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I think it's a matter of scale. That's a 50W panel, it would relatively expensive to get an inverter and an inspection/plan from your power company just to be a

I think it's a matter of scale. That's a 50W panel, it would relatively expensive to get an inverter and an inspection/plan from your power company just to be able to use the grid as a battery. Also it would be less efficient because of the AC conversion. My personal preferred way to do this would be to have a stationary battery to charge up, and better solar panel positioning like you say, but that costs a bit more for that stationary battery. And if the only thing that battery/solar setup is used for is charging the bike, and you don't actually need more power then all that extra power is just gonna go to waste.

fomine3 4y ago
Yeah, such cost is my blocker to install cheap solar panel on my home. On-grid solar system equipment is expensive but I don't have any good use case for unstable off-grid solar. If I drive e-bike, charging removable batteries by off-grid solar looks perfect use case, but I always drive a car.
- ThatPlayer 4y ago
  The solar inverter for my off-grid setup does allow for fallback to grid power if the solar and battery are out. So I would be able to do stable "partially solar" power without having to dump power back into the grid. Still not sure it's worth the cost, as you'd need a very consistent power draw to make a return, or batteries that make the return take even longer. Still a fun project though, and not something I built to make a return on.
Scoundreller 4y ago
I'm waiting for someone to build a grid-solar hybrid refrigerator/freezer that can attach to a 50w or 100w PV running at "low-voltage" ie: < 48V. No permit/electrician required, no grid-intertie inspection required. Modern fridges are often inverter drive, so should be easier to incorporate a DC power source. And they generally run all the time because they do variable-frequency drive. Best part, it keeps working during power outages. Extra points for putting on a USB charging port (only works during the day, but still!).
- fbdab103 4y ago
  I am waiting for the same, but with air conditioners. A crappy $100-$200 window unit, plugged into an equally baseline solar panel. Free opex cooling that could be installed for basically no work.
  - irq 4y ago
    An air conditioner - even a crappy $200 window unit - will draw an order of magnitude more power than OP’s 50 watt refrigerator. You’ll need much more solar, either more panels or bigger panels (likely both).
    - fbdab103 4y ago
      Ah nuts, you are right. Cursory glance is showing smallest AC units at 450 watts. Still kinda-sorta-attainable by a couple of bigger panels, but significantly more capital expenditure when hoping to get some minor "free" cooling.
- adrianN 4y ago
  Joey Hess built one: https://joeyh.name/offgrid/fridge/ https://joeyh.name/offgrid/fridge/

fomine3 4y ago

Yeah, such cost is my blocker to install cheap solar panel on my home. On-grid solar system equipment is expensive but I don't have any good use case for unstable off-grid solar. If I drive e-bike, charging removable batteries by off-grid solar looks perfect use case, but I always drive a car.

ThatPlayer 4y ago
The solar inverter for my off-grid setup does allow for fallback to grid power if the solar and battery are out. So I would be able to do stable "partially solar" power without having to dump power back into the grid. Still not sure it's worth the cost, as you'd need a very consistent power draw to make a return, or batteries that make the return take even longer. Still a fun project though, and not something I built to make a return on.

Scoundreller 4y ago

I'm waiting for someone to build a grid-solar hybrid refrigerator/freezer that can attach to a 50w or 100w PV running at "low-voltage" ie: < 48V. No permit/electrician required, no grid-intertie inspection required. Modern fridges are often inverter drive, so should be easier to incorporate a DC power source. And they generally run all the time because they do variable-frequency drive. Best part, it keeps working during power outages. Extra points for putting on a USB charging port (only works during the day, but still!).

fbdab103 4y ago
I am waiting for the same, but with air conditioners. A crappy $100-$200 window unit, plugged into an equally baseline solar panel. Free opex cooling that could be installed for basically no work.
- irq 4y ago
  An air conditioner - even a crappy $200 window unit - will draw an order of magnitude more power than OP’s 50 watt refrigerator. You’ll need much more solar, either more panels or bigger panels (likely both).
  - fbdab103 4y ago
    Ah nuts, you are right. Cursory glance is showing smallest AC units at 450 watts. Still kinda-sorta-attainable by a couple of bigger panels, but significantly more capital expenditure when hoping to get some minor "free" cooling.
adrianN 4y ago
Joey Hess built one: https://joeyh.name/offgrid/fridge/ https://joeyh.name/offgrid/fridge/