Dump net metering [in NJ]?

[DSE25]

I have Tesla solar with PSEG (NJ) net metering and now two Tesla cars. Charging both cars is giving me a monster electric bill even with the solar. PSEG told me I cannot have a time of use plan (to charge my cars cheaply overnight or on weekends) and still have net metering. So, here’s my idea. I’m looking into getting a whole home battery that can be charged from the grid or solar, dumping the net metering, and, instead, getting time-of-use metering (“RLM” in NJ). I need a home power backup anyway because we’re routinely having blackouts in NJ.

Thoughts?

Thanks!

 

[mswlogo]

I have Tesla solar with PSEG (NJ) net metering and now two Tesla cars. Charging both cars is giving me a monster electric bill even with the solar. PSEG told me I cannot have a time of use plan (to charge my cars cheaply overnight or on weekends) and still have net metering. So, here’s my idea. I’m looking into getting a whole home battery that can be charged from the grid or solar, dumping the net metering, and, instead, getting time-of-use metering (“RLM” in NJ). I need a home power backup anyway because we’re routinely having blackouts in NJ.

Thoughts?

Thanks!

Batteries don’t replace net metering. Where are you going to store your excess Solar from Summer for winter.

Sounds like you need a bigger solar system. Not batteries.

Batteries are good for off grid or off peak if you have no Solar.

 

[DSE25]

Batteries don’t replace net metering. Where are you going to store your excess Solar from Summer for winter.

Sounds like you need a bigger solar system. Not batteries.

Batteries are good for off grid or off peak if you have no Solar.

Thanks for the response. I cannot upgrade my solar panels as they’re on a long term lease. If I get a whole home battery system with time of use metering I can charge during peak solar, discharge during peak use/peak rate (6PM to 10PM) and then top them off during off peak hours when I’m also charging my cars. Obviously, both net metering and time of use plan would be better but PSEG NJ does not let me have both.

 

[jjrandorin]

There is no guarantee that you would be able to "top off your batteries with off peak grid energy". Im not sure what triggers tesla to allow or disallow grid charging, but everyone does not have that available.

 

[DrSmile]

I'm curious as to what your situation is for the electric bill to be that big. I'm in northern NJ, have 2 Teslas and 13.4KW of solar, and even with a very inefficient house and old central A/C units my solar system produces 97-98% of what I consume. I don't have electric heat (I'm considering a heat pump for part of the house though) or electric hot water but I can't imagine it being that much of a difference. Are you driving a Model X plaid like it's stolen 200 miles a day?

 

[DSE25]

this is what My Home Energy shows. As you can see, Solar often doesn't do it.

 

[DrSmile]

Your solar production seems very low. To compare I made 46 Kwh today (pretty cloudy), so 2.5x more. Your system is either way too small or you have a lot of shading. To supplement 100Kwh per day you're going to need at about 20Kw of panels, which requires a lot of roof space.

 

[Redhill_qik]

this is what My Home Energy shows. As you can see, Solar often doesn't do it. View attachment 933986

That is a by really weird graph as the solar looks like it is running at a fraction of the house load at all times. What did the Solar graph look like?

 

[jgleigh]

That is a by really weird graph as the solar looks like it is running at a fraction of the house load at all times. What did the Solar graph look like?

And the house is tracking the solar which usually points to a CT that isn't setup properly.

 

[DSE25]

I have thought this is strange

Your solar production seems very low. To compare I made 46 Kwh today (pretty cloudy), so 2.5x more. Your system is either way too small or you have a lot of shading. To supplement 100Kwh per day you're going to need at about 20Kw of panels, which requires a lot of roof space.

counting weekends we combined do maybe 50 miles a day so call it 20kwh during the winter so that's, hah, $2 a day. Maybe my problem is elsewhere?

 

[DSE25]

And the house is tracking the solar which usually points to a CT that isn't setup properly.

Sorry what's a CT? Thanks.

 

[DSE25]

There is no guarantee that you would be able to "top off your batteries with off peak grid energy". Im not sure what triggers tesla to allow or disallow grid charging, but everyone does not have that available.

Thanks, I was looking into Franklin WH which does allow that.

 

[jjrandorin]

Sorry what's a CT? Thanks.

"Current Transformer" ("Current Transducer? I can never remember the exact name). Its the device that is used to measure power flow by being clamped around power cables. When a Solar install is done, these devices are the ones that measure power and show it to you in whatever app the solar company is using.

Sometimes they are not configured properly since its not just "plug em in".

 

[jgleigh]

Current transducer is correct. They are sometimes installed in the wrong location or installed backwards. The Home data isn't directly measured. It's calculated from Solar and Grid (and battery if present). Can you post all three screens?

 

[BGbreeder]

"Current Transformer" ("Current Transducer? I can never remember the exact name). Its the device that is used to measure power flow by being clamped around power cables. When a Solar install is done, these devices are the ones that measure power and show it to you in whatever app the solar company is using.

Sometimes they are not configured properly since its not just "plug em in".

In my experience both phrases are used, and also a "current sensor". It is technically a transformer, but used to monitor current, so often called a current transducer.

Current transformer - Wikipedia

en.wikipedia.org

Current sensors and transducers | LEM

LEM is leading the world in electrical measurement and offers the widest range of current transducers and sensors using all the best technologies available.

www.lem.com

Since CTs supply a current created by an induced current from the wire that they monitor, there is a direction to how the wires are hooked up, and to complicate matters further there are software settings that can switch the sign of the flow. However, the electricians wiring them up have to get them on the right wires for whatever their function is to be in the software. Because the currents are small, the CTs need to be close to wherever the measurement point is, and their wires must be tightly and uniformly twisted together for the whole length, and ideally, not close to other wires carrying currents, and only crossing other wires at 90 degrees, i.e. perpendicularly. The last bits can be difficult to do in congested service panels.

All the best,

BG

 

[cwied]

Current transducer is correct. They are sometimes installed in the wrong location or installed backwards. The Home data isn't directly measured. It's calculated from Solar and Grid (and battery if present). Can you post all three screens?

Are you sure? My understanding is that the Neurio uses a current transformer to get an AC input signal to the main unit that is then measured there (possibly with a built in transducer). The parts are described as "current transformers" in the catalogs: Neurio SEK-2U Universal Current Transformer Kit

 

[BGbreeder]

A neurio digitizes the current values from up to four CTs, scales the readings to the amperage in the wire(s) being measured, and then transmits the digital readings to the Tesla Gateway. They are often used where the distance from the Gateway to the measurement point is "too far". If you browse the web for neurio information, be aware that Tesla's neurio's have different specifications and performance compared to other versions, and newer neurio are different for older ones. (Version 2 vs Version 1.X)

All the best,

BG

 

[jgleigh]

Are you sure? My understanding is that the Neurio uses a current transformer to get an AC input signal to the main unit that is then measured there (possibly with a built in transducer). The parts are described as "current transformers" in the catalogs: Neurio SEK-2U Universal Current Transformer Kit

I stand corrected. Tesla also calls them Current Transformers. A quick Google search shows the terms are almost used interchangeably.

Is there a difference between a current transformer, current transducer, and a current sensor?​

Technically yes, but these terms are often used interchangeably. These devices are all used to measure current and operate based on the same principles, but there are distinct technical differences between them that are good to be aware of. Technically, current transformers step-down current so it can be monitored efficiently and safely, whereas current sensor is a general term for a device that senses and measures current. Transducers convert one input into a different output. For instance, they may covert AC to DC signals. However, all these devices work similarly to measure current and create an output that is readable by a power meter.

 

[jjrandorin]

I stand corrected. Tesla also calls them Current Transformers. A quick Google search shows the terms are almost used interchangeably.

I remember googling these terms before when someone asked "whats a CT?" here, and thats what I found as well (that they are used interchangeably for this meaning). I then just told myself, "well, I guess I will just stick to "CT" lol...

 

[DSE25]

Current transducer is correct. They are sometimes installed in the wrong location or installed backwards. The Home data isn't directly measured. It's calculated from Solar and Grid (and battery if present). Can you post all three screens?