Posted by ads on June 21, 2018, 6:37 am
On Sun, 17 Jun 2018 16:02:16 -0400, "Jim Wilkins"
><ads> wrote in message
>> wrote:
>>
>>>Dear All,
>>>
>>>Can anyone update me on latest home solar system technology?
>>>
>>>I appreciate anyone inputs.
>>>
>>>Regards,
>>>Yan
>>
>> Do you want grid-tied solar that augments what the power compoany
>> provides but goes away when the grid is down or do you want
>> independent solar power that works when the power company doesn't?
>>
>> A few grid-tied systems can be converted to off-graid but you'll
>> probably be better off with a designed to fit off-grid system. They
>> are NOT cheap.
>>
>> By doing a lot of scrounging and bargain hunting, I put together a
>> small system that can best be described as a "solar generator". The
>> battery bank is charged by solar panels with a couple of gasoline
>> generator options if there is no sun.
>>
>> In 10+ years at this location, the longest outage was 16 hours.
>> Depending on the season, I can get 10 to 20 hours or "Wait until
>> daylight" power from the system. If commercial power was off for an
>> extended period(weeks), we would have enough power to drop back to a
>> 4
>> cu ft fridge, 7" TV and charging laptops, tablets and cell phones
>> (if
>> cell service is up). The total cost was $100 for 900 watts or
>> solar
>> panels, two MPPT charge controllers, two 2000 watt sine wave (PSW)
>> inverters, a 500 watt PSW inverter, a 12 volt 540AH battery bank and
>> lots of wire, fuses, circuit breakers, metering, etc,
>>
>> For a larger system, you'd want a 48 volt battery bank. I went with
>> 12 volts because of the number of 12 volt lights and other
>> accesories
>> available - such as the 12 volt DC-DC converter that runs and
>> charges
>> the laptop. With that converter providing power, the laptop idles
>> at
>> 15 watts. Using an inverter and the usual AC power supply/charger,
>> the idle power for the laptop is 35 watts.
>>
>> Note that there's no mention of washing machine, clothes dryer,
>> dishwasher, air conditionibng or any of a number of modern
>> "necessities". If you want those items, you will need a solar
>> system
>> that's at least 10 times the size of my backup power.
>>
>
>My solar backup system assumes I'll start a generator for the
>intermittent large loads you mentioned plus the microwave, so it's
>sized for the 120VAC refrigerator and 12VDC freezer which run 24/7. My
>largest "3750W" generator can only start the old Maytag if I nudge the
>motor inward with my foot to slip the belt. I dry laundry on a
>clothesline.
>
>What did you choose for MPPT controllers and how do you like them?
>
>It puzzles me that they are still so expensive when this has a better
>display and all their functionality except for tracking software for a
>much lower price.
>https://www.aliexpress.com/item/RD-DPS5020-Constant-Voltage-current-Step-down-communication-digital-Power-Supply-buck-Voltage-converter-LCD-voltmeter/32821185351.html
>
>I have the older DPS5015 which is easy to adjust for maximum current
>to the battery. The smaller text at the bottom is input voltage which
>shows the array's Maximum Power Point voltage and when it has been
>overloaded and trapped in a low voltage state. Then the battery
>current must be briefly reduced or shut off to allow the panel voltage
>to recover.
>
>-jsw
>
I have two EPEver/EpSolar Tracer 3210A 30amp MPPT controllers. Bought
on ebay from sure electronics about 6 months apart. One was $7; the
other was $7 including shipping.
The difference between the DC-DC converter in the link and the MPPT
controller is that the MPPT controller does a regular scan (45-60
minutes when looking for enough power to enter MPPT mode; don't have
the timing when it's in operation) to check for a better transfer
configuration (searching for the maximum power point). If there is
sun, then clouds, then sun, then clouds the controller automatically
adjusts as needed. The 3210A doesn't seem to respond to changes as
fast as some of the more expensive brands (Outback, others) but I can
accept that limitation when I'm looking at a three or more times price
difference (MidNite solar 30A MPPT is $00).
These units idle at 0.015 amp (15ma) if the load control is turned off
or about 0.035 amp (35ma) with the load turned on (15 ma is less idle
power than some basic PWM controllers). The units go into MPPT mode
when there's enough solar power to run the DC-DC conversion and charge
the battery. It needs about 8 or 9 watts from solar to trigger MPPT
mode. Once in MPPT mode, it stays there as long as it can - typically
down to about 1 watt of solar input.
If there's not enough power to enter MPPT mode, the 32XX controillers
run in PWM mode so they are always trying to get the battery to your
selected charge/float voltage if the solar voltage is greater than the
battery voltage. Using the software, you can specify the minimum
(during discharge) and maximum (during charge) battery voltages
allowable and what the boost and float voltages should be. The
controller does an equalization charge on the 28th of each month and
you can set the voltage and number of hours for that charge, among
many other parameters. If you're using multiple controllers to handle
a large number of solar panels, you only need to configure one
controller's parameters because you can save the parameters and load
them into another controller.
I've been doing some testing of solar panel placement, so I've been
using one panel (100 watt or 250 watt) in various locations. The
3210A consistently performs the same, with the 100 watt panel taking
longer to charge the battery bank than the 250 watt panel but the
difference matches the 2.5 to 1 difference in panel power.
The 32XX series controllers are available in models up to 40 amps and
they are 12/24 volt capable with auto select based on battery voltage.
The free software talks to the 32XX charge controller via an RS485
adapter (USB-to-RS485 dongle is $ on ebay) and the connection uses
two wires of a standard CAT5 cable. Using the software, you can
configure the various charge controller parameters for lithium battery
packs as well as lead acid batteries (I'm using AGM's because I got
them for a very good price). The software displays the controller's
voltages, currents and power (battery, solar, load) in near-real-time
(default is 30 second updates). You can print these graphs to have
hard copy of daily status. They also offer the eLog01 device that can
record several months of ALL the data (volatge, current, power,
temperature, power consumed, power generated, etc, etc and you can
save that data in .csv format which any spreadsheet can read. This
can provide even more information about the ongoing opeartion and
status of your system.
The original 32XXA series use common positive (positive ground) The
newer 32XXAN (introduced this year and about the same price) is common
negative (negative ground). I would prefer the negative ground
version but it's not worth replacing tested units with a newer model.
The software works on either version but some of the accessories
(MT-50 remote meter, others) are not compatible between the A and AN
versions.
---
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Posted by Jim Wilkins on June 21, 2018, 12:39 pm
<ads> wrote in message
> On Sun, 17 Jun 2018 16:02:16 -0400, "Jim Wilkins"
>
>>What did you choose for MPPT controllers and how do you like them?
>
> I have two EPEver/EpSolar Tracer 3210A 30amp MPPT controllers.
> Bought
> on ebay from sure electronics about 6 months apart. One was $7;
> the
> other was $7 including shipping.
>
> The difference between the DC-DC converter in the link and the MPPT
> controller is that the MPPT controller does a regular scan (45-60
> minutes when looking for enough power to enter MPPT mode; don't have
> the timing when it's in operation) to check for a better transfer
> configuration (searching for the maximum power point). If there is
> sun, then clouds, then sun, then clouds the controller automatically
> adjusts as needed. The 3210A doesn't seem to respond to changes as
> fast as some of the more expensive brands (Outback, others) but I
> can
> accept that limitation when I'm looking at a three or more times
> price
> difference (MidNite solar 30A MPPT is $00).
>
> These units idle at 0.015 amp (15ma) if the load control is turned
> off
> or about 0.035 amp (35ma) with the load turned on (15 ma is less
> idle
> power than some basic PWM controllers). The units go into MPPT mode
> when there's enough solar power to run the DC-DC conversion and
> charge
> the battery. It needs about 8 or 9 watts from solar to trigger MPPT
> mode. Once in MPPT mode, it stays there as long as it can -
> typically
> down to about 1 watt of solar input.
>
> If there's not enough power to enter MPPT mode, the 32XX
> controillers
> run in PWM mode so they are always trying to get the battery to your
> selected charge/float voltage if the solar voltage is greater than
> the
> battery voltage. Using the software, you can specify the minimum
> (during discharge) and maximum (during charge) battery voltages
> allowable and what the boost and float voltages should be. The
> controller does an equalization charge on the 28th of each month and
> you can set the voltage and number of hours for that charge, among
> many other parameters. If you're using multiple controllers to
> handle
> a large number of solar panels, you only need to configure one
> controller's parameters because you can save the parameters and load
> them into another controller.
>
> I've been doing some testing of solar panel placement, so I've been
> using one panel (100 watt or 250 watt) in various locations. The
> 3210A consistently performs the same, with the 100 watt panel taking
> longer to charge the battery bank than the 250 watt panel but the
> difference matches the 2.5 to 1 difference in panel power.
>
> The 32XX series controllers are available in models up to 40 amps
> and
> they are 12/24 volt capable with auto select based on battery
> voltage.
> The free software talks to the 32XX charge controller via an RS485
> adapter (USB-to-RS485 dongle is $ on ebay) and the connection uses
> two wires of a standard CAT5 cable. Using the software, you can
> configure the various charge controller parameters for lithium
> battery
> packs as well as lead acid batteries (I'm using AGM's because I got
> them for a very good price). The software displays the controller's
> voltages, currents and power (battery, solar, load) in
> near-real-time
> (default is 30 second updates). You can print these graphs to have
> hard copy of daily status. They also offer the eLog01 device that
> can
> record several months of ALL the data (volatge, current, power,
> temperature, power consumed, power generated, etc, etc and you can
> save that data in .csv format which any spreadsheet can read. This
> can provide even more information about the ongoing opeartion and
> status of your system.
>
> The original 32XXA series use common positive (positive ground) The
> newer 32XXAN (introduced this year and about the same price) is
> common
> negative (negative ground). I would prefer the negative ground
> version but it's not worth replacing tested units with a newer
> model.
> The software works on either version but some of the accessories
> (MT-50 remote meter, others) are not compatible between the A and AN
> versions.
https://www.amazon.com/Upgraded-Controller-Display-Charging-Negative-Grounded/dp/B01GMUPH0O
So you like how they perform.
My measurements with a DC Volt-Amp-Wattmeter and rheostat load suggest
the power loss from directly connecting the panel to the battery
(=PWM) is no more than 10% after the battery voltage reaches 13.8V,
supposedly at SOC of 70% to 80%. For example on June 19 at 3PM with a
hazy sky the max from a 100W Grape panel was 77W at 16.8V, decreasing
to 70W at 14.0V. The current did increase as the voltage lowered. The
only parasitic loss was the 6.2mA drain of the wattmeter.
The current needed to hold that voltage on a 105Ah battery soon
decreases below the full output of one 100W panel. At that point I
separate the panel downleads and distribute them among the batteries
to charge and monitor each independently. Panel output is no longer a
limit.
When the sky becomes clear enough I plan to measure down to 11.5V and
compare the current from a direct connection with the highest current
available from the DPS5015, manually adjusted to the MPP. This appears
to be the charging region where MPPT holds the greatest advantage over
PWM, however I need a generator and high current chargers anyway for
overcast days.
I think I'd need to add at least two more $9 100W panels to reach the
cost break-even point for an MPPT controller, where the gain over a
PWM controller equals the gain from adding another panel.
Perhaps my best investment into this power outage backup sytem would
be a storm shelter for the generator instead, such as a folding A
frame roof over an HF steel service cart. I can run the genny at meal
times for food prep and a fast charge and use any available solar in
between. A roll-around tool cart is very useful for outdoor carpentry
such as repairing storm damage. My HF inverter genny fits the lower
shelf.
The data I've seen on lead acid battery life suggests the replacement
cost cancels any savings from free solar input. Lower depth of
discharge may give longer life but the total KWH delivered over its
life is almost constant.
-jsw
Posted by ads on June 21, 2018, 10:20 pm
On Thu, 21 Jun 2018 08:39:02 -0400, "Jim Wilkins"
><ads> wrote in message
>> On Sun, 17 Jun 2018 16:02:16 -0400, "Jim Wilkins"
>>
>>>What did you choose for MPPT controllers and how do you like them?
>>
>> I have two EPEver/EpSolar Tracer 3210A 30amp MPPT controllers.
>> Bought
>> on ebay from sure electronics about 6 months apart. One was $7;
>> the
>> other was $7 including shipping.
>>
>> The difference between the DC-DC converter in the link and the MPPT
>> controller is that the MPPT controller does a regular scan (45-60
>> minutes when looking for enough power to enter MPPT mode; don't have
>> the timing when it's in operation) to check for a better transfer
>> configuration (searching for the maximum power point). If there is
>> sun, then clouds, then sun, then clouds the controller automatically
>> adjusts as needed. The 3210A doesn't seem to respond to changes as
>> fast as some of the more expensive brands (Outback, others) but I
>> can
>> accept that limitation when I'm looking at a three or more times
>> price
>> difference (MidNite solar 30A MPPT is $00).
>>
>> These units idle at 0.015 amp (15ma) if the load control is turned
>> off
>> or about 0.035 amp (35ma) with the load turned on (15 ma is less
>> idle
>> power than some basic PWM controllers). The units go into MPPT mode
>> when there's enough solar power to run the DC-DC conversion and
>> charge
>> the battery. It needs about 8 or 9 watts from solar to trigger MPPT
>> mode. Once in MPPT mode, it stays there as long as it can -
>> typically
>> down to about 1 watt of solar input.
>>
>> If there's not enough power to enter MPPT mode, the 32XX
>> controillers
>> run in PWM mode so they are always trying to get the battery to your
>> selected charge/float voltage if the solar voltage is greater than
>> the
>> battery voltage. Using the software, you can specify the minimum
>> (during discharge) and maximum (during charge) battery voltages
>> allowable and what the boost and float voltages should be. The
>> controller does an equalization charge on the 28th of each month and
>> you can set the voltage and number of hours for that charge, among
>> many other parameters. If you're using multiple controllers to
>> handle
>> a large number of solar panels, you only need to configure one
>> controller's parameters because you can save the parameters and load
>> them into another controller.
>>
>> I've been doing some testing of solar panel placement, so I've been
>> using one panel (100 watt or 250 watt) in various locations. The
>> 3210A consistently performs the same, with the 100 watt panel taking
>> longer to charge the battery bank than the 250 watt panel but the
>> difference matches the 2.5 to 1 difference in panel power.
>>
>> The 32XX series controllers are available in models up to 40 amps
>> and
>> they are 12/24 volt capable with auto select based on battery
>> voltage.
>> The free software talks to the 32XX charge controller via an RS485
>> adapter (USB-to-RS485 dongle is $ on ebay) and the connection uses
>> two wires of a standard CAT5 cable. Using the software, you can
>> configure the various charge controller parameters for lithium
>> battery
>> packs as well as lead acid batteries (I'm using AGM's because I got
>> them for a very good price). The software displays the controller's
>> voltages, currents and power (battery, solar, load) in
>> near-real-time
>> (default is 30 second updates). You can print these graphs to have
>> hard copy of daily status. They also offer the eLog01 device that
>> can
>> record several months of ALL the data (volatge, current, power,
>> temperature, power consumed, power generated, etc, etc and you can
>> save that data in .csv format which any spreadsheet can read. This
>> can provide even more information about the ongoing opeartion and
>> status of your system.
>>
>> The original 32XXA series use common positive (positive ground) The
>> newer 32XXAN (introduced this year and about the same price) is
>> common
>> negative (negative ground). I would prefer the negative ground
>> version but it's not worth replacing tested units with a newer
>> model.
>> The software works on either version but some of the accessories
>> (MT-50 remote meter, others) are not compatible between the A and AN
>> versions.
>
>https://www.amazon.com/Upgraded-Controller-Display-Charging-Negative-Grounded/dp/B01GMUPH0O
>
>So you like how they perform.
>
>My measurements with a DC Volt-Amp-Wattmeter and rheostat load suggest
>the power loss from directly connecting the panel to the battery
>(=PWM) is no more than 10% after the battery voltage reaches 13.8V,
>supposedly at SOC of 70% to 80%. For example on June 19 at 3PM with a
>hazy sky the max from a 100W Grape panel was 77W at 16.8V, decreasing
>to 70W at 14.0V. The current did increase as the voltage lowered. The
>only parasitic loss was the 6.2mA drain of the wattmeter.
>
>The current needed to hold that voltage on a 105Ah battery soon
>decreases below the full output of one 100W panel. At that point I
>separate the panel downleads and distribute them among the batteries
>to charge and monitor each independently. Panel output is no longer a
>limit.
>
>When the sky becomes clear enough I plan to measure down to 11.5V and
>compare the current from a direct connection with the highest current
>available from the DPS5015, manually adjusted to the MPP. This appears
>to be the charging region where MPPT holds the greatest advantage over
>PWM, however I need a generator and high current chargers anyway for
>overcast days.
>
>I think I'd need to add at least two more $9 100W panels to reach the
>cost break-even point for an MPPT controller, where the gain over a
>PWM controller equals the gain from adding another panel.
>
>Perhaps my best investment into this power outage backup sytem would
>be a storm shelter for the generator instead, such as a folding A
>frame roof over an HF steel service cart. I can run the genny at meal
>times for food prep and a fast charge and use any available solar in
>between. A roll-around tool cart is very useful for outdoor carpentry
>such as repairing storm damage. My HF inverter genny fits the lower
>shelf.
>
>The data I've seen on lead acid battery life suggests the replacement
>cost cancels any savings from free solar input. Lower depth of
>discharge may give longer life but the total KWH delivered over its
>life is almost constant.
>
>-jsw
>
I'm very pleased with the 3210A performance.
In addition to the 100 watt panels I started out with,, I picked up
some used Jinko 250 watt polycrystalline panels for $50 each from a
local solar installer. They're pulls, but only a few years old and
they deliver 235 watts in backyard sun (94% of the rated 250 watts
under Standard Test Conditions). The $/watt are much better than the
100 watt panels but they are more than twice the size and they are
twice the weight of the 100 watt panels. The sizing is obvious, as
solar power depends on surface area. 2.5 times the power needs 2.5
times the surface area.
I have two backup gas generators. a 3000 watt Champion 120 volt only
and a 5000 watt Generac 120/240 volt. My third option is waiting for
me to assemble the pieces, with a lawnmower engine and an 85 amp CS130
alternator. It should be a little more efficient to produce the DC
via the alternator (I know, it's 3 phase AC and goes through a diode
bridge to get DC) but it's still more efficient than running a 3000
watt gen to power a couple of battery chargers to get 850 watts of DC
to charge the batteries - and alternator provides a faster charge
(still 65 amps when the alternator is hot from being loaded). At full
output, 85 amps at 14 volts is almost 1200 watts.
---
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https://www.avast.com/antivirus
Posted by Jim Wilkins on June 22, 2018, 1:41 am
<ads> wrote in message
> On Thu, 21 Jun 2018 08:39:02 -0400, "Jim Wilkins"
>
>>.................
>
> I'm very pleased with the 3210A performance.
>
> In addition to the 100 watt panels I started out with,, I picked up
> some used Jinko 250 watt polycrystalline panels for $50 each from a
> local solar installer. They're pulls, but only a few years old and
> they deliver 235 watts in backyard sun (94% of the rated 250 watts
> under Standard Test Conditions). The $/watt are much better than
> the
> 100 watt panels but they are more than twice the size and they are
> twice the weight of the 100 watt panels. The sizing is obvious, as
> solar power depends on surface area. 2.5 times the power needs 2.5
> times the surface area.
>
> I have two backup gas generators. a 3000 watt Champion 120 volt
> only
> and a 5000 watt Generac 120/240 volt. My third option is waiting
> for
> me to assemble the pieces, with a lawnmower engine and an 85 amp
> CS130
> alternator. It should be a little more efficient to produce the DC
> via the alternator (I know, it's 3 phase AC and goes through a diode
> bridge to get DC) but it's still more efficient than running a 3000
> watt gen to power a couple of battery chargers to get 850 watts of
> DC
> to charge the batteries - and alternator provides a faster charge
> (still 65 amps when the alternator is hot from being loaded). At
> full
> output, 85 amps at 14 volts is almost 1200 watts.
https://en.wikipedia.org/wiki/Load_dump
https://www.vishay.com/docs/49748/49748.pdf
You want your battery clamps well insulated when you grab and remove
one at full charging current.
When electronic fuel injection came out in the mid 70's I built a
custom battery fault simulator for [a major carmaker] that could
generate 100V load dumps in rapid succession, like driving down a
rough dirt road with a loose battery clamp making intermittent
contact.
The customer's engineers were eager to try their new toy, whose power
greatly exceeded what they could do with standard lab equipment. They
hooked up a prototype fuel injection controller and told me to start
at full power. On the third pulse the prototype's magic smoke escaped.
I had been building test stations for General Electric's 1200V, 1000A
"hockey puck" SCRs for Buddliners, so this project wasn't unusual.
---
XML site map
>> wrote:
>>
>>>Dear All,
>>>
>>>Can anyone update me on latest home solar system technology?
>>>
>>>I appreciate anyone inputs.
>>>
>>>Regards,
>>>Yan
>>
>> Do you want grid-tied solar that augments what the power compoany
>> provides but goes away when the grid is down or do you want
>> independent solar power that works when the power company doesn't?
>>
>> A few grid-tied systems can be converted to off-graid but you'll
>> probably be better off with a designed to fit off-grid system. They
>> are NOT cheap.
>>
>> By doing a lot of scrounging and bargain hunting, I put together a
>> small system that can best be described as a "solar generator". The
>> battery bank is charged by solar panels with a couple of gasoline
>> generator options if there is no sun.
>>
>> In 10+ years at this location, the longest outage was 16 hours.
>> Depending on the season, I can get 10 to 20 hours or "Wait until
>> daylight" power from the system. If commercial power was off for an
>> extended period(weeks), we would have enough power to drop back to a
>> 4
>> cu ft fridge, 7" TV and charging laptops, tablets and cell phones
>> (if
>> cell service is up). The total cost was $100 for 900 watts or
>> solar
>> panels, two MPPT charge controllers, two 2000 watt sine wave (PSW)
>> inverters, a 500 watt PSW inverter, a 12 volt 540AH battery bank and
>> lots of wire, fuses, circuit breakers, metering, etc,
>>
>> For a larger system, you'd want a 48 volt battery bank. I went with
>> 12 volts because of the number of 12 volt lights and other
>> accesories
>> available - such as the 12 volt DC-DC converter that runs and
>> charges
>> the laptop. With that converter providing power, the laptop idles
>> at
>> 15 watts. Using an inverter and the usual AC power supply/charger,
>> the idle power for the laptop is 35 watts.
>>
>> Note that there's no mention of washing machine, clothes dryer,
>> dishwasher, air conditionibng or any of a number of modern
>> "necessities". If you want those items, you will need a solar
>> system
>> that's at least 10 times the size of my backup power.
>>
>
>My solar backup system assumes I'll start a generator for the
>intermittent large loads you mentioned plus the microwave, so it's
>sized for the 120VAC refrigerator and 12VDC freezer which run 24/7. My
>largest "3750W" generator can only start the old Maytag if I nudge the
>motor inward with my foot to slip the belt. I dry laundry on a
>clothesline.
>
>What did you choose for MPPT controllers and how do you like them?
>
>It puzzles me that they are still so expensive when this has a better
>display and all their functionality except for tracking software for a
>much lower price.
>https://www.aliexpress.com/item/RD-DPS5020-Constant-Voltage-current-Step-down-communication-digital-Power-Supply-buck-Voltage-converter-LCD-voltmeter/32821185351.html
>
>I have the older DPS5015 which is easy to adjust for maximum current
>to the battery. The smaller text at the bottom is input voltage which
>shows the array's Maximum Power Point voltage and when it has been
>overloaded and trapped in a low voltage state. Then the battery
>current must be briefly reduced or shut off to allow the panel voltage
>to recover.
>
>-jsw
>