Comment by zaarn | Hacker News Reader

Comment by zaarn | Hacker News Reader

I've been looking into a bit of DIY solar lately. Not for powering the house but for lights and other low-voltage (9 to 24V) tools, probably even charging my laptop if I find a good adapter and a voltage regulator that can handle a few amps.

Handling DC is much easier than AC here since you don't need to keep the grid in sync with the inverter and you win efficiency due to not needing the inverter either.

I'll probably switch out all my lamps for LED strips, RGBW and controlled by arduino, so I could light up the house purely from solar without having to think about the grid, store energy into a battery and get light overnight too. The efficiency of the LEDs would help reduce power usage too.

I think about 200W should be peak usage if I do everything and charge my laptops and use some tools like my soldering iron plus the wifi router. Should be manageable at 24V (10A cables aren't too expensive). If all else fails, go to 48V.

I looked into this some and found some of the most useful advice was for people going to Burning Man. For example: https://www.theplayalabs.com/shopping-list-solar

My understanding is that for anything big like a fridge (even a minifridge) the efficiency and reliability of standard well-optimized 120V AC appliances means it's worth it inverting to AC instead of sticking to DC. Lots of RVs use/used 12V DC systems so things are available, they're just not very good. Inverters are very efficient these days. Plus it's really helpful to have a way to run AC things you already have if you need to.

Though if you only want lights, I do see how DC could make more sense if you can either find or DIY the right electronics to handle the voltage issues.

I'll probably not hookup fridges or anything large like that. My laptop would be fine, it uses a switching power supply to 19V (though it charges of 12 to 24V just fine).

Most of what I want to power basically uses a power supply to go to DC already including router and wifi, so it's not a problem, I just need to either find the right DCDC converter or solder one myself (I'm confident I can solder something together that should be able to hold 4 or 5 amps, above might need thicker copper plating on the PCB).

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