Solar soon in our future!

[kimo]

Welcome to the neighborhood.

Since your asking:

1.) What array orientation and shading were used for the PVWatts modeling that produced 4,700 - 4,900 kWh/yr. system output ?

I ask because I plugged in Honolulu. At 20 degree tilt and 180 azimuth with no shade, I got about 5,800 kWh annually for a roof mounted 3.4 STC system. I'm aware that HI has varying climates, some with a lot of rain/cloud cover. What's your zip ?

2.) How long is the "average basis" time period you write of ? 1 month ? 1 year ? Something else ?

3.) To be clear, is the 900 - 1000 kWh/month based on historic usage or estimated future usage with the newer A/C loads included ?

4.) Once how the model works is understood, PVWatts can be a good model for preliminary design of PV systems with respect to long term average annual output, but I've found the estimates of the $$ value of PV production it pukes out to be less than satisfactory. Sometimes it's close, and your average per kWh cost may indeed be $0.351 as the model uses, but depending on how your electric rates are structured and how your usage pattern(s) interact with that structure, the PVWatts annual savings estimate can be misleading, particularly when multiple rate plans are available.

I'd spend some time with your POCOs tariffs and rate plans and figure out annual POCO charges and any subsequent estimated long term average savings on a monthly basis.

5.) From how I read what you wrote, sounds like the bid you got doesn't include storage.

6.) I know stuff costs more in HI - you want nice, you pay nice - and I admit ignorance on the PV marketing situation in HI, but $17,000/3,400 STC W = $5.00/STC W seems a bit steep. That nice round $5.00/STC W figure also seems like it might be a wall throw.
Decent systems in CA are running ~ $2.50/STC W before tax credit or so with some not too sharp negotiating.
How many bids have you received ?

7.) On getting more bids: Even if all the vendors are in kahoots on pricing, and they probably are, actively or tacitly, I'd still get a few bids - and not reveal competitors prices - that, BTW, being a sure fire way to lock in a price that's about $0.01less than the next lowest bid.
People who do reveal prices do the vendors price fixing job for them.
Doing the "price match" game amounts to the same thing.
Decent vendors probably know where they need to be on price anyway, but sharing bids only makes their job easier and removes their uncertainty - an uncertainty that can only work in your favor.
Think about all that from the vendor's side of the table.

8.) Before getting any more bids - if that's what you choose - and if you haven't done so already, download a free PDF of a slightly dated but still info filled book: "Solar Power Your Home for Dummies", or buy a newer version hard copy at bookstores/Amazon. You'll get a lot of info that's useful in decision making, increase the probability of a more fit for use PV system, and get a usually overlooked side bennie: Your new found knowledge will help with vendor selection in that you'll already know the answers to questions you will be asking vendors. That can be of use when separating the wheat from the chaff in that it'll be easier to spot vendors who are trying to B.S. you.

Take what you may want of the above. Scrap the rest.

I'm on the East side of Kauai so we get a bit more cloud cover here on average being this close to the wettest spot on earth, MT. Waialeale. I've owned the house a long time but only recently living here fulltime. So I cannot get a long term average on our monthly energy costs. But it did jump up considerably after running our new AC system on a daily basis. We are starting to cut back on the hours of daily use and turning the AC off if were out of the house for two or more hours.
When I put in my info on pvwatts the only number I changed was the cost per kwh. I know the bid sounds high compared to CA rates but it is on par with others here according to people I talked to. The only other bid I got was a pre paid solar lease. It came in at just under $30k my cost after they get the tax credit. Now that is for a full PV system 22 panels and 2 LG batteries. If I wasn't against getting into a lease, that would be something I would consider more.

Thanks for reply

[kimo]

I am trying to size the right solar system for our home here in Hawaii. I do not want to invest in battery storage at this time and I plan to pay up front for the system vs leasing it. Our utility company requires a curtailment meter on the system if it produces more electricity than we use on a average basis. Since recently installing AC in the house our usage has gone up 30%.
So if we average 900 to 1000 monthly KWH we can go up to a 3.5kw system without needing curtailment according to their requirements. I got a bid for a 3.4kw 10 panel system and the price seems good and it gives us the option to expand the system and add a battery if we choose later on.

Of course I would love to just go for the full solar pkg with a Tesla battery and 20+ panels. But other repairs and upgrades to this home are in the works so I want to stay on budget. I am trying to keep the solar investment under $20k and the 3.4kw system is just the right price at around $17K.

Now after plunking in my info on pvwatts I am trying to decide if the small system is worth the savings we will get out of it. Pvwatts says it will produce on average 4500 to 4900kwh/year with a value of $1637.

I would appreciate anyone's opinion/advice.

Mahalo

With power rates that low I probably wouldn't bother investing in solar. Here it fluctuates between $0.32 & $0.35 khw. It appears to be a worthwhile investment if I can size it right for our usage.
Thanks for reply

[J.P.M.]

Welcome to the neighborhood.

Since your asking:

1.) What array orientation and shading were used for the PVWatts modeling that produced 4,700 - 4,900 kWh/yr. system output ?

I ask because I plugged in Honolulu. At 20 degree tilt and 180 azimuth with no shade, I got about 5,800 kWh annually for a roof mounted 3.4 STC system. I'm aware that HI has varying climates, some with a lot of rain/cloud cover. What's your zip ?

2.) How long is the "average basis" time period you write of ? 1 month ? 1 year ? Something else ?

3.) To be clear, is the 900 - 1000 kWh/month based on historic usage or estimated future usage with the newer A/C loads included ?

4.) Once how the model works is understood, PVWatts can be a good model for preliminary design of PV systems with respect to long term average annual output, but I've found the estimates of the $$ value of PV production it pukes out to be less than satisfactory. Sometimes it's close, and your average per kWh cost may indeed be $0.351 as the model uses, but depending on how your electric rates are structured and how your usage pattern(s) interact with that structure, the PVWatts annual savings estimate can be misleading, particularly when multiple rate plans are available.

I'd spend some time with your POCOs tariffs and rate plans and figure out annual POCO charges and any subsequent estimated long term average savings on a monthly basis.

5.) From how I read what you wrote, sounds like the bid you got doesn't include storage.

6.) I know stuff costs more in HI - you want nice, you pay nice - and I admit ignorance on the PV marketing situation in HI, but $17,000/3,400 STC W = $5.00/STC W seems a bit steep. That nice round $5.00/STC W figure also seems like it might be a wall throw.
Decent systems in CA are running ~ $2.50/STC W before tax credit or so with some not too sharp negotiating.
How many bids have you received ?

7.) On getting more bids: Even if all the vendors are in kahoots on pricing, and they probably are, actively or tacitly, I'd still get a few bids - and not reveal competitors prices - that, BTW, being a sure fire way to lock in a price that's about $0.01less than the next lowest bid.
People who do reveal prices do the vendors price fixing job for them.
Doing the "price match" game amounts to the same thing.
Decent vendors probably know where they need to be on price anyway, but sharing bids only makes their job easier and removes their uncertainty - an uncertainty that can only work in your favor.
Think about all that from the vendor's side of the table.

8.) Before getting any more bids - if that's what you choose - and if you haven't done so already, download a free PDF of a slightly dated but still info filled book: "Solar Power Your Home for Dummies", or buy a newer version hard copy at bookstores/Amazon. You'll get a lot of info that's useful in decision making, increase the probability of a more fit for use PV system, and get a usually overlooked side bennie: Your new found knowledge will help with vendor selection in that you'll already know the answers to questions you will be asking vendors. That can be of use when separating the wheat from the chaff in that it'll be easier to spot vendors who are trying to B.S. you.

Take what you may want of the above. Scrap the rest.

[SunEagle]

Wow. That is about a 10 year payback by my calculations.

I have also run the numbers and for me a solar install between 6 & 7kw still has a payback of almost 14 years due to the low rate of about $0.09/kWh. Even with Net metering that makes it real hard for me to justify.

I would think that with a rate around $0.34/kWh range it would be much easier to justify a solar pv system but if you can't sell back any amount back to the POCO the price is much more difficult.

Maybe you can look at the cost of adding on the battery system some time in the future if they come down in price. At least then you won't be throwing away any kWh the system over produces.

Unfortunately each person needs to decide what a solar pv system is worth to them and if it makes sense to spend the money there or somewhere else.

[kimo]

I am trying to size the right solar system for our home here in Hawaii. I do not want to invest in battery storage at this time and I plan to pay up front for the system vs leasing it. Our utility company requires a curtailment meter on the system if it produces more electricity than we use on a average basis. Since recently installing AC in the house our usage has gone up 30%.
So if we average 900 to 1000 monthly KWH we can go up to a 3.5kw system without needing curtailment according to their requirements. I got a bid for a 3.4kw 10 panel system and the price seems good and it gives us the option to expand the system and add a battery if we choose later on.

Of course I would love to just go for the full solar pkg with a Tesla battery and 20+ panels. But other repairs and upgrades to this home are in the works so I want to stay on budget. I am trying to keep the solar investment under $20k and the 3.4kw system is just the right price at around $17K.

Now after plunking in my info on pvwatts I am trying to decide if the small system is worth the savings we will get out of it. Pvwatts says it will produce on average 4500 to 4900kwh/year with a value of $1637.

I would appreciate anyone's opinion/advice.

Mahalo