New 5.25kW project

ArizonaEngineer
ArizonaEngineer Registered Users Posts: 10
Hi forum members,

I want to use this thread to document my 5.28kW solar install on my house in Buckeye, AZ. I will eventually take it over to another dedicated website to house the project.

I have a 2 person household, average of 280 off peak Kwh, 40 on peak throughout the winter. ( Moved in November). I sized up the system in preparation for electric car in somewhat near future.

I initiated the project in March and am expecting to have the install happen at the end of this month. The permitting plans are going to the city tomorrow for approval and then they are ready to go!

I have 22 Kyocera KD240GX-LPB panels going in with a tilt of 25 degrees facing just west of south that will be connected to a 5 KW powerOne inverter.

Some questions I have for you all:

1) I brought up a question to to installer about the inverter only being rated at 5kW with a 5.28kW array. He said that it was capable of handling the load, I still am questionable that it can output rated power. It seems some peoples arrays on this forum actually put out more then rated power. Thoughts?

2) For those in APS territory, I am currently on the 12-7pm time of use plan. I have set up to roll over to the net-metering time of use plan, EPR-6 when the time comes. What is the most cost effective/best plan that people are using?

Comments

  • solar_dave
    solar_dave Solar Expert Posts: 2,397 ✭✭✭✭
    Re: New 5.25kW project

    Well you didn't really address what the summer electric load looks like, Ask APS they have the records.

    That being said I have a 2500 sq ft in Arrowhead and have over killed my solar system in anticipation of having 2 Chevy Volts (one in transit already to AZ) I am on the grandfathered 9AM - 9PM Mon - Fri Peak TOU plan, I think you have selected you best available option for APS plans currently available. This property has 2 3ton Trane high efficiency Heat pumps and a swimming pool. We CFL or LED all lighting, increased out insulation changed the pool pump for a VFD based pump, caulked, sealed and foamed every nook and cranny. We also changed out all the appliances for Energy Star, and added Solar thermal for hot water.

    As you probably have read everywhere here do some conservation efforts for sure, a watt can be saved for a lot less than produced with Solar.

    I think your key is to load shift as much as you can to the off peak rates which are way cheap @ something like $0.055 per Kwh. Laundry, cooking, car charging ... all off peak and you can probably get a sizable reduction in your APS bill. One nice thing in the fall is APS will credit your account for any excess Kwh on EPR6 on the last day of the year, and you can start out the year with a credit. I still have about $80 in credit with APS so far this year.

    You don't tell us much about your loads, take a little inventory and understand where you opportunities for improvement lay.

    In AZ you will be unlikely to get anywhere near over capacity on a 5K watt inverter using 5.28 Kw of panels. Low winter sun angle and summer heat will be a reduction in panel output.
  • BB.
    BB. Super Moderators, Administrators Posts: 33,431 admin
    Re: New 5.25kW project
    Some questions I have for you all:

    1) I brought up a question to to installer about the inverter only being rated at 5kW with a 5.28kW array. He said that it was capable of handling the load, I still am questionable that it can output rated power. It seems some peoples arrays on this forum actually put out more then rated power. Thoughts?

    That is normal... Panels rarely output their "marketing" rated power--Typically closer to 80-85% of their marketing numbers. Solar panels heat up in sunlight and their output voltage falls some as they get hot--Therefore, their output power falls some too.

    You could put a 6kW inverter on the 5.28 kW DC array--but you will not gather very much more power (if any) because of the larger inverter--You will probably only clip a couple hundred watts a few days a year for less than an hour a day (giant SWAG). Maybe a few dollars more worth of electricity a year.

    More or less, the "law of diminishing return" as one new poster summarized the other day.
    2) For those in APS territory, I am currently on the 12-7pm time of use plan. I have set up to roll over to the net-metering time of use plan, EPR-6 when the time comes. What is the most cost effective/best plan that people are using?

    I live in Northern California and we had the same thing--an old E-7 plan with peak power from Noon-6pm... And a new E-6 plan (mandatory for new solar RE installs) with partial peaks from 10am to 9pm.

    For my family, it was easy to describe when not to "waste" electricity--Noon to 6pm weekdays during "summer".

    The new plan had off peak, partial, and full peak, different between weekdays and weekends, different between summer and winter, etc... A real mess--and it was much harder to push electric use to after 9pm (cooking, etc.). But we were able to stay with the old E-7 plan (grandfathered in--in fact, the grandfathered plan was one thing that pushed me to buying/installing solar GT at that time).

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • solar_dave
    solar_dave Solar Expert Posts: 2,397 ✭✭✭✭
    Re: New 5.25kW project

    If you haven't already, take a look at the PVWatts site, pretty accurate from what I have seen overall as a great estimation tools

    http://rredc.nrel.gov/solar/calculators/PVWATTS/version1/

    My system is 12.5Kw (6250 watts per inverter) name plate with two 5.2 Kw inverters and have never actually seen a peak plateau on the inverter data. It has touched the max for a minute or 2 on a very good day. but mostly runs in the 9000-10000 watt range midday this time of year which is optimal angle and temp kinds of days. Yesterday was great one mid 70's with a breeze until the clouds moved in.
  • solarix
    solarix Solar Expert Posts: 713 ✭✭
    Re: New 5.25kW project

    You sound good. Must live an exemplary lifestyle to need only a 5kw system when planning for an EV. I do know that Buckeye will require you to put in a superfluous DC disconnect in addition to the one in your inverter. Why did you choose kyocera and power one if I might ask? Are you doing the install yourself? What kind of roof and what racking will you use? The ET-2 rate plan will work great for you if your on-peak percentage is that low. What will it be in August though when peak rate is 3 times higher than the off-peak. The cost effective system size is usually to just replace your on-peak power with solar and pay APS for their off peak power.
  • ArizonaEngineer
    ArizonaEngineer Registered Users Posts: 10
    Re: New 5.25kW project
    solar_dave wrote: »
    Well you didn't really address what the summer electric load looks like, Ask APS they have the records.

    That being said I have a 2500 sq ft in Arrowhead and have over killed my solar system in anticipation of having 2 Chevy Volts (one in transit already to AZ) I am on the grandfathered 9AM - 9PM Mon - Fri Peak TOU plan, I think you have selected you best available option for APS plans currently available. This property has 2 3ton Trane high efficiency Heat pumps and a swimming pool. We CFL or LED all lighting, increased out insulation changed the pool pump for a VFD based pump, caulked, sealed and foamed every nook and cranny. We also changed out all the appliances for Energy Star, and added Solar thermal for hot water.

    As you probably have read everywhere here do some conservation efforts for sure, a watt can be saved for a lot less than produced with Solar.

    I think your key is to load shift as much as you can to the off peak rates which are way cheap @ something like $0.055 per Kwh. Laundry, cooking, car charging ... all off peak and you can probably get a sizable reduction in your APS bill. One nice thing in the fall is APS will credit your account for any excess Kwh on EPR6 on the last day of the year, and you can start out the year with a credit. I still have about $80 in credit with APS so far this year.

    You don't tell us much about your loads, take a little inventory and understand where you opportunities for improvement lay.

    In AZ you will be unlikely to get anywhere near over capacity on a 5K watt inverter using 5.28 Kw of panels. Low winter sun angle and summer heat will be a reduction in panel output.


    The house was built in November so It doesnt have any summer data. It is APS energy star so the insulation is decent and everything is sealed up. The A/C is 13 SEER. Range, Hot water and furnace are are gas. Dryer is electric. I converted to CFLs the first day I moved in. I run a pretty tight ship, so I try and use as little as possible, especially on peak. My lady wants to put a pool in, so I can definetly see some more use there.
  • solar_dave
    solar_dave Solar Expert Posts: 2,397 ✭✭✭✭
    Re: New 5.25kW project
    The house was built in November so It doesnt have any summer data. It is APS energy star so the insulation is decent and everything is sealed up. The A/C is 13 SEER. Range, Hot water and furnace are are gas. Dryer is electric. I converted to CFLs the first day I moved in. I run a pretty tight ship, so I try and use as little as possible, especially on peak. My lady wants to put a pool in, so I can definetly see some more use there.

    If you do a Pool look at intelleflo VFD pump and one of their programmable controllers, It will cut the power consumption by like half. I run one hour full speed for in floor cleaning and then 2-4 hours 25% speed for mixing and filtration.
  • ArizonaEngineer
    ArizonaEngineer Registered Users Posts: 10
    Re: New 5.25kW project
    BB. wrote: »
    That is normal... Panels rarely output their "marketing" rated power--Typically closer to 80-85% of their marketing numbers. Solar panels heat up in sunlight and their output voltage falls some as they get hot--Therefore, their output power falls some too.

    You could put a 6kW inverter on the 5.28 kW DC array--but you will not gather very much more power (if any) because of the larger inverter--You will probably only clip a couple hundred watts a few days a year for less than an hour a day (giant SWAG). Maybe a few dollars more worth of electricity a year.

    More or less, the "law of diminishing return" as one new poster summarized the other day.



    I live in Northern California and we had the same thing--an old E-7 plan with peak power from Noon-6pm... And a new E-6 plan (mandatory for new solar RE installs) with partial peaks from 10am to 9pm.

    For my family, it was easy to describe when not to "waste" electricity--Noon to 6pm weekdays during "summer".

    The new plan had off peak, partial, and full peak, different between weekdays and weekends, different between summer and winter, etc... A real mess--and it was much harder to push electric use to after 9pm (cooking, etc.). But we were able to stay with the old E-7 plan (grandfathered in--in fact, the grandfathered plan was one thing that pushed me to buying/installing solar GT at that time).

    -Bill
    solar_dave wrote: »
    If you haven't already, take a look at the PVWatts site, pretty accurate from what I have seen overall as a great estimation tools

    http://rredc.nrel.gov/solar/calculators/PVWATTS/version1/

    My system is 12.5Kw (6250 watts per inverter) name plate with two 5.2 Kw inverters and have never actually seen a peak plateau on the inverter data. It has touched the max for a minute or 2 on a very good day. but mostly runs in the 9000-10000 watt range midday this time of year which is optimal angle and temp kinds of days. Yesterday was great one mid 70's with a breeze until the clouds moved in.
    solarix wrote: »
    You sound good. Must live an exemplary lifestyle to need only a 5kw system when planning for an EV. I do know that Buckeye will require you to put in a superfluous DC disconnect in addition to the one in your inverter. Why did you choose kyocera and power one if I might ask? Are you doing the install yourself? What kind of roof and what racking will you use? The ET-2 rate plan will work great for you if your on-peak percentage is that low. What will it be in August though when peak rate is 3 times higher than the off-peak. The cost effective system size is usually to just replace your on-peak power with solar and pay APS for their off peak power.



    I would have gone larger, but that really was the most that my southern facing roof could handle, and the cost effectiveness for anything else really didn't make sense.

    The installer put together the package, so I wasnt really involved much in the selection of components. I was happy with the powerOne since they have a local west valley facility and a nice easy interface to connect to for data collection. I wish I could have done it myself, but with work and other stuff it was easier to just pay up.

    The electric car probably wont be for a couple years yet. But buying some power off peak will be ok.

    I work 4-10s so I am out of the house for most of the day. This will help keep power use down, especially in the summertime.

    Thank you for the responses. I look forward to posting up the pictures and other details as soon as the project moves along.
  • solar_dave
    solar_dave Solar Expert Posts: 2,397 ✭✭✭✭
    Re: New 5.25kW project

    Did you look at the Buckeye city program to help out?

    http://az-buckeye2.civicplus.com/index.aspx?nid=278
  • ArizonaEngineer
    ArizonaEngineer Registered Users Posts: 10
    Re: New 5.25kW project

    I did take a look at that. Thanks for the link, though.

    Anyway, my interconnection was approved today by APS and now I am just waiting on the city to approve the permit and I am good to go.
  • solar_dave
    solar_dave Solar Expert Posts: 2,397 ✭✭✭✭
    Re: New 5.25kW project
    I did take a look at that. Thanks for the link, though.

    Anyway, my interconnection was approved today by APS and now I am just waiting on the city to approve the permit and I am good to go.

    Great news, one more step forward.
  • ArizonaEngineer
    ArizonaEngineer Registered Users Posts: 10
    Re: New 5.25kW project

    Welp, installation starts tommorow morning. Ill be sure to post pictures.

    Going through my HOA was a bad show. They wanted 2 panels to be moved, one of which would sit under a gas vent shadow in the winter sun and another that would cause an exhaust vent stack to be moved. Thankfully the installer explained it to them nicely, I would have just showed them the law books and told them to :grr off

    Hopefully APS is quick with the inspection and start-up! The AC has been cranking now that it has gotten warm.
  • solar_dave
    solar_dave Solar Expert Posts: 2,397 ✭✭✭✭
    Re: New 5.25kW project

    APS is usually really good about showing up for the buy off withing a couple business days. Yeah the AC has been hitting now, I am just under break even so far, like yesterday was a 6 kwh draw off the ~3000 kwh bank @ APS. If it keeps up we should have a largish excess at year end.

    Your HOA deal sounds a lot like mine. It took a letter with the laws spelled out showing the HOA is liable for any attorney fees resulting in a court battle and any requirements they impose that lowers the efficiency or raises costs are disallowed by law. Your F off is right on.

    PS I asked APS when they were going to show up, and did a dry run for a couple days over the weekend to see how it ran.
  • sub3marathonman
    sub3marathonman Solar Expert Posts: 300 ✭✭✭
    Re: New 5.25kW project
    The house was built in November so It doesnt have any summer data. It is APS energy star so the insulation is decent and everything is sealed up. The A/C is 13 SEER.

    In Arizona, I think I would have opted for a more efficient A/C unit. I think here in Florida they are now requiring 15 SEER. But, there is one more step you can take to make a real improvement, and that is a Heat Recovery Unit on the A/C to heat your hot water. The previous A/C system we had was the 13 SEER with the HRU, and we turned off the water heater from May through October, or sometimes even later. The other side benefit is that it adds 0.5 SEER efficiency to the A/C also. I think a unit would cost about $500 to initially install with the A/C, or now that the A/C is installed it may run about $750. They ran a water line from the A/C into the attic and over to the water heater in the garage.
  • tonystewart
    tonystewart Solar Expert Posts: 54 ✭✭
    Re: New 5.25kW project
    In Arizona, I think I would have opted for a more efficient A/C unit. I think here in Florida they are now requiring 15 SEER. But, there is one more step you can take to make a real improvement, and that is a Heat Recovery Unit on the A/C to heat your hot water. The previous A/C system we had was the 13 SEER with the HRU, and we turned off the water heater from May through October, or sometimes even later. The other side benefit is that it adds 0.5 SEER efficiency to the A/C also. I think a unit would cost about $500 to initially install with the A/C, or now that the A/C is installed it may run about $750. They ran a water line from the A/C into the attic and over to the water heater in the garage.

    I asked for heat recovery for my new Trane 2 & 4 ton 16 seers, last June. Cassidy A/C warned me it wouldnt make enough hot water like my old a/c's did. I went with solar hot water and haven't looked back.

    I temp checked the return lines, on the old system (10 seer) they would burn you, on the new systems they are barely warm.
  • BB.
    BB. Super Moderators, Administrators Posts: 33,431 admin
    Re: New 5.25kW project

    Are you checking the temperature of the output (high pressure gas) line of the pump? That should be pretty hot with any SEER system--I would guess.

    That output pressure/temperature may be low(er) if the pump is cycling (not calling for maximum cooling) and/or the condenser temperature is cool (cold ambient temperatures).

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • solar_dave
    solar_dave Solar Expert Posts: 2,397 ✭✭✭✭
    Re: New 5.25kW project

    In AZ I suspect that heat recovery to a fixed tank may be an issue.

    According to this article:
    http://www.heatharvester.com/html/heat_recovery.html
    your heat recovery would be 15-25 gallons of hot water raised from 70F to 140F for every hour of AC operation on a 3 ton unit. I have two 3 ton units. What would I do with all that recovered heat? With an 80 gallon storage I would need to shed it elsewhere pretty quick.
  • ArizonaEngineer
    ArizonaEngineer Registered Users Posts: 10
    Re: New 5.25kW project
    In Arizona, I think I would have opted for a more efficient A/C unit. I think here in Florida they are now requiring 15 SEER. But, there is one more step you can take to make a real improvement, and that is a Heat Recovery Unit on the A/C to heat your hot water. The previous A/C system we had was the 13 SEER with the HRU, and we turned off the water heater from May through October, or sometimes even later. The other side benefit is that it adds 0.5 SEER efficiency to the A/C also. I think a unit would cost about $500 to initially install with the A/C, or now that the A/C is installed it may run about $750. They ran a water line from the A/C into the attic and over to the water heater in the garage.


    It's a production house. It just came with the 13 SEER when I bought it, they are offering 14 seer now standard which ticked me off.


    Anyways, Pics!

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  • ArizonaEngineer
    ArizonaEngineer Registered Users Posts: 10
    Re: New 5.25kW project

    th_IMAG0076.jpg
    th_IMAG0075.jpg


    They have been working since Thursday and expect to finish tomorrow. Project was scheduled to be completed today. The rails are up on the roof. It looks like they mis-measured the first try on the penetration into the garage and patched the stucco and drywall up, but is still noticeable. Not too happy about that... Hopefully things go well tomorrow. In the mean time I have 22 240w panels sitting in my garage waiting to go up on the roof.

    I got the chance to attend the Canadian F1 grand prix this past weekend so I missed the first 2 days of the install, but the person watching my house said they have been extremely nice and helpful with questions and such.
  • ArizonaEngineer
    ArizonaEngineer Registered Users Posts: 10
    Re: New 5.25kW project

    My AHJ from Buckeye went into APS today.


    How long did it take APS to come out for you in their territory?
  • ArizonaEngineer
    ArizonaEngineer Registered Users Posts: 10
    Re: New 5.25kW project

    Well, APS came out this morning and turned on the system at around 9:15


    The system made 31 kWh with a maximum power output of 4.11 kW that occured about 1:45 pm. Not Bad for a scorching hot 115F degree day. 8) Ill expect it to make a tiny bit more tomorrow since there was already sun at 915.

    With the majority of that being on-peak usage, that is worth around 6 bucks!

    I think I probably spent a combined hour watching the meter / playing with the inverter. Watching it spin backwards is entertaining.


    Mods please feel free to move into grid-tied or wherever is more appropriate
  • solar_dave
    solar_dave Solar Expert Posts: 2,397 ✭✭✭✭
    Re: New 5.25kW project

    Yeah the heat is brutal, glad you got it commissioned. Yep pretty quick to roll the dollars up with the on peak rates.