Quote for new 9K PV system

Hi all, first time poster, long time lurker. Have learned alot reading your posts and was wondering if you can help me out.
I've decided to take the next step with a roof mounted PV system for my home in MA and reached out to Alteris for a site visit quote. I have a large roof that is almost perfectly south facing with no shading other than a chimney. Keep in mind I asked them to provide a system that would give me the maximum output for the size of roof. They have quoted me the following:

9.0K DC system, 40 SunPower SPR-225E-BLK-D panels, 1 SunPower SPR-8000f inverter, SolarMount mounting system
$57,099 before any Federal/State incentives

Two questions I have:
1. is this resonable - $6.34/KW
2. is the inverter correct? According to the specs I have found, the max load for this inverter is 9,200 KW. Should I go with something bigger to maximize peak generating?

Would appreciate any and all thoughts - Thanks!

Comments

  • Solar GuppySolar Guppy Solar Expert Posts: 1,963 ✭✭✭
    Re: Quote for new 9K PV system

    Get a quote using Evergreen panels, sunpower IMHO is not worth the extra $$

    You could easily save 1-2 dollars watt on the panels for maybe a 3-5% difference in total generation for the same roof size

    Using for example Evergreen panels and Sunnyboy inverters your parts cost would be about 25K fro a 9Kw system .. Even if you pay the installer 10K, thats still 18K less than your quote
  • BB.BB. Super Moderators, Administrators Posts: 31,149 admin
    Re: Quote for new 9K PV system

    Also, is that price before or after local and federal tax breaks/other rebates?

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • BartenderBartender Registered Users Posts: 6
    Re: Quote for new 9K PV system

    Thank you both - I will look into the Evergreen components

    The price of $57K ($6.44kw) is raw, before any incentives, state incentive would be about $5K and another $16K in federal credit = ~$35K after incentives
  • BB.BB. Super Moderators, Administrators Posts: 31,149 admin
    Re: Quote for new 9K PV system

    Have you defined what you want this system to do? Save money, "go green", or do you need emergency backup power?

    A pure Grid Tied system is certainly the least costly and most efficient method for a home owner to generate electric power.

    For emergency power, it will not help. Grid Tied systems turn off when the utility power fails.

    Have you worked out the amount of power and cost to generate from your system? Just using a simple PV Watts website for Boston, 9kW of solar panels, fixed on the roof:
    "Station Identification"
    "City:","Boston"
    "State:","Massachusetts"
    "Lat (deg N):", 42.37
    "Long (deg W):", 71.03
    "Elev (m): ", 5
    "PV System Specifications"
    "DC Rating:"," 9.0 kW"
    "DC to AC Derate Factor:"," 0.770"
    "AC Rating:"," 6.9 kW"
    "Array Type: Fixed Tilt"
    "Array Tilt:"," 42.4"
    "Array Azimuth:","180.0"

    "Energy Specifications"
    "Cost of Electricity:","11.8 cents/kWh"

    "Results"
    "Month", "Solar Radiation (kWh/m^2/day)", "AC Energy (kWh)", "Energy Value ($)"
    1, 3.36, 752, 88.74
    2, 4.36, 882, 104.08
    3, 4.79, 1033, 121.89
    4, 4.92, 1003, 118.35
    5, 5.33, 1071, 126.38
    6, 5.41, 1014, 119.65
    7, 5.60, 1082, 127.68
    8, 5.64, 1099, 129.68
    9, 5.13, 992, 117.06
    10, 4.65, 963, 113.63
    11, 3.14, 651, 76.82
    12, 2.98, 651, 76.82
    "Year", 4.61, 11193, 1320.77

    So, it will generate around 651 to 1071 kWHr per month (varies by season) and 11,193 kWH over the year.

    Assume 20 year pay back and you need to replace an inverter after ~10 years (assume $4k for replacement).
    • ($35,000 + $4,000) / (20 years * 11,193 kWH per year) = $0.174/kWH
    Not a bad cost--but you have chosen to "pre-pay" (at least part of) your electric bill for the next 20 years.

    You can play with present value/future worth and take your guess at what power bills are going to do in the future.

    In Northern California, for heavy power users (over ~1,000 kWH per month) can pay upwards of $0.40 to $0.60 per kWHr today)--So a Grid Tied system can really make economic sense.

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • BartenderBartender Registered Users Posts: 6
    Re: Quote for new 9K PV system

    Thanks Bill - this is really helpful. My biggest driver in going PV is to save $, hence looking for the biggest system possible for my site. I already have an automatic back-up genset (propane) so it's really to take advantage of net metering. Electric here is about $.145/KWh but there is also a SREC market in MA with a floor of $300/MW so factor I can factor in another $3K annually for the next 9 years (program is already one year in on a 10 year program)

    the annual savings on electricity is ~$1,500 (@$.145Kwh) + $3K SREC = $4,500

    Assuming this the $35K net investment is paid in 7.8 years - still within the SREC program window. Add a replacement inverter for $4.5K and it adds another year to the payback. Is this payback timeframe high, low, about right?
  • BB.BB. Super Moderators, Administrators Posts: 31,149 admin
    Re: Quote for new 9K PV system

    From my point of view--You are protecting yourself against future cost increases--and assuming that you will live in your home and continue to use that level of power for the next 10-20 years.

    From what little I have seen, having an Grid Tied solar system on your home will not add much to the value to your home if you need to sell it in the future (and your real-estate agent may request you remove the system because is "scares" some potential buyers).

    For investment--I am a huge believer in conservation (insulation, more insulation, double pane vinyl windows, energy star appliances, review heating/cooling needs vs heat pump based systems, review electric heating/cooking vs alternative natural gas/propane/solar thermal systems, using laptop vs desktop computers, following kids around and turning things off, etc.).

    Generally address the big loads first before causing your spouse to consider divorce because you want them to unplug the cell phone charger when not in use.

    In general, conservation is both a better investment and frequently makes the home more livable (fewer hot/cold spots), and simply lower power bills.

    Personally, I would do all of the conservation you can first, before doing the solar PV / Thermal thing.

    Of course, if your home is newer and well constructed. And you have perfect kids that turn everything off when they are done :roll:;), then looking at Solar PV GT power and Solar Thermal (space heating/hot water) would be the next thing to look at.

    You are in a cold climate, but for warmer weather/climates, there are heat pump based water heaters that are great energy savers if you don't have natural gas/propane available at your home (above ~54F, you can get a 2:1 return vs simple electric water heaters.

    Here is a thread with lots of random solar/conservation links and projects.

    -Bill

    PS: I should add that your return is very good... Most of us will be lucky if we break even (if there is no huge future increases in the cost of electricity).

    I am a big believer in having savings--around 6-12 months minimum of cash on hand in case job goes south, etc. I would not recommend taking a loan out for your solar PV system if you do not have the 6-12 cash cushion.

    At least many conservation measures actually add value to the home (50% to 100% of your costs--depending on lots of things--but 50% is probably a good assumption). Solar PV array--not so much.
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • BartenderBartender Registered Users Posts: 6
    Re: Quote for new 9K PV system

    Yes, it's basically protecting against future increases. My house is fairly new, only 6 years old but my heat and hot water are oil fired which is common in the Notheast. I've been thinking that perhaps that's where I should focus my energy (no pun intended) by looking at a more efficient system but how much efficiency am I going to get out of replacing somethig that's only 6 years old? is it going to be enough to make the payback worth it? I know there are super efficient oil boilers out there but what's the maintenence/am I going to be able to find someone to service something from Sweeden at 2am when it decides to stop working.

    We use quite a bit of electricity so i figured going to a PV system is low hanging fruit but then again electricity prices are regulated (to some degree at least) oil is not......
  • BB.BB. Super Moderators, Administrators Posts: 31,149 admin
    Re: Quote for new 9K PV system

    There have been some marked increases in efficiency for heating/cooling appliances.

    And oil prices (as I understand) can vary dramatically (3:1 between seasons/crises?).

    It would not hurt to have a Heating Contractor review your current setup and see what you could do to improve your efficiency.

    Your power company may also offer some form of home energy audits too.

    But take everything that these guys say with a grain of salt. Some folks are just there to generate sales for boilers, and the home audit guy may not know as much about conservation as you (especially after you do a little research on the web and play with some of the on-line conservation estimators.).

    Even with fairly new homes--many people can still have significant savings from adding insulation in the attic (minimum required when built, insulation packing over time, etc.).

    Also, I added a PS on my previous post you may not have seen about cash savings in the bank vs PV power.

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • BartenderBartender Registered Users Posts: 6
    Re: Quote for new 9K PV system

    Sorry - did not see your p.s.

    Yes, this would be funded from savings, no loan. After making this kind of investment I would still have over 6 months of living exps banked so I not sticking my neck out. I look at this cash earning 1% in the bank and start thinking of other ways to "invest" without the risk. I agree 100% with your philosophy around conservation - I see no better investment than to sink the money into improving something that we know is not going to go down (energy costs) especially considering that those costs are, by and large, unavoidable

    The most efficient oil fired boilers are around 86% efficient, my current one is about 82% at last check so saving 4% on my oil consumption is no great annual savings unless the price of oil increases 5 fold
  • xiphiasxiphias Solar Expert Posts: 52 ✭✭✭✭
    Re: Quote for new 9K PV system

    To save energy, tighten up the building.

    Lots of PV installers here in MA, some of whom have been around a long time; consider giving them a shot at your business.

    About the MA program.

    The SREC program in 2011 still allows enrollment for 10 years (40 quarters) from date of interconnect. So you are not losing a year if you install this year.

    The floor price is $285/SREC. The ceiling is effectively $600/SREC, which is the alternative compliance payment. There is a journal paper by the consultants who did the SREC program modeling for MA DOER that shows potential SREC prices for the next 10 years or so. It's here:

    http://www.mdpi.com/2071-1050/2/9/2746/


    You will qualify for an MA rebate "adder" of $0.10/watt if you use a major component manufactured in MA. Evergreen is in MA. So is Solectria inverters. Both are good products. Either would qualify for the adder.

    You can also qualify for a home value or income adder of $0.75/watt. This is a change from 2010.

    The letter describing the new rebates is here:
    http://www.masscec.com/masscec/file/CSIIRebateUpdateLetterWeb.pdf

    The overall program is described here:
    http://www.masscec.com/index.cfm/page/Commonwealth-Solar-II/cdid/11241/pid/11159

    Rebates, however, are capped at 5 kW for residential systems. You can install more than 5 kW, but your rebate will be figured on 5 kW.


    It's pretty easy to run the numbers and come up with an ROI for your system.
  • BB.BB. Super Moderators, Administrators Posts: 31,149 admin
    Re: Quote for new 9K PV system

    Getting a few percent improvement in efficiency sounds nice--but when you work out the details--It does not always work out.

    For example I can replace my tanked water heater with a tankless and save "up to" 25% on my hot water costs... Given that my hot water costs only ~$20 per month--the savings is only $5 per month or $60 per year... To install tankless would probably cost north of $2,500 and a $1,500 fed tax credit--It would take a minimum of almost 17 years to pay that back... Not thrilled with that. Possible savings as tanked water heaters are not cheap anymore (~$400-$500+ for a 50 gallon natural gas) and they last around a dozen years or so...

    For my brother, he would probably gain by installing more oil storage so he can buy a year's worth of oil in the spring or summer when prices are low(er)--and ride through the winter price cycle.

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • BartenderBartender Registered Users Posts: 6
    Re: Quote for new 9K PV system
    xiphias wrote: »
    To save energy, tighten up the building.

    Lots of PV installers here in MA, some of whom have been around a long time; consider giving them a shot at your business.

    About the MA program.

    The SREC program in 2011 still allows enrollment for 10 years (40 quarters) from date of interconnect. So you are not losing a year if you install this year.

    The floor price is $285/SREC. The ceiling is effectively $600/SREC, which is the alternative compliance payment. There is a journal paper by the consultants who did the SREC program modeling for MA DOER that shows potential SREC prices for the next 10 years or so. It's here:

    http://www.mdpi.com/2071-1050/2/9/2746/


    You will qualify for an MA rebate "adder" of $0.10/watt if you use a major component manufactured in MA. Evergreen is in MA. So is Solectria inverters. Both are good products. Either would qualify for the adder.

    You can also qualify for a home value or income adder of $0.75/watt. This is a change from 2010.

    The letter describing the new rebates is here:
    http://www.masscec.com/masscec/file/CSIIRebateUpdateLetterWeb.pdf

    The overall program is described here:
    http://www.masscec.com/index.cfm/page/Commonwealth-Solar-II/cdid/11241/pid/11159

    Rebates, however, are capped at 5 kW for residential systems. You can install more than 5 kW, but your rebate will be figured on 5 kW.


    It's pretty easy to run the numbers and come up with an ROI for your system.


    Thanks for the paper on the SREC program. Certainly supports an assumption for using a higher value on the credits rather than the $285 floor.

    I'm basically looking at two systems - a 9KW system using SunPower and a 7.4KW system using Schuco. Looked into Evergreen but the panels are larger in size so the max i could get was 6.5KW in the same space. The price was also $3K higher than the Schuco system.
    Running the numbers including the SRECs, Fed & State incentives - the ROI in $ is the same on the SunPower and Schuco systems - all things being equal. The SunPower system is $11K more after Fed/State incentives so the upfront is higher and ROI % is lower. BUT that's assuming a static cost of energy over the 25 year life of the system - factor in a 3% yearly increase in electricity cost and the larger SunPower system starts to look better in ROI.....
  • wdegracewdegrace Registered Users Posts: 8
    Re: Quote for new 9K PV system

    I think your numbers look good. In NC i have been giving quotes for right about $6.25/watt. However, it all depends on the equipment specified in the estimate. Most of my ROI's on residential systems are around 7.5-8 years for typical residential grid-tied systems. Battery back-up and hybrids shoot to $10/watt easily.
  • LucManLucMan Solar Expert Posts: 223 ✭✭✭
    Re: Quote for new 9K PV system
    Bartender wrote: »
    The most efficient oil fired boilers are around 86% efficient, my current one is about 82% at last check so saving 4% on my oil consumption is no great annual savings unless the price of oil increases 5 fold

    Check out the Buderus site they have 90+ eff. oil boilers.
    http://www.buderus.us/products/oilheating/oilcondensing/logano-gb125be.html
    These boilers are in my opinion the best you can get. Great efficiency and reliability.
    You can expect 30% savings in oil consumption. But they are still oil fired so yearly service is highly recommended, and oil prices will never be stable.

    Installing a 9KW pv system should leave you with excess power production. Why not install a high efficiency heat pump and get away from oil completely. Electric prices should be more stable in the future if you need to purchase power from your utility.
    I have done the calculations for my house and with a 10KW system I would be completely energy independent. :D
  • SolarLurkerSolarLurker Solar Expert Posts: 122 ✭✭
    Re: Quote for new 9K PV system

    I have a 31kw system feeding my barn, that uses sun power panels. I also have a 11.2kw system feeding my residence using kyocera panels.

    No shading on either array, the arrays are less than 30 ft from each other.

    The residential array uses a sunny boy inverter, identical to the sun power.

    The sunpower system wakes up sooner, shuts down later and daily generates more than 3 times the residential. Thursday my residential system did 28.9kwh where the sunpower did 99.80kwh.

    I installed the 31kw system for the srecs. I signed a guaranteed 5 year contract specifying a specified price per srecs. I look at it as an investment, in 4 years I will have all my money back, in year five I will turn a profit besting CDs. It's unclear what the srec maker will look like in 5 years so I figure if I can earn all my money back before my contract expires there is really no risk.

    One nice thing about the sunny boy/sunpower inverter is that you can install a sunny island to add batteries and integrate your generator so that you will have power should the grid fail.
  • SolarLurkerSolarLurker Solar Expert Posts: 122 ✭✭
    Re: Quote for new 9K PV system

    I would suggest you get the biggest PV system you can. Then get a ground source heat pump. A ground source heat pump may heat and cool you house for less than 800 dollars a year. If your house is of average size you may be paying 3000 or more for oil.

    You could add a solar thermal system in the mix to increase efficiency of the heat pump.

    I would finance the solar, preferably a low interest home equity loan. 60k financed and at 5% should equal about what you are paying in electricity each month.
    Then you can dump your srec and state incentive money into investments. By financing the system you will be cash flow positive in year one. Ie you make 4000 in electricity and srecs you have a cost for 1800 so you can 2200 more dollars in year one.

    You will have a loan, for 25 years, however it's of little consequence because you would of had to pay the money to the electric company anyway.
  • russruss Solar Expert Posts: 593 ✭✭
    Re: Quote for new 9K PV system

    The solar thermal won't make a whole lot of difference with the GSHP performance/operating costs unless you have a monster sized thermal system.

    If you have cold winters the GSHP is worth the extra cost. If you were in a milder climate the ASHP would be a better choice.
  • SolarLurkerSolarLurker Solar Expert Posts: 122 ✭✭
    Re: Quote for new 9K PV system

    I think Massachusetts would qualify for a cooler climate and support the choice of a ground source heat pump.

    A large solar thermal system really is not necessary check out solarbair.com, he's in Michigan and has a neat setup.
  • xiphiasxiphias Solar Expert Posts: 52 ✭✭✭✭
    Re: Quote for new 9K PV system

    GSHP is really expensive to install. GSHP and/or solar thermal in terms of efficiency and economics depends a lot on the structure being served. It's really about the building envelope and how the heat load is met....

    The level of incentivization in MA makes PV pretty much a no-brainer. In some ways that's unfortunate as it bypasses a lot of easy stuff like better building envelopes that will long outlast a PV array.
  • LucManLucMan Solar Expert Posts: 223 ✭✭✭
    Re: Quote for new 9K PV system
    xiphias wrote: »
    GSHP is really expensive to install. GSHP and/or solar thermal in terms of efficiency and economics depends a lot on the structure being served. It's really about the building envelope and how the heat load is met....

    The new air to water HP's eliminate the costs for the wells and efficient to 5 F, they are being utilized all over Europe and now the US.
    The overall seasonal COP is about the same as a GEO system with out the complexity of the wells.
    As you stated the building envelope is the most important factor, a tight home now has many other options as to fuel selection with an over sized grid tie PV array.
  • cpetkucpetku Registered Users Posts: 22
    Re: Quote for new 9K PV system

    I beat the larger inverter question to death in my post under Grid Tiied system (8.8K array posting). Basically there are so many losses in the DC section that you will not benefit from having an oversized inverter.

    Look at your PTC rating then consider 0.5% degredation/yr for the panels aging. Drop another 1% for DC wiring and another for contamination (dirty birds) pretty soon you'll see that you have already oversized your inverter and anything more is just wasting money.
  • ggunnggunn Solar Expert Posts: 1,973 ✭✭✭
    Re: Quote for new 9K PV system
    cpetku wrote: »
    I beat the larger inverter question to death in my post under Grid Tiied system (8.8K array posting). Basically there are so many losses in the DC section that you will not benefit from having an oversized inverter.

    Look at your PTC rating then consider 0.5% degredation/yr for the panels aging. Drop another 1% for DC wiring and another for contamination (dirty birds) pretty soon you'll see that you have already oversized your inverter and anything more is just wasting money.
    I agree. IMO the only reason to oversize an inverter is if you intend to add to the array later.
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