Solar Panels

[DaveEV]

Plug-n-Play Solar Panels.....

Will be very interesting if they can get something UL certified that is truly plug and play.

 

[LEAFfan]

I've decided to go with a 4.1KW instead of a 3.1. It is only $1300 more and has a payback of only 5 years. My net cost per watt will be $1.58. We're going to be a guinea pig for those new Honeywell AC panels.

 

[Gonewild]

I've decided to go with a 4.1KW instead of a 3.1. It is only $1300 more and has a payback of only 5 years. My net cost per watt will be $1.58. We're going to be a guinea pig for those new Honeywell AC panels.

i went with 5.16kw because I got the full SRP rebate of $13,500 at the time.

 

[sjfotos]

I've decided to go with a 4.1KW instead of a 3.1. It is only $1300 more and has a payback of only 5 years. My net cost per watt will be $1.58. We're going to be a guinea pig for those new Honeywell AC panels.

Very interesting! Let us know how it goes!

 

[garygid]

Since you are getting such a SPLENDID price, and will be charging an EV, I suggest you consider an even larger system, up to perhaps 7kW, depending upon your usage.

Consider generating a surplus, even after LEAF-charging. This year is requiring more A/C, since it is hotter (100 today) and I am home more.

 

[LEAFfan]

Since you are getting such a SPLENDID price, and will be charging an EV, I suggest you consider an even larger system, up to perhaps 7kW, depending upon your usage.

Consider generating a surplus, even after LEAF-charging. This year is requiring more A/C, since it is hotter (100 today) and I am home more.

I know Gary but credit unions and banks aren't loaning any money now, not when your home is worth less than what you owe. We can always add more panels later when more funds become available. It's really easy (so they say) to add more of these, almost plug-in-play.

 

[garygid]

OK, I understand the panels and inverters are expensive.

Then, consider laying out the larger system, and having the mounting rails, conduit, junction boxes, and wiring put in for your "goal" system. Then, adding panels can be relatively easy as money becomes available.

But, without the extra rails and wiring in place, there is "considerable" overhead to adding on. The extra labor and material costs now should not add much real cost to the job.

Drawing up, submitting, getting permit, ordering, transporting, and receiving materials, scheduling and getting labor to the site are almost "included" in the first job. Trying to pull extra wires down an already "too-full" conduit is often difficult, and aditional conduit and junction boxes are needed. Well, enough said.

Whatever you do, you will enjoy seeing the PU meter "spin" backwards!

 

[LEAFfan]

OK, I understand the panels and inverters are expensive.

Then, consider laying out the larger system, and having the mounting rails, conduit, junction boxes, and wiring put in for your "goal" system. Then, adding panels can be relatively easy as money becomes available.

But, without the extra rails and wiring in place, there is "considerable" overhead to adding on. The extra labor and material costs now should not add much real cost to the job.

Drawing up, submitting, getting permit, ordering, transporting, and receiving materials, scheduling and getting labor to the site are almost "included" in the first job. Trying to pull extra wires down an already "too-full" conduit is often difficult, and aditional conduit and junction boxes are needed. Well, enough said.

Whatever you do, you will enjoy seeing the PU meter "spin" backwards!

Thanks Gary! That's a good idea. I'll ask him about that today.

 

[LEAFfan]

OK, I understand the panels and inverters are expensive.

Then, consider laying out the larger system, and having the mounting rails, conduit, junction boxes, and wiring put in for your "goal" system. Then, adding panels can be relatively easy as money becomes available.

But, without the extra rails and wiring in place, there is "considerable" overhead to adding on. The extra labor and material costs now should not add much real cost to the job.

Drawing up, submitting, getting permit, ordering, transporting, and receiving materials, scheduling and getting labor to the site are almost "included" in the first job. Trying to pull extra wires down an already "too-full" conduit is often difficult, and aditional conduit and junction boxes are needed. Well, enough said.

Whatever you do, you will enjoy seeing the PU meter "spin" backwards!

Thanks Gary! That's a good idea. I'll ask him about that today.

I found on the Honeywell website that these AC panels come in pairs WITH the racking. The company charged me separately for the racking, so I sent him an email with the pricing...he ended up charging almost 1K more for the job than it should be. Haven't heard back yet, but decided to go 4.8KW (almost max for rebate) and hoping he'll change the pricing or I'm going to have to report his company to the BBB. They have an 'A' rating and have been in business since 2007.

 

[GeorgeParrott]

Getting an inverter with extra/reserve capacity is MOST important if you have any possibility of needing more panels. However simply adding panels to a prior inverter install MIGHT not be eligible for the rebates and tax credits. MIGHT is operative here.

We had a 3.7 kW Sunpower sysem of 18 panels installed in August of 2007; it wiped out ALL of our monthly electricity use cost, BUT in planning to "go EV" in late 2010, I added a SECOND system of 7 more panels and a second inverter (Because the first inverter had NO capacity for more than a couple of additional panels). We now have about 5.5 kW raw and about 5.1 kW AC capacity which this past year has given us a cash credit with PG&E of around $450. Even with charging two EV cars (We are getting BOTH the LEAF and the VOLT), it appears we will still have "cash credit" with our utility company at the end of each billing year.

This is because EV charging, done between midnight and 7 am, can be "time of day" metered under PG&E special EV rates at between 5 cents to at most 6.4 cents per kW. Our solar panels generate max EXCESS output during "peak day rates" and thus produce credits of around 31 cents per excess kW. At this time of year, we are producing about 20-22 kW EXCESS every day and this is mostly at the 31 cent payback rate. Even charging 20 kw per night at 5 cents/kw....Solar panel homeowners are WAY ahead.

NOTE: We also have a solar hot water system which reduces our annual gas bill from PG&E to about $300 max for the WHOLE YEAR.

 

[LEAFfan]

Getting an inverter with extra/reserve capacity is MOST important if you have any possibility of needing more panels. However simply adding panels to a prior inverter install MIGHT not be eligible for the rebates and tax credits. MIGHT is operative here.

We had a 3.7 kW Sunpower sysem of 18 panels installed in August of 2007; it wiped out ALL of our monthly electricity use cost, BUT in planning to "go EV" in late 2010, I added a SECOND system of 7 more panels and a second inverter (Because the first inverter had NO capacity for more than a couple of additional panels). We now have about 5.5 kW raw and about 5.1 kW AC capacity which this past year has given us a cash credit with PG&E of around $450. Even with charging two EV cars (We are getting BOTH the LEAF and the VOLT), it appears we will still have "cash credit" with our utility company at the end of each billing year.

This is because EV charging, done between midnight and 7 am, can be "time of day" metered under PG&E special EV rates at between 5 cents to at most 6.4 cents per kW. Our solar panels generate max EXCESS output during "peak day rates" and thus produce credits of around 31 cents per excess kW. At this time of year, we are producing about 20-22 kW EXCESS every day and this is mostly at the 31 cent payback rate. Even charging 20 kw per night at 5 cents/kw....Solar panel homeowners are WAY ahead.

NOTE: We also have a solar hot water system which reduces our annual gas bill from PG&E to about $300 max for the WHOLE YEAR.

These panels don't use a DC inverter. They are wired directly to AC. The micro-inverters are on the back of the panels so no DC loss. Here's a description of these new panels: Honeywell Solar SmartGrid™ AC Solar ModulesSolar panels, usually referred to solar modules by solar installers, use semi-conductor materials know as solar cells to convert the sun's radiation energy into Direct Current (DC) electricity. Honeywell Solar SmartGrid modules represent the next generation of solar panels because they generate pure photovoltaic alternating current (PVAC), thus no DC wiring or DC components are needed.
Those are really great rates you have. Here in AZ, on the EZ3 time-of-use plan, the lowest is .08 now (sp/su) and .07 fall/winter. The peak rate is .35 between 3 and 6 PM and the panels will be all on the West side unless I choose to have some on the East side. I'm wondering which would be better, the old tou or this 3-hour one? The old one is on peak from 1-8 PM (.19-.21) sp/su and 5-9 AM/5-9 PM (.10) f/w. Can anyone do the math? SRP said we will bank credits and then they pay .03-.04/w. which is deducted from the bill. There are no cash payouts. If anyone needs more info to figure this out, please let me know. Thanks!

 

[garygid]

Sorry, each micro-inverter IS a DC to AC inverter, though often a few percent less efficient that a "big" inverter.

However, handling variable shading is probably their biggest advantage. Also, adding-on smaller sections is a lot easier.

 

[mwalsh]

However, handling variable shading is probably their biggest advantage. Also, adding-on smaller sections is a lot easier.

And being able to efficiently handle panels at different orientations.

 

[LEAFfan]

Sorry, each micro-inverter IS a DC to AC inverter, though often a few percent less efficient that a "big" inverter.

However, handling variable shading is probably their biggest advantage. Also, adding-on smaller sections is a lot easier.

There's no DC wiring so I would think they would be more efficient than the panels that use DC wiring all the way to the box. According to the company, this is the ONLY solar panel that doesn't use DC wiring. All the others that have micro-inverters, still have to use DC wiring to the box, so that would lose some efficiency.
One big difference I found with these Honeywell's is that they are plug-in-play into each other (comes with built-in micro inverters), but with the other micro inverters, they have to be wired in.

 

[AndyH]

Sorry, each micro-inverter IS a DC to AC inverter, though often a few percent less efficient that a "big" inverter.

However, handling variable shading is probably their biggest advantage. Also, adding-on smaller sections is a lot easier.

There's no DC wiring so I would think they would be more efficient than the panels that use DC wiring all the way to the box. According to the company, this is the ONLY solar panel that doesn't use DC wiring. All the others that have micro-inverters, still have to use DC wiring to the box, so that would lose some efficiency.

Sorry...solar inverters output AC.

I used to have a small array with Trace microSine (OK4U) micro-inverters - same thing. The panel makes DC, the inverter converts to AC, synchronizes with the grid, and handles 'anti islanding'.

Here's a recent article on micro inverters with more info:
http://www.absoluteefficiency.com/LEAF/micro.pdf

Andy

 

[LEAFfan]

Sorry, each micro-inverter IS a DC to AC inverter, though often a few percent less efficient that a "big" inverter.

However, handling variable shading is probably their biggest advantage. Also, adding-on smaller sections is a lot easier.

There's no DC wiring so I would think they would be more efficient than the panels that use DC wiring all the way to the box. According to the company, this is the ONLY solar panel that doesn't use DC wiring. All the others that have micro-inverters, still have to use DC wiring to the box, so that would lose some efficiency.

Sorry...solar inverters output AC.

I used to have a small array with Trace microSine (OK4U) micro-inverters - same thing. The panel makes DC, the inverter converts to AC, synchronizes with the grid, and handles 'anti islanding'.

Here's a recent article on micro inverters with more info:
http://www.absoluteefficiency.com/LEAF/micro.pdf

Andy

Here's a description of these new panels: Honeywell Solar SmartGrid™ AC Solar Modules
Solar panels, usually referred to solar modules by solar installers, use semi-conductor materials know as solar cells to convert the sun's radiation energy into Direct Current (DC) electricity. Honeywell Solar SmartGrid modules represent the next generation of solar panels because they generate pure photovoltaic alternating current (PVAC), thus no DC wiring or DC components are needed.

 

[AndyH]

You got it right in your earlier post:

The micro-inverters are on the back of the panels so no DC loss.

Photovoltaic cells are direct current devices. They don't conduct electricity backward and cannot create alternating current on their own.

http://en.wikipedia.org/wiki/Solar_cell

Due to the special composition of solar cells, the electrons are only allowed to move in a single direction.

http://honeywellsolarsystems.com/solar-installation/solar-installation-steps.asp

Honeywell Solar SmartGrids use AC solar modules that are coupled with a micro-inverter mounted on the underside of the solar panel, which converts DC to AC power. This next generation design eliminates the need for expensive DC wiring components, centralized power inverters and the complex nature of designing and installing DC solar power arrays.

Sorry...canna break the laws of physics...

 

[mitch672]

Yes, AndyH, the only difference here is, the microinverters are PART of the panel, in the case of Honeywell. It is not a seperate component, and is integrated into the panel during manufacturing. So, there is no DC wiring to deal with, at all.

http://www.honeywellsolarpower.com/products/12345

 

[evnow]

Yes, AndyH, the only difference here is, the microinverters are PART of the panel, in the case of Honeywell. It is not a seperate component, and is integrated into the panel during manufacturing. So, there is no DC wiring to deal with, at all.

http://www.honeywellsolarpower.com/products/12345

OTOH, you can make a high voltage DC quick charger with these ... :lol:

Standard DC string voltages can reach up to 600VDC.

 

[Spies]

We're going to be a guinea pig for those new Honeywell AC panels.

These micro inverters sound great and having them built into the panel at the factory sounds like a fantastic idea!

I have not been following solar as closely in the past mostly because I live in a town house association with roof restrictions. Our association recently created a waiver for installing solar on the roof so that is not the hurdle it once was. Knowing about these micro inverters has now really sparked my interest in solar again. Now to compute my roof area, direction and angles