Comment by abdullahkhalids

4 months ago

I heard that they are trying to restructure the billing in this way for next fiscal year (July 2026- ), but its really difficult to find a non-regressive scheme. Electricity per-unit prices in Pakistan are set by the government, they vary depending on how much you consume [1], and they play a pretty significant role in government popularity.

[1] There is a price for the first 50 units you consume, then a higher price for the next 150 units, etc. Similar system to income taxes.

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.

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    • 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.

    • > Wouldn't even a very cheap and small battery (definitely small enough to keep inside an appartment)

      Like namibj mentioned, this does not apply for residential contracts.

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