Comment by Maxion
6 hours ago
Installation labour cost and inverter cost are now the largest expenses.
I wonder if as panel costs goes down, will people start to wire their homes again for 48V DC? You could conceivably run your HVAC and fridges at least off of it, this would negate the need for a larger (more costly) inverter.
Unless you build from scratch, and white box stores suddenly start selling a 48v version of every standard household appliance (with industrial supply chain to support that market), inverters are not going anywhere.
The only place it makes sense is personal tech and computing, where USB chargers are cheap and ubiquitous, with technology replacement in 2-5 years instead of 5-10 for standard appliances.
it would probably slowly start coming out as dual ac and dc connections and start with "garage appliances" like your laundry, central ac / vac and car charger since the garage is the cheapest place to wire something into.
I run my garden tools and shed on a 1.2kVA 12V inverter, bought for pennies off eBay. It's just about enough to run my little "lunchbox" flux-core welder on a low enough setting to do thin metal and tubing, perfect for sticking exhaust pipes and such together.
Fridges is doubtful. But HVAC... yeah i'd put that at increased possibility because you probably won't have to rewire your house to do it.
> Installation labour cost and inverter cost are now the largest expenses.
That's true for the solar development project, but such a project typically ignores grid costs.
so Edison's dream will finally come to be
Why not 120V DC?
Mainly thinking 48V as that is already a standard in the marine and automotive world. AFAIK 120V DC is not a commonly used standard ? (Maybe in aviation?)
Most modern aircraft have a 400V 360-800Hz three-phase grid, as this allows thinner (read:lighter) conductors. There are some high voltage DC rails on some plains in the range 270VDC or ±270VDC.
On the usage side for instrumentation, avionics etc. it is usually 28 VDC.
50V is the limit for "safe extra low voltage" rules. Considered to be touch safe.
It would be great to work on my home's electrical system without the risk of straight-up killing myself. Especially considering most of the things I plug into my wall (lighting, TVs, tablets, phones, etc.) don't need to draw anything like 120/240V. I've debated installing low volt circuits for things like lighting and such, but I think the hassle won't make it worth it.
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1. It is not considered safe voltage, so you have all the downsides of the current AC grid with the downsides of high DC voltages
2. Nearly no equipment uses 120VDC by itself, so you would need specialized DC-DC converters that can deal with the 120VDC input to go down to usual voltages like 48VD, 24VDC or 12VDC
> Nearly no equipment uses 120VDC by itself, so you would need specialized DC-DC converters that can deal with the 120VDC input to go down to usual voltages like 48VD, 24VDC or 12VDC
Most switched-mode power supplies ought to cope with 120V DC. If you look at a circuit diagram the first thing they go through is a bridge rectifier and smoothing cap to provide a 165V (or 340V outside the US!) DC supply for the chopper.
I have some Thinkpad charging bricks I'm prepared to sacrifice for the cause, if you want me to try it.
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DC also has issues with arcing, so switches get complicated and expensive.