've overbuilt your system.  When I lived in MD you could "reclaim" the excess generation credits without paying the transmission charge.  BGE was trying to make a case that net generators/customers should pay transmission fees when they reclaim their excess credits.  I'm not sure where things stand now...but it does make a difference.

Battery backup is another option...but probably cost prohibitive for many people.  In theory, net metering should do the same things.

It may be tough to justify solar based on economics alone, but solar does protect you from increases in electricity prices.  If I could afford it, I'd add a small system and offset my carbon footprint.  Solar is pretty far down the list of priorities.  For what it's worth, solar hot-water is a relatively small investment with a much quicker breakeven.  


Boost_Crazy HalfDork
1/14/19 11:13 p.m.

The payback timeframe depends a lot on the rate you pay, if your rate is on a tiered system, and if you have net metering. 

Here in CA, with the high energy rates and steep pricing tiers, payback should be in about 6-7 years on a good system. 

Do some research on the products. Not all solar is equal! You wouldn't go into a car dealer and say, "Well, I guess since the average new car is $35k, that sounds perfectly reasonable for that Mitsubishi Mirage." Yet that's what a lot of solar customers do. They go for the cheapest price, which is often crap products with a crappy install. The good manufacturers are not often much more than the cheap ones, but some installers try to cheap out wherever possible. This is extremely important with solar. Don't be concerned about 25 year warranties. Odds are that the manufacturer and the installer will be long gone before then. Choose a good product and good installer so you will be less likely to need a warranty. 

The most important part is the mount. They range from very good almost fool proof to guaranteed to leak. Not much a problem for a standing seam roof.

All modules are not equal. Do your research. A good module should still be producing for over 30 years.

inverters are the weak point. A string inverter is good for 10 years, more than that is bonus. So plan on 2 replacements over 25 years. Plus deduct the energy bills you had to pay since you system was down while you waited for the repair. Micro inverters cost a little more, but should be good for 25 years. If one fails, you lose production from one module, not the whole system. If they do fail, it's usually early when still under warranty and while the installer is still in business. 

You rarely want to size a grid tie net metered system for 100%. Quickest payback is a smaller system that knocks out higher tier energy rates. Let's say your base rate is $.20 per kWh, next tier is $.30 per kWh, then $.40 per kWh. Say the first 10 modules you install knock out the tier 3 charges. That would make for a quick payback. Add 10 more, knock out tier 2. Not bad, but slower payback than the first 10 installed. Want to zero your bill? Now install 10 more. But it will take much longer to pay off those last 10 than the first. Sized for 85-90% is usually a good balance between quicker payback and greater payback over the life of the system. 

If you are on this site, there is a good chance you can do the install yourself. If you are comfortable on the roof, standing seam is easy with the right clamps. Racking nowadays is easy. Micro inverters are easy for the DIY'er. No calculations involved, just 1 for 1 with the modules. They turn the DC to AC right at the roof, so it's just running a circuit to the panel. An electrician can do the final connection. Labor is more than half the cost, so doing it yourself can cut your payback in half.

volvoclearinghouse UberDork
1/15/19 1:59 p.m.

I did some research into costs for panels and inverters and mounting, made a few SWAGs based on what the Sunrun rep told me, and came up with this:

About $11,500 to do the system, assuming the labor numbers are somewhere in the ballpark.  That's 3 guys working one day to do the install (the rep told me they'd install it in one day),  8 hours labor for a skilled electrician, 8 hours labor for the designer, 10% profit, and the permit costs (which I researched for my county).  The 11,500 would not include the built-in warranty, which would add somewhat - the rep had said the warranty would add about 2,000 to the cost.  

I contacted another local company and they're going to give me an estimate tomorrow.  I think if I can get the system in for something around the 13-14k mark (including the warranty) I might pull the trigger.  10 year financing on that (after the fed / state tax credits) would be a bit more than the current electric bill, but then it would be "free" power after that.  

SVreX MegaDork
1/15/19 2:56 p.m.

I’ll be interested to see. 

Fladiver64 Reader
1/15/19 7:22 p.m.

I have looked into this as a Florida resident, you would think the sunshine state would be the best location. Couple of things I noticed in going through the sales process is most of the Solar Companies are selling like other high-pressure rip off products, like $8k water treatment systems.

When we got down to the contract I noticed the contract I would have signed ( I didn't I just wanted to see the contract) was not with the big name company, but a similarly named installation company. A little research showed that the installation company had only been in business 6 months and a very similar name had gone out of business after running for 3 years.  This is a very common tactic here with lifetime warranty water treatment companies, the warranty is with a company that goes out of business every three years or so. 

I also find it nearly impossible that these electronic devices are going to last the 20 to 30 years that are being claimed. How many 20-year-old electronic devices are still working in your house? 

The biggest issue I noticed in the loan contract is there is not a lean against your house. The loan is done as a personal line of credit. This means that if you ever want to sell your house, the new owner is not required to buy your solar system in order to buy the house. Solar systems are a bit like pools in that they cost way more than the value they add to your property.  You could end up still making payments on a solar system that is on someone else house.

So far I have yet to see a deal that makes sense financially, there are no guarantees that the power company will continue to buy back power and there is no guaranty of rate so the assumptions the sales companies are using to get 7 year paybacks are hugely out of scale to reality, at least here in Fl. 

I also had Tesla come out as we had to replace our roof after the last hurricane, new solar roof with dual battery backups and inverters to meet our power needs $97K. I had a 50 year asphalt roof installed for $18K. I never would see a payback on that system, but I guess the same people buy the cars for the fuel savings.

Boost_Crazy HalfDork
1/15/19 8:56 p.m.

In reply to volvoclearinghouse :

I think you way underestimated the profit part of your cost estimate. Installers "make" way more than 10%. If you look at your total divided by the number of watts, you are below $2.00 per watt. Not sure about your area, but I believe $2.50 per watt is on the real low side with $3.00 per watt about the norm for a decent installation, higher in some areas. Solar companies spend a lot of time and money generating sales, which is a large part of their cost that you don't see. Part of the reason they need to make such a large gross profit. Your materials cost looks pretty close if a little low. It looks like you are using a Solar Edge inverter, which needs optimizers for each module- figure about $1400 total for those. You racking cost is a bit high, but there are a lot of odds and ends that you will need, so call that a wash. If your electrical service needs any major changes to accommodate the solar, that can add up. The design charge is high, there are lots of companies that will do the design and drawings for much less. Be sure to check the permit costs, they can vary greatly from city to city. 

ProDarwin UltimaDork
1/15/19 9:39 p.m.
Fladiver64 said:

I also find it nearly impossible that these electronic devices are going to last the 20 to 30 years that are being claimed. How many 20-year-old electronic devices are still working in your house? 

The speakers/sub on my computer here are circa 1998.

The electronics in my 1998 Saturn still work fine.

Plenty of Gen1 Priuses never had electronics failures - and they have similar systems to a solar setup.

I can't say I've had many home electronics fail - they mostly go obsolete.  And those that have failed are on items with a 1-3 year warranty.  I'm betting the design/construction on the solar equipment is a bit better. 

SVreX MegaDork
1/15/19 9:48 p.m.
SVreX said:

I’ll be interested to see. 

I pulled my punch with this comment. 

I think you are kidding yourself.  You’re not buying a solar system for $11K, and you are grossly underestimating the markups and margins companies in this business need to make. 

I think you have established an unreasonable baseline which will lead you to walking away from this before you analyze the honest pluses and minuses. 

Its too bad. 

WonkoTheSane GRM+ Memberand Dork
1/15/19 10:59 p.m.

VCH - If you're interested, I can dig up the paperwork for exact cost of my ground-mount setup from 5ish years ago.  It uses Solar World 270 W USA made panels and Enlight micro inverters.  I did nothing other than sign papers for it, so all of the profit and labor was done by the company that's probably 10+ years old now (not fly-by-night) and personally known in the network for at least double that.

volvoclearinghouse UberDork
1/16/19 6:13 a.m.

In reply to SVreX :

I don't take my numbers as gospel, obviously I'm not in the industry so I don't know what the margins and markups are.  But the reason I did this is because the first quote I got didn't give any sort of a breakdown of why their number was $22k.  But they did provide the details on some of the parts used, and some of the labor involved.  I know how much electricians make, and have a decent idea of what a laborer would make.  I could see if a company came in 25% higher than my estimate, but double?  

I don't see what's "too bad" about it.  On the same spreadsheet that I did the cost estimation I built a payments calculator to determine payback on the system.  Even at 12k for the system, including the federal rebates, the payback isn't for 13 years.  At 22k the payback is "near as makes no difference" never.  There aren't any pluses that will outweigh overall more money out of pocket for the same amount of electricity.  

It's also telling that I still have yet to receive a reply to my email and questions I had.  That alone turns me off.  

Appt. with company #2 is tonight.  

volvoclearinghouse UberDork
1/16/19 6:26 a.m.

On some of the other comments...(thank you for those, BTW, very constructive)

  • A grid-tied system does not protect from power outages.  If power goes out, we have no power.  That's the way they work.  An (expensive) battery backup would protect against this. We have a gas generator sized large enough to power our well pump and a few lights, which is all we need.  Power outages around here are pretty infrequent- maybe twice a year for a few hours.
  • Maryland is a Net Metering state, but there's a catch.  I did some poking around and it looks like Net Metering has a provision to sunset once total solar power installations in MD reach something like 10% of peak power requirements- something like 1500 mW.  I haven't been able to determine how close we are to that, but the potential seems like it would exist that Net Metering would go away.  Not sure if those who put in solar before it goes away would be "grandfathered" for some time, or if it just ends.  A question I need to get clarified, as it could make a big difference.  
  • Wind is a non-starter.  While we probably get plenty of wind, I'm not terribly keen on the aesthetics, plus I have heard some issues with noise.  Also a big spinny blade 100 feet up near my house is not something I'm too comfortable with.  
  • Not willing to DIY this.  I'm not really comfortable working on roofs, or hauling 40 lb panels up on a roof.  Especially by myself.  


ScottyB Reader
1/16/19 2:52 p.m.

something i haven't seen mentioned much here is to be sure you consider a solar photovoltaic map in relation to your location before you even consider solar.  panels need to be well adjusted to the overhead sun throughout the seasons to be efficient, and for many areas of the northern US you're going to have a hard time making the best possible power per panel.  if i was in the rust belt or new england, i think it would be a non-starter for me unless heavily subsidized like others mentioned, or if i was committed to being completely off grid.

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