Solaria panels worth a 20% premium?

[J.P.M.]

Thanks for the info. Seems like my pricing is inline with that.

Our house is new so a lot has been built into reducing the load already. it is about 2500 sqft w/ geothermal hvac, supplemental wood heat, closed cell foam throughout, radiant floor heat.. and we use about 850kwh/month. A lot of thought was put into energy efficiency. Not to say more couldn't be done.

Understood. Thanx for the info. W/any net metering, use the PVWatts output, orient most panels as possible at optimum annual orientation and then next most favorable orientation for the remaining panels, etc. until the total annual output is what you want to offset in terms of annual load. If ground mounted, set high off the ground and use one orientation that gives max. annual output per installed STC kW. That'll probably be close to south facing tilted at a bit less than local latitude +/- a bit.

A respectful suggestion: Spend ~ $20 and buy a copy of "Solar Power Your Home for Dummies" @ bookstores/Amazon/etc. It'll help get to the preliminary design easier and help avoid gross overdesign from things you may not know about.

[JSchnee21]

From a DIY standpoint, there's nothing simpler than an Enphase microinverter solution. Daisy chain them together and add a few breakers to your existing load center. May not be the least expensive or most reliable solution, but performance and monitoring are equivalent to SolarEdge. Microinverter reliability might be slightly less than DC Optimizers (though Enphase seems to be getting better every year) but if you are okay with the risk of occasionally switching out a failed microinverter, you benefit from totally avoiding the high voltage DC side of the equation. This will make permitting and install much, much easier. Don't forget to research your power company's requirements (and paperwork) for their interconnect and net metering agreements.

[ButchDeal]

From a DIY standpoint, there's nothing simpler than an Enphase microinverter solution. Daisy chain them together and add a few breakers to your existing load center.

you need a single AC disconnect in most locations so you will need an AC combiner with disconnect, and a single breaker in your load center.
I would also state that SolarEdge is a bit simpler to install than enphase with Enphase using custom wiring bus, caps, connectors, etc.

May not be the least expensive or most reliable solution, but performance and monitoring are equivalent to SolarEdge.

Enphase performance monitoring is similar but not as nice as SolarEdge and costs money after the first year for module level.

Microinverter reliability might be slightly less than DC Optimizers (though Enphase seems to be getting better every year) but if you are okay with the risk of occasionally switching out a failed microinverter,

you benefit from totally avoiding the high voltage DC side of the equation. This will make permitting and install much, much easier.

SolarEdge also has a Safe DC bus to operate on as well so you totally avoid the high voltage DC side.
Enphase system does NOT make permitting or install or inspections easier

[df0rster]

you need a single AC disconnect in most locations so you will need an AC combiner with disconnect, and a single breaker in your load center.
I would also state that SolarEdge is a bit simpler to install than enphase with Enphase using custom wiring bus, caps, connectors, etc.

speaking of the AC disconnect since you mention it, The PoCo does not specify many details here other than it has to be a "visible load break disconnect switch, readily accessible and a type that can be secured in open position by a Cooperative lock"

I had planned to install this disconnect on my power pole where my service originates so as to make it accessible and visible to the PoCo. This is under the meter and under the 200 amp breaker where my service starts. (the breaker is required and installed by the Poco right under their meter).

The solar array and inverter will be installed after my main panel in my house (load side). So the AC disconnect will be connected on the supply side. Does this sound right? I just remember reading that some areas might require a disconnect between the inverter and main panel as well but I'm not sure about that.

[TAZ427]

Great ideas!

How does one go about figuring out the baseline consumption? If you're talking things like dc transformers for laptops, etc, does one simply go around unplugging tranformers and power bricks, etc?

We already use smart lights and switches with occupancy sensors and timers that help reduce waste. Although the smart switches themselves probably consume a few kwh/month.

Also with all the new wifi stuff running all the time I'm sure there is waste there. security cameras, wifi appliances, etc.

Finding that baseline really isn't that hard, shut off everything that would normally be shut off overnight while sleeping. Unplug anything that runs sporadically (i.e. refrigerator/deep freezer) and go look at your meter and determine your consumption rate. Another way, is if your PoCo provides hour by hour power consumption. Find the minimum consumption amount in the middle of the night, you may be a little lower than that depending on when things like the refrigerator ends up cycling. If you can get a full years worth of data and download to a spreadsheet then you can search for for the minimum.

Now, determining where that vampire consumption is usually getting a 'Kill-a-watt' meter and going around and checking. Believe it or not things like those smart switches occupancy timers can be major culprits to vampire usage depending on how they're used. If it's 2W to use, and it's on 24hrs for 48W a day, and you only save yourself an average of 1hr worth of shutting off a light, that should be LED if you've gone efficient, well that's spending 48W a day to save 12W of electricity... There great in a work environment were everyone just leaves crap on, but may not be great in a home environment were one dictates their own behavior. I still have to yell at my 16yr old about turning the lights off that he's not using, but not very frequently.

I keep my laptop charger, and phone chargers on mechanically switched power strips, so that I simply turn it off when not in use, for one example. But you can put a kill-a-watt meter on it and see what the draw is, and start adding all of these up for the simple things. Some clock radio's in rooms you're not using maybe sucking up 10-15W... These start adding up.

Do you have a VCR or DVD player that's been plugged in and sucking down power, but get's used once a year at best? Unplug it. A TV in the guest room, plugged in is likely drawing power when off, how much is it? Unplug it.

I also have a number of WiFi items (security camera's, thermostats, etc...) but are there ones that you don't need overnight that can be unpluged/put on a low power timer?

[ButchDeal]

speaking of the AC disconnect since you mention it, The PoCo does not specify many details here other than it has to be a "visible load break disconnect switch, readily accessible and a type that can be secured in open position by a Cooperative lock"

I had planned to install this disconnect on my power pole where my service originates so as to make it accessible and visible to the PoCo. This is under the meter and under the 200 amp breaker where my service starts. (the breaker is required and installed by the Poco right under their meter).

The solar array and inverter will be installed after my main panel in my house (load side). So the AC disconnect will be connected on the supply side. Does this sound right? I just remember reading that some areas might require a disconnect between the inverter and main panel as well but I'm not sure about that.

How can you connect the inverter on the load side and the AC disconnect on the supply side? you can not do both.

Most of the requirements come from your AHJ and permit. With a few additions from the power company. if you need to have the AC disconnect by the meter and a label will not suffice then do a line (supply) side tap and be done with it. If a label will suffice and you can put the AC disconnect by the inverter on the house, then do a load side connection.
IF you use SolarEdge or a central inverter you might have more leniency as their inverters are not only rapid shutdown equipped the new HDWave units have automatic rapid shutdown. This means that if the meter is pulled or AC disconnect tripped, it does a rapid shutdown.

[df0rster]

How can you connect the inverter on the load side and the AC disconnect on the supply side? you can not do both.

Most of the requirements come from your AHJ and permit. With a few additions from the power company. if you need to have the AC disconnect by the meter and a label will not suffice then do a line (supply) side tap and be done with it. If a label will suffice and you can put the AC disconnect by the inverter on the house, then do a load side connection.
IF you use SolarEdge or a central inverter you might have more leniency as their inverters are not only rapid shutdown equipped the new HDWave units have automatic rapid shutdown. This means that if the meter is pulled or AC disconnect tripped, it does a rapid shutdown.

I may be using terms wrong.

I will try to draw a simple and incomplete diagram of what I am thinking the PoCo wants.

When you say supply side tap, does that mean I have to connect the inverter before the MSP?

As I say, I'm still early in my research and learning..

I guess this is part of my question. The PoCo doesn't seem to specify where the AC disconnect should go other than visible location. The pole (line side) would be more convenient for them and less convenient for me (if they actually lock it out for some reason)
simple_dia.png

[df0rster]

Most of the requirements come from your AHJ and permit. With a few additions from the power company.

Oh, also, there is no permit and the AHJ as far as I can tell is my county. They don't issue permits or do inspections. The only inspections will be the PoCo and they only care about the AC disconnect as far as their documentation reads. I do however wish to build the system in compliance with NEC.

[TAZ427]

I may be using terms wrong.

I will try to draw a simple and incomplete diagram of what I am thinking the PoCo wants.

When you say supply side tap, does that mean I have to connect the inverter before the MSP?

As I say, I'm still early in my research and learning..

I guess this is part of my question. The PoCo doesn't seem to specify where the AC disconnect should go other than visible location. The pole (line side) would be more convenient for them and less convenient for me (if they actually lock it out for some reason)
simple_dia.png

Not sure why you would do that, or what value it adds over the Main Breaker in the first place. You want to be able to still get electricity from the grid if you open your AC Disconnect. You still won't be able to feed power from the Solar Inverters (unless you've got another supply hooked in that's not labeled.)

[df0rster]

Not sure why you would do that, or what value it adds over the Main Breaker in the first place. You want to be able to still get electricity from the grid if you open your AC Disconnect. You still won't be able to feed power from the Solar Inverters (unless you've got another supply hooked in that's not labeled.)

I agree, The ONLY purpose for that AC disconnect is to satisfy their requirement. I'm not sure exactly where they want the disconnect yet. For convenience at the pole would be easier for them since they asked for it to be visible and readily accessible, and it would be easy for me or an electrician to install. I'm sure it will never be used. I don't know if they will consider 200' away on the back side of my house visible and accessible. Although I agree that is better for me in the event that they ever do lock that disconnect open for whatever reason.

Yeah, I realize the inverter will not supply any power if that disconnect it open. Unless of course I am using an SMA w/ the secure power outlet.

[ButchDeal]

I may be using terms wrong.

I will try to draw a simple and incomplete diagram of what I am thinking the PoCo wants.

When you say supply side tap, does that mean I have to connect the inverter before the MSP?

As I say, I'm still early in my research and learning..

I guess this is part of my question. The PoCo doesn't seem to specify where the AC disconnect should go other than visible location. The pole (line side) would be more convenient for them and less convenient for me (if they actually lock it out for some reason)
simple_dia.png

that is not a Solar AC disconnect. That is a whole house disconnect. it might work for them as one but generally the AC disconnect is between the inverter and whatever it is attaching to, in your case your MSP.
Do you already have a 200A breaker on the pole? if so that would suffice for them if the box can be locked.

you are doing a load side connection in your MSP.

[SunEagle]

I agree, The ONLY purpose for that AC disconnect is to satisfy their requirement. I'm not sure exactly where they want the disconnect yet. For convenience at the pole would be easier for them since they asked for it to be visible and readily accessible, and it would be easy for me or an electrician to install. I'm sure it will never be used. I don't know if they will consider 200' away on the back side of my house visible and accessible. Although I agree that is better for me in the event that they ever do lock that disconnect open for whatever reason.

Yeah, I realize the inverter will not supply any power if that disconnect it open. Unless of course I am using an SMA w/ the secure power outlet.

I would say the AC disconnect switch would go between the inverter and that 35A CB. Even though the inverter will shut down if that 35A CB is opened the POCO wants a hard disconnect device that can be locked out to keep power from being sent to the house panel from the solar array.

[df0rster]

that is not a Solar AC disconnect. That is a whole house disconnect. it might work for them as one but generally the AC disconnect is between the inverter and whatever it is attaching to, in your case your MSP.
Do you already have a 200A breaker on the pole? if so that would suffice for them if the box can be locked.

you are doing a load side connection in your MSP.

Yes, they require a 200A breaker on the pole. I had to pay for it and they installed it. I believe that box is lockable so you are correct in pointing that out and it will save me $100 for a new disconnect switch

I don't think they will require a specific solar AC disconnect, although if that is code then I will surely install one. I already have a 125a sub panel on the house that I can run the inverter AC side through if that works out. It is the power supply for my shop which is using 1-50 amp 2 pole breaker in that box I believe.

[df0rster]

I would say the AC disconnect switch would go between the inverter and that 35A CB. Even though the inverter will shut down if that 35A CB is opened the POCO wants a hard disconnect device that can be locked out to keep power from being sent to the house panel from the solar array.

Yes, that's what they want. But I think the reason for it is in case the grid already goes down and they are working on it somewhere (in which case I am out of power anyway), or someone else thinks there is no power on the grid, etc. So that's why I was thinking about locating it on the pole just to satisfy their requirement.

If I have to install a solar AC disconnect between the 35A CB and inverter and they require it to be on the pole, that will force me to send 200' of additional wire from my inverter to a disconnect on the pole. So I am hoping they will either be fine with the whole house lockable disconnect that is already there (200a main breaker) or be fine with me placing the solar disconnect next to the inverter on the house 200' away from the pole/meter.

[SunEagle]

Yes, that's what they want. But I think the reason for it is in case the grid already goes down and they are working on it somewhere (in which case I am out of power anyway), or someone else thinks there is no power on the grid, etc. So that's why I was thinking about locating it on the pole just to satisfy their requirement.

If I have to install a solar AC disconnect between the 35A CB and inverter and they require it to be on the pole, that will force me to send 200' of additional wire from my inverter to a disconnect on the pole. So I am hoping they will either be fine with the whole house lockable disconnect that is already there (200a main breaker) or be fine with me placing the solar disconnect next to the inverter on the house 200' away from the pole/meter.

Most POCO's just want a place that is accessible and visible for them to "lock out" the solar pv power . Turning the CB for solar off does not provide the full protection that a "Lock Out, Tag Out" procedure requires. That disconnect device can be located on the property right next to the inverter if it is considered accessible.