Anyone with a grid-tied hybrid install in the US?

krobertson

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I was hoping to see if there was anyone in the states who uses a hybrid setup that is actually tied in to the grid.

What was your experience with getting your system permitted and operational with your local gov't and power company?

I was initially hoping to do setup with an automatic transfer switch so I'd not be tied in to the grid and simplify the process, but that has some complications. I wanted the battery to cover the house, but not our two EVs. I was planning ~30kWh system, but the cars average charging ~40kW/night, and regularly spike up to ~80kW/night. It'd be hard to exclude the EVs. Our house just sucks in how utilities were laid out. The house is very long, with the main panel on one side, and the garage on the other. The garage side of the house is on a separate 100A subpanel, along with that side of the house, and the main AC system. The cost to do a separate 50A+ subpanel 150ft through the crawl space to the main panel would likely cost more than a full UL listed hybrid inverter.

I don't want the batteries to do just the EVs, since the main goal is the house and avoiding PG&E's multiple yearly outages. Some alternatives I could do would be to have multiple inverters to be able to cover the EVs + ACs (15-20kW). I'd like to figure outwhat the cost gap between this and full hybrid though. And lastly, think though a setup whereI'd always switch back to grid power ~10:45pm (off-peak starts at 11pm, so that is when cars start charging), and have the chargers on a contactor where if power goes out, batteries can kick in, but disconnect the chargers.

If anyone has gone down this path, would love to know and may ask about your experiences... what the requirements where, how much you had to document, which parts you could do or couldn't, etc.
 
Too bad you can't use your EV's to power the house when needed?
Of coarse you couldn't drive again until the power is returned the cars charged.
 
Bubba said:
Too bad you can't use your EV's to power the house when needed?
Of coarse you couldn't drive again until the power is returned the cars charged.

I think I saw a video where people were using their cars for putting power back in the grid and could tell the car when to stop discharging to the grid. It would be cool if you just charged your car to max while at work and then drive the car home and repeat the cycle. make the employer or Municipality pay for part of your energy bill.
 
krobertson said:
If anyone has gone down this path, would love to know and may ask about your experiences... what the requirements where, how much you had to document, which parts you could do or couldn't, etc.

I create off-grid power and distribute to the housevia automatic + manual transfer switches. My inverter is hooked to a sub-panel. From the sub-panel I feed 5 automatic transfer switches around the house. 3 of them are 240v@50a auto-transfersand 2 of them are 120v@30a auto-transfers. In normal times (e.g. consuming all the PV array will create) Ienable circuits to maximize consumption / minimize battery. In a disaster I canchoose different options and not worry aboutbattery life.

The Inverter Subpanel feeds the following
- Main panel - 240v@50aauto-transfer+ manual transfer for individual circuit control. This is whatever I want from main house panel - e.g. cooktop, hot water heater, lights, refrigerators, garage, kitchen, bathrooms, etc. With this in place, I can pick/choose circuits and power anything in the main panel. No problem expanding to a 2nd (RV?)or 3rd (EV?) and so on. just need enough inverter power.

image_mkince.jpg


In addition to main panel above, I have:
- Shop subpanel - 240v@50a auto-transfer- option tosupply power the shop/tools/lightswhen circuit breaker enabled at inverter sub-panel.
- AC Unit power pull- 240v@50a auto-transfer - option to supply power to AC outdoor unit when circuit breaker enabled at inverter sub-panel.

- APC UPS #1 - Go-Power120v@30amp -->3000w of APC UPS ->120v sockets thru house where computers/tv exist. This takes care of Inverter / Grid automatic switch switch-overs each day.
- APS UPS #2 - Go-Power120v@30amp -->3000wof APCUPS ->120v sockets thru house for additional electronic equipment that loose settings on Inverter / Grid switch-overs.

image_lxwfup.jpg




Overall - this system lets me power about 40% of the house in the summer.Lights, Refrigerators, Furnace Fan, Garage Door opener, Shop Tools, Computers/TV equipment, Cooktop, Hybrid Hot Water Heater,AC from an AIMS 12,000watt (240v @ 50a) inverter... AND can be expanded with 2nd or even 3rd inverter to eventually power 100% of the house.

The 6 transfer switches cost about $1200. I have another $800 in wiring (#6 3wire/1grd for 240v@50a) + $200 in subpanels = $2200 to wire up about 80% of the house. Plusan electrician might be another $1500? That's $3700 so far.

Some pros
- House is powered when grid is down
- Can consume 100% ofPV array output, no technical problem expandingPV array, batteries, inverters
- When Inverter is off (choose to turn off solar system to work on it, turn off for vacation, etc) thegrid *automatically* takes over... the house runs normally with no special action required.
- No connection to power company andcannot backspin the power meter - e.g. power company sees lower consumption but has no idea its solar related

Some cons are
- Cannot generate more than the house is wired to consume.
- Battery bank does at least a 20-30% DOD daily (battery will wear)as itsdifficult to balance PV power / house consumption to make it so the battery is not used


Now that I understand things better... I can see the case for Hybrid. I just didn't understand / didn't really see examples or equipment to purchase when I started 2 years ago... so I didn't pursue it.

Some pros (I'm sure there are others)
- The $$ might make more sense and you'd still have power with grid down.
-The battery (large expense)could sit there and only be used with grid down ... so DOD is very small and (Lithium)battery should last very long time

Some cons (I'm sure there are others)
- Connected to power company - equipment/permits/rules might be burdensome
 
OffGridInTheCity said:
I create off-grid power and distribute to the housevia automatic + manual transfer switches. My inverter is hooked to a sub-panel. From the sub-panel I feed 5 automatic transfer switches around the house. 3 of them are 240v@50a auto-transfersand 2 of them are 120v@30a auto-transfers. In normal times (e.g. consuming all the PV array will create) Ienable circuits to maximize consumption / minimize battery. In a disaster I canchoose different options and not worry aboutbattery life.

Thanks for your detailed post! I hadn't thought of separating out optional workloads as well... that would be nice where could decide whether things like ACs are on the inverter or not.

Ultimately I think a new subpanel to the other end of the house is almost inevitable. It probably doesn't need to be a very high amp one. It could likely be a 50A run and move the lights/outlets to it, then leave the 100A panel for the AC, kitchen appliances (minus fridge), and EV chargers. That would likely reduce the parts cost by a good chunk. The house is just wired so weird, like the bedroom lights are off the main panel, but the outlets are off the subpanel. But with this separated out, it'd be what I want without creating extra automation. If grid goes out, easy enough to switch ACs on to inverters and not the chargers.

In your setup, without the UPSes, do you get a flicker/surge that causes the computers and what not to reboot? Our power flickers out about once a month here. I work from home and got tired of it rebooting the wifi/router/modem and all. Recently is did multiple back to back flicking on/off for several seconds, luckily only blew out the power adapter for one of the Nest cams that wasn't on a surge protector.

How do you like the AIMS inverter? I was looking at it, but couldn't find documentation if it had external monitoring capabilities like USB/serial/RS485 like the MPP Solar LV5048. Doing 2x MPPs would be close the same output and 1/3rd less, but an extra $1k for the AIMS being UL certified and likely better warranty may be worth it.
 
krobertson said:
OffGridInTheCity said:
I create off-grid power and distribute to the housevia automatic + manual transfer switches. My inverter is hooked to a sub-panel. From the sub-panel I feed 5 automatic transfer switches around the house. 3 of them are 240v@50a auto-transfersand 2 of them are 120v@30a auto-transfers. In normal times (e.g. consuming all the PV array will create) Ienable circuits to maximize consumption / minimize battery. In a disaster I canchoose different options and not worry aboutbattery life.

In your setup, without the UPSes, do you get a flicker/surge that causes the computers and what not to reboot?

How do you like the AIMS inverter? I was looking at it, but couldn't find documentation if it had external monitoring capabilities like USB/serial/RS485 like the MPP Solar LV5048. Doing 2x MPPs would be close the same output and 1/3rd less, but an extra $1k for the AIMS being UL certified and likely better warranty may be worth it.

> In your setup, without the UPSes, do you get a flicker/surge that causes the computers and what not to reboot?
Yes, the power 'flickers' twice a day as the relays switch from grid -> inverter power and vice versa. Refrigerators, Microwave, Cooktop,motors, lights, Hybrid water heater are not harmed by this. The UPS(s) smooth the power flicker so computers (or other electronic equipment) don't shutdown/reboot/loose settings etc.

Over time, I had 9 UPSs around the house - 1 at each TV and computer work area.I learned that each APC UPS 1500uses 40watts per hour. 40 * 24 = 960watts/day- so that's 9 x 960 = 8.6kwh per day! To combat this, I used my 'big' (3000watt)UPSs in the picture above toconsolidate - so 2 bigger UPS instead of 9 smaller ones. APC UPSs are not that expensive.



>How do you like the AIMS inverter? I was looking at it, but couldn't find documentation if it had external monitoring capabilities like USB/serial/RS485

They have 12,000watt and 8,000watt that are ETL (UL) certified for very competitive price.Like you, I'm hoping ETL/UL is better components and I sleep a bit better in terms of fire etc. I started with very cheap "Reliable"(s) and had failures - did not perform up to specs and in one casecreated a dead shortto the battery... .

I have the12,000watt 240v ETL version and itworks great so far. Has beenused every dayfor the last 6 months for a cumlative runtime of 2,130hrs @average of 2,007watts per hour. Its has a remote 'panel/on-off-switch' option butdoes not have ethernet/wifi/etcconnection or record use/metrics. The remote on-offcan be hooked to a relay - which is how I automatically turn it on/off at battery voltage set points.

$17 AC meters are wiredon the inverter output with acamera pointing at them / recording - soI can view & writedown poweruse. I'm still looking for a internet based power monitor system.
 
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