Interfacing Solar, Battery Storage, EV Charging and Residential Load

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Toolworker

Toolworker

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Are there battery storage systems capable of interfacing among different power sources and sinks to optimize the use of solar generation?

Here in California, proposed solar tariff changes may drastically reduce the value of excess solar power exported to the grid. So I'd like to have all my solar generation stay at home, going first to household loads, and then to my EV and/or a battery storage system.

This would require a separate EVSE connection to the storage system, the ability to program it flexibly, and the availability of program inputs such as the storage system state, residential load currently and over time, whether the EVSE is currently accepting a charge, etc.

Does a storage system like that exist?
 
Toolworker said:
Here in California, proposed solar tariff changes may drastically reduce the value of excess solar power exported to the grid.
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I'm sure California's change will ensure the kind of system you're suggesting will be in great demand. Hopefully, there will be enough competition to keep costs reasonable.
 
I'd also like to find out what user-programmable storage systems are out there, and what their capabilities are, even if they don't have a separate EVSE connection. Links to instructions for programming would be appreciated.
 
Enphase allows you to chose between solar, battery EVSE and the grid and also allows you to designate charging via solar for any excess. I believe Emporia also does this. I am in the process of installing a Solar with battery back up using Enphase batteries and micro inverters. It not up and running yet so I haven't got into the weeds of it operations. I plan on hooking up my F150 lighting to the generator input so I can select solar, back up batteries and the F150 as storage or source of power.

Here are links to Enphase
https://enphase.com/

and
Emporia
https://www.emporiaenergy.com/?gcli...dA8oQiJoplkGyao3qcmW9NrVvndIsfIgaAv4SEALw_wcB
 
I read that ClipperCreek (who made my EVSE) was acquired by Enphase (who I never knew about before). Clearly, Enphase wants charging EVs to be a key part of their alternative-energy portfolio.
 
Enphase made the inverters that connect my solar panels to the grid. They had a ton of failures early on and almost went bankrupt so to warranty expenses. I’m glad they didn’t, and my 25 year warranty is still valid for another 14 years.

I knew they extended into battery systems for backup and/or load shifting. I did t know they were getting into EVSEs but it seems a natural extension to their core business.


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Be sure to plan accordingly as there are additional components for Enphase backup beyond the AC coupled battery.

If you plan on using the Ford 9.6kW Home Integration system with the Charge Station Pro, then it's probably 90% efficient and the AC coupled battery would probably be in the 70-80% efficiency (round-trip from F-150 lighting DC -> Home Integration AC -> Battery DC -> Battery to load AC)
 
teslarati97 said:
Be sure to plan accordingly as there are additional components for Enphase backup beyond the AC coupled battery.

If you plan on using the Ford 9.6kW Home Integration system with the Charge Station Pro, then it's probably 90% efficient and the AC coupled battery would probably be in the 70-80% efficiency (round-trip from F-150 lighting DC -> Home Integration AC -> Battery DC -> Battery to load AC)
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You are correct for proper use of the Enphase batteries an Enphase Smart switch and an Enphase Envoy communication gateway is required. The Smart switch is an automatic transfer switch with additional features for directing power from the solar and batteries and generator. I always permit my systems and also have professional engineering sign off as required for the permits. My system will be grid tied to SCE and also will be approved by them with a PTO (permit to operate). I am also installing a RSD (rapid shutdown device) at the meter so that emergency responders can shut everything down at once. If the RSD is turned to off the solar and or generator shutdown and the batteries are disconnected

I am a couple month out form delivery of the Lighting but once it arrives I will be working with enphase to integrate it in to the system.
 
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Fastnf said:
You are correct for proper use of the Enphase batteries an Enphase Smart switch and an Enphase Envoy communication gateway is required. The Smart switch is an automatic transfer switch with additional features for directing power from the solar and batteries and generator. I always permit my systems and also have professional engineering sign off as required for the permits. My system will be grid tied to SCE and also will be approved by them with a PTO (permit to operate). I am also installing a RSD (rapid shutdown device) at the meter so that emergency responders can shut everything down at once. If the RSD is turned to off the solar and or generator shutdown and the batteries are disconnected

I am a couple month out form delivery of the Lighting but once it arrives I will be working with enphase to integrate it in to the system.
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I think Enphase renamed some products since the release of IQ8, so you will have to check with the IQ8 system use cases so you don't get caught with items on backorder!
 
teslarati97 said:
I think Enphase renamed some products since the release of IQ8, so you will have to check with the IQ8 system use cases so you don't get caught with items on backorder!
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Thanks for heads up. I already have the equipment and the permit. I am literally installing it this week. I am using the IQ 8A inverters, 2 EnPower 10 kwhr batteries, Enphase Smart Switch 200 amp and a IQ Envoy Communication Gateway. I chose not to use there combiner as I wanted an external disconnect for the solar. I went with a Midnite solar combiner with disconnect.
 
Fastnf said:
Thanks for heads up. I already have the equipment and the permit. I am literally installing it this week. I am using the IQ 8A inverters, 2 EnPower 10 kwhr batteries, Enphase Smart Switch 200 amp and a IQ Envoy Communication Gateway. I chose not to use there combiner as I wanted an external disconnect for the solar. I went with a Midnite solar combiner with disconnect.
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Do you know how many installations like yours Enphase has operating in the field? Are there any near you that you were able to visit?

I have another big question, but I can't figure out how to ask it.
 
insightman said:
Do you know how many installations like yours Enphase has operating in the field? Are there any near you that you were able to visit?

I have another big question, but I can't figure out how to ask it.
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California should have plenty of solar + backup installations and even more with the NEM 3.0 tariff on the horizon.
 
No I didn't ask. I did check on their contractor list to see who is available in the area. There are a good number of installers in south and central California I usually to all my own work being a hands on retired engineer but the state rebate program requires a licensed electrical contractor install the batteries. So I guess if the sates going to pay for it via the rebate I will have a licensed electrician do the final install for the batteries. I had one electrician lined up but then he kind of disappeared on me.

Now I am curious to know what you big question is.
 
insightman said:
The BIG question: How much would it cost me to set up a similar system if I didn't have the California rebate?
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The basic system, solar 5.6 kw, battery 20 kwh and smart switch ~$30K. Permitting and engineering was ~$1.5k Batteries are the major part of this cost at $20K. I am installing myself but if you are paying for the install probably $5-10k depending on your location details, ie: ground mount or roof mount, distance from panel to meter and batteries etc. Copper wire has become very expensive. I have ground mount and placing the panels and batteries away from the house has cost me about $5k in extra wire costs.

I am running a Mitsubishi heat pump and it is quite economical to heat the house. Less than 15 kwh per day and we have lows in the teens and highs in the 40's where I live in the mountains. So I should recover my cost fairly quickly from propane heating savings.

Summary: DYI ~$35-40K Contractor installed $45-50k

Happy to answer any other questions on the system you might have.
 
insightman said:
The BIG question: How much would it cost me to set up a similar system if I didn't have the California rebate?
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Don't forget about the 30% federal solar tax credit on the entire solar PV system. It's literally the equivalent of buying a qualified $25,000 EV and getting the full $7,500!

You will have to work out the numbers to see if it is worthwhile for solar. Generally speaking in MI you export at quasi-wholesale rate and import electricity at retail if you include all variable rates (distribution, etc.). At a rate of $0.07746/kWh wholesale and $0.155/kWh retail, you would have to have to export 2kWh to get the value of importing 1kWh. Batteries can certainly help maximize self-consumption and larger systems are capable of whole home backup (with the 30% tax credit).

Other cost considerations will be the age of your roof and your main panel service level.
 
teslarati97 said:
Other cost considerations will be the age of your roof and your main panel service level.
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And the age of me, which will probably have me and my wife moving to a retirement community within a decade.

I wonder how much a $50K (- whatever discount) solar installation adds to the value of a home?
 
papab said:
What's going on in Cali with grid tie net metering credits?
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PG&E and the other investor-owned utilities are getting their tame California Public Utilities Commission to reduce by 75% the compensation for solar power sent to the grid. It'll destroy the economics of new solar installations.

A year ago the solar coalition and a huge public outcry sent them back to the drawing board, so they took out a few nasty little things but kept the big one - the reduction. Now it's back on the CPUC's docket for next month.

The whole story is on the Solar Rights Alliance site. (In the first photo, my wife and I are way in the back on the left.)

Californians: Opposition from over 100,000 people stopped this the first time. You can be part of stopping it this time. It's easy and quick. Send Governor Newsom an email here. Then call him.
 
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