Solar Quote Oahu Hawaii

[shaka]

Need help deciding my best route on purchasing my solar system in Oahu Hawaii. Quotes based to zero out a $400/month HECO bill. Rates here on the island are .37/kWh.

Also, one of the vendors mentioned that I should not be using micro inverters that are less kW than the panel size because of clipping. He said that I am in the highest sun zone in the island (500 sun zone) and we live in Hawaii that the panels will produce more than the PTC rating. I'm specifically talking about the systems that are paired with the Enphase M215's and the Solarworld 270/Enphase M250's. Your advice is greatly appreciated.

Vendor 1

System 1
9.9kW
(37) Solarworld 270
(37) Enphase M215 Microinverters
Price Per Watt - $3.60
Total Price - $35,954.52
Price after Federal & State credits - $15,168.16

System 2
10.15kW
(35) LG290
(35) Enphase M250 Microinverters
Price Per Watt $3.88
Total Price - $39,428.35
Price after Federal & State credits - $17,395.90

Vendor 2


System 1
8.37kW
(31) Solarworld 270
(31) Enphase M250 Microinverters
Price Per Watt - $4.00
Total Price - $33,480.00
Price after Federal & State credits - $13,718.00

Vendor 3


System 1
7.95kW
(30) LG 265
(2) SolarEdge 3800
Price Per Watt - $4.01
Total Price - $31,895.06
Price after Federal & State credits - $11,902.56

System 2
7.95kW
(30) LG 265
(30) Enphase M215 Microinverters
Price Per Watt - $3.84
Total Price - $30,541.35
Price after Federal & State credits - $12,412.41

Vendor 4


System 1
7.21kW
(29) LG 290
(29) Power One 300
Price Per Watt - $4.86
Total Price - $35,000.00
Price after Federal & State credits - $15696.37

System 2
7.29kW
(27) Solarworld 270
(27) Power One 300
Price Per Watt - $4.07
Total Price - $29,700.00
Price after Federal & State credits - $12,527.89

[itnetpro]

First question do you even need micro inverters meaning do you have shading issues?
You might also wan't to look into Canadian Solar panels. They are a decent quality inexpensive panel with very good price/performance ratio. I live in the Philadelphia, PA area and have 40 250w C6SP Canadian Solar panels paired to Enphase 215w inverters. My inverters will actually clip at 225w. During the winter when its cold outside I will often get a number that will clip mid day. With snow on the ground reflecting from the hill across the street most of mine have been clipping like crazy over the past few weeks in this region.

With that said where you live using even more efficient panels I would be concerned with any more then 25w difference between the panel and micro inverter. So if your 215 clips at 225w I'm not sure I would go over 250w on my panels. FYI my understanding is the 250w inverter clips at 250w.

I don't know what you local temperature range is but remember, every degree over 72 degrees your panel temp is the less efficient they will run. So if your panel temp will often exceed 90 degrees where you live my suggestion may be flawed and your system might be paired up just fine with the quoted inverters.

Smarter people on this forum to answer these questions, thats just my 2 cents worth...

John

[shaka]

First question do you even need micro inverters meaning do you have shading issues?
You might also wan't to look into Canadian Solar panels. They are a decent quality inexpensive panel with very good price/performance ratio. I live in the Philadelphia, PA area and have 40 250w C6SP Canadian Solar panels paired to Enphase 215w inverters. My inverters will actually clip at 225w. During the winter when its cold outside I will often get a number that will clip mid day. With snow on the ground reflecting from the hill across the street most of mine have been clipping like crazy over the past few weeks in this region.

With that said where you live using even more efficient panels I would be concerned with any more then 25w difference between the panel and micro inverter. So if your 215 clips at 225w I'm not sure I would go over 250w on my panels. FYI my understanding is the 250w inverter clips at 250w.

I don't know what you local temperature range is but remember, every degree over 72 degrees your panel temp is the less efficient they will run. So if your panel temp will often exceed 90 degrees where you live my suggestion may be flawed and your system might be paired up just fine with the quoted inverters.

Smarter people on this forum to answer these questions, thats just my 2 cents worth...

John

The only shading issues I have are the clouds and it's been cloudy and raining here recently. Most of the companies here are pushing the Enphase micro inverters with the M250 being the most common. Outside temp is in the high 70's - low 80's and humid. Summer it gets a lil warmer. I'm thinking the guys selling me the M215's are trying to get my money by getting the price per watt down.

[Volusiano]

Your price on the first quote after federal and tax credits are 42% of the original price. With 30% being the federal tax credit, does that mean your state tax credit is the other 28%? WOW! That's a phenomenal state tax credit then!

[shaka]

Your price on the first quote after federal and tax credits are 42% of the original price. With 30% being the federal tax credit, does that mean your state tax credit is the other 28%? WOW! That's a phenomenal state tax credit then!

30% Federal credit and 35% State credit. The state credit you get $5000 for each 5kW system.

[Volusiano]

30% Federal credit and 35% State credit. The state credit you get $5000 for each 5kW system.

35% state credit??? That's unbelievable, and I'm so jealous. Here in AZ the state credit is a flat $1K and that's it.

[SunEagle]

35% state credit??? That's unbelievable, and I'm so jealous. Here in AZ the state credit is a flat $1K and that's it.

The sad part about that great state credit is that a lot of people installed pv systems to get their costs down and now there are areas in Hawaii that have so much "self generation" that the Utility has put a stop on any more installs until they figure out how to fix their problem. They claim that their infrastructure can't handle the swings in supply and demand due to high percentage of renewable generation turning off suddenly due to the weather.

There has been talk about at what point a Utility has enough "ready to go or rolling standby power" (which is costly) to off set the sudden loss of solar pv systems. I think most mainland Utilities don't want the percentage of solar to exceed 15 to 20% of total generation. In Hawaii the percentage has gone past 40% in some areas.

[wwu123]

The sad part about that great state credit is that a lot of people installed pv systems to get their costs down and now there are areas in Hawaii that have so much "self generation" that the Utility has put a stop on any more installs until they figure out how to fix their problem. They claim that their infrastructure can't handle the swings in supply and demand due to high percentage of renewable generation turning off suddenly due to the weather.

There has been talk about at what point a Utility has enough "ready to go or rolling standby power" (which is costly) to off set the sudden loss of solar pv systems. I think most mainland Utilities don't want the percentage of solar to exceed 15 to 20% of total generation. In Hawaii the percentage has gone past 40% in some areas.

Yeah, now that I've got solar installed on my home in NorCal, I'd really like to help my sister on Oahu get solar as they really need it with their pool pump and the high HECO rates. She also has a perfect south-facing roof with no shading issues, and is on the side of the island that probably gets the least cloud cover and most insolation. I'd be her SolarCity offering no money down, if you will. I priced out solar PV and solar hot water for them about three years ago, the PV came in at a whopping $6.50/watt installed for a 7 KW array. At the prices today that shaka is getting quoted, it'd be a no-brainer - except we missed the boat with the utility now blocking new installs in their neighborhood.

Surprised that PV is 40% in some neighborhoods. I noticed maybe a third of roofs in my sister's 'hood have solar hot water, but solar PV is still less than 1 in 10.

[Volusiano]

Yeah, now that I've got solar installed on my home in NorCal, I'd really like to help my sister on Oahu get solar as they really need it with their pool pump and the high HECO rates.

Tell your sister to get a variable speed pool pump if she doesn't have one already. I used to have a 3HP single speed pool pump and it easily consumed 30% of my overall usage (and I have everything on electricity, no gas in our 'hood). It consumed 2550 W when running at 3450 RPM. After I switch to a variable speed pump, the new pump consumes 260 W when running at 1400 RPM. That's a whopping 90% reduction in energy. OK, I have to run it 2.5x as long for the same water turn-over, but that's still a 75% energy reduction for the same turn-over.

[shaka]

Yup! before September it was relatively easy to get solar installed. Now they changed the rules because of the solar saturation. You have to get approval from HECO to get solar installed now. The companies I talked too said that only 10% of the people have gotten approved. Most have been waiting since September. I am also pricing solar hot water systems so at least I can get savings immediately instead of waiting in limbo land for HECO.

When I used to live in the Bay Area I would never have thought of getting solar but now that I moved to Hawaii electricity costs arm and a leg here.

[boostinsteve]

Yup! before September it was relatively easy to get solar installed. Now they changed the rules because of the solar saturation. You have to get approval from HECO to get solar installed now. The companies I talked too said that only 10% of the people have gotten approved. Most have been waiting since September. I am also pricing solar hot water systems so at least I can get savings immediately instead of waiting in limbo land for HECO.

When I used to live in the Bay Area I would never have thought of getting solar but now that I moved to Hawaii electricity costs arm and a leg here.

Are you out here on the Leeward side of the island? I am in Waianae and can tell you it is getting extremely difficult to get the permits. I was one of the last few that got the permit very easily.

I am working with a couple of PV companies, and Heco on a good resolution, but to be honest, it isn't looking good. The only way we have found a good resolution is moving the house to off grid, and using a transfer switch to isolate from Heco, and use the off grid system as the primary source, Heco as the secondary source.

[wwu123]

Tell your sister to get a variable speed pool pump if she doesn't have one already. I used to have a 3HP single speed pool pump and it easily consumed 30% of my overall usage (and I have everything on electricity, no gas in our 'hood). It consumed 2550 W when running at 3450 RPM. After I switch to a variable speed pump, the new pump consumes 260 W when running at 1400 RPM. That's a whopping 90% reduction in energy. OK, I have to run it 2.5x as long for the same water turn-over, but that's still a 75% energy reduction for the same turn-over.

I've been thinking to still target the solar hot water and the pool pump, as you suggest. I'm just not sure whether the dealer network is mature on variable speed pool pumps. I'd like to take it further and take the pool pump off-grid with three solar panels and a DC pump, just let it run whenever the sun's out with enough insolation - seems like one way to circumvent the utility PV restrictions, and there's seems like a solar supply company that sells panels and parts. Sadly the solar water pumping forum here on Solarpaneltalk seems hostile to any discussion of directly driving pool pumps.

[Volusiano]

I've been thinking to still target the solar hot water and the pool pump, as you suggest. I'm just not sure whether the dealer network is mature on variable speed pool pumps. I'd like to take it further and take the pool pump off-grid with three solar panels and a DC pump, just let it run whenever the sun's out with enough insolation - seems like one way to circumvent the utility PV restrictions, and there's seems like a solar supply company that sells panels and parts. Sadly the solar water pumping forum here on Solarpaneltalk seems hostile to any discussion of directly driving pool pumps.

That's a good idea to isolate the pool pump and the solar hot water from the grid.

By the way, there are only a few companies that make variable speed pump -> Pentair, Hayward, Jandy... You can google them up and research them. Many states, AZ especially, don't even allow new pool construction to use single speed pump anymore. So most new pumps sold in the market nowaday are either dual speed or variable speed anyway.

If you have water features in your pool like an in-floor cleaning system or big water falls, you may need the high speed pump to do the job. But variable speed pump like Pentair is 3HP and capable of running at full speed 3450 RPM 2550 W anyway. The beauty is for the rest of the time when you don't need to activate that water features, you can run at the lower speed and conserve.

[shaka]

Are you out here on the Leeward side of the island? I am in Waianae and can tell you it is getting extremely difficult to get the permits. I was one of the last few that got the permit very easily.

I am working with a couple of PV companies, and Heco on a good resolution, but to be honest, it isn't looking good. The only way we have found a good resolution is moving the house to off grid, and using a transfer switch to isolate from Heco, and use the off grid system as the primary source, Heco as the secondary source.

Yup, I live in Ewa Beach. I'm not too sure if my association will even let me have a battery system. Will HECO even let you off the grid entirely? I gues if you use them as a secondary it's ok?

[boostinsteve]

Yup, I live in Ewa Beach. I'm not too sure if my association will even let me have a battery system. Will HECO even let you off the grid entirely? I gues if you use them as a secondary it's ok?

In reality, they can't stop you from going off grid. HECO tried a couple years ago to keep people from doing just that, but they failed. Not sure about Ewan, but they already stopped issuing permits for Waianae for grid tie application PV.