General info on solar heater

[Venezuela Solar]

Im currently looking information about solar heaters, i plan to install one on this location (8.985, -70.7567) Venezuela, this is south America, this is considered a "cold" place for this country average, the average temperature is 12.9°c and the max temperature is 19°c (66°F) so i dont know how much could i get from a heater at this temperature, also, this solar heater is to avoid using a resistance heater of 3000w, in the event of the solar heater not working as expected i will have to over built the solar system and there is no grid energy most of the time, also i plan on using the mpp solar LV5048 and it worries me that the lv5048 will not last with a constant use of the heater in the case of the solar heater not working as expected

Where can i get some good info about solar heaters?

What experiance have you had with this devices?

I like the lv5048 but will i need something bigger??

Extra info
3000w solar array (if solar heater works)
8 200AH AGM batteries (4Sx2P)
Load, 1kw to 1.5kw (w/o heater)

With heater at least 6000w solar array
Same battery bank (no heater at night, to expensive)

Thanks you all.

 

[kernel]

Home power magazine back issues have the absolute best solar thermal gear reviews and diy info. I install these in michigan since 2002. Good technology. You could have heated air or hydronics for collection, storage and distribution depending amd a mix if required.

It will work absolutely fine at 50 deg F. And lower. 60 deg., unimaginable heat from 4'x10' collectors. 28kbtu-32kbtu/hr about 2000W each, multiply by however many peak sun hours you get on site.

Ch3ck out cybo energy for microinverters you can allow either your inverter or the grid or both to feed into and run heaters, air conditioners, dehumidifiers, water heaters etc.

They have automatic transfer, do not insert power into the grid and will take the passthrough from your pv system/utility power combo so as to leave the battery and power bill untouched unless you allow it.

 

[fat_old_sun]

Im currently looking information about solar heaters, i plan to install one on this location (8.985, -70.7567) Venezuela, this is south America, this is considered a "cold" place for this country average, the average temperature is 12.9°c and the max temperature is 19°c (66°F) so i dont know how much could i get from a heater at this temperature, also, this solar heater is to avoid using a resistance heater of 3000w, in the event of the solar heater not working as expected i will have to over built the solar system and there is no grid energy most of the time, also i plan on using the mpp solar LV5048 and it worries me that the lv5048 will not last with a constant use of the heater in the case of the solar heater not working as expected

Where can i get some good info about solar heaters?

What experiance have you had with this devices?

I like the lv5048 but will i need something bigger??

Extra info
3000w solar array (if solar heater works)
8 200AH AGM batteries (4Sx2P)
Load, 1kw to 1.5kw (w/o heater)

With heater at least 6000w solar array
Same battery bank (no heater at night, to expensive)

Thanks you all.

If your goal is warm (45-60 C) water, your best bet is a solar thermal system. Even simple solar thermal heaters are 50-60% efficient, with some designs exceeding 80% efficiency. You may combine the solar thermal with a small PV to run a pump. Heating water from PV energy is at most 20% efficient.

Do a google search for DIY solar thermal water heater.

 

[kernel]

If your goal is warm (45-60 C) water, your best bet is a solar thermal system. Even simple solar thermal heaters are 50-60% efficient, with some designs exceeding 80% efficiency. You may combine the solar thermal with a small PV to run a pump. Heating water from PV energy is at most 20% efficient.

Do a google search for DIY solar thermal water heater.

Or just buy a heliodyne and be done with it. I watch 150degF fluid circulate in january and february in michigan....... it works fine without the caveat at michigan. The guy lives in venezuela!

 

[fat_old_sun]

... buy a heliodyne .....

He's in a DIY forum. why buy an overpriced system when he can make something as good at 1/4 the cost?

 

[kernel]

He's in a DIY forum. why buy an overpriced system when he can make something as good at 1/4 the cost?

Because you cannot make it nearly as good. And the trouble isnt wort the result unless heating air. Hydronic collectors are a work of art and will last a hundred years if cared for...... no acidic fluid. Performance and aesthetics are not happening in a diy.

Let me know how much a soldering oven and selective surface coating costs or for that, a sheet of the proper thickness copper, plus waterways, plus brass or copper unions, plus glass 250$ alone, epdm gasket and box aluminum with proper channels, dont forget stainless screws.......

Then get back to me on 800$ per collector.

 

[fat_old_sun]

'selective surface coating'? that's some marketing crap. paint it black, the best broad spectrum absorber. There are several UV stable black coatings available. I happen to live in a house that has more than 250 sq ft of thermal panels, a hydronic floor heating system & a 10K gallon super insulated water tank for heat storage that I built & installed 33 years ago. I also have about 8.5 kW of PV I installed 25 yrs ago.

Here in this forum, we're discussing the finer points of BMS designs, high side vs low side switching with FET's & the relative merits of various lithium chemistries, but a DIY solar thermal water heater is best left to the professionals!

OP, go ahead & do a web search. There are several very effective and low cost solar thermal that you can fabricate using locally available materials.

 

[kernel]

'selective surface coating'? that's some marketing crap. paint it black, the best broad spectrum absorber. There are several UV stable black coatings available. I happen to live in a house that has more than 250 sq ft of thermal panels, a hydronic floor heating system & a 10K gallon super insulated water tank for heat storage that I built & installed 33 years ago. I also have about 8.5 kW of PV I installed 25 yrs ago.

Here in this forum, we're discussing the finer points of BMS designs, high side vs low side switching with FET's & the relative merits of various lithium chemistries, but a DIY solar thermal water heater is best left to the professionals!

OP, go ahead & do a web search. There are several very effective and low cost solar thermal that you can fabricate using locally available materials.

I absolutely know. I have three 4x 12' hydronic collectors, 2 air heaters, and 4500w of off grid pv all diy, except for parts and equipment.

My point was if you simply buy the materials you will not come ahead on cost. If you attempt to build much less design a hydronic collector amd its system most would be at a total loss.

Selective surface coatings like black chrome, ti-ni, there are a few others mentionable which are all metal depositions, they work outstanding, do not fade...... ever, transmit heat energy without insulating the absorber, which all paint does.

Ever hear of reflective film on the back side of a pv cell, bi facial?
It is exactly the trick black chrome does and is hands down the best performing and longest lasting selective surface coating for the purpose that is in use to my knowledge.

I have been building, designing and installing solar thermal since 2002...... orphan systems, jew systems, diagnosis and repair, etc. I cut my solar teeth on pv direct drive stand alone solar thermal hydronics........

I have made some stuff amd seen others make some collectors too. Not pretty, not high performance, not long lived.

Not at all. Better to diy storage, and heat exchangers than collectors and pumps. Id like to see a diy built Ivan labs el sid magnet coupled circulator!

"Get out the sand, we gotta cast a nautilus to precision, and then machine it with files and a grinder......"

Sorry just realistic observations from years, of service in the industry.

 

[fat_old_sun]

Ever hear of reflective film on the back side of a pv cell, bi facial?

Bifacial cells *do not* have reflective films at the back. If they do, they won't be bifacials! Single crystal solar cells have an anti-reflective layer on the Sun side, usually a thin layer of silicon nitride. In bifaccials cells, the back side is designed to harvest the scattered light and have a thin layer of silicon nitride.

 

[Steve_S]

I would HIGHLY Recommend having a look at this site: https://www.builditsolar.com/Projects/SpaceHeating/Space_Heating.htm
It has a wealth of information on Good Working DIY Solar Heating systems, both passive & active. Systems which can just use the Thermosyphon effect with air to more robust systems using water & insulated tanks, all DIY of course.

The whole site is a great general resource for many projects related to more than just solar electricity.

 

[kernel]

I would HIGHLY Recommend having a look at this site: https://www.builditsolar.com/Projects/SpaceHeating/Space_Heating.htm
It has a wealth of information on Good Working DIY Solar Heating systems, both passive & active. Systems which can just use the Thermosyphon effect with air to more robust systems using water & insulated tanks, all DIY of course.

The whole site is a great general resource for many projects related to more than just solar electricity.

Fat old, i got it wrong on nomenclature....... cells do come with reflective backing to reflect light back onto the back side of each cell, hanwha q cell possibly, rec, sunpower, etc.

Build it solar is great. I built my immersed coil HE tank from guides there, plumbed with pex and holds reverse osmosis water as storage and boiler loop fluid all diy, even used a pickle drum and double bubble for better cobbler effect. Works outstanding and has 2 degF. per hour loss.

Collectors are the main store bought gift from the gods unless heating air.

The op simply asked about heating systems and since hes not building modules, inverters and controllers, im pretty sure hes gonna buy off the shelf and install himself.......... a DIY still.....

Dont know why i would catch flack for that, but there it is.... not sure i like this anymore, too adversarial a forum. Reminds me of the 4x4 groups........

 

[GVSolar]

Fat old, i got it wrong on nomenclature....... cells do come with reflective backing to reflect light back onto the back side of each cell, hanwha q cell possibly, rec, sunpower, etc.

Build it solar is great. I built my immersed coil HE tank from guides there, plumbed with pex and holds reverse osmosis water as storage and boiler loop fluid all diy, even used a pickle drum and double bubble for better cobbler effect. Works outstanding and has 2 degF. per hour loss.

Collectors are the main store bought gift from the gods unless heating air.

The op simply asked about heating systems and since hes not building modules, inverters and controllers, im pretty sure hes gonna buy off the shelf and install himself.......... a DIY still.....

Dont know why i would catch flack for that, but there it is.... not sure i like this anymore, too adversarial a forum. Reminds me of the 4x4 groups........

I always appreciate your input @kernel. Stick around pls.

 

[fat_old_sun]

Fat old, i got it wrong on nomenclature....... cells do come with reflective backing to reflect light back onto the back side of each cell, hanwha q cell possibly, rec, sunpower, etc.

Yes, cells do come with a rear reflector. They're multi-purpose - reflect photons for a 2nd pass thru the silicon, to reflect electrons towards the collector electrode and as the positive (holes) electrode. They are usually a thin layer of silver, aluminum, or eve copper. However, bifacial cells do not have rear reflectors. Instead, they have a 2nd collector on the rear and a very thin pn-type silicon region. And that side is also topped off with a silicon nitride film for anti-reflective reasons.

Build it solar is great. I built my immersed coil HE tank from guides there, plumbed with pex and holds reverse osmosis water as storage and boiler loop fluid all diy, even used a pickle drum and double bubble for better cobbler effect. Works outstanding and has 2 degF. per hour loss.

Yes, Build it solar is a very good site.

Dont know why i would catch flack for that, but there it is.... not sure i like this anymore, too adversarial a forum. Reminds me of the 4x4 groups........

Not giving you a bad time at all. I do value to contributions to this forum. I was just being a 'Sheldon' (BBT reference)! If I did come across as picking on you, I apologize.


edits in red

 

[tictag]

Well, my solar collector creates 38,000BTUs, and has a 3 micron thick layer of unicorn piss sandwiched between two unobtanium catalysers...

FFS