[testing22321]

We use the grid like a battery, getting a one for one credit for everything we put in. So during summer/daytime we put in enough to then use up our credit in winter/nighttime.

The power we put in even covers the monthly connection fee.

I’m just about to hit 12 months with mine, 8 Mwh generated, never paid a bill.

In our area the cost of electricity is already Confirmed to increase 5% a year forever, so this will only get better for us.

[belorn]

Subsidies like one for one credit are generally going away since those are prohibitively expensive and not sustainable when the ratio of renewables start to climb. It can be useful to jump start adoption, but having the government pay the true cost of the grid only moves the energy bill to the tax bill.

[testing22321]

When that happens, I’ll get batteries.

[tasuki]

You'll need a lot of batteries. It might or might not be economical, but definitely not ecological. So... depends on your values and goals.

[bryanlarsen]

Compared to what? Yes, batteries have ecological costs, but compared to fossil fuels it's minor. Home storage batteries will likely be LFP which are all abundant and recyclable.

[berdario]

A Tesla Powerwall3 (which apparently uses LFP) has a capacity of 13.5kWh

A household uses up at least around 2MWh per year, most of which during the winter, if you don't use air conditioning in the summer and don't have an electric car to charge.

That means you'd need around 150 (!) Powerwall 3 units. At a price of around 10k GBP each, you'd have to shell out more than 1 million pounds just for the batteries. Not to mention the space that they'd have to take, and the increased risk in having something failing.

In the USA, homes are even less efficient (and depending on locale, people run AC all year round, and drive tens of thousands of kilometers on cars which also need to be powered). 2 years ago MKBHD published a video about his experience with the Tesla roof:

https://youtu.be/UJeSWbR6W04

In it, he revealed that his yearly power consumption is 55MWh. His battery was able to tide him over the next cloudy day, and during the winter the solar panel wouldn't ever fully recharge again.

Expecting every household to be energy independent year-round via solar is patently absurd. Renewable energy tided over with massive batteries upstream? Maybe that could work, I haven't run the numbers... But you cannot hope to push that responsibility downstream to every household. Reliable baseline is still going to be necessary for the foreseeable future.

[hiatus]

Why would a household need enough batteries to store a year's worth of energy?

[tasuki]

This is unsustainable: you deliver power when its real market value is close to zero, and you want to take power out of the grid when its real market value is large.

[morcus]

I don't follow - where I am, peak demand seems to be in the summer during the day when everyone has air conditioning on.

[LunaSea]

Sure, but everyone else with solar panels will produce more than they consume at the same time as you.

[tasuki]

Good. Then you can live off grid actually! "Using the grid as a battery" is the unsustainable part.

[morcus]

That is not at all what I said. Thanks for the snark, though!