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Comment by Gravityloss | Hacker News Reader

Having solar panels, batteries, heat pumps and electric cars could make society quite a lot more resilient to these kind of things.

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I just built a house with that. The one problem is that my heat pump uses so much electricity that it's impractical to put on the battery. The battery basically powers everything but HVAC and the level 2 charger.

is it a ground or air heat pump?

Air.

Ground heat pumps are very uncommon; "heat pump" is assumed to be air based.

Ground heat pumps are common here where there is large temperature variation. They are a more expensive investment but much more efficient.

%s/electric cars/personal electric vehicles/g. Cars are too inefficient. Right now our "power goes out for two weeks" contingency is the solar-paneled RV and a Honda generator. Neither the panels nor the generator can charge the car in a reasonable amount of time. The RV solar panels can charge the scooter (or electric bicycles) in the same amount of time as house AC (big inverter in the RV). It won't get you to the mountains to your remote cabin (that's what the RV is for <g>), but it's enough to get around town if need be, and can do so indefinitely.

On a related note, as I've researched solar panels for the house, it came as a surprise to me that by default grid-tied solar won't keep the lights on when the power goes out (nothing to sync to). So if one goes that route, don't forget the batteries and inverter.

The electric car is useful because in the event of a power outage, a decent one will have a 60KWH+ battery. Assuming it's even partially charged, that's enough energy to power personal electronics for weeks. You could probably even power a fridge, TV, and some basic household equipment for a week if you had a decent inverter.

On the other note, if you get grid tied solar you can use them if the power is down, but you need to buy an SMA inverter with secure power supply. The inverter will give you an outlet that will work if the grid is down, even without a battery system.

You're just doing a global search-and-replace and replacing with "big ass battery". :-) I take your point, but I was referring to transportation. As you point out, ride the scooter and use that big ass battery in the car for something else.

by default grid-tied solar won't keep the lights on when the power goes out (nothing to sync to).

Indeed, but some inverters have emergency outlets where they can supply power on a dedicated circuit as long as the panel output is enough. The amount of power is limited and it can't sustain any surges so it can't run e.g. motors, but having 1500W is tons better than having 0...

I've verified that my big-ass UPS that I use for the computer can run the refrigerator and be charged from this outlet.

That's an interesting thought. I wonder how many cars a charging station could handle in the event of a grid outage?

Wise people would use the power stored within the cars batteries?

Think the OP meant in conjunction with each other, I.e going off grid. Solar panels on the roof, a full power wall and an electric car. That’s enough to keep you going as long as you can manage food and water.

Or if you're rural, an external combustion engine of some sort, so you can keep the lights on with firewood.

You must mean steam engine.

Sterling engine, peltier chip...

You can find peltier chip phone chargers that work by being placed in or near a campfire.

Extract gas out of firewood to fuel the combustion engine? Doable but nothing without consideravle knowledge and welding tools. Unless you are prepared. A nice stock of heating oil (doesn't contain degradeavle components as regular diesel now at least in Europe) will also get you through for some time.

If you actually are rural, there are substantially better ways to do this. Most people who live in a rural area have 500+ gallon fuel tanks, either heating oil or propane. Even my mom has one and she's not a "prepper" or technically sophisticated or anything. With a properly set up standby generator (The diesel ones are super quiet) you could be rocking a month long power outage and not even know that the power was out.

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