Comment by djhworld | Hacker News Reader

Comment by djhworld | Hacker News Reader

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Explained above, I WFH, single (no kids) and have an EV - but I don't use the car for commute etc so I can be choosy about when I charge the car and take advantage of the ultra cheap periods.

Fixed price advantage is you use power whenever you want. Your average unit rate is just the price on the tariff. Predictable and safe.

Agile price changes every 30 minutes, so you need to do a little planning. But if you take advantage of the cheap periods you'll generally come out on top. My average unit rate last year was like 16.5p p/kWh whereas the standard tariff was 23-24p, so some nice savings. There's also some risk involved - the price can go up to £1 p/kWh and a few days in winter in 2024 it did that for a short while (around the peak periods) so you have to take on that risk - and obviously being exposed to the world energy markets does mean you get exposure to stuff like wars impacting global markets.

I mean there's nothing stopping you from using lots of power between 4pm-7pm it's just you'll drag that average unit rate up to the point where it's probably not worth it. When I say "use lots of power" I don't mean like I sit in the dark between 4-7pm, it's just I avoid the big ticket power users like ovens, showers, cookers etc

Yeah, and the really important point is that you get to see the prices a day ahead, which is what makes it actually pretty easy to live with.

For instance, if I know it's going to be expensive when I'd be cooking tomorrow's evening meal, then I won't make something that would need a long time in the oven. And if it's going to be particularly cheap around lunchtime, then I'll plan to do a big load of laundry then.

I have electric heating, which I thought might be a cause of anxiety but it's not really worked out that way. The temperature in my flat won't go down by more than a degree or two with the heating off over the course of the sort of 4 hour price spikes you tend to see in mid-January. If it looks like it's going to be unusually bad, I could always raise the temp by half a degree beforehand, but in reality I've only bothered to do that maybe three times in the past couple of years.

Basically, it's just another thing to factor in when planning my day. No more of a hassle than checking the weather forecast or glancing at my calendar.

> Basically, it's just another thing to factor in when planning my day. No more of a hassle than checking the weather forecast or glancing at my calendar.

Sounds like an incredible hassle at a level I would pay hundreds of dollars per month to avoid. That sort of mental overhead is crazy to me. But I'm also someone who finds having a single event on my calendar for the day disrupts my productivity and mental peace to an absurd level.

Time of day billing is definitely the future for renewables though, once they hit a saturation point for the grid it's the only thing that makes any sort of sense. Perhaps residential is the last place it needs to happen, but eventually it will be the norm. I see it working more in an automated fashion though. Smart load centers (panels), smart appliances, etc. that are connected to the local power company's API. Then you set some rules around it.

Stuff like cooking dinner though? I cannot imagine planning my day around saving a couple bucks. That's just insane to me. Energy use and all this mechanization/automation/technology exists to make life more convenient in the first place! Stuff like EV charging, raising/lowering temps in anticipation of power pricing, laundry (dryer) scheduling, etc. seems to be where 80% of the wins can be made, and are all much more automatable to avoid having to think about it. That last 20% can simply be taken up by whole-home battery storage, which by the time any of this happens at scale will be pretty much the norm.

The thing that concerns me most though are regional "seasonal" events where a once-a-decade lul in energy production happens and there is simply not enough dispatchable power on the grid to meet demand due to everyone hyper-optimizing their loads in such a fashion.

> That sort of mental overhead is crazy to me.

I've been on the tariff for 2 years now, at first I was looking at the prices every day, but over time you get used to how it works and the price watching starts to tail off. The rule of thumb is just to avoid high load stuff during the peak window (load shift) - sticking to those principles you generally come out of on top. Playing the averages is the key.

Nowadays I don't really look at the prices that much other than when it's windy as I might be tempted to charge the car.

That being said though, if current world events continue and the energy situation degrades further - causing my average unit rate to start creeping up, I might consider getting a home battery , solar etc to compensate, or leave the tariff entirely.

Yeah, it's definitely a bit of a game for me, and my electricity bill was already low enough that the savings are trivial.

But I'm the sort of person who enjoys being flexible when planning my day. I'll fit chores such as laundry around work meetings. Decide whether to go for a lunchtime run (and thus have an extra shower) based on the weather and having an a big enough gap in my day. Buy ingredients for dinner based on the weather and how I'm feeling. Expected energy cost is just another factor in the mix - and one that only rarely becomes decisive.

The closest the UK grid has ever come to not being able to cover demand was a few years ago when most of our nuclear fleet went offline at the same time in the middle of a January cold snap due to the discovery of a potential maintenance problem in the steam plant. If there were to be a repeat of that scenario, then the spread of domestic dynamic pricing would actually help matters by driving load shifting behaviour.

Some people enjoy this sort of hyper optimisation, even if they don't really need to do it.

Bananas. I hope you do this because it appeals to you at some level.

> For instance, if I know it's going to be expensive when I'd be cooking tomorrow's evening meal, then I won't make something that would need a long time in the oven. And if it's going to be particularly cheap around lunchtime, then I'll plan to do a big load of laundry then.

That sounds like something out of a dystopian novel lol.

Imagine setting up a complex system like this where you have to plan your food choices around energy prices when people in other countries pay a fraction of what you do all day around.

A decade back, in the US, the local power company would give you a discount if you used less energy than average during peak hours. At the time I had a vacant rental, very little energy use. (FWIW I’ve since sold it, being a landlord isn’t a good time)

I watched a specific neighbor go through great pains to honor this system and so as to reap the benefits of a much lower bill. Sweating their buns off during the hottest part of the day, open windows, no tv on, etc. fully committed.

They saved 8 dollars that month. My vacant rental, not doing a goddamn thing, saved 6 dollars.

If your system is similar, you’re optimizing your life around the cost of a monthly Netflix subscription, at best.

There is an element of truth in that if you go to the extremes, where it's almost definitely not worth it.

I don't sit in the dark during the peak times, during the week I'm working during that time anyway and I still have my monitors etc on. It's just I don't usage high-draw appliances like cookers during that time. I eat dinner after 7pm anyway.

Also I have an EV, but don't commute or travel long distances regularly, so I charge my car when opportunity strikes, especially when the prices go negative - this means I don't really spend that much on fuel really. The savings really start to come in if you have "bursty" high energy stuff that can take advantage of the cheapest periods like an EV or home battery. If you just have "baseload" stuff that runs all day like A/C or whatever then yeah you won't really see any significant savings.

I contend you’re still saving the cost of a lunch meal… per month.

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