First month with solar

[daniel]

I've actually had my solar for almost two months, but it was turned on a few days into my electric utility billing cycle. So I've just gotten the bills for my first fill billing cycle with solar. This is for a 30-day cycle.

I use a little over one MWh per month. I pulled 20 kWh from the grid. I pay the $25 minimum plus $1.17 "green infrastructure fee." Apparently the solar+Powerwall system cannot react to changing demand fast enough to be completely independent of the grid. So if I wanted to disconnect completely, the cost of the system would not be worth it. Plus I have the grid as a backup if my system goes down for some reason.

The renter in the cottage uses about 570 kWh per month. Because she is at work all day and except for daytime A/C uses all her energy at night, she sometimes drains the Powerwall, and this billing cycle she pulled 45 kWh from the grid. So she went over the minimum usage, so the minimum charge does not apply, but the Green Infrastructure Fee still applies. The bill for the cottage is $27.26, or a dollar more than the minimum charge.

Both the house and the cottage can be kept as cool as we like for free since most of the A/C demand comes when the sun is shining. We had a couple of cloudy days when my solar production was down, but the A/C didn't run as much either. I'm still looking into getting soft-start for the A/C compressor so that I'll have A/C when the grid is down. My system has enough power to run it, but cannot supply sufficient amperage to start it. Otherwise I have power when the grid is down.

 

[SilverShadow]

Daniel,
Can you give us more info on what size system you have, etc?

 

[daniel]

Daniel,
Can you give us more info on what size system you have, etc?

There are two systems, both mounted on my two-story house. One of them is for the cottage behind the house.

For the house, there are 32 panels, 11.68 kW DC but only 10 kW AC because they're mounted on three sides of the roof so they'll never all get maximum sunlight at the same time and will never produce the rated maximum DC and so there was no need for a larger inverter than 10 kW. I think I maybe saw 9 kW once or twice and I've seen 8.5 kW regularly. There are also two Powerwalls, each with a 13 kWh capacity and each with the ability to deliver 5 kW, though I don't know how that changes with SoC.

For the cottage there are 16 panels rated at 6 kW DC and AC, and one Powerwall.

The panels are LG365Q1C-A5, the optimizers (whatever that means) are SolarEdge P370, the gateway is Tesla. I do not have net metering and the utility will not take my excess even though I'd happily give it to them for nothing. Apparently there's already so much rooftop solar on Maui that when the sun is shining they cannot accept any more power.

The total cost, installed, with tax, for everything, both systems, was $99,800 but subsidies will return close to half of that in the form of tax breaks from the state and the feds. My estimated break-even time is just under 5 years for the house and just over 5 years for the cottage. Based on the fact that the U.S. average CO2 production is about one pound per generated kWh, my system prevented a thousand pounds of CO2 from being dumped into the atmosphere last month alone. Though I'd probably have used a little less air conditioning if my electricity had come from fossil fuel. So maybe I really only "saved" 750 pounds of CO2 from being produced.

Being Hawai'i, most of my electric use is for A/C and is in the daytime when the sun is shining. We had a cloudy day when the output was significantly less, but so was the A/C usage. I'm at home much more than not, so I charge the car when the sun is shining, and if on occasion I use the car in the afternoon or on a cloudy day I'll wait until the next day to charge it. With 310 miles of range on an island that's 50 miles long and 25 miles wide, I could go days or weeks without charging. (Bought the car literally weeks before deciding that moving to Maui might be an idea to consider. Otherwise I'd have gotten the SR.)

 

[Quickstart88]

I've actually had my solar for almost two months, but it was turned on a few days into my electric utility billing cycle. So I've just gotten the bills for my first fill billing cycle with solar. This is for a 30-day cycle.

I use a little over one MWh per month. I pulled 20 kWh from the grid. I pay the $25 minimum plus $1.17 "green infrastructure fee." Apparently the solar+Powerwall system cannot react to changing demand fast enough to be completely independent of the grid. So if I wanted to disconnect completely, the cost of the system would not be worth it. Plus I have the grid as a backup if my system goes down for some reason.

The renter in the cottage uses about 570 kWh per month. Because she is at work all day and except for daytime A/C uses all her energy at night, she sometimes drains the Powerwall, and this billing cycle she pulled 45 kWh from the grid. So she went over the minimum usage, so the minimum charge does not apply, but the Green Infrastructure Fee still applies. The bill for the cottage is $27.26, or a dollar more than the minimum charge.

Both the house and the cottage can be kept as cool as we like for free since most of the A/C demand comes when the sun is shining. We had a couple of cloudy days when my solar production was down, but the A/C didn't run as much either. I'm still looking into getting soft-start for the A/C compressor so that I'll have A/C when the grid is down. My system has enough power to run it, but cannot supply sufficient amperage to start it. Otherwise I have power when the grid is down.

What is this $25 minimum plus $1.17 "green infrastructure fee"?
So sort of administration fee from your power company?

 

[daniel]

What is this $25 minimum plus $1.17 "green infrastructure fee"?
So sort of administration fee from your power company?

If you are connected to the grid, there's a minimum bill. I suppose that pays for the meter and the infrastructure (power lines to your house). You get around 40 kWh for that $25, so you pay $25 if you use less than about that much. The $1.17 "green infrastructure fee" is if you have your own "green" power generation they charge you that on top of whatever your bill is.

I suppose the idea is that the more people are producing their own power, the more the capital cost of the power plant has to be born by the dwindling number of people buying power from the utility. I'm certainly not going to complain about the $14/year fee. And the $25 monthly minimum seems reasonable for the meter and power lines. If I wanted to go completely off-grid I'd need at least one more Powerwall for the house and one for the cottage, and that would not be worth it.

Or, I don't know, maybe everybody pays the green infrastructure fee to pay for the wind turbines up on the West Maui Mountain and any solar the utility has installed. Our grid does get a small part of its energy from renewables. If that's the case, I don't mind paying an extra $14/year for that.

 

[Quickstart88]

If you are connected to the grid, there's a minimum bill. I suppose that pays for the meter and the infrastructure (power lines to your house). You get around 40 kWh for that $25, so you pay $25 if you use less than about that much. The $1.17 "green infrastructure fee" is if you have your own "green" power generation they charge you that on top of whatever your bill is.

I suppose the idea is that the more people are producing their own power, the more the capital cost of the power plant has to be born by the dwindling number of people buying power from the utility. I'm certainly not going to complain about the $14/year fee. And the $25 monthly minimum seems reasonable for the meter and power lines. If I wanted to go completely off-grid I'd need at least one more Powerwall for the house and one for the cottage, and that would not be worth it.

Or, I don't know, maybe everybody pays the green infrastructure fee to pay for the wind turbines up on the West Maui Mountain and any solar the utility has installed. Our grid does get a small part of its energy from renewables. If that's the case, I don't mind paying an extra $14/year for that.

Thanks Daniel for the explanation. I don't mind paying an extra $14 a year.
Does the size of your system matter? That $25 per month seems high if we go with the Tesla smaller 3.8 kilowatt system?

 

[daniel]

Thanks Daniel for the explanation. I don't mind paying an extra $14 a year.
Does the size of your system matter? That $25 per month seems high if we go with the Tesla smaller 3.8 kilowatt system?

$25/month is simply the minimum bill. Your electric usage from your meter is recorded and they charge you so much per kWh (actually it's a lot more complicated, but they figure out how much you owe) and if that's less than $25, then you pay $25. This would also apply, for example, with a conventional home if you went on vacation and shut off all your appliances. If your house uses less than about 40 kWh you'd pay $25. If you use more, you pay for the actual usage.

There's actually a flat monthly rate of about $11.50 just for being connected, then two different amounts per kWh which are added together, then several different kinds of taxes and fees, and the green infrastructure fee, which as I said might or might not be applied to everyone, but in my case was applied after the $25 minimum. The other taxes and fees are applied before the minimum.

The upshot was that the last month before I had solar I paid around $350 for the house and the cottage was about half that, and now I pay $26.17 for the house, and a bit more for the cottage because, as noted earlier, the cottage only has one Powerwall, and coming home after sunset the renter sometimes depletes that and uses some grid power. 45 kWh last month, so that bill was $1.09 over the minimum. (When I bought the property I inherited a peculiar lease whereby I pay the first $100 of the electric bill and the renter pays anything over that. So now she pays nothing for electricity and I get to keep about $75 of rent that used to go to the utility.)

 

[Quickstart88]

$25/month is simply the minimum bill. Your electric usage from your meter is recorded and they charge you so much per kWh (actually it's a lot more complicated, but they figure out how much you owe) and if that's less than $25, then you pay $25. This would also apply, for example, with a conventional home if you went on vacation and shut off all your appliances. If your house uses less than about 40 kWh you'd pay $25. If you use more, you pay for the actual usage.

There's actually a flat monthly rate of about $11.50 just for being connected, then two different amounts per kWh which are added together, then several different kinds of taxes and fees, and the green infrastructure fee, which as I said might or might not be applied to everyone, but in my case was applied after the $25 minimum. The other taxes and fees are applied before the minimum.

The upshot was that the last month before I had solar I paid around $350 for the house and the cottage was about half that, and now I pay $26.17 for the house, and a bit more for the cottage because, as noted earlier, the cottage only has one Powerwall, and coming home after sunset the renter sometimes depletes that and uses some grid power. 45 kWh last month, so that bill was $1.09 over the minimum. (When I bought the property I inherited a peculiar lease whereby I pay the first $100 of the electric bill and the renter pays anything over that. So now she pays nothing for electricity and I get to keep about $75 of rent that used to go to the utility.)

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Basically you are paying $25 per month at a minimum. This includes taxes, green infrastructure fees, and connection fees?
Or $25 per month plus the $11.40?

I've posted on a few threads elsewhere and I plan to get that small system 3.8 kilowatt system.
I use on average 20 to 22 kilowatt a day. Someone mention he get 15 kilowatt generated per day on average in CA.
Given my usages history i am a little short and need tp pull from the grid.
Just not sure if spending 10k for the small system worth it since there's all these fees I am not familiar with.
I figured I'll be pulling from the grid base on TOU and at a lower rate. The rest will be use during the day.
My current bill on average is $120 ish.

Not sure if spending 10k or 7.5K after incentive is worth it.

 

[Dan123]

You have two separate electric meters for your house and your cottage? It seems like it results in two separate "minimum charges."

Are there restrictions on exporting power to the grid? I heard Hawaii doesn't allow it, or severely restrict it.

 

[daniel]

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Basically you are paying $25 per month at a minimum. This includes taxes, green infrastructure fees, and connection fees?
Or $25 per month plus the $11.40?



I've posted on a few threads elsewhere and I plan to get that small system 3.8 kilowatt system.
I use on average 20 to 22 kilowatt a day. Someone mention he get 15 kilowatt generated per day on average in CA.
Given my usages history i am a little short and need tp pull from the grid.
Just not sure if spending 10k for the small system worth it since there's all these fees I am not familiar with.
I figured I'll be pulling from the grid base on TOU and at a lower rate. The rest will be use during the day.
My current bill on average is $120 ish.

Not sure if spending 10k or 7.5K after incentive is worth it.

Keep in mind that I'm on Maui, in Hawaii, so the billing for you in California is bound to be different. Last month I used about 20 kWh. So I paid a total of $26.17. That is the $25 minimum plus the $1.17 green infrastructure fee. The cottage used about 45 kWh so for the cottage I paid $27.26. They add up the $11.50 plus the charge for kWh plus all taxes and fees except the $1.17 GIF. If this amount is less than $25, then they round it all up to $25. The GIF is added at the end. Since the bill for the cottage added up to more than $25, there was no rounding and I paid the actual amount, including the $1.17 GIF.

The $25 minimum includes taxes and connection fees and everything except the green infrastructure fee.

You have two separate electric meters for your house and your cottage? It seems like it results in two separate "minimum charges."

Are there restrictions on exporting power to the grid? I heard Hawaii doesn't allow it, or severely restrict it.

Yes, there are two separate meters. It was probably intended that the renter would pay their own electric bill. Then they rented to someone who wanted to pay an additional $100 in rent but have that applied to her electric bill. I inherited that lease. I have considered unifying the two systems under one meter, but if a future renter has a lot of electric usage, and I have no way to meter the cottage separately, I could end up with a big electric bill. This way I do pay two bills, each with a $25 minimum, but I also get the extra $100 in rent, of which I get to keep about $75, with the renter's present consumption pattern.

MECO (the electric utility here) does buy back electricity from some people. Some folks get net metering, which is a one-for-one exchange. Others get a less generous credit. But the system can only accept a certain amount of daytime power, and solar is very popular here. I just bought my house a few months ago, so I was too late. MECO will not buy back my excess power. I can export a very small amount of power, which is done for load balancing. E.g., when my A/C shuts off it takes a fraction of a second (or more?) for my system to cut back production, and for that moment my system is exporting power. I don't know what the limit is. And MECO will not pay me or credit me for that power. I would give them my excess (and I have a LOT of excess production capacity on sunny days, which is almost every day) just for the good of the environment, but they won't take it because they're already getting all the power they can utilize.

I could have installed a smaller system, but this way I'm covered for cloudy or rainy days, if it ever rains again (we're having a drought on this part of the island).

 

[troptop]

Please let us know how it goes with the soft-start for your AC.

 

[daniel]

Please let us know how it goes with the soft-start for your AC.

So far nobody has gotten back to me on that. I'm going to have to renew my inquiries.

 

[Dan123]

Yes, there are two separate meters. It was probably intended that the renter would pay their own electric bill. Then they rented to someone who wanted to pay an additional $100 in rent but have that applied to her electric bill. I inherited that lease. I have considered unifying the two systems under one meter, but if a future renter has a lot of electric usage, and I have no way to meter the cottage separately, I could end up with a big electric bill. This way I do pay two bills, each with a $25 minimum, but I also get the extra $100 in rent, of which I get to keep about $75, with the renter's present consumption pattern.

If you combine the systems and have 3 Powerwalls, then you probably will be able to run your AC without softstart. And you will have fewer days with solar overproductions, and underproduction.

As for the tenant overusing, you an in theory install some CT monitor on their subpanel and make sure that their electric usage is within normal limits.