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Energy limit from solar sending back to PGE?
- Thread starter h2ofun
- Start date
charlesj
Active Member
Get a community energy set up in your area. They will pay for full over production at better rates than PG&E. 
We have one in my area. Started with 3 counties and spreading out as other counties want to join in.
We have one in my area. Started with 3 counties and spreading out as other counties want to join in.
Yes you are time shifting. You are not exporting beyond what you harvest. In fact you are exporting less than you harvest because some of that harvest goes to charge your Powerwall. Technically you are also not buying power from the grid at off peak rates and selling the same amount of energy stored to the grid at peak rate. It is the best any of us can hope for without risking our ITC credit or violating some obscure term of our PTO. You are also not at risk of exporting more than the amount estimated.
One could conceivably program a hybrid inverter to charge at off peak rates and power all the house loads from batteries so that 100% of solar production would be exported. The cost of that hybrid system would not qualify for the ITC because the batteries were not charged from solar. There is technically no other reason other than the loss of ITC why one could not do that, There is also no financial incentive for the above scheme since the True Up dividend on excess production uses a discounted rate to calculate the dividend at True Up. None of the above is possible with a Powerwall because of the way a Powerwall is configured and limited by Tesla.
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Yes, I agree. My Community Choice Aggregation is Sonoma Clean Power. I received a $250 dividend last year which more than covered my Minimum Delivery Charges and Non Bypassable Charges from PG&E.
SCP like other CCAs is lowering the payback on overgeneration for this year but it is still better than PGE.
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I understand. I was merely over articulating a response because it appeared @h20fun may have implied that you were doing something more than optimizing your use of your Powerwall.
aesculus
Still Trying to Figure This All Out
Well you could weasel word what you wrote to just mean that you were only going to buy power and use it real-time when it is cheap and export as much solar as you can when it's expensive but this statement would not be considered that mode at face value IMHO.
I intend to discharge 100% of peak solar to the grid and only take energy off the grid off peak. The powerwalls will let me do that. As a result, for every 1 kwh I sell to the grid at peak, I'll get back 2 to 3 kWh off peak from the grid for the same price. I thought I was pretty clear about this.
Im not sure I quite follow what you are saying here, but you will not be selling much electricity at "peak" because peak is so late in the day (4pm) that you will not be generating that much electricity from start of "peak" to when the sun goes down. What your powerwalls allow you to do is not CONSUME much if anything during peak, but you will not be selling much during peak.
And yes, its based on when the kWh are produced. The rate is the rate at the time of consumption / generation. So, any energy you produce during off peak is credited at off peak rates if you are producing more than you consume. When peak rates start, same thing. if you are over producing during peak, you would be credited at peak rates (but not many people will be over producing for very long after 4pm).
So, I am not following what you are saying. Powerwalls help you avoid paying peak rates by time shifting. They dont really help you sell back at peak rates (in the US).
You are not going to be selling very many kW to the grid between 4pm to 9pm. You are "pretty clear" about what you are saying, but the way you are saying it you seem to believe there is a lot of production you will be selling back "at peak" and there isnt.
There's only a penny difference where I am between peak and part peak which starts at 3 pm. In the summer, given my southwest facing orientation, peak time production is 33.27% on 6/21, 21.58% on 3/21 and 18.5% on 12/21. In all about 27% of all the sun I capture year round will still make it back to the grid at peak time. The rest of the sun captured off peak I'll need to store for off peak time usage which is higher for us than off peak usage.
I agree with your philosophy and I admit I jumped to conclusion about it as well. Apologies if I started something that you do not deserve. You are optimizing the use of your Powerwall.
In the summer when my peak rates are $0.55 I get significant revenue from peak rate generation. In June I accumulated 300 kWh of net peak generation. A lot of that was because like @sorka, I used my batteries to carry the household loads through the day after solar production went to zero so there was little consumption to erode that benefit. I am burning that off now on purpose because True Up is in February and there is no incentive for me to carry a True Up credit balance because it will wash out at True Up and disappear. It all depends on where you are standing and unless you are in my shoes or the shoes of Sorka you may not have the same situation.
That is exactly what I do. I do not mean weasel word, I mean exactly that I export as much solar as I can when it is expensive and use it in real time when it is cheap. I have accumulated over 1000 kWhs of generation credit for the 9 months but used 1700 off peak and still have a credit of over $200
I am not sure what the benefit is of putting more attention on what or how someone says something. What really matters is that he seems to be optimizing the use of his Powerwall.
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Okay, lets try with you my questions.
I am assuming a person does not have an EV car. I am assuming one has solar which lets assume is on the tou-c plan.
Lets assume one puts enough solar on their house to have a zero true up bill.
This basically means the cost off peak vs on peak is basically the same. Therefore one really does not need to adjust their
life style to anything relating to electricity cost.
This is the assumption I am making when I read most posts about batteries, meaning, they do not say they have an EV car, which would have forced them on the ev2a rates, which do have some huge non peak vs peak costs.
So, if the above assumptions are made, why would one ever buy batteries which forces one into the ev2a rates, and yep, would have one having to start playing with their lives and how and when one uses electricity. If one say but power outages, great. Lets assume calif. I had one outage, for 1 day. I can buy a 500 dollar generator for the refrig, and battery lights for the house.
Now, I understand we all spend our excess money in different ways, so I am just looking at a business 101 excel spreadsheet.
I just keep asking since maybe, just maybe, I am missing something non emotional. Meaning, lets see a month by month cost assumption, comparing the tou-c rates vs ev2a battery rates, and help me understand how one would ever pay the money back.
So, do you have an EV car?
I posted month by month year over year with and without PWs and showed savings in another thread. You keep ignoring and keep going on and on and on about it
I forget, do you have a EV car? If not, your numbers only work if you went on ev2a which was your choice when you put in batteries.
Show a spreadsheet month by month comparing tou-c cost with solar, and the negative cost of batteries and having to change your lifestyle to go to ev2a.
i am not asking question to anyone who has a ev car. asking only to folks with no ev car and say batteries save them money. with an ev car totally different question which i am not asking
I don't see the relevance of an EV. If I did not have an EV, I would still save money
