WorldwideDave
New Member
I’m currently paying SCE $0.39 per kwh. If you multiply that by monthly usage of 744kwh, it is a $290 SCE bill. Higher months are about $350.
Very high rate. I want to pay zero.
Very high rate. I want to pay zero.
Is it just me?
- Thread starter WorldwideDave
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WorldwideDave
New Member
My pool is 2400 watts max, 240v. Does that mean 10 amp breaker would work for that? In my panel the pool equipment- pump and gas heater - has two 15 amp breakers connected.
SunDave
Solar Enthusiast
No. 10 amp would not work. Breakers are wire sizes have to be carefully planned, and you can't exceed certain percentages. For example, you can't run a breaker at 100% of the rating. Changing the breaker out gives you no benefit anyways. It does not change how much power an appliance demands.
WorldwideDave
New Member
Thank you I thought that was the case. I wasn’t trying to reduce usage by switching out a breaker. I was just seeking to understand what was already installed in the panel.
With 215 amp breakers connected, is it a 15 amp 240 circuit, or is it a 30 amp circuit?
I have seen where a portable air conditioner plugged into a 15 amp circuit causes the breaker to pop when it initially starts up. Air conditioner has only rated for 12 A. When I plug it into a 20 amp dedicated circuit it does not pop the breaker. I wonder what that is all about. I think it has to do with surgery or something.
With 215 amp breakers connected, is it a 15 amp 240 circuit, or is it a 30 amp circuit?
I have seen where a portable air conditioner plugged into a 15 amp circuit causes the breaker to pop when it initially starts up. Air conditioner has only rated for 12 A. When I plug it into a 20 amp dedicated circuit it does not pop the breaker. I wonder what that is all about. I think it has to do with surgery or something.
SunDave
Solar Enthusiast
Hi. There is this smart guy @timselectric that may be able to let you know with more clarity than I can. If he has time that is.
Hedges
I See Electromagnetic Fields!
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Zip code 90266 is Manhattan Beach, CA.
Net metering is dead in CA, unless you put in a reservation no later than April 14th, 2023.
This means you get zilch for backfeed most of the time, and pay retail.
You want to:
1) Consume power while PV makes it.
2) If something cycles on and off, like an A/C, you probably want a battery to clip the peaks and valleys, leaving zero import, zero export.
Turnkey PV costs $0.10/kWh (amortized over 20 years), and DIY costs $0.025.
Batteries cost $0.05/kwh (over 6000 cycle, 16 year life.) Calendar life could be shorter if multiple cycles in a day.
It could make sense to put in PV able to supply peak A/C draw rather than only enough for average A/C draw + batteries.
But NEM 3.0 (Solar Billing Plan) rules may forbid you to install PV producing 2x average consumption. Maybe you can do it with zero or limited export.
Solar Billing Plan normally gives paltry credit for backfeed, like about $0.02/kWh (less than it costs you to produce.)
However, it gives credit varying between $3.00 and $4.00 per kWh for 2 hours per day in September. And $1.00 per kWh/day in August. This is early evening, 7 to 9 PM. It could be worthwhile to have batteries to charge during the day, backfeed during those couple hours. A kWh exported at $3.50 in September allows you to draw close to a kWh per day every other month of the year.
Once you buy a battery to earn that super-peak backfeed credit, it is available for peak/valley shaving the rest of the year, and for night time use. Those credits will be useful in winter (if that season exists in your location) and for cloudy days.
When you can make power for $0.025/kWh and store it for $0.05/kwh, I'm not sure it's true that saving a watt is cheaper. I'd be inclined to use cheap reliable resistance water heater and dryer, rather than newfangled heat pump technology.
Control of loads (enable heating and pumping loads to minimize import/export) I'd put as a higher priority.
Net metering is dead in CA, unless you put in a reservation no later than April 14th, 2023.
This means you get zilch for backfeed most of the time, and pay retail.
You want to:
1) Consume power while PV makes it.
2) If something cycles on and off, like an A/C, you probably want a battery to clip the peaks and valleys, leaving zero import, zero export.
Turnkey PV costs $0.10/kWh (amortized over 20 years), and DIY costs $0.025.
Batteries cost $0.05/kwh (over 6000 cycle, 16 year life.) Calendar life could be shorter if multiple cycles in a day.
It could make sense to put in PV able to supply peak A/C draw rather than only enough for average A/C draw + batteries.
But NEM 3.0 (Solar Billing Plan) rules may forbid you to install PV producing 2x average consumption. Maybe you can do it with zero or limited export.
Solar Billing Plan normally gives paltry credit for backfeed, like about $0.02/kWh (less than it costs you to produce.)
However, it gives credit varying between $3.00 and $4.00 per kWh for 2 hours per day in September. And $1.00 per kWh/day in August. This is early evening, 7 to 9 PM. It could be worthwhile to have batteries to charge during the day, backfeed during those couple hours. A kWh exported at $3.50 in September allows you to draw close to a kWh per day every other month of the year.
Once you buy a battery to earn that super-peak backfeed credit, it is available for peak/valley shaving the rest of the year, and for night time use. Those credits will be useful in winter (if that season exists in your location) and for cloudy days.
When you can make power for $0.025/kWh and store it for $0.05/kwh, I'm not sure it's true that saving a watt is cheaper. I'd be inclined to use cheap reliable resistance water heater and dryer, rather than newfangled heat pump technology.
Control of loads (enable heating and pumping loads to minimize import/export) I'd put as a higher priority.
WorldwideDave
New Member
The problem in that home is that there is a generation gap. There are 3 generations living there, and so getting them to change behaviors has not happened since the time of use plan went into effect. Lights and TVs left on all the time. Cooking is at 6 PM during peak charges. Washer and dryer run during peak times, too. Old habits/routines die hard.
They are slowly upgrading appliances, but that is expensive to do. Gas water heaters were changed to on demand types. Not sure if any savings now that gas has gone up so much. Gas dryer went to electric, thinking it would be a savings. It has not been. Honestly the costs just keep going up, so finding a way to get them back close to zero as possible is the way to go.
I expect this to cost a lot. Not happy about that. But it sounds like an inverter that takes power and stuffs it into a battery (even if from the grid) and then kills the grid feed during peak times so you can use it from the battery might be a good start. Not sure the ROI is there for that, though.
I feel like adding PV cells to charge said batteries would enable us to use the batteries more and more and eventually stop using the grid for power.
Sounds like panels and all-in-one inverters are cheap right now, and putting panels up and using solar power when it is bright like today would be the best time to use the heavy load appliances. But again - getting people to change their ways on when they do laundry and such would be difficult, so perhaps best to figure out batteries to store it first (something that switches between grid and battery based on time-of-use?), all in one to charge the batteries from the grid when cheaper, then do PVs to charge the batteries.
I think the inverter is the tech that knows how to pull from grid to charge batteries and when to turn off grid to use batteries. Am I right?
Thanks for reading.
They are slowly upgrading appliances, but that is expensive to do. Gas water heaters were changed to on demand types. Not sure if any savings now that gas has gone up so much. Gas dryer went to electric, thinking it would be a savings. It has not been. Honestly the costs just keep going up, so finding a way to get them back close to zero as possible is the way to go.
I expect this to cost a lot. Not happy about that. But it sounds like an inverter that takes power and stuffs it into a battery (even if from the grid) and then kills the grid feed during peak times so you can use it from the battery might be a good start. Not sure the ROI is there for that, though.
I feel like adding PV cells to charge said batteries would enable us to use the batteries more and more and eventually stop using the grid for power.
Sounds like panels and all-in-one inverters are cheap right now, and putting panels up and using solar power when it is bright like today would be the best time to use the heavy load appliances. But again - getting people to change their ways on when they do laundry and such would be difficult, so perhaps best to figure out batteries to store it first (something that switches between grid and battery based on time-of-use?), all in one to charge the batteries from the grid when cheaper, then do PVs to charge the batteries.
I think the inverter is the tech that knows how to pull from grid to charge batteries and when to turn off grid to use batteries. Am I right?
Thanks for reading.
Hedges
I See Electromagnetic Fields!
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Off-peak electric rates are about $0.40 and on-peak about $0.60/kWh
With that spread, I don't recommend buying battery for the purpose of arbitrage. If you've already bought it for other purposes, then you might use it this way because it could cost $0.05/kWh. Just don't count on rules or rates staying the same for 16 years.
But rules that let you backfeed from battery don't let you also charge battery from grid. So system needs to charge battery from PV, if necessary supply house from grid at same time.
Can you DIY? If so, you can roll your own kWh with PV for about $0.025/kWh. Otherwise, turnkey for $0.10/kWh.
Those prices include grid tie PV inverter. You may find a hybrid (batteries optional) for the same price (suspect lower quality.)
Midnight's AIO (China manufactured, at least part US designed by respected pioneers of the industry) may be a good match, together with their soon to be announced batteries. You will need a UL Listed ESS (battery + inverter) which these should be.
Given how cheap PV is, I favor massive over-paneling. NEM 3.0 rules may not allow, but there is something about grid-tie vs. separate off-grid system, possibly zero-export system, that could allow it. They don't intend to make it easy or cheap.
How much area do you have for rooftop and/or ground mount?
PV panels are STC rated 200W to 220W per square meter. Expect 70% to 90% of that (varies by brand and temperature) in direct sun. Use an on-line Insolation calculator to determine monthly production for your location and panel orientation.
I'm working with SMA support trying to get Sunny Boy Storage + LG RESU-10H to do what I want.
Earlier firmware delayed charging battery until almost end of the day's off-peak every other day. But it let me set a negative current limit resulting in forced export to grid during peak.
Latest firmware appears to charge and discharge every day reliably. But it now enforces no negative values, can't set any new current levels for forced backfeed to grid. Only got one small value in a named profile I used for experimentation. Tried unsuccessfully to roll back firmware. Exported configuration to modify, tried to import (even original unmodified file) and it garbled the data.
Be afraid of software/firmware. Be very afraid.
If it doesn't support the functions you require out of the box, it may never.
No refunds in the future, so you need to get everything working as desired during whatever return window there is. Not that there is any way to go back after drilling a bunch of holes in your roof.
With that spread, I don't recommend buying battery for the purpose of arbitrage. If you've already bought it for other purposes, then you might use it this way because it could cost $0.05/kWh. Just don't count on rules or rates staying the same for 16 years.
But rules that let you backfeed from battery don't let you also charge battery from grid. So system needs to charge battery from PV, if necessary supply house from grid at same time.
Can you DIY? If so, you can roll your own kWh with PV for about $0.025/kWh. Otherwise, turnkey for $0.10/kWh.
Those prices include grid tie PV inverter. You may find a hybrid (batteries optional) for the same price (suspect lower quality.)
Midnight's AIO (China manufactured, at least part US designed by respected pioneers of the industry) may be a good match, together with their soon to be announced batteries. You will need a UL Listed ESS (battery + inverter) which these should be.
Given how cheap PV is, I favor massive over-paneling. NEM 3.0 rules may not allow, but there is something about grid-tie vs. separate off-grid system, possibly zero-export system, that could allow it. They don't intend to make it easy or cheap.
How much area do you have for rooftop and/or ground mount?
PV panels are STC rated 200W to 220W per square meter. Expect 70% to 90% of that (varies by brand and temperature) in direct sun. Use an on-line Insolation calculator to determine monthly production for your location and panel orientation.
I'm working with SMA support trying to get Sunny Boy Storage + LG RESU-10H to do what I want.
Earlier firmware delayed charging battery until almost end of the day's off-peak every other day. But it let me set a negative current limit resulting in forced export to grid during peak.
Latest firmware appears to charge and discharge every day reliably. But it now enforces no negative values, can't set any new current levels for forced backfeed to grid. Only got one small value in a named profile I used for experimentation. Tried unsuccessfully to roll back firmware. Exported configuration to modify, tried to import (even original unmodified file) and it garbled the data.
Be afraid of software/firmware. Be very afraid.
If it doesn't support the functions you require out of the box, it may never.
No refunds in the future, so you need to get everything working as desired during whatever return window there is. Not that there is any way to go back after drilling a bunch of holes in your roof.
Last edited:
WorldwideDave
New Member
Holes in roof would be to just install PV on the roof. Our roof is very large, flat, and painted white already. Code says must be flat mounted, and leave a 3' walkway around the outside for firemen. Honestly the roof is so soft I am thinking of doing a major remodel, which sucks, because it won't add any square feet to the house. Just don't know what is best to do.
Hedges
I See Electromagnetic Fields!
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See if "ballasted" mount can meet requirements. Will have to be engineered for wind, not a simple on-line permit.
And then I'd tie it down with cables too.
Flat roofs are a common commercial installation.
I learned that this was Solyndra's killer app: Bunch of round tube cells, wind passes through them with far less lift, so ballasted mounts easy.
I'm not so sure flat on roof is the only thing allowed by code. Might be a requirement for expedited permit. Or might be an ordinance related to beautification. Los Gatos said a shop in a commercial district had to conceal panels behind parapet.
Maybe in your location flat is close enough to optimal.
Mounts properly screwed into roof and sealed could allow more optimal tilt, if it makes a difference.
Figure out the numbers regarding electric rates, net metering credits, capacity and cost of PV system and battery.
Make sure the ROI is there even if PUC pulls the rug out from under you. Like charging a flat $135/month for infrastructure as previously adopted. Or a photon tax - proposed for California and dropped, but in effect in one other state already.
And then I'd tie it down with cables too.
Flat roofs are a common commercial installation.
I learned that this was Solyndra's killer app: Bunch of round tube cells, wind passes through them with far less lift, so ballasted mounts easy.
I'm not so sure flat on roof is the only thing allowed by code. Might be a requirement for expedited permit. Or might be an ordinance related to beautification. Los Gatos said a shop in a commercial district had to conceal panels behind parapet.
Maybe in your location flat is close enough to optimal.
Mounts properly screwed into roof and sealed could allow more optimal tilt, if it makes a difference.
Figure out the numbers regarding electric rates, net metering credits, capacity and cost of PV system and battery.
Make sure the ROI is there even if PUC pulls the rug out from under you. Like charging a flat $135/month for infrastructure as previously adopted. Or a photon tax - proposed for California and dropped, but in effect in one other state already.
Nobodybusiness
Solar Sponge.
Gas heated pool.
Nice..
Horsefly
Solar Wizard
Wow! I pay $0.11/kWh in the burbs of Denver. No wonder it seems like I'm spending nothing charging my Tesla.
Hedges
I See Electromagnetic Fields!
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Add a story?
Re-shape roof and add an attic that serves as living space?
Shed roof style could support more area to mount panels.
And relocate vents to the walkway left for firemen, far enough from panels to not cast a shadow on them.
Zwy
Emperor Of Solar
Heat pump water heaters are proven technology, get with the times.
I see OP installed on demand water heaters. On demand does not save any money in a normal household with day to day activity. Only if one leaves for a few weeks at a time would it save anything but one can program a smart heat pump hybrid for vacation, specific time of day and temp. All can be done remotely.
Our biggest load is the electric dryer, it might be gone before winter.
OffGridForGood
Catch, make or grow everything you can.
Hedges
I See Electromagnetic Fields!
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That depends on your electric cost.
Resistance heating, 46 gallon, 62 gallons first hour recovery. $569 to buy
3531 kWh/year. At $0.025/kWh (DIY cost for PV), $88/year operating cost. (not the $494 on energy label)
Heat pump, 46 gallons, 65 gallons first hour. $1950 to buy
854 kWh/year, $21/year operating cost (not the $120 on the label).
$88 - $21 = $67 annual savings with HPWH, assuming $0.025/kWh DIY PV cost.
$494 - $120 = $374 annual savings assuming $0.14/kWh as on label.
For California $0.45 to $0.60 rates, about $1100 to $1500 annual savings!
$1950 HPWH - $569 resistance water heater = $1381 more for HPWH
$1381 / $67/year savings = 20 year break even. Just buy the D*mn resistance water heater (if you roll your own kWh)
3.7 year payback at the $0.14 rate on label (who gets power for that price??)
1 year payback at California electric prices. So you are correct, or rather you would be if not on a DIY Solar Forum.
Note that label $/year is based on $0.14/kWh, true for some parts of the company and close to the $0.10/kWh that turnkey PV costs (or used to cost, when net metering was alive.)
Operating water heater from surplus PV is a way to still utilize your low-cost power; don't let it run from grid.
Next lesson: "Do HPWH Rob Peter to Pay Paul?"
OffGridForGood
Catch, make or grow everything you can.
When I compared - it was better to keep the resistance HWT and spend about the same money (actually a bit more) on a ducted mini-split for the whole house. Gives me whole house A/C for summer and a dump load for spring/fall heating option when the sun is co-operative.
SunDave
Solar Enthusiast
I'm not taking a side on this one. But I will say I am weird enough to still rock halogen bulbs, and some good quality CFL's. Much of the led lighting I find to be depressing, and too blue. I figure since I make my own watts, I make my own rules 
I guess I just don't do everything I'm told...
I should say: I have tried some LED flood lights for the can lights, but couldn't find a good one that doesn't flicker. I think there are good regular LED bulbs now, but I see the low "refresh rate" ones like I see taillights that ghost in the cheaper LED taillights.
I guess I just don't do everything I'm told...
I should say: I have tried some LED flood lights for the can lights, but couldn't find a good one that doesn't flicker. I think there are good regular LED bulbs now, but I see the low "refresh rate" ones like I see taillights that ghost in the cheaper LED taillights.
Hedges
I See Electromagnetic Fields!
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Try these. I tracked some down and like them.
diysolarforum.com
Philips may have created the best LED bulb yet
100% real frosted glass bulb 2700k LED filament Weight like incandescent Filament gently shakes while handling Suitable for wet locations Suitable for enclosed fixtures Title 20 Compliant (legal in California) Dimming with certain compatible dimmers "Flicker Free" - To be confirmed by off grid...
diysolarforum.com
Zwy
Emperor Of Solar
It requires a larger system. Conservation whether using PV or not always is cheaper. One doesn't have to pay for capacity if it isn't needed.
Heat pump water heaters qualify for 30% federal Energy Efficiency tax credit. I paid around $1500 for mine (not $1950) and minus 30% = $1050
You must have missed the thread where with state rebates in CA, it is actually cheaper to buy a heat pump water heater than resistance.
When doing a comparison, one should not cherry pick data in an attempt to prove a point. A 6 year warranty resistance water heater is not even close to 10 year resistance water heater in price. When you cherry pick, it makes your side of the debate much weaker.
Here is one member in CA and yes, it was cheaper to purchase a HPWH than resistance. Wait for a sale like I did and collect the rebates and tax credit. When the government is handing out money for energy efficiency, one should take advantage of it.
I consider a HPWH to just be a battery.
Zwy
Emperor Of Solar
Still use clothes line in spring/summer/fall but she drys her towels in the dryer year round. She is a cosmetologist. I should buy one and write it off her business because I've never included the cost of drying towels in her PNL.are you planning on a HP dryer ? or gas?
She made me take down the clothes line that was on the property when we bought it...I KNEW that was a mistake...
I've been eyeing the hybrid Samsung. I've had this in my cart for some time. https://www.homedepot.com/p/Samsung...al-Dry-in-Brushed-Navy-DV53BB8900HD/323975827
I can get it for $1398 right now with the extra $100 off plus tax so about $1K after 30% tax credit. If the current electric dryer dies today, this is the one I'd purchase. I'd consider the LG heat pump dryer but with the LG refrigerator failures, I'd wait until that gets sorted out.
I'm increasing battery bank to 72Kwh and adding about 3700W of panels to the house system so may not need to upgrade dryer. I have too many other projects right now and not enough time to change out the dryer and run the drain line for it. If she runs the dryer on sunny days for an hour, it takes 6.5Kwh. Not a problem in summer. We still air dry some clothes in winter in the house. My jeans seems to shrink or maybe it is too many donuts.
Zwy
Emperor Of Solar
Sounds more realistic, 25Kwh per day.
That is about what we use. Much depends on location as far as battery bank size (you have NEM 3.0). If we cut usage to absolute minimum which means no laundry, heat pump or using dishwasher, we can get by for 5 days just off the battery. I built my battery bank at 58Kwh capacity but increasing it to 72Kwh. Total spent was about $13K for entire 78Kwh but received 30% tax credit so net cost was about $9K. Figure battery bank at 1/4 the cost of a complete system. If battery bank lasts 16 years or more, my cost per Kwh will be less than $0.004 per Kwh for battery storage based upon current usage.
The first 90% of usage is easy to cover with solar, it is fairly cheap. The last 10% gets costly. I'd look into energy efficiency first before I'd build a system. Our house was fairly efficient electrically wise with propane appliances except dryer but it still cost enough before I finished. We used $5 of power off the grid last winter for the house which was under 3% of total usage. Zero is not that easy to achieve unless you want to run a generator, build a very large system or make sacrifices.
WorldwideDave
New Member
This is all interesting, but perhaps should’ve been started in its own thread different from mine?
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