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When I see articles like this I immediately go to Ali Express and search for the appropriate term - in this case "solar power refrigerator". The exact solution

When I see articles like this I immediately go to Ali Express and search for the appropriate term - in this case "solar power refrigerator". The exact solution isn't there but there are DC fridges for sale and examples of the set-up you require for solar charging. So this is a solved problem. Shenzhen is well ahead in the hardware innovation game. If you have a hardware idea look there first.

davidhyde 7y ago
A DC fridge does not "solve the problem". The problem the author solved was not having to use a battery to keep the fridge cold at night or when it rains. He did this with a thermal mass (a large tank of water in the fridge) that takes a while to heat up. Kind of like using an ice pack in a cooler box. I'm assuming that he used an AC fridge / freezer with an inverter because he already had one. Besides, I've never seen a large inexpensive DC fridge before. They just don't enjoy the same economies of scale.
- tim333 7y ago
  I've used the thermal mass of water to keep the darn thing quiet at night in a studio flat - put bottles of water in the ice box and turn it off over night.
- jkoudys 7y ago
  Plus DC motors are just fundamentally different from ac. AC is generally simpler and less maintenance, so it's not purely a question of scale.
  - kozak 7y ago
    A modern "inverter" fridge has a three-phase AC motors with, well, an inverter in front of it. It would be easy for the manufacturer to makes such fridges accept DC without a major redesign.
    - myself248 7y ago
      There's a good chance that such a machine may accept DC just fine without even knowing it. Assuming the inverter/VFD has a simple full-bridge as its first stage, the DC would just flow through the same half of the bridge all the time. A lot of PSUs can do this too; I just bought a Mean Well RSP-1500-48 which specifies its input voltage as AC 90-264V, or DC 127-370V. This means I can run it straight from the traction battery in my car (200V DC) if I care to...
      - deleted 7y ago
        [deleted]
    - namibj 7y ago
      Many likely already do exactly that. It's similar to computer power supplies, which can often (at least if they don't claim active PFC) just take DC at 320 V if set to 230 V AC, because the current handling on the bridge rectifier is specified for 115/120V, which results in a their current rating only being half-used at 230 V. Which reminds me to check a modern server power supply for whether it could just be switched over to a battery bank at a suitable voltage on power loss. Most load should be easy to shed in a couple seconds by triggering suspend-to-RAM, and UPS are wastefully expensive if they only exist to tank full load for a moment and standby/idle for long enough to handle manual filling and starting of a generator.
DoctorOetker 7y ago
Of course this is the long term solution, but replacing all refrigerators in operation, even the ones just manufactured is a total environmental waste compared with getting efficient inverters for solar panels!

davidhyde 7y ago

A DC fridge does not "solve the problem". The problem the author solved was not having to use a battery to keep the fridge cold at night or when it rains. He did this with a thermal mass (a large tank of water in the fridge) that takes a while to heat up. Kind of like using an ice pack in a cooler box. I'm assuming that he used an AC fridge / freezer with an inverter because he already had one. Besides, I've never seen a large inexpensive DC fridge before. They just don't enjoy the same economies of scale.

tim333 7y ago
I've used the thermal mass of water to keep the darn thing quiet at night in a studio flat - put bottles of water in the ice box and turn it off over night.
jkoudys 7y ago
Plus DC motors are just fundamentally different from ac. AC is generally simpler and less maintenance, so it's not purely a question of scale.
- kozak 7y ago
  A modern "inverter" fridge has a three-phase AC motors with, well, an inverter in front of it. It would be easy for the manufacturer to makes such fridges accept DC without a major redesign.
  - myself248 7y ago
    There's a good chance that such a machine may accept DC just fine without even knowing it. Assuming the inverter/VFD has a simple full-bridge as its first stage, the DC would just flow through the same half of the bridge all the time. A lot of PSUs can do this too; I just bought a Mean Well RSP-1500-48 which specifies its input voltage as AC 90-264V, or DC 127-370V. This means I can run it straight from the traction battery in my car (200V DC) if I care to...
    - deleted 7y ago
      [deleted]
  - namibj 7y ago
    Many likely already do exactly that. It's similar to computer power supplies, which can often (at least if they don't claim active PFC) just take DC at 320 V if set to 230 V AC, because the current handling on the bridge rectifier is specified for 115/120V, which results in a their current rating only being half-used at 230 V. Which reminds me to check a modern server power supply for whether it could just be switched over to a battery bank at a suitable voltage on power loss. Most load should be easy to shed in a couple seconds by triggering suspend-to-RAM, and UPS are wastefully expensive if they only exist to tank full load for a moment and standby/idle for long enough to handle manual filling and starting of a generator.

DoctorOetker 7y ago

Of course this is the long term solution, but replacing all refrigerators in operation, even the ones just manufactured is a total environmental waste compared with getting efficient inverters for solar panels!