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Maybe this applies in normal markets, but in Puerto Rico the grid is both shit-tier reliability and horribly expensive. Rooftop solar and lithium batteries in

by rdl 8y ago

Maybe this applies in normal markets, but in Puerto Rico the grid is both shit-tier reliability and horribly expensive. Rooftop solar and lithium batteries in an off-grid format are both far more reliable and far cheaper than the grid, assuming a 5% cost of capital. I might throw in some LP or diesel generation capacity too, but solar plus battery is an easy choice.

nine_k 8y ago
Are lithium batteries the best choice here? They have superior energy density, but IIRC there are choices that are heavier but cheaper (per kWh installed), like ready-made car acid-lead batteries, or industrial Ni-Cd batteries. What do people actually use?
- vorpalhex 8y ago
  Not sure for Solar, but most HAMs using field radio setups still use deep cycle marine batteries as they withstand abuse and are much cheaper.
  - tjohns 8y ago
    The big benefit lead acid batteries have is that it's easy to find surplus SLA batteries from businesses, and even new cells aren't that expensive. That said, I've started seeing lithium batteries slowly catch on in amateur radio as the price on the LiFePo4 cells go down. Especially for portable setups.
- rdl 8y ago
  Tesla PowerWall is only an Apple-level premium (and not a Vertu-level premium) for what it is. I would probably just go with 1-4 of those for residential unless getting something more capable. I don’t own a house yet, though. My ideal situation would be a microgrid with 10-20 homes (in a compound/neighborhood or condo building) and some commercial/office, which pushes all the electronics costs down to something more reasonable.
RankingMember 8y ago
What would you say grid uptime (%-wise) is there for you right now?
- rdl 8y ago
  Depends on where. There are a couple of remote areas with no power still, but generally in San Juan and the areas where most people live it has been good in q2, with a couple of multi-hour outages. Still, at $0.35/KWh in a high sun place solar is obvious.
rm_-rf_slash 8y ago
That’s a good point. If a grid is unreliable then an off-grid solar investment would have to factor in the opportunity cost of things like spoiled food, productivity (can’t work remote with no power), amenity offerings (restaurant with A/C versus not) and so on.
dublin 8y ago
Of course. Islands are one of the only places where solar truly makes economic sense - having to ship your fuel in changes the economics equation a LOT...

by rdl 8y ago

nine_k 8y ago

Are lithium batteries the best choice here? They have superior energy density, but IIRC there are choices that are heavier but cheaper (per kWh installed), like ready-made car acid-lead batteries, or industrial Ni-Cd batteries. What do people actually use?

vorpalhex 8y ago
Not sure for Solar, but most HAMs using field radio setups still use deep cycle marine batteries as they withstand abuse and are much cheaper.
- tjohns 8y ago
  The big benefit lead acid batteries have is that it's easy to find surplus SLA batteries from businesses, and even new cells aren't that expensive. That said, I've started seeing lithium batteries slowly catch on in amateur radio as the price on the LiFePo4 cells go down. Especially for portable setups.
rdl 8y ago
Tesla PowerWall is only an Apple-level premium (and not a Vertu-level premium) for what it is. I would probably just go with 1-4 of those for residential unless getting something more capable. I don’t own a house yet, though. My ideal situation would be a microgrid with 10-20 homes (in a compound/neighborhood or condo building) and some commercial/office, which pushes all the electronics costs down to something more reasonable.

RankingMember 8y ago

What would you say grid uptime (%-wise) is there for you right now?

rdl 8y ago
Depends on where. There are a couple of remote areas with no power still, but generally in San Juan and the areas where most people live it has been good in q2, with a couple of multi-hour outages. Still, at $0.35/KWh in a high sun place solar is obvious.

rm_-rf_slash 8y ago

That’s a good point. If a grid is unreliable then an off-grid solar investment would have to factor in the opportunity cost of things like spoiled food, productivity (can’t work remote with no power), amenity offerings (restaurant with A/C versus not) and so on.

dublin 8y ago

Of course. Islands are one of the only places where solar truly makes economic sense - having to ship your fuel in changes the economics equation a LOT...