... during daytime, in summer.
Or did you install a load of batteries, too?
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.
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:
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.
https://news.ycombinator.com/item?id=43751178
> 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.
And later the same commenter argues
> When that happens, I’ll get batteries.
If I have to get batteries one day, I sure as heck won’t get a whole years worth of energy. In summer I’ll only need enough to get through the night ( very little ). In winter I’ll obviously need more, and I would have to carefully look at how much the house is using and how much solar I’m generating, but something like one or two power walls would do it. In five or ten years that’s going to be cheap.
Solar and batteries works great in climates with highly predictable weather and where demand only exceeds supply during very short burst. Europe, especially the northern part, are prime example where this is not the case and where supply shortages can occur for months. This is the reason why a single month of energy can cost more than the collective sum of all the other 11 months, since market prices follows supply and demand. This is where government subsidies will hide things with government funded fossil fueled power plants (under the euphemism of reserve energy and grid stability), and they can also just straight pay citizens energy bill when the price hit certain levels. When the government is responsible for energy storage, the cost is placed through taxes or tax-related fees. A common red flag here is when grid connection fees start to become bigger than actually consumption cost.
In 12 months the 7.8kw system has generated smack on 8Mwh.
While the very short days, snow and cloud cover reduce output a lot, it still makes power year round.
It is not absolute zero, but it kind of close, and there is a large period that storage would need to fill. For Sweden it is also the inverse for the demand spike, with winter demanding more energy than during the summer.
November and January were 200kwh each, and October and February were 400kwh each.
So it’s very low in the worst of winter, but it comes back very quickly.
Using the power walls examples above, you then need around 10 units.
How and why does that change anything in any way?