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The solar boom is rapidly transforming emerging economies (www.dw.com)
submitted 1 month ago by to c/energy@slrpnk.net
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[–] 2 points 1 month ago (2 children)

Whoops. I got it wrong, sorry. If we follow Victron's recommendations (4.8 kWh backup for 1.5 kWp generation) than for 6 kWp the LiIon backup (AC-coupled) would be pretty exactly 20 kWh. So your numbers are perfectly balanced.

The problem with just scaling up is that in winter months I can easily see 1/20th to 1/40th of PV nameplate during daytime, and such conditions can persist for more than a month. So without the grid as a backup the only option is diesel generation backup, or going entirely without any major power drain.

For low-consumer countries in the tropics the equation is much easier, since they're consuming less than Westerners in general.

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  • [–] 1 point 1 month ago (1 child)

    A model for Canada, does require enough solar for just 1 hour total sun to meet electricity needs (for winter). Backup heating necessary, but hydronic and heat pump (reversible heat/AC split units per room) is good use of fall solar to charge up a hot water reservoir that also gets recharged on sunny winter days. An EV that can charge the home counts as a backup heat source. This can mean much higher solar production for 9-10 months than you can use, but also means profitable bitcoin mining or GPU rental for that period. And/or free EV charging, hottub/pool heating, or other energy sinks that become free, off grid.

    Canada/Ontario has corrupt electricity system, with $50/month flat fee. So a $50-$100/month equivalent (5x above investment) off grid cost is a better energy opportunity/alternative especially including vehicle fuel savings, but also in new construction heating system cost savings. A fireplace or woodstove may be an arguable quality of life improvement, instead of just a heating appliance.

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  • [–] 1 point 1 month ago

    If I look at my DIY 2 kWp PV output right now (about noon), it's pretty much exactly 100 W. I'm going to double that this month, but it's still only 200 W then under such conditions. It's just not cost effective to overbuild that (physically, it's not even possible for me) to cover an average 24 h period during the darker time of the year. I'm lucky that my meter is old enough to be able run backwards, otherwise I'd have to invest a few kEUR into a battery backup, which still be no bueno for the winter months. Only hydrogen storage can load level seasonally, and that's entry level a 100 kEUR spend, and bleeding edge technology.

    I heat with locally sourced (why, last year was mostly from the own garden, and for the next year a neighbor just felled a tree, otherwise it's from a local forest close enough to walk to) so that's not an issue.

    I'm hesitating into investing into a split AC, though the heat spells are starting to be serious trouble. EV is right out of budget. In order to use the overcapacity from the future 4 kWp I'm thinking about running a local LLM.

    First world problems, I know.

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