by @edent | # # # | 5 comments | Read ~1,250 times.

My solar panels deliver pure Direct Current electricity into my house.

All my house has Alternating Current circuits. Therefore, I need an inverter to change the DC to AC. This is inefficient.

Most of the electronic devices I own are powered by DC. So I plug little wall-warts into the AC sockets to convert back to DC. This is also inefficient.

One of the DC devices I'll be getting soon is the Maslow Battery. It's like the Tesla home battery. A several kWh array which can power my home once the sun has gone down. It discharges via AC. Again, another inefficiency.

  • Solar Panels - DC-AC
  • Maslow Battery Charging - AC-DC
  • Discharging into the mains - DC-AC
  • Powering a phone, computer, TV, etc - AC-DC

Generally speaking, inversion is around 95% efficient. Worst case scenario, that's an 18.5% loss of energy through inefficiency.

Now, it's not all doom and gloom. The Maslow battery has a dedicated DC circuit which can power light and some USB devices - that takes us down to a 10% loss.

It Doesn't Have To Be This Way

Those of you who've studied history may recall "The War of the Currents". In the early days of electricity there were constant arguments over how electricity should be distributed - AC or DC? Think of it like the iPhone/Android war of its day.

There were lots of scare stories over AC (used in the first electric chair) and DC (you won't be able to let go of the wire) - but both are equally deadly if mishandled.

Eventually - and I'm simplifying - the world settled on AC for long distance transmission of electricity. It's perfect for keeping polluting power plants away from residential areas. For general use in the modern house, DC is far more practical.

Can we change the world? Would it make more sense to carry on distributing AC power - but have every home use a single, efficient inverter?

There are a few devices in the home which would still need unadulterated AC - fridges, cookers, vacuum cleaners - which can still run off the power supplied to the home. So perhaps we still need dual circuitry in our homes.

Consider these plug sockets which you can retro fit -

But that's still using lots of small inverters rather than one big one.

And it uses the older version of the USB standard. USB C will allow for 100W to be delivered via a standard cable. So you can power laptops and TVs, as well as smaller devices.

Perhaps, in the glorious future, all our power-sockets will be USB-C by default - with a few legacy AC connections for older devices.

USB-C UK Power Socket

Isn't that what we want? An efficient transport mechanism transformed once into DC for the devices which need it?

Ah well, a boy can dream, eh?

5 thoughts on “AC DC AC DC AC DC AC DC

  1. I love the idea of having USB-C sockets around the home, with the occasional traditional socket - strategically placed, for the heavy duty appliances. It's nice to imagine a future where we don't have to carry PSUs around with us because we are able to plug our electronic devices directly into the wall with a single, standardised USB-C cable. Imagine how much pain this would take out of international travel too.

    Of course, the costs of upgrading all those billions of sockets would be huge and who knows how long it will be before the next iteration of USB arrives - making our USB-C sockets obsolete?

  2. Andorin says:

    The photo of the 20V@5A socket... is that an image of a real product that exists on the market? I've been trying to find one but can't.

    1. Terence Eden says:

      Sorry my friend - I photoshopped that image.

      1. Andorin says:

        You should find someone to make one! I'll be your first customer.

        1. Oleksiy says:

          the only product in EU I am aware of:

Leave a Reply

Your email address will not be published. Required fields are marked *