advice needed on budgeting for solar panels, charging

[Nosken]

This great iPhone app will analyze your current and past bills, and break down how much you pay or credit you get on your usage. It lays out all the plans, including power wall and EVA
My PG&E Toolkit Lite by Ndili Technologies, Inc.
https://appsto.re/us/gDEfS.i

 

[brucet999]

@JCL, you probably don't have the awful "tiered use" plans that we see in California. The more you use, the higher the per kWh rate (till it approaches $.32/kWh in Tier 3). Even with your home at net zero consumption, if you drive 100 miles a day, you're looking at up to 950kWh per month just from the Tesla. Again, in California most of that 950kWh would be at the highest rates. Assuming you pay about $.10/kWh with no progressively costly tiers, you're looking at about $95/mo to operate your Tesla. Still FAR FAR cheaper than an ICE vehicle.

Your system and mine are almost identical, but mine are the 275W panels with a 6kW inverter.

California residents will have another chance to get a submeter and pay the EV rate ($.13/kWh off peak) when Phase II of the pilot program resumes in November. However, I'm now looking at changing to time of use (TOU), which has that same or slightly lower off-peak rate.

Sorry for the California-centric rant.

You need to switch to TOU rates. My tiered rates edged into tier 3 before I got the Tesla, and of course all the added power use was at high rates. I changed to time of use and now I charge the Tesla overnight at super off peak rate of $0.125/kWh. Edison's people are quite willing to look up past usage (for a few selected weeks) and compare how those times would have compared under the TOU versus the tiered rate you paid. In my case, I would have saved $27 over the course of a year (pre Tesla) under TOU, so the change decision was a no-brainer.

 

[Electric700]

Hello, I am getting my 60D in about a week.

I have 24 300W panels, in real-world use I have seen them hit 6kW peak, and I have hit 1.2MWh in one month. My entire house is LED, and it is only 2 years old, and I have done allot to conserve. Right now I can go the whole year with no electric bill, using my credit from the summer to get through the winter, with a slight extra maybe. I have 12 months to use any credits I get.

I own my panels rather than lease, so I could add some, but I don't have that much room left on my roof. And my inverter is 7.2kW max I think, so too many more and I would need a bigger one. Although I may need to replace it anyway if I get batteries.

I expect the car to put me over and that I will have a small electric bill again. But, I am not unhappy about this, because I would actually rather use all of what I am generating, it is worth more to me to use it than what I get back from net metering. If it really got high and/or electric rates went up, I could see adding panels, but I am happy to wait and see.

I am considering power wall also, but I don't have enough info on it really yet.

I can report back as things progress.

JCL

Very nice! Have you considered adding a micro wind turbine?

 

[rxlawdude]

You need to switch to TOU rates. My tiered rates edged into tier 3 before I got the Tesla, and of course all the added power use was at high rates. I changed to time of use and now I charge the Tesla overnight at super off peak rate of $0.125/kWh. Edison's people are quite willing to look up past usage (for a few selected weeks) and compare how those times would have compared under the TOU versus the tiered rate you paid. In my case, I would have saved $27 over the course of a year (pre Tesla) under TOU, so the change decision was a no-brainer.

Yes, but we have someone home all day and a rather ravenous A/C system. However, I downloaded a year's worth of data (consumption recorded in 15 minute increments), and massaged 37,000 records to determine how much our past consumption would be on TOU (segregating each time period and multiplying by the per kWh rate). In spite of a lot of use during peak hours (somewhat offset by the PV system), it does look like TOU is cheaper. But that assumes we don't continue the EV Submetering Pilot, which starts anew in Phase 2 in November. Still dithering.

 

[wrysys]

thanks andresf. and others. i'm always amazed by old fogies like sasgebrush on forum sites

 

[miimura]

@wrysys where are you located exactly? I have a spreadsheet that I have posted before that uses SmartMeter data downloaded from PG&E to calculate the cost of energy on the various PG&E rate plans. The advantage of my spreadsheet versus the app mentioned above is that you can do things like add Off-Peak EV charging to your historical usage. If you live in an area that uses significant A/C I would be willing to put in the time to run the analysis for you. I have done the analysis for my house and my relatives, but we all live in west Santa Clara County, so the A/C usage is not that much.

 

[SageBrush]

thanks andresf. and others. i'm always amazed by old fogies like sasgebrush on forum sites

Thank you for removing any polite doubts. Welcome to my ignore list.

 

[ThortsMD]

Don't worry about the inverter limit. I have a mixed system....I put up my first batch of panels in 2009, tied to a single inverter. When I got my S, I added more panels, but these were the type with their own inverters. So, although I was near my original larger inverter limit, the built-in panel based inverters saved the day.