30% tax credit on solar generation and grid-connected batteries?

[jflorey2]

System B is a UPS and has nothing to do with the ITC as it is not an alternative energy system....

From the article:

"Solar energy property includes equipment that uses solar energy to generate electricity, and includes storage devices, power conditioning equipment, transfer equipment, and parts related to the functioning of those items."

An AC coupled system would qualify under those rules.

[ButchDeal]

From the article:

"Solar energy property includes equipment that uses solar energy to generate electricity, and includes storage devices, power conditioning equipment, transfer equipment, and parts related to the functioning of those items."

An AC coupled system would qualify under those rules.

No because an AC coupled system is two different system. System a that is grid tied is a PV system that qualifies.
System b which is unrelated and nit a PV system at all.

[adoublee]

No because an AC coupled system is two different system. System a that is grid tied is a PV system that qualifies.
System b which is unrelated and nit a PV system at all.

It's not unrelated for a grid interactive battery (several hundred volts DC will be typical application) used in combination with solar to reduce demand charges. And the battery is not used like or equal to a UPS.

[ButchDeal]

Residential demand charges..... Load shifting, but still not a renewable energy source


You seem pretty vested in tax credit for AC coupled sonnen.

[adoublee]

Nope, just letting others know you might (very well) be wrong. You're sure solar and batteries are unrelated because of a box that sits between them, but it would be nice if you just admitted it is up to IRS interpretation.

[ButchDeal]

I never said it wasn't up to the IRS. I stated that nothing you stated indicated that an AC coupled system is allowed.
Even the articles you stated mentioned that an AC coupled system installed latter is unlikely to be approved.

There are many other reasons not to consider an AC coupled system. It makes very little since to design an AC coupled system from the start given the constraints and limitations of AC coupled systems.

[jflorey2]

No because an AC coupled system is two different system. System a that is grid tied is a PV system that qualifies.
System b which is unrelated and nit a PV system at all.

If such a system is proposed to the IRS as a combined system, the IRS (as most agencies do) will refer to the manufacturer's documentation as to whether they are one or two systems. That is generally the ultimate authority on the functionality of any solar hardware, and will in general trump people's opinions.

Take the case of an Outback AC coupled system. The AC-coupling documentation includes the following statements:

"If the array is 6 kW then three strings would be required, as the battery bank must be sized large enough to handle the maximum unregulated charge rate in a worst-case scenario."

"The OutBack inverter power rating should be 1.25% of the GT inverter power rating."

"Integrated with a more advanced, smarter inverter/charger such as OutBack’s Radian series with dual AC inputs and advanced generator features . . . ."

Given that the documentation calls out that the two systems must be integrated - and provides requirements and specs for integrating the two systems - then the IRS would likely consider it an integrated system provided the documentation was adhered to.

[ButchDeal]

An outback inverter does not need to be integrated with a grid tie inverter. I have one. They all are designed for DC coupled.

The documentation is talking about if you already have a grid tie system that works fine you CAN add an outback inverter to it to get backup capabilities via AC coupling. It is telling how to do that but the grid tie inverter works fine without the outback system. This is the nature of AC coupled systems. The grid tie works just fine without it.

It isn't as integrated as you might think from those statements, it is just telling you to size the battery bank to handle the uncontrolled charge rate. That isn't integration, just sizing.

[jflorey2]

It is telling how to do that but the grid tie inverter works fine without the outback system. This is the nature of AC coupled systems. The grid tie works just fine without it.

Definitely. And similarly, a DC coupled system works just fine without solar (then it's just a battery backup system.) It also works fine with solar but without the backup function (i.e. grid tie only; no loads on the output.) Nevertheless, it _functions_ as an integrated system, and is also considered as such.

[ButchDeal]

well a DC coupled bimodal system does not work without batteries (Except the StorEdge systems ). No batteries and they don't turn on. So other than StorEdge, the batterie is very integral to DC coupled bimodal systems. For AC coupled the battery and bimodal inverter are in no way required for the PV and grid tie inverter to work.

[cracovian]

This is an awesome discussion - learning a lot and I'm excited that there's a chance/possibility to get some money back one way or another.

A couple of things... Once the word gets official, confirmed, and picked up by marketing of battery companies, combined with ever-falling prices and growing competition, it has potential to be huge in terms of speeding up the residential adoption within the next five years, no?

Also, in reality, even the smallest of the smallest and simplest systems (let's say 4 kWh though Enphase is going smaller in Australia, I think) would optimize my own solar usage (during cloudy days) and provide a more normalized energy supply and demand in my relationship with the POCO.

As a taxpayer, I would let others keep some of their own money for those reasons

[ButchDeal]

A couple of things... Once the word gets official, confirmed, and picked up by marketing of battery companies, combined with ever-falling prices and growing competition, it has potential to be huge in terms of speeding up the residential adoption within the next five years, no?

Marketing is not known for being truthful anyway. I don't see this taking off in a big way as there are few locations with financial advantages to having a battery system and DC coupled batteries are cheaper and more efficient.

Also, in reality, even the smallest of the smallest and simplest systems (let's say 4 kWh though Enphase is going smaller in Australia, I think) would optimize my own solar usage (during cloudy days) and provide a more normalized energy supply and demand in my relationship with the POCO.

Batteries don't optimize your solar usage. If you have time of use billing they can help optimize your financials usage other wise, net metering is far more efficient than a battery system with all its losses. Particularly an AC coupled system with its multiple conversions and losses, as well as added costs.

[cracovian]

It's not just financials. Based on my readings, the new Sonnen Eco Compact can be set to only accept solar charge during the day, for example.

On intermittently-cloudy days, my production varies between 8 kW (of which I use about half or more) and 1 kW when the cloud comes over every few minutes or so.

This will indeed optimize my solar usage (along with financials: Georgia Power pays 4 cents/kWh) since I won't have to pull coal/nuke energy from the grid for a few minutes at a time.

[ButchDeal]

It's not just financials. Based on my readings, the new Sonnen Eco Compact can be set to only accept solar charge during the day, for example.

yes the outback inverter can be configured to do all kinds of things. Just about any decent bimodal system can do this.

On intermittently-cloudy days, my production varies between 8 kW (of which I use about half or more) and 1 kW when the cloud comes over every few minutes or so.

This will indeed optimize my solar usage (along with financials: Georgia Power pays 4 cents/kWh) since I won't have to pull coal/nuke energy from the grid for a few minutes at a time.

Ok so you DON'T have net metering? Did your rates change after installing?
Georgia power seems to have net metering monthly with NEG being credited to next bill at avoided cost. Batteries will do little to change the monthly NEG.

[ButchDeal]

you could get a contract as well for $0.17/kWh https://www.georgiapower.com/docs/ra...e/11.20_SP.pdf

[cracovian]

That 17-cent tariff has been oversold for years now.

Residential customers pay the monthly $2.86 interconnection fee (meaning they will get your 70 kWh for "free") which the green tea party along with United liberals stopped from going up to $20 not long ago. GP will try again and probably aim higher soon enough.

For any overproduction, GP will credit you the cost avoidance in the amount of 4 cents/kWh.

My current TOU keeps my offpeak rates lower but it hits me with 25 cents/kWh between 2:00 - 7:00 PM during four summer months. Therefore, the clouds are costly and may offset a cost of a simple battery system just not the $15K one those jokers were trying to push to me.

GP loves solar as long it's them installing it for themselves and the taxpayers picking up the tab.

[ButchDeal]

Residential customers pay the monthly $2.86 interconnection fee (meaning they will get your 70 kWh for "free") which the green tea party along with United liberals stopped from going up to $20 not long ago. GP will try again and probably aim higher soon enough.

For any overproduction, GP will credit you the cost avoidance in the amount of 4 cents/kWh.

you should have monthly net metering though. The kWh you produce in a month that go to the grid you are trading for kWh you get back. That is the kWh above your self consumption.
any kWh you produce OVER your consumption for the month is NEG and that is payed out at 4 cents/kWh
so say you generate 70kWh a month, and consume 60kWh in that same month. You have net metering on the 60kWh. the 10kWh is NEG and you get 4 cents for that.

A battery will not help you with that NEG as you would have to hold it for months...

My current TOU keeps my offpeak rates lower but it hits me with 25 cents/kWh between 2:00 - 7:00 PM during four summer months. Therefore, the clouds are costly and may offset a cost of a simple battery system just not the $15K one those jokers were trying to push to me.

you still have net metering so if you are producing at say 5kw rate and consuming at 4kw rate at say 4pm. When a cloud goes by and you produce at 1kw rate for a few minutes, then you are still net metering so it makes no difference, no need for a battery.
if it is cloudy all day, well the PV you generated extra the other months between 2 and 7 can be used...

[cracovian]

There's definitely NO net metering with Georgia Power at all. You only get the 4 cent cost avoidance credit for any kWh sent back to the grid on the statement for that month (minus $2.86 for the pleasure.)

[ButchDeal]

I see from the dsire site, http://programs.dsireusa.org/system/program/detail/574
I seem to have missed "Georgia Power does not offer a net energy metering tariff", my apologies. I guess it is a good think I am not in sales

Of course you have the enphase option as well. but again AC coupled, but a bit more consolidated monitoring
https://enphase.com/en-us/products-a...e/introduction

[ButchDeal]

you would need the new envoy for the enphase battery...

[cracovian]

A basic 1.2 kWh AC-coupled Enphase battery would be a great start and quite useful with my TOU rate, intermittently-cloudy days and in my residential solar-unfriendly environment. It might even pay for itself eventually and before I die (but only if I claim that 30% tax credit, of course...)

Once installed, is the new Envoy all that I'd need? I already have 24 M250s that I'd like to keep. Do those have to be replaced with S-series?

How would my ten LG ACe panels (built-in unmonitored micros) fit into the equation?

[ButchDeal]

I am under the understanding that just the new envoy is needed to deal with the batteries.
the S-series would be ignored but the production would not. you could get the RGM envoy which has a built in meter to measure the total production of all systems. I think you would want to combine them to easily measure them all at one point but that is not that hard with a small sub panel rated for all the PV.