Planning to reduce electric bill by solar push, no feed back to grid. Daylight hours only.

[roadrunner]

So your total KWH fir the month is 402KWH @ $31.14, so that comes out to be about 3114/402 = 7.75 cent per KWH.
14KWH @ $1.11 = 7.9 cent per KHW.

yes, total for month is 402,for march 2021, but my bill for sept of 2020 was 841====total kwh, with a bill of $106.70
so this for sept would be 12.68 kwh., i have 2 rates, an on peak, and off peak, i have never even looked at my bill to see how much i was apying because ive always worked and made good money so didnt care. now it does matter as my situation above has changed.
Every little bit helps now.

 

[Q-Dog]

You are in Arizona, not too far from SanTan Solar. Pick up a couple of their 250 watt used panels for $40 each. Use one during the winter and 2 during the summer.

Affordable Solar Panels & Accessories: New & Used Available!

Discover our affordable solar panels & accessories! Explore our range of new & used solar options to power your sustainable lifestyle efficiently. Shop now!

santansolar.com

 

[Bud Martin]

yes, total for month is 402,for march 2021, but my bill for sept of 2020 was 841====total kwh, with a bill of $106.70

Please read my edited reply.

 

[roadrunner]

You are in Arizona, not too far from SanTan Solar. Pick up a couple of their 250 watt used panels for $40 each. Use one during the winter and 2 during the summer.

Affordable Solar Panels & Accessories: New & Used Available!

Discover our affordable solar panels & accessories! Explore our range of new & used solar options to power your sustainable lifestyle efficiently. Shop now!

santansolar.com

thanks, but i cant go over the wattage of my cooler or the utility could bust me,but you are right as long as a 250 watt panel only puts out 200 watts, i could use 1 in summer and only need 1 panel, instaed of buying 2 panels for $150, as long as their good panels, i will check into it

 

[roadrunner]

I am not a lawyer, but as I understand it, Arizona is one of the states that says you cannot be prevented from installing solar panels on property you own. It may be worthwhile to call a solar company and ask them how this applies to property you own on a rented lot. If you own the shed, you may be able to put as many panels as you can fit up there without having to hide them.

"Arizona law protects individual homeowners’ private property rights to solar access by dissolving any local covenant, restriction or condition attached to a property deed that restricts the use of solar energy. This law sustained a legal challenge in 2000."

trailer park rules and i dont own my trailer, i am trying to find one to buy.

 

[fafrd]

yes, total for month is 402,for march 2021, but my bill for sept of 2020 was 841====total kwh, with a bill of $106.70

$106.70 for 841kWh = $0.127/kWh.

Your goal is to save ~$25/month, meaning ~197kWh/month or ~6.6kWh/day.

Your swamp cooler on high consumes 420W or 0.42kWh/hour (assuming it stays on continuously).

Your swamp cooler would need to be running on high for 15.7 hours straight to consume 6.6kWh/day (which won’t work because you’ll only have solar power for ~12 hours per day and it’s unlikely to reach 420W early in the morning or late in the afternoon.

So your math doesn’t add up - your swamp cooler alone isn’t costing you ~$25/month and if you want to shave that much off of your electrical bill, supplying the swamp cooler alone with solar is not going to make it.

This means you’ll need to start looking at a battery-based system, offsetting some evening/nighttime consumption, and $$$s and complexity will both increase.

If you put in 2 250W panels costing you $80 total plus a SUN GTIL costing you $275 means you’ll be spending ~$400 for a system that can supply a peak of ~0.4kW during the peak part of the day.

So let’s say you can offset 2kWh of consumption per day of 60kWh/month with a value of $7.62 per month or ~$91/year (assuming you run your swamp cooler even in winter).

That translates to payback in less than 5 years, which is an achievement in this domain.

If you don’t use your swamp cooler all year round and/or you want to nibble more off of your bill, you’ll need to add a 24V battery and an MPPT charge controller and select which other appliances consumption you want to offset. The charge controller is cheap but the battery isn’t - you’ll easily double the cost and complexity of the system.

 

[roadrunner]

14KWh @ $1.11 = 7.9 cent per KHh.
Your total KWh for the month without cooler is 402 KWh @ $31.14, so that comes out to be about 3114/402 = 7.75 cent per KWh.
Your total KWh for the month with cooler is 841 KWh @ $106.70, so that comes out to be about 10670/841 = 12.69 cent per KWh.
You are using 439 KWh (841 KWh - 402 KWh = 439 KWh) more when you have coller running.
So 439 KWh/30 days = 14.63 KWh per day you need to produce from your solar system to keep your bill at aorund $30 range.

Thank you for your time and calculations, that gives me something to work off of thats for sure, thats why iwas thinking of what i originally started out on this thread, if i can get solar to the cooler, without the utility seeing it, for the strongest daylight hours, just when it is on, if i could actually run it with a total of about 30-40 watts, 420 watts on high usage, minus 200 watts solar would only leave me with 200 watts usage so high would using what low does.

 

[roadrunner]

$106.70 for 841kWh = $0.127/kWh.

Your goal is to save ~$25/month, meaning ~197kWh/month or ~6.6kWh/day.

Your swamp cooler on high consumes 420W or 0.42kWh/hour (assuming it stays on continuously).

Your swamp cooler would need to be running on high for 15.7 hours straight to consume 6.6kWh/day (which won’t work because you’ll only have solar power for ~12 hours per day and it’s unlikely to reach 420W early in the morning or late in the afternoon.

So your math doesn’t add up - your swamp cooler alone isn’t costing you ~$25/month and if you want to shave that much off of your electrical bill, supplying the swamp cooler alone with solar is not going to make it.

This means you’ll need to start looking at a battery-based system, offsetting some evening/nighttime consumption, and $$$s and complexity will both increase.

If you put in 2 250W panels costing you $80 total plus a SUN GTIL costing you $275 means you’ll be spending ~$400 for a system that can supply a peak of ~0.4kW during the peak part of the day.

So let’s say you can offset 2kWh of consumption per day of 60kWh/month with a value of $7.62 per month or ~$91/year (assuming you run your swamp cooler even in winter).

That translates to payback in less than 5 years, which is an achievement in this domain.

If you don’t use your swamp cooler all year round and/or you want to nibble more off of your bill, you’ll need to add a 24V battery and an MPPT charge controller and select which other appliances consumption you want to offset. The charge controller is cheap but the battery isn’t - you’ll easily double the cost and complexity of the system.

here in Az sunrise in summer is 5:30am, and sunset is around 8 pm, at 10 oclock at night it can still be 90-95 degrees, so yes my swamp cooler in summer usaly runs on high from 10 in morning until 10 at night. the only other thing i have is an electric water heater, which doesnt come on during the day because of the heat and maybe not at night, cant get to it with out taking panel off of closet wall. this is a mobile home, trailer
Look at my electric bills i posted, the differece with the swamp cooler running is $70 dollars a month

 

[fafrd]

I cant go over what my cooler runs at or it might back feed and the utility will see it then im in trouble,

With GTIL, you will never export (back-feed) - the inverter will supply as much of the power consumed by the cooler as it can,

The GTIL inverters are only ~75% efficient, so 250W of solar will only translate to 200W of 120V AC.

In addition, panels rarely achieve full rated efficiency, especially used/recycled panels like those $40 panels from Santran Solar.

Those panels have probably degraded to ~80% of rating, meaning the most you will get out of them during the peak part of the day is unlikely to exceed 200W (meaning a maximum of 150W of 120V power from the inverter).

I guess what i should is hook up my kilowatt meter and see what the cooler uses in 24hrs, all i know is when i hooked it up, it uses 222watts on low, and 420 on high, or i should run it for an hour and see what my kwh usage is,and then i can multiply ect to get full usage

If the cooler is running overnight as well, you will need a battery or you will never reach your objective. I’d suggest you keep a log of on-time over 24 hours on high and on low to get a handle of how much of your daily consumption is going to the cooler. Sizing a system with battery and panels to offset that consumption is doable.

I have all LED light bulbs in my house that only use 7-9 watts per bulb, and none are on during the day, i have a electric hot water heater but it doesn't run during the day because its so hot in the summer in my mobile home.

I dont have a heater in my home and i have a 220 electric stove and oven but the oven doesnt work, and in summer we always grill out because trailer is to hot to cook in

The hot water heater probably consumes more than you realize, especially over winter. If you get the system built to offset cooler and see that you end up with unused solar power in the winter when the cooler is not used, expanding the system to offset a portion of the water heater and/or the stove could be possible (but more $$$s and complexity, again, because they are probably 240V and not 120V...).

 

[fafrd]

here in Az sunrise in summer is 5:30am, and sunset is around 8 pm, at 10 oclock at night it can still be 90-95 degrees, so yes my swamp cooler in summer usaly runs on high from 10 in morning until 10 at night. the only other thing i have is an electric water heater, which doesnt come on during the day because of the heat and maybe not at night, cant get to it with out taking panel off of closet wall. this is a mobile home, trailer
Look at my electric bills i posted, the differece with the swamp cooler running is $70 dollars a month

An increase of consumption $70/month = $2.33/day, or 18.4 kWh @ 0.127/kWh.

18.4kWh/day= 44 hours of continuous operation at 420W (your cooler on high), so again, the math is not adding up (I know Arizona bucks the trend and skips Daylight Savings Time, but I doubt that gains them another 20 hours in a day .

When your electrical bill increases by $70/month, you need to figure out where that additional electrical energy is going.

I bought a cheap clamp meter to measure AC amps: https://www.amazon.com/3266TA-Auto-...ocphy=9057125&hvtargid=pla-374110770394&psc=1

This will allow you to measure yourself how much power your cooler is consuming rather than relying on nameplate rating.

Also, do you own a refrigerator? In the summer, over half of my consumption goes to powering my 5 fridges/freezers...

 

[roadrunner]

With GTIL, you will never export (back-feed) - the inverter will supply as much of the power consumed by the cooler as it can,

The GTIL inverters are only ~75% efficient, so 250W of solar will only translate to 200W of 120V AC.

In addition, panels rarely achieve full rated efficiency, especially used/recycled panels like those $40 panels from Santran Solar.

Those panels have probably degraded to ~80% of rating, meaning the most you will get out of them during the peak part of the day is unlikely to exceed 200W (meaning a maximum of 150W of 120V power from the inverter).



If the cooler is running overnight as well, you will need a battery or you will never reach your objective. I’d suggest you keep a log of on-time over 24 hours on high and on low to get a handle of how much of your daily consumption is going to the cooler. Sizing a system with battery and panels to offset that consumption is doable.



The hot water heater probably consumes more than you realize, especially over winter. If you get the system built to offset cooler and see that you end up with unused solar power in the winter when the cooler is not used, expanding the system to offset a portion of the water heater and/or the stove could be possible (but more $$$s and complexity, again, because they are probably 240V and not 120V...).

yes, both are 220 volt, and i would have to find out a way to check when the water heater came on, maybe hook up my klein clamp meter to the wires in the fuse panel and see when it comes on, or maybe a way to hook up some kind of meter like the killo watt meter but haas clamps for the wires and can log the usage, because tank is behind a panel in closet completely enclosed, not behind a door like most are, or in a shed, ect where its easy to get at, its built into the wall so to speak. as you can see, my total bill for the month in winter is only $28 to $31 dollars, and that includes stove and water heater.

 

[fafrd]

yes, both are 220 volt, and i would have to find out a way to check when the water heater came on, maybe hook up my klein clamp meter to the wires in the fuse panel and see when it comes on, or maybe a way to hook up some kind of meter like the killo watt meter but haas clamps for the wires and can log the usage, because tank is behind a panel in closet completely enclosed, not behind a door like most are, or in a shed, ect where its easy to get at, its built into the wall so to speak. as you can see, my total bill for the month in winter is only $28 to $31 dollars, and that includes stove and water heater.

Here in California, peak rates in summer are more than double winter rates, so $30 of your increased $70 in summer could just be that (all usage including hot water heater and stove are more expensive).

Also, you never mention your fridge, and I suspect it is consuming almost as much as your cooler in the summer.

If you’ve already got a clamp meter, you can put it on the main leg the fridge is connected to and then either manipulate the thermostat or unplug/plug to turn the he fridge on and off - the difference in current being consumed is the fridges consumption. (Or if you have access to the plug, you can modify and extension cord and directly measure the fridges consumption with your clamp meter using that).

The GTIL can easily supply both the fridge and the cooler as long as they are both powered by the same hot leg.

 

[roadrunner]

An increase of consumption $70/month = $2.33/day, or 18.4 kWh @ 0.127/kWh.

18.4kWh/day= 44 hours of continuous operation at 420W (your cooler on high), so again, the math is not adding up (I know Arizona bucks the trend and skips Daylight Savings Time, but I doubt that gains them another 20 hours in a day .

When your electrical bill increases by $70/month, you need to figure out where that additional electrical energy is going.

I bought a cheap clamp meter to measure AC amps: https://www.amazon.com/3266TA-Auto-...ocphy=9057125&hvtargid=pla-374110770394&psc=1

This will allow you to measure yourself how much power your cooler is consuming rather than relying on nameplate rating.

Also, do you own a refrigerator? In the summer, over half of my consumption goes to powering my 5 fridges/freezers...

I have a killo watt meter i use. but the appliance has to be plugged in, so the cooler is easy, your math is wrong i think, it is not 0.127kwh, so my bill of $106.70 /841 equals 12.68 kwh, so 8 hours equals 101.44, so what does the 101.44 equal, dollars or cents. ill look at the clamp meter to see what my wtr heater uses, but just by looking at the bill, why would my water heater be coming on that much in 120 degree weather inside a wall built of an outside skin of sheet metal and thin insulation. i will have to buy a meter to find out

 

[fafrd]

Here in California, peak rates in summer are more than double winter rates, so $30 of your increased $70 in summer could just be that (all usage including hot water heater and stove are more expensive).

Also, you never mention your fridge, and I suspect it is consuming almost as much as your cooler in the summer.

If you’ve already got a clamp meter, you can put it on the main leg the fridge is connected to and then either manipulate the thermostat or unplug/plug to turn the he fridge on and off - the difference in current being consumed is the fridges consumption. (Or if you have access to the plug, you can modify and extension cord and directly measure the fridges consumption with your clamp meter using that).

The GTIL can easily supply both the fridge and the cooler as long as they are both powered by the same hot leg.

For what it is worth, I have a large but energy-efficient Samsung fridge. Here in the Bay Area where we average ~70F over summer, my fridge consumes ~4A or ~480W on a ~40% duty-cycle, meaning 4-5kWh per day.

 

[fafrd]

I have a killo watt meter i use. but the appliance has to be plugged in, so the cooler is easy, your math is wrong i think, it is not 0.127kwh, so my bill of $106.70 /841 equals 12.68 kwh,

$106.70 / 841 kWh = $0.1268/kWh (which I rounded up to $0.127).

so 8 hours equals 101.44, so what does the 101.44 equal, dollars or cents.

8kWh x $0.1268/kWh = $1.0144 (or 101.44 cents).

ill look at the clamp meter to see what my wtr heater uses, but just by looking at the bill, why would my water heater be coming on that much in 120 degree weather inside a wall built of an outside skin of sheet metal and thin insulation. i will have to buy a meter to find out

Focus on your fridge before worrying about your water heater...

 

[roadrunner]

Here in California, peak rates in summer are more than double winter rates, so $30 of your increased $70 in summer could just be that (all usage including hot water heater and stove are more expensive).

Also, you never mention your fridge, and I suspect it is consuming almost as much as your cooler in the summer.

If you’ve already got a clamp meter, you can put it on the main leg the fridge is connected to and then either manipulate the thermostat or unplug/plug to turn the he fridge on and off - the difference in current being consumed is the fridges consumption. (Or if you have access to the plug, you can modify and extension cord and directly measure the fridges consumption with your clamp meter using that).

The GTIL can easily supply both the fridge and the cooler as long as they are both powered by the same hot leg.

I have a plug in kilowatt meter that i used on my fridge already, 4.24 kwh in a 48 hour period, so for 2 days it used only 4.24 kwh.
so its not the fridge that is using lots of power, will have to check in summer when it gets hot because i have never checked it.

I have a Klein clamp meter but doesnt store the power used, only tells me how amps when running, i need to see how much it consumes over a time period.
right, my summer and on peak are what hurts us the most, i tried my central air for 1 month when i first moved in this trailer, $300 dollar increase just for the ac.
For the fridge all i have to do is turn the breaker off on the panel, should be by itself.

 

[fafrd]

I have a plug in kilowatt meter that i used on my fridge already, 4.24 kwh in a 48 hour period, so for 2 days it used only 4.24 kwh.
so its not the fridge that is using lots of power, will have to check in summer when it gets hot because i have never checked it.

Do that - you will discover that it uses at least twice as much during the summer and probably as much or more than your cooler. It’s the only explanation for the gap in your math. Good news is the fridge is only 120V so easy to have the same solar GTIL supply both fridge and cooler.

I have a Klein clamp meter but doesnt store the power used, only tells me how amps when running, i need to see how much it consumes over a time period.

Full logging is nice, but you can get a rough idea by just measuring current consumption when in and approximate duty-cycle. Spend an hour watching the fridge and take notes on the times it turns on and off. You’ll quickly get a pretty good idea how much it is consuming.

right, my summer and on peak are what hurts us the most, i tried my central air for 1 month when i first moved in this trailer, $300 dollar increase just for the ac.
For the fridge all i have to do is turn the breaker off on the panel, should be by itself.

Yeah, get the actual current measurements from both fridge and cooler, along with an estimate of duty-cycle % in different ambient conditions, and you’ll be able to get a handle on your increased consumption during summer when peak rates are higher.

 

[Q-Dog]

I bought a used trailer after I got tired of apartment living so I could save up for a house. Lot rent was cheap but electricity in the summer was outrageous. My current house is twice the square footage of that trailer and the trailer easily used twice as much electricity as my house. In August the A/C could run for hours without shutting off. You could feel the heat radiating from the ceiling. A lot of folks here used to build a roof over the trailer to cut the solar gain on the roof and it helps a lot, but you can't do that in a park.

New models are built with shingle roofs and some insulation, not like the tin can I had.

 

[fafrd]

I bought a used trailer after I got tired of apartment living so I could save up for a house. Lot rent was cheap but electricity in the summer was outrageous. My current house is twice the square footage of that trailer and the trailer easily used twice as much electricity as my house. In August the A/C could run for hours without shutting off. You could feel the heat radiating from the ceiling. A lot of folks here used to build a roof over the trailer to cut the solar gain on the roof and it helps a lot, but you can't do that in a park.

New models are built with shingle roofs and some insulation, not like the tin can I had.

Good point. Not sure whether it is an option given regulations/constraints, but putting $400 into better insulation may well be wiser investment than putting that same amount into solar...

 

[pollenface]

Don't do the suicide cord. If you need that, not using the right hardware and in danger of killing your inverter and your friendly local lineman.

Grid tie inverters need to sense power from the grid in order to operate. If you disconnect the grid power, the inverter faults and stops producing power.