Battery cooling from excess solar power?

[Warmaier]

I live in an area where it is very cloudy most of the year, but dry and sunny (and sometimes very hot) for three months of the year. In order to get adequate solar power during the cloudy months, I have to have about 5X the solar panel area that I'd need in summer. My question is what to do with the excess power in the summer. My needs are pretty basic: refrigerator, lighting, charging a few electronic devices. I don't need or want to add more electric luxuries. My thought was to add Peltier thermoelectric cooling to the battery box, which should improve battery life(it can get up to ~44 degrees C /110 F here.) You can view here this cooler. Peltier coolers aren't efficient, but they are by far the simplest cooling method, and they are cheap on ebay. I would use a thermostat and voltage level detector to make sure that they only operate during the sunniest/hottest part of the day. Has anyone tried this? Is there any downside? If so, what size Peltier cooler did you use? Any other thoughts on using the excess solar power?

[Mike90250]

1st, where will you dump the excess heat from the Peltier cooler ? I think I recall the ratio was move 10 watts of heat, dump 50 watts . You need a cooling fan for the hot side, because thats the only way to move the heat away. All the power you put into the module, comes out as heat, plus however much it moves from the cold side. if you have a 12V 20A cooler, you 240 watts of heat to dump, keeping the hot side cool, to make the cold side cooler.

[J.P.M.]

I live in an area where it is very cloudy most of the year, but dry and sunny (and sometimes very hot) for three months of the year. In order to get adequate solar power during the cloudy months, I have to have about 5X the solar panel area that I'd need in summer. My question is what to do with the excess power in the summer. My needs are pretty basic: refrigerator, lighting, charging a few electronic devices. I don't need or want to add more electric luxuries. My thought was to add Peltier thermoelectric cooling to the battery box, which should improve battery life(it can get up to ~44 degrees C /110 F here.) Peltier coolers aren't efficient, but they are by far the simplest cooling method, and they are cheap on ebay. I would use a thermostat and voltage level detector to make sure that they only operate during the sunniest/hottest part of the day. Has anyone tried this? Is there any downside? If so, what size Peltier cooler did you use? Any other thoughts on using the excess solar power?

Ever consider covering some of the panels in a way that doesn't change the charging harm the batteries when excess generation is likely ?

Or, dumping the excess generation before it get to the batteries in some way, analogous to gas often or at one time got flared off an oil well ?

[Ampster]

Ever consider covering some of the panels in a way that doesn't change the charging harm the batteries when excess generation is likely ?

Or, dumping the excess generation before it get to the batteries in some way, analogous to gas often or at one time got flared off an oil well ?

I think the charge controller will throttle back the panels when the batteries are full. That is probably what is happening now. There is no need to get up on the roof to cover the panels. What the poster was asking for is some way to use that energy to optimize his system.
I am in a similar situation but with a grid tied system and I use the excess in summer to charge my EV, my golf cart or my electric bike. I understand that the OP did not want to add any luxuries, but my EV, golf cart and electric bike are necessities for me.

[Paul Land]

I have two PV strings A-B with A/B bypass. String B is taken out of service June-August

[Ampster]

I have two PV strings A-B with A/B bypass. String B is taken out of service June-August

Do you do that with a switch, relay or contactor? Have you ever speculated about what you could do with that excess capacity in the summer?

[Paul Land]

Just a #1 contact #2 no contact VDC multi-position switch mounted on perf board in project box with connectors that I had on hand. I can flip switch #3 to shed lighting & DC Drink Blender and vintage farm radio. Me and chickens share the Man Cave.

[Ampster]

You could boil some eggs with that excess summer solar. Do the chickens in your man cave lay eggs or are they all roosters?

[Paul Land]

You could boil some eggs with that excess summer solar. Do the chickens in your man cave lay eggs or are they all roosters?

Well, In today's pc culture we all must let the chicks decide there gender oops! did I say chicks.
chix.jpg

[TomP]

The excess power is no issue. Your CC will handle that just as it does when in float mode. I harvest my excess with AC, and today we had had 2 electric heaters on as soon as the bats went into float. How is your water supply, do you have enough to maybe create a water jacket around your batteries using a small continuous flow during the day?