Grids in Germany if you're not a "typical household/office" with therefore atypical grid usage bill for peak power and energy separately; the billing related peak power is measured by averaging power over 15 minute chunks, and taking the worst one of a year.
Alternatively it's also practical for such solar situations to bill for market rate price of the energy in each 15 minute chunk separately; this doesn't correctly attribute transformer and other transmission equipment expenses between solar houses and non-solar houses, but it's still handling the grid tie solar load on the grid's power plants during periods of very little sun.
> averaging power over 15 minute chunks, and taking the worst one of a year.
What an interesting metric. Wouldn't even a very cheap and small battery (definitely small enough to keep inside an appartment) provide enough smoothing to, like, halve this peak number? You could rig it to not even output energy until you are beyond the current year's peak usage... How much money would you save this way?
I just feel this number is so prone to small mistakes (grandma plugs in the wrong things at the wrong times) and hacks (like the above) that the relationship between users' reward/punishment and the grid's health seems wildly disproportionate.
> market rate price of the energy in each 15 minute chunk separately
I am currently on a plan with 5 minute market rates, can buy and sell in (sell prices can go negative - as can buy, actually), all automated. At least I feel we am working with the grid, not against it, and we make a small net profit (before depreciation).
> relationship between users' reward/punishment and the grid's health seems wildly disproportionate.
It's still much closer to the real costs for the grid operator than $/kWh. The fundamental problem that rooftop solar has revealed is that people think they are paying for the electricity, but they are not. Electricity is dirt cheap. Most of what they are paying for is the maintenance of the grid, and simple usage based billing crushes the system because of freeloader problem once rooftop solar is added.
Long term, the likely thing you pay for will be the size of the main fuse that connects you to the grid. Because that's the thing that scales with the costs you impose on the operator.
Actually the local cost is not the fuse size, but how much smaller the first transformer after you could be if you weren't there.
Though it's often more fair to determine such for each user; then take those as a relative scale, then split the transformer's actual TCO by the determined share sizes between the users. Because the first user needs the transformer to it's peak size; the second only by the instantaneous-added peak size, which is lower as they won't use it peak at the same time.
> the first user needs the transformer to it's peak size; the second only by the instantaneous-added peak size
Of course, how does the electricity company determine which user was first in this situation. A tariff that depends on the order of connection may not be practical for domestic situations, although it may be OK for very large users, e.g. factories, data-centres.
Using fuse size seems a more reasonable and fair proxy for cost, assuming the same load patterns as the rest of the users. Then again, consumers with EVs might argue that their load pattern is different to the average user (e.g. filling up with off-peak electricity). Also consumers with air conditioning might argue for special treatment given their usage correlates with solar output (except where it does not).
You don't; you let the second one pay more than what the marginal cost was, in order to make the first one not pay so disproportionally.
That only has to happen once there is a second one, though.
Punishing a mere "large enough to not worry about popping it" fuse by billing shared infrastructure based on it (not just billing the stub line from the main in the street to the fuse/meter box in one's home in relation to what wire gauge is needed based on the fuse choosen) is pretty stifling.
If e.g. your furnace fails in the middle of the winter and the repair guy tells you it needs replacing, you might want to get some space heaters and run them for a few days until your actually-wanted new furnace/heatpump/whatever can get delivered, instead of having to get installed whatever the HVAC guy has in the local storage, because if you wait more than on the order of 12 hours, you'll start to get frost damage from pipes and such.
Having to be beholden to an electricity company having time to upgrade your fuses on such short notice so that you can plug in the space heaters without blowing them might be a problem.
But paying say 300 bucks extra because you did that for like 3 days or so would easily be cheaper than the cost of temporarily installing an available loan furnace and then having to remove it again to make way for the actually-wanted one.
They do though bill you if you make them dig the street up to say pull a medium voltage line into your factory that previously just got low voltage from a shared street transformer, but now that you've plans to use a lot more, you'd need the higher feed. Then they bill you and if within like 10 years or so someone else orders service that can piggyback on what capex you paid for, then you'd get a proportional refund from them having to pay off part of your share.
But that's not for just getting normal basic electric service to a normal residential building in a city, that's for building a new farmhouse on the other end of some field where there never was electricity, or for getting unusual service that wouldn't be in the street if you didn't request it.
Merely sizing the transformers/substations to handle the aggregate current of the users attached is not typically handled by the above mechanism, especially because it only covers initial buildout.
This is how it works in Japan for the newer rate plans for consumers now (replacing the previous method of charging you based on the size of your main breaker), but checked in 30 minute increments rather than 15.
The steps are pretty coarse - on my rate plan there are just 3 steps: 0-10 kW, 11-15 kW, 15 kW+. You're not going to surpass peak 10 kW in an apartment anyway.
It's legacy tactics; against the hacking the comparable thing for internet connections has historically been iirc 5 minute chunks and then taking the 95th percentile (like, charging not the highest, but the one 5% away from the highest). Not sure about the 5 min aggregation tbh.
The 15 minute chunks are due to the German and much of the European grid market being in that chunk size.
I don't think it's necessarily impossible to get that billing model as a household; it's just not an interesting one to have as it's not competitive for the usage patterns of a household.
Alternatively it's also practical for such solar situations to bill for market rate price of the energy in each 15 minute chunk separately; this doesn't correctly attribute transformer and other transmission equipment expenses between solar houses and non-solar houses, but it's still handling the grid tie solar load on the grid's power plants during periods of very little sun.