diy solar

diy solar

Direct to water heating.

Whether you use an mppt-type controller or not, when you tie to an array directly you have to match the array's "equivalent resistance" (working voltage / working amps) to the heating element's resistance. E.g., a common 4500 watt 240v element has 12.8 ohms resistance, so for that element you'd set up your array to provide [working volts/amps] = as close to 12.8 ohms as possible. This is what David Poz eventually discovered. (And series or parallel is not really relevant, except that generally you do want to get voltage as high as possible while balancing the equation, so to speak.) But, even when you do this balance, without mppt the performance will become terrible when the light decreases. This is because the [volts/amps=equivalent resistance] value of the array changes. Anyway, my controller gives me 800-950 watts in good sunlight, from a 960 watt array, and 150-300w in overcast conditions.
Thanks for some specific lesson type info. rooted in real life experiences. ... Helping me understand a little bit more on my Learning More All The Time Program :+)
 
I run 3, 305 watt panels in parallel with a 36 volt dc 600 watt element. Actually It is a split element 600 watt on each side. I/2 of the element is on straight panels and the other half is powered by off another solar setup, 1200 watts, when the solar controller goes in float mode on the batteries. Off of the direct panels i get close to 600 watts about 6 hours a day and on the other side, i get about 500 watts for the same amount of time.
 
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I've seen here and seen & lost descriptions of divergent "sipper" loads that send power to heaters only after other loads are met, batteries full, et cetera. What are these circuits generally called?

I know that diversion loads are often heaters or water heaters. What about the switch, or logic circuit, that connects a load after the batteries are full?
 
I've seen here and seen & lost descriptions of divergent "sipper" loads that send power to heaters only after other loads are met, batteries full, et cetera. What are these circuits generally called?

I know that diversion loads are often heaters or water heaters. What about the switch, or logic circuit, that connects a load after the batteries are full?
I do not run any relays. I can actually feed the power direct from my solar controller by programing it. EPever 40 amp. There are some simple relay boards that can be purchased that will turn on your load at a preset volt and disconnect the load at another preset voltage.
 
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I run 3, 305 watt panels in parallel with a 36 volt dc 600 watt element. Actually It is a split element 600 watt on each side. I/2 of the element is on straight panels and the other half is powered by off another solar setup, 1200 watts, when the solar controller goes in float mode on the batteries. Off of the direct panels i get close to 600 watts about 6 hours a day and on the other side, i get about 500 watts for the same amount of time.
Interesting Info: 3 x PV Panels in parallel matches my view of simple with good efficiency for PV Solar direct to heating coils in water. I wonder if you could share more specifics about how you accomplished (if I understand this correctly) ... sending your PV power to heating coil when your solar controller goes into battery float mode (Good timing for sending excess solar power that is otherwised not needed/ or being used to a water heating task).
 
I will be doing a detailed write up this weekend after i tally some more information. Just look for it on my origional post in hot water heating section.
 
I do not run any relays. I can actually feed the power direct from my solar controller by programing it. EPever 40 amp. There are some simple relay boards that can be purchased that will turn on your load at a preset volt and disconnect the load at another preset voltage.
So Is this the Solar Control you are using, and maybe your dumping PV Solar Power to Water Heating Coils is going through the "Load" circuit, and you can somehow program load circuit that to turn on at battery float voltage? https://www.amazon.com/EPEVER-Controller-Regulator-Backlight-Lead-Acid/dp/B077HHYYHT

... Looks interesting, and I am looking for the pdf manual next :+) ... & looking forward to when you post next :+)
 
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Uhh... Isn't this exactly what the Electrodacus SMBS0 and DMPPT were built for? Charge batteries off a large array and then dump/divert excess into a energy sump (e.g. a water heater to heat water to store energy). Am I missing something?
 
Thre are a number of cheap controllers out there that will switch the " dump" load. Many of them mark the terminal as " Lights"
It's really just an output. On the ones I have you can turn the load on by time, for so many hours and at voltage levels.
These are Cheap PWM type Controllers but work pretty well when they are programmable.

Not sure of the amp output but really does not matter. You could use a relay or Mosfet connected to the battery and it will just turn it on and off the same.
I have a bit of work details to finish on my solar system before I get to this: I want to send my solar watts to a water heating task (to water heating coils) when my battery get up to float voltage. From kind of brainstorming options here with fellow forum members, while consider my options, .... I just figured out my control route. I have three MPP brand LV2424 All In One on my Solar Wall configured for 240vac split phase. Those units each have "Dry Contact Signal" (which could also be used to start and stop a generator) that I can easily tap into, to trigger a relay when my Battery Voltage becomes > above a value I can set in #21 or #20, depending on which route I set up. As for the relay electrical route, ... I am still not sure if I will go with PV watts to water heating task, or 120vac or 240 ac to a water heating task (both option make sense to me). I will look at my pros and cons with a desire to make efficient use of my options, later, when I get there. And will enjoy reading about how other folks accomplish specific control options that we are comparing notes on here :+)
 
So Is this the Solar Control you are using, and maybe your dumping PV Solar Power to Water Heating Coils is going through the "Load" circuit, and you can somehow program load circuit that to turn on at battery float voltage? https://www.amazon.com/EPEVER-Controller-Regulator-Backlight-Lead-Acid/dp/B077HHYYHT

... Looks interesting, and I am looking for the pdf manual next :+) ... & looking forward to when you post next :+)
Yes you are correct, I actually have three of these on different systems. they are pretty well indestructible.
EPever 40 amp controller
 
Yes you are correct, I actually have three of these on different systems. they are pretty well indestructible.
EPever 40 amp controller
In asking a seller on Amazon about the controller I found (lesser version of the one you are using): I asked: Can your epever 40 amp model with remote be programed to send pv watts to a dump load when the battery hits float voltage? One Seller Answered: "Can't adjust. The power of the controller load is provided by the battery. must be connect the battery before connect the solar panel,disconnect in reverse order." ... So I am still wondering about specifics ways to send PV directly to a water heating coil when battery hit float voltage; or maybe you are doing so with the battery too (as in PV InPut with Battery going to water heating coil until battery voltage drops below float voltage (and that might be better way to do it than direct PV to Water heating coil(s); ... and maybe I misunderstood some aspects of what you shared. :+)
 
In asking a seller on Amazon about the controller I found (lesser version of the one you are using): I asked: Can your epever 40 amp model with remote be programed to send pv watts to a dump load when the battery hits float voltage? One Seller Answered: "Can't adjust. The power of the controller load is provided by the battery. must be connect the battery before connect the solar panel,disconnect in reverse order." ... So I am still wondering about specifics ways to send PV directly to a water heating coil when battery hit float voltage; or maybe you are doing so with the battery too (as in PV InPut with Battery going to water heating coil until battery voltage drops below float voltage (and that might be better way to do it than direct PV to Water heating coil(s); ... and maybe I misunderstood some aspects of what you shared. :+)
Their answer is correct and incorrect at the same time. Yes you do need a battery to activate the solar controller to draw energy off of the load center. The controller that i have can be programmed four different ways to divert energy from the panels / batteries per your instructions/needs. Yes the power can be drawn straight from from the panels if you are producing more power that you need to charge your batteries. You can also send power straight from solar panels not going through a solar controller to a water heater element. Either way your choice if you are using a DC water heating element.
 
Their answer is correct and incorrect at the same time. Yes you do need a battery to activate the solar controller to draw energy off of the load center. The controller that i have can be programmed four different ways to divert energy from the panels / batteries per your instructions/needs. Yes the power can be drawn straight from from the panels if you are producing more power that you need to charge your batteries. You can also send power straight from solar panels not going through a solar controller to a water heater element. Either way your choice if you are using a DC water heating element.
I look forward to a read of the manual for those really nice kind of options. :+) Sounds great for using PV solar to heat water after the battery bank is full. :+)
 
Hey guys, i was reading some of you are using the Actii Hot Water Controller together with the Photo Booster. I got mine today. If you look at the connectors of the Foto Booster, one side has a diode and one is without. Which side is in and which is out? Thanks.
 
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Hey guys, i was reading some of you are using the Actii Hot Water Controller together with the Photo Booster. I got mine today. If you look at the connectors of the Foto Booster, one side has a diode and one is without. Which side is in and which is out? Thanks.
Where did ya get that; maybe share web link; ... and how much did it cost?
 
I am generating more watts of PV Power than I can use mid day after my battery is charged (actually, still in initial testing and dialing in phase, for options w my 3x MPP (brand name) LV2424s, that will soon to have 6K Input via my three 2000 watt PV panel arrays (got two in place now); I am planning to "auto-on" a 3.5kw 240ac heater coli n tube n type water heater, with my slow speed spa pump also circulating water through my spa filter ect. to heat up my 450 gallon hot tub, w auto off via thermostat when water temp is about 102 F (as a start). My current big BTU natural gas heater for my hot tub will remain in place for quick heat at the inlet jets ... I figure I can use my inexpensive 24v power voltage monitor w it's small 6A rated relay to trip bigger amp relay(s) or SSR(s) to turn on my spa pump and 3.5kW 240vac heater coil ON when my battery voltage is near it's upper charge voltage. I just hope my inexpensive voltage monitor control with up to 15 second delay will not be switching off and on, when I get my relay(s), or SSRs switching the bigger amps for the water heating task. I think I will eventual try out other ways to heat water, while the 120ac route seems an easy no brainer for now. I would like to know if DC direct to a water heating task would be more efficient use of my Solar Watts IN, as opposed to heating via my Solar Watts going through an MPPT solar charger to my battery, and then my Inverter conversion of 23vdc -27vdc to 120vac ??? I currently think with 6k Watts of PV online (actually 4k, while building my tilt rack for last 2K array next week) ... makes that question a low priority at present. That is where I am heading.

Other Ideas that light up along these lines: Might add a 7 gal Bosch Hot Water Tank w a mid day ON timer, or possiblyuse the same battery voltage monitor circuit I figure out for my spa to turn it ON) placed somewhere near my shower to feed to my (current set up) 240ac 30 Amp (currently separate grid feed powered) Steibel Electron instantanious type water heater /// to get a bigger winter time water flow out of it. (Steibel = German made/ = dependable https://www.amazon.com/dp/B00DSKJ3AM/ref=twister_B0744KQCVQ?_encoding=UTF8&th=1 ... dials in and stabilizes max water temp desired/ the DHC-E 8/10 model uses 240vac 30 amps or 40 amps (user selected). .. My experiences knows Steibel to be dependable (unless you have to chemical balance your water ph, etc.); ... but when winter brings down the temp of cold water coming into your house, you need a bigger amp model, or you have to turn down your water flow, or you need a pre-heated water source like a small tank Bosch sink heater feed into the Steibel (I like those Bosch unit for using just a 120vac/ 9 amp draw, and for great insulation of their glass lined tank). Might put a tempering valve inbetween my small Bosch tank water heater, and my 240 vc Steibel brand instant type water heater to get way larger shower water flows available for my next girlfriend. ... These are the more promient Ideas hitting me for updating and experimenting with. ... Happy Days :+) Bill
 
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Where did ya get that; maybe share web link; ... and how much did it cost?
 
This looks very interesting, I don't have any idea on the diode end, but will be glad to hear how it is going, thanks for the info!
 
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