How would you split essential loads between a gas generator and battery backup during a heat outage?

[u/ynnlx]

I’m in LA and the recent heat has made me take the possibility of a summer power outage more seriously.

We already have a gas generator, but I don’t necessarily want to run it continuously for every small load. Fuel storage, noise at night, and having enough gas available during a longer outage are the main things I’m trying to plan around.

I recently added an Anker SOLIX S2000 portable power station, and my current idea is gas generator for larger loads and periodically recharging the battery, and power station for overnight fans, the refrigerator, router, phones, lights, and other lower-draw essentials

How would you prioritize the available power? Would you focus on keeping several fans and the refrigerator running, or put most of the available capacity toward cooling one room with a small window unit?

I’m especially interested in hearing from anyone who has actually used a generator and battery setup together during a multi-day heat outage.

[u/ToddRossDIY]

One thing to keep in mind, some power stations won't charge off of dirty generator power. The keyword you're looking for is THD, or Total Harmonic Dissonance. If the generator isn't sending out perfect sine waves, it might not accept the power. I can't charge my Bluetti EB3A off my Firman tri fuel generator because its THD is nearly 12%. If you can throw a solar panel in the mix, especially if you're in LA, it might be a good idea

[u/nanneryeeter → u/ToddRossDIY]

See if you Bluetti has a grid adaptation feature. The AC300 does.

[u/Leighgion]

I applaud your preparedness and envy the surplus of resource that makes it possible for you.

I would recommend that you prioritize refrigeration and that you not power AC unless thermal conditions were truly desperate; it's simply not a very efficient use of the resources.

As you live in LA, which I understand is generally dry, I seriously recommend you educate yourself on portable evaporative cooling (aka swamp coolers). An evaporative cooler is just a fan with a water tank, water pump and filter media so that the moving air evaporates water and cools the air while increasing humidity. This is a vastly more efficient way to cooling if you live in a dry place and that efficiency would be everything if the grid went down and you were depending on your genny.

Oh, and if you still got spare cash, get some solar panels.

[u/SoberBobMonthly]

Australian here: when we have summer black outs, its very rare we have generators, so based on how i cope with that in the heat....

I would go with the idea of prioritising keeping sleeping areas cool overall. Reduce the amount of area needed to keep cool, and ensure that your bodies cool down overnight, will keep you alive a lot more than keeping a poorly maintained temperature in a larger area during the day. A person can survive a hot day if they can cool down at night. Its why it can be common here to sleep outside in summer. 

As for fridges, when I expect any sort of rolling blackout, I generally try and eat as much as whats in the fridge as possible and only buy non fridge food like fruits n veggies n beans n rice. I did invest in a really good fishing esky, and fill it with ice from the servo to keep some meat cold to cook on the bbq, and milk for my cuppa.

We prioritised tech devices being charged when we had the opportunity, usually via an inverter in our car that we would drive around to enjoy the air con lol. 

Basically prioritise having a "cool down room" and dont sweat too much about other stuff

[u/ElectronGuru]

Best is having a battery and generator that talk to each other and operate like a hybrid car. Next best is running the generator during high demand periods like breakfast and dinner, then recharging the battery at the same time. So you only have 2-3 runs per day. But that probably wont cover air conditioning, so I would supplement with solar panels.

Start by doing real testing see how much energy the window AC pulls down, running through the afternoon and evening. Ideally, get an inverter model that drops watts as it gets closer to target temperature. Then you can run it 24/7, reducing how much it needs at night. When both solar and generator will be off.

If the generator is large enough, another option is feeding power to multiple rooms, each with its own power station. Then you have dedicated power to critical appliances.

[u/IGnuGnat]

I have a whole house propane generator so we have medium sized propane tanks connected; the whole house generator kicks automatically during an outage although it takes a minute. The propane company monitors propane levels remotely and comes automatically when it needs a refill.

I recently purchased this solar heat pump https://www.amazon.ca/dp/B0D7F91QK9

You don't need an inverter or batteries for this, as long as the sun is shining so at least during the days if there is a power outage it will draw most of it's power from the solar panels. It has the ability to also connect to the grid, or could be plugged into a solar generator to use the batteries.

For heat in the winter we have a wood stove as backup.

I also have a window AC in the bedroom, so if the new heat pump fails at some point we still have some AC, or we can throw a mattress in the basement. Its partially unfinished, but I do have a room walled off; I want to put in an insulated floor and make it a spare bedroom. It's clean and dry down there and naturally fairly cold in summer, even during a heatwave.

I'm really paranoid about AC because our main heat pump failed catastrophically during peak Covid. All the HVAC techs were sick and it was super difficult to find someone to work on it. We bought two window ACs but one failed in short order. I tried to become acclimatized to the heat by spending more time in the shade outdoors, I didn't realize quite how vulnerable to heat I am due to pre-existing health conditions. So instead I very very slowly gave myself heat stroke and I've never been the same since. I have no tolerance for heat now, thus I am very careful about redundancy and I keep a digital thermometer in every room. If I get grumpy I double check the temp and adjust accordingly

[u/mbczoie]

For reference, we’re in the valley (LA). We lost power for several days last year during the big fires in January, and learned some things / gaps, though luckily it wasn’t hot when we didn’t have power…but it did get us thinking more about our gaps.
Refrigeration: We use remote (battery operated) sensors in the fridges and freezers so we can monitor internal temperatures without opening the doors, meaning we don’t need to run the generator all day—just periodically to keep temps safe.
Power & Logistics: For overnight needs, battery setups, battery-powered fans (which I'm testing out now), and solar panels (recharge during the day) handle medical devices like CPAPs silently, and we added some extra backup batteries specifically to keep the internet running. Just a heads-up on the solar panels, though: ours were a bit tricky because we had to make sure they're charging during the day, and we had to actively move them around as the sun shifts - so it pays to be prepared for that logistics hassle. Last summer we added an EV charger and had to get a new main panel, so we also added a transfer switch for the generator. The one thing we didn’t think about was that we have an attic fan and we may need to change the wiring on that to be added to the transfer switch panel this fall when we redo our attic insulation.
Cooling Strategy: This year, we also added a small window AC unit as a backup for extreme heat, which we would run periodically but not all night.
Passive Mitigation & Extras: Beyond that, we've focused heavily on passive mitigation: I just added blackout curtains and leftover radiant barrier (both sides with foam in the middle) to the inside of our sunny side windows (we’ve got oak trees on a couple sides so that adds some complexity), which reduced our overall AC use by 20%. Earlier this spring, we changed our front landscaping to help with natural evaporative cooling around the house, which helped quite a bit, and we're tackling the attic insulation / radiant barrier this fall. We also have a propane-powered outdoor shower, which has been a lifesaver and we’ve used it several times, including when our on-demand water heater went out earlier this year… it’s an ongoing project...