YHK - yet another hacker news clone

> Wouldn't the charge / discharge cycles reduce the life of the car battery?

While I'd presume the answer here is "yes", I'd also presume we're talking like a fraction of the vehicle's lifetime charge cycles. Like, (generously/conservatively) 20 to 40 cycles total over the life of the vehicle, no? How often would you estimate your power going out?

For something you (hopefully) don't have to do that often, it seems negligible. But ig you're charging and discharging the car daily to do arbitrage you might eventually notice the degradation

For something you (hopefully) don't have to do that often, it seems negligible. But if you're charging and discharging the car daily to do arbitrage you might eventually notice the degradation

Oil generators have an “artificially” low price because there’s a lot of demand for oil for other things. If the other sources of demand go away, the price may become unfavorable even if gas generators make a lot more sense from a redundancy perspective.

Yeah it's hard for batteries alone to compete with generators, unless we put a lot of weight on things like noise, or are just focused on small loads like fridges.

I think the more interesting comparison is generators vs solar, though it depends on the local weather etc.

There is something in between flashlights and a grid scale battery that van power your full electric home.

I just have a plugin battery that I can run the lights, fridges, phone chargers off of for 24 hrs. That is good enough for me, and I think most people. Anything shorter, and it's not necessary to run the rest, much longer, there also isn't because apparently shit hit the fan and we're not necessarily assuming the power comes back on in the next weeks or ever.

>I think a simple generator on an ATS remains undefeated from an engineering perspective.

Let me just inject a bit of nuance here to avoid what I think is an unintentional sleight if hand...

For the small sliver of the population that lives under threat of a large area week long blackout in a hot humid climate, I think a simple generator on an ATS remains undefeated from an engineering perspective.

For the vast majority of the population, it's incredibly rare to lose power for that long, and need AC 24/7 afterwards. It basically only happens in the gulf.

Assuming you have enough solar, how about running your 5+ ton HVAC system only when there is enough production? And properly insulating your home, of course, using it as a thermal battery of sorts.

If there is a grid outage, surely one can shift consumption to solar production hours while using the battery for the always-on systems (fridge, lights, some computing...).

Batteries alone are not suitable for long duration outages, but solar+batteries, designed correctly, can not only supply enough power during long outages, it can get you to be off-grid entirely in the first place at a dramatically more cost effective number than your $500k quoted - perhaps 1/5 or less for a system suitable for your needs of 115kWh per day. So while the system might be more expensive than a generator alone, it can still beat on value because it provides power all year round.

You also do an unfair comparison here - you are OK with portable batteries providing only fridge & WiFi for a couple hours, but expect whole-hole batteries to last a week. Many people use whole-home batteries to bridge typical outages that last <24 hours, and do so without ever having to notice any change of use of their home - powering their full heating/cooling etc.

Batteries and generators are also not mutually exclusive. You can install a solar+battery system because it makes economic sense and pays for itself while providing zero-downtime backup for most outages, while also backing that up with a generator for longer term edge case outages eg long extended outages during the winter or where there is an unusually long “solar drought” - it really depends on how much resilience you are designing for.

I’ve been looking into a smaller scale option to run limited items medium term on part time hours…

Best option so far involves a mix of batteries that are charged from the mains when available and topped up from a mix of solar and a LPG/multi-fuel generator.

But unless you want to go very large on the solar and generator size it’s unlikely to cover everything full time.

I have 18kw of solar and 30kwh of batteries with a 5ton ac it will run it will run indefinitely assuming the sun comes out, if it doesn’t I have a chargeverter that can keep the batteries charged off my RV’s diesel generator or gas portable.

My solar system generates excess power daily and has zero maintenance, the generators are pure money sinks for backup power and require regular maintenance.

Options are nice.

Also heat pump water heater and dryer help reduce load along with efficient variable speed hvac and good insulation.

Fuel is a problem during a storm too and a buried large propane tank is a good way to go but very expensive on top of installation.

An electric car with bi directional charging would add to flexibility either charging from home system or being able to go find power and bring it home.

How about reducing energy use? In general, but then especially after a grid-destroying event that keeps you offline for a week? You surely don't need to have everything HVAC running on full blast in the whole house during that time. And your laundry and next oven long cook can probably also wait until the grid power is back.

If you then add some solar into the mix, it doesn't sound as dramatic anymore.

And then after a little while you can be without power AND stranded!

CHAdeMO had that spec, but of course is obsoleted now.

If I understand things correctly tho many of the V2L solutions just work with pretty much any car that does CCS, regardless of whether the manufacturer officially supports this or not. My Polestar2 for example doesn't official have any kind of V2H/V2L option but I've heard of many success stories.

Why shouldn't utilities pay for this? You're provide grid load balancing. Theoretically their pricing should be considering this? It's not actually free to you since charging and discharging your battery costs money.

But naturally the situation is they want to be the ones paid the big bucks for such services.

Why? That's the entire point of moving towards dynamic tariffs. In the systems I'm familiar with the utility company makes money through a fee charged on top of the market purchase/sale price, much like an investment broker.

Maybe. I did the math and in our area a Powerwall would roughly pay for itself over the speced lifespan of the device, IIRC that was just the cost of the device not the cost of installation. I did that calculation ~4 years ago, so maybe it has changed, but definitely do the math, I was surprised.

LiFePO4 are much more robust against thermal runaway, omit a lot of the expensive materials that are in typical Li-NMC batteries, and have a better cycle life. They still can't be charged below 0°C, they have worse specific energy, and they generally can't handle the same peak power output, but they're a better choice for fixed storage applications IMO.

> I have an islanding system for my (house) battery and solar, so in theory, I could have a bidirectional charger whilst being off grid. However both my car and charger don't support that (my charger is also deeply shit, and has no local API access

...

> The amount of sysadminig to make that work reliably means that no normal person is able to achieve it. The problem for consumers is that there isn't any motivation for manufactures to work together on this. because they want to vertically integrate.

We are in a very similar position. The issue is every company in this area is like you say: deeply shit with limited local API access. Setting up bidirectional charging in the UK is technically, really not that hard, especially with islanding handled at the household level.

Good luck trying to get someone willing to put their career and certifications on the line to actually do it though.

Part of the challenge is finding an electrician willing to thing like a sysadmin and do things because they know how they work, rather than only doing things they've explicitly been taught as in line with regulations.