The award for the worst idea in solar energy goes to...

[mciholas]

Yotta Energy for putting battery storage under the panels on the roof.

There is no worse place you could possible put the battery than the extreme temperatures and exposure of the roof. The heat will chemically aged the cells quickly, the cold will reduce their capacity, and the thermal cycling will lead to premature failure and possible lithium fires.

Revolutionary tech company transforms home energy storage with simple, modular method — here's how it works

Texas-based Yotta Energy has an innovative solar-plus-storage solution for small- and medium-sized businesses.

www.thecooldown.com

Mike C.

 

[timselectric]

Sounds like a horrible idea.

 

[yodamota]

they are using phase change materials to regulate the heat/cold. pretty neat.

I don't think its a great place to put the batteries however!

 

[mciholas]

they are using phase change materials to regulate the heat/cold. pretty neat.

There is no way they can provide enough thermal mass to effectively regulate the battery temperature even with a phase change. Just not enough energy storage.

Are they going to have a phase change for being hot or for being cold? You can't make a material do both since a gas state isn't workable.

Besides the short battery life induced by the environment, batteries also need to be changed more often than the panels, and the roof is a terrible place to do servicing.

Mike C.

 

[Dagoth Ur Does Solar]

I won't even leave my power tool batteries in the shed overnight, no way in hell would I want batteries on my roof in 100F weather getting baked under my panels.

 

[hwy17]

This thecooldown website is the next iteration of gag inducing "green tech" boosterism ala matt farrell and cleantechnica. The whole site is basically one big advertisement and then they write these fake articles to get spread around like it's "news".

 

[Dagoth Ur Does Solar]

This thecooldown website is the next iteration of gag inducing "green tech" boosterism ala matt farrell and cleantechnica. The whole site is basically one big advertisement and then they write these fake articles to get spread around like it's "news".

The internet is general is an absolute nightmare in the year 2024. Trying to search for something on Google and get a result actually written by a human without specifying something like "reddit" in the query is near impossible. You get flooded with crap like this at best, or search engine optimized Lorem Ipsum-tier garbage if you're unlucky.

That said, this forum is a godsend since the mods actually have to approve user accounts and there's a wealth of information from experienced people here.

 

[hwy17]

without specifying something like "reddit"

Sometimes I block reddit for myself when I am trying to quit and then inevitably have to unblock it again when I need some actual good info on something specific.

 

[mciholas]

This isn't a fake thing, they really mean to do it:

Solutions — Yotta Energy | Energy Made Simple

www.yottaenergy.com

Manual attached.

There are some interesting things in the specs:

Temperature Range
-20°C to 43°C

Enclosure Rating
Do not immerse in water, Outdoor only, IP 67
Do not keep under RH> 90 % (non-condensing)
Do not expose to direct sunlight

I believe a roof mount in many places will violate at least one of the above four requirements pretty regularly. For example, RH near 100% happens all the time on a rainy day.

I also think this will be expensive per KWH.

How do ideas like this get funded?

Mike C.

 

[meetyg]

Stupid idea...
Not only the heat, but now your roof needs to accommodate more weight. Not sure if this is reasonable for most home residential roofs.

 

[Hedges]

Gee, I wonder what the fire rating is?

Fire Safety In PV Systems: Understanding Fire Rating And Prevention | Solartechadvisor

Photovoltaic (PV) systems are increasingly popular as a clean energy source for homes, businesses, and communities. These systems convert sunlight into

solartechadvisor.com

"As of January 1st, 2015 many jurisdictions are now enforcing codes based upon updates to the International Building Code (IBC) and UL Standards 1703 (modules) and 2703 (mounting systems). The language included in the 2012 and 2018 IBC requires that the combination of roof mounted solar modules and racking components is to be considered a system (IBC Section 1509.7.2).

Additionally, it requires that this system shall meet or exceed the fire classification of the roof assembly. The objective is to ensure that the PV system does not adversely affect the fire rating of the roof. Roof surface fire ratings are classified either A, B, or C; Class A being the most resistant to the spread of flame."

https://snapnrack.com/wp-content/uploads/2019/07/SnapNrack_Fire_Classification_Tech_Bulletin_v.3.pdf

 

[sunsurfer]

"The batteries use lithium-iron phosphate (LFP) chemistry, a type of battery made by larger manufacturers, including CATL, and others. It's cheaper than traditional power packs because LFP uses less expensive materials.

Yotta's battery has successfully operated in the Texas heat. The white batteries reflect the sun and are well-insulated. Furthermore, the designers created the power packs with fins that allow them to self-cool without external coolant."


Yea, stupid idea for sure.

 

[timselectric]

On the roof, underneath solar panels, is the last place that I want to do maintenance and troubleshooting.