4 ms·

I was just looking at getting a NG generator installed for my parents on the east coast, after watching these recent storms come through. I'd dawdled on this f

I was just looking at getting a NG generator installed for my parents on the east coast, after watching these recent storms come through. I'd dawdled on this for years, because it was just infrequent enough. Anyway, I also looked at battery backup systems (Tesla, Enphase, etc). Unfortunately, it seems they haven't reached cost competitiveness with the plain old gas generator yet. Not a lot of power density (time), and too expensive for the benefit in noise/fumes/etc. $15000 for 2-3 days worth of backup, compared to $5000 for installing a Kohler run of the mill NG unit, etc. I was disappointed -- was hoping that batteries were further along than they are. Anyway, I'm sure there's going to be a run on getting these installed for the next few months, so clearly there's plenty of time to think it over.

pfdietz 6y ago
An inverter that runs off the 12V battery in your car is very cheap. Get one, and an extension cord, and you have an emergency power source to cool down your freezer every few days.
- gregwebs 6y ago
  This is the approach I am taking (bought inverter, will test it out next weekend). I don't think you can really run this off the battery (it will be on the order of 1000 watts): instead you need to have the car turned on and will be essentially running it off the inverter. So it's essentially an inefficient gas-powered generator that you already have on-hand and you need to make sure you have some gas in the tank.
  - pfdietz 6y ago
    I don't think a freezer draws anywhere close to 1000W when running. Perhaps you are talking about a startup transient?
- pedrocr 6y ago
  That's one thing that's annoying in the current crop of EVs. Almost none of them support drawing power from the cars even though they have those huge batteries just standing there. I understand not wanting to add the cost of the inverter to every car but it seems it should be relatively straightforward to support external inverters that plug into the DC part of the CCS connector.
  - supernova87a 6y ago
    I think it's because the car companies don't want people meddling, draining their car batteries with poor power management and degrading the lifetime, and then coming to them and asking them to repair the damage.
- Tylast 6y ago
  Years ago, I installed a Tripp Lite inverter/charger along with two 120AH deep cycle marine batteries - all sitting on top of my fridge. I calculated that I can get a few days of power. Also have another 1500w inverter for emergencies. And I always ensure vehicles are complete full before any large storms. Losing all your cold food is expensive!
pedrocr 6y ago
You may be able to get back some of the difference by requiring less total power from your utility and thus lowering the power availability part of the electric bill that applies all day and all year. It's also possible to time shift energy from lower cost times to higher cost ones if you can get time of day billing. And then there's solar of course. I wouldn't be surprised that having that 5k in extra benefit from the system tipped the scales for a battery+solar system in a lot of places with a modest cost of capital.

pfdietz 6y ago

An inverter that runs off the 12V battery in your car is very cheap. Get one, and an extension cord, and you have an emergency power source to cool down your freezer every few days.

gregwebs 6y ago
This is the approach I am taking (bought inverter, will test it out next weekend). I don't think you can really run this off the battery (it will be on the order of 1000 watts): instead you need to have the car turned on and will be essentially running it off the inverter. So it's essentially an inefficient gas-powered generator that you already have on-hand and you need to make sure you have some gas in the tank.
- pfdietz 6y ago
  I don't think a freezer draws anywhere close to 1000W when running. Perhaps you are talking about a startup transient?
pedrocr 6y ago
That's one thing that's annoying in the current crop of EVs. Almost none of them support drawing power from the cars even though they have those huge batteries just standing there. I understand not wanting to add the cost of the inverter to every car but it seems it should be relatively straightforward to support external inverters that plug into the DC part of the CCS connector.
- supernova87a 6y ago
  I think it's because the car companies don't want people meddling, draining their car batteries with poor power management and degrading the lifetime, and then coming to them and asking them to repair the damage.
Tylast 6y ago
Years ago, I installed a Tripp Lite inverter/charger along with two 120AH deep cycle marine batteries - all sitting on top of my fridge. I calculated that I can get a few days of power. Also have another 1500w inverter for emergencies. And I always ensure vehicles are complete full before any large storms. Losing all your cold food is expensive!

pedrocr 6y ago

You may be able to get back some of the difference by requiring less total power from your utility and thus lowering the power availability part of the electric bill that applies all day and all year. It's also possible to time shift energy from lower cost times to higher cost ones if you can get time of day billing. And then there's solar of course. I wouldn't be surprised that having that 5k in extra benefit from the system tipped the scales for a battery+solar system in a lot of places with a modest cost of capital.