You missed the point. What's to be gained by doing it at all if you only run the miners 1/3 of the time?

Why? If you're only running the equipment 8 hours per day it will take 3 time longer to ROI.
Consider the trucking expression: "If the wheels aren't turning, the truck isn't earning".
Same thing here, if you're spending a lot of money on equipment you want it running 24/7.

That would mean your solar batteries would sustain the GPUs for not more than an hour before they run out of juice if running in times when there is no sun like at night. Also during the day there will be fluctuations of light intensity from the sun due to weather changes so, you won't be able to run the equipment on that solar power constantly.

You would need a solar power system with capacity way more than 500w for it to handle the two running GPUs day and night.

Do you think it's worth it? Personally, I don't think so. IMO solar system is just good for backup.

500watts (0.5Kw) isn't that much mate.

Remember mining gear has to always run day and night if you are to go anywhere close to the daily profit target. I don't know what kind of mining equipment you have but you can't even run some GPUs on power of 500 watts

Ravencoin (RVN) is an old coin and one of the forks of bitcoin. At that time, it was fashionable to fork bitcoin. It is not the price of the coin that matters, but the profit. But this coin will not save the situation with mining after the end of ethereum mining.

When it will no longer be possible to mine eth you can switch to other altcoins, with less profit it is true but the alternatives there are some examples ergo, ravencoin, ton, etc

If you have stable 500w from solar panels you still need a bigger power supply at least a 750W i personally would still opt for eth mining with some powerful gpu

The most effective Asic miners takes more than 500watt from the wall, in your own case Asic is a bad idea, go for graphic cards, like RX6600XT, four pieces of this cards will give you 120MH using 240watt from wall, better than what @Takyeon suggested, 8x of 6600XT will use 500watt and you will get 240MH..

A single 3070Ti is a perfect fit for your setup, this GPU gives 82MH using 193watt in miner and 230watt from wall.

If 500watt is what your solar panel can provide it will be stupid to use 500watt machine on it because

1. Sun isn't going to be stable, there will be fluctuations.
2. You will need to recharge your backup batteries.

A 500W solar setup is for a 250watt load max, if your mining machine is going to use 500watt go with a 1000watt solar setup..

I think if you’re expecting solar power to run your miners you have a lot to learn. The amount of batteries you would need to keep it going through the night or cloudy days would be so much that it isn’t even worth mentioning that you plan to install solar. It’s nice to have solar to help with long term electricity costs, but it’s really more of a home choice than an addition to a home mining setup. Even if you spend nearly $50K on your solar setup like I did, it would still barely power a small mining setup.

lets see there so much you can mine with anything these  days

XMR

Zcash

ETH

any of the above is Good to mine right now with no end in site like before ....   you can mine all of those with GPU's or CPU's an i wouldn't worry to much about Tech keeping up and or not being able to afford it unless you mine with Acis miners.

to me and it a debate thing the best cards to use right now are

Nvidia 1060 and up ...

AMD is good mostly for ETH mining.

That's coming from a miner who uses a mix of both cards in different rigs.

I don't mix cards per RIG to many issue pop up when i do. so I keep amd to amd and Nvidia to Nvidia less issue for me .

AMD CPU's are good for mining as well . the 1700 series  line and up ...

as for whats most profitable to mine with GPU's  ETH.

followed close by two others Zcash and XMR.

but that all depends on the demand .

Yikes ... I wouldn't touch either one of those either.  Two 850W or 1000W EVGA Gold's will make you sleep better at night.

Oh and go with semi modular.  Paying extra for fully modular is a total waste of money, in my opinion.  The cable that goes to your board has to be there no matter what, so why do you care if it's permanently attached to the psu or not?