Does anyone happen to have a Prius Prime & live off grid? Need insight, tia!

Discussion in 'Prime Main Forum (2017-Current)' started by MMBH, Nov 14, 2020.

  1. MMBH

    MMBH Member

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    I was wondering if anyone lives off grid with a Prius Prime.

    Once we retire, I hope to move off this god-forsaken county highway/cutover road that we moved to for a better school district when my teenage son was in high school.

    [I cannot wait another moment to move off this road to our property on a dirt road in a rural small town off the beaten path, that we have owned for decades now. Although, the issue we are faced with is that it's cost prohibitive to run grid power to it, not to mention the easements for multiple properties in between that falls on us to obtain! Got to love National Grid (sarcasm, ;< ) - but I've digressed!] And now back to my original dilemma.

    Hence, using net metering is not going to be an option in this scenario, and as I have a 2017 Prius Prime, and am wondering how much more solar one would need just to charge the Prime.

    (Also, since this pandemic hit, so I haven't really driven anywhere and haven't kept the car plugged in and I've seen that it's really brought down the monthly electric bill daily usage and subsequently the amount of the bill - although the delivery rate is insanely higher than the actual electric we are using and paying for. How is that even allowed? It seems like it should be a percentage of what one uses. I really hate paying a greater group rate and subsidizing those that are using more. Unlike businesses, we do not get to write off any utilities. But that's a separate soapbox for a different forum I guess. So back to my dilemma and inquiry related to living off grid with a Prius Prime.)

    I was hoping someone here on the PC group might be living off grid in order to try to find out the pros and cons of being off grid with a Prime, as well as find out how much bigger a PV system was needed; as I'm guessing I wouldn't really need additional batteries for the system as it would be going into the batteries of the Prius primarily while anything additional would just go to the battery bank that we will have set up for the off grid residence.

    So… my question is … would I be better off using it just as a regular Prius off grid instead… or …
    does it make sense to invest in a solar PV system to supplement the PV system we will have for the residence? (I'm also kicking myself in hindsight for not keeping the 2004 Prius prime and using it as a battery bank of sorts seeing as we had RVs with solar at that point and probably could have used the batteries from it for a solar storage bank! Maybe when the 2005 Prius starts needing too much money invested to keep it running, we will do that with that one, now that its on my outside the box radar! But again-I digressed!)

    Please advise and thanks in advance!
     
  2. ForestBeekeeper

    ForestBeekeeper Active Member

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    I have a farm that does have access to grid power, but we live in an area where the power grid is not reliable. So we also have solar-power powering our home with a battery-bank. With a flip of a breaker, we can be on-grid or off-grid.

    I drive a Prius Prime plug-in that recharges from our household battery-bank.

    With a full charge, I can drive into town, and back home again before the vehicle battery runs out.
     
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  3. MMBH

    MMBH Member

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    TY for your reply!!!

    Question #2 - Can I ask what size Solar PV and battery bank you have?
    [I know it's not exactly "apples to apples", but I'm curious as to what size I might want to start looking for quotes to see if we will need to go up (or need to go down) in sizing of the PV array and battery bank storage. I'm not against using a generator if necessary, but just wondering if I need like a 10K PV system with maybe only a 4K battery bank for the residence.)]

    The average for the last 13 months was just shy of [correction: (28)] KWH a day, but that is with me not driving much these last 8 months (since the pandemic started, I've been working from home and not going out very much. Yet, I think it will be similar to what I'll be driving when retired.)

    TAIA!
     
    #3 MMBH, Nov 14, 2020
    Last edited: Nov 15, 2020
  4. Trollbait

    Trollbait It's a D&D thing

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    Have no experience with the Prime or being off grid, but if you planning going off grid, getting a Kill-a-Watt now would be a good idea. it is a mini electric meter that plugs between the appliance and the outlet, so you can directly measure what energy amount they are using, including the Prime. It isn't expensive, and I am sure there are other brands.

    With details on what amount of electricity is going to which appliance, you can make a more informed decision on what you need for PV panels and batteries.

    I'm assuming city water and sewer isn't available at this property. if you are on those now, you'll need to factor in the consumption of a well pump. There are solar options that would use their own panels. If there is a hill on the property, or if you are willing to put in a tower, the pump can fill an elevated tank during the day. Then gravity supplies house pressure, so you don't need to run the pump off the battery at night.
    The lost opportunity... Solar Deep Well Pump | PriusChat

    "I'm not against using a generator"
    A poster that was off grid years ago recommended just using a portable generator for high draw items that were infrequently used, like power tools. Though that was before panels and and batteries had come down in price, and there is now a wide selection of cordless drills to lawnmowers to vacuums to choose from.

    There are also options besides solar, Eco-friendly hydropower from whirlpools | PriusChat
     
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  5. m8547

    m8547 Senior Member

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    Are you using 39kWh a day? Or generating that much? That sounds really high. I don't think you can use usage at one house as a baseline for what to expect at another, because the large energy wasting devices will likely be completely different.

    I don't think we can answer your question without knowing how much electricity you'll use at the new property, and how much energy the existing solar generates. But if you're careful with your usage, you can almost certainly charge the Prime some of the time.

    It also depends on your expectations. Do you want 24/7 uninterrupted electricity? Or are you OK with running out occasionally? Do you have a backup plan like a generator for cloudy weeks?

    The ~6.5kWh it takes to charge the Prime is not the largest demand in a typical home. For example, things that use more energy (each) than my 30 mile commute include my dehumidifier, my electric water heater, and my air conditioner. Of course in an off grid house you will probably be more careful about large electricity demands.
     
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  6. Trollbait

    Trollbait It's a D&D thing

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    Depending on priorities, there are other options. Propane for heating and cooking is one, and there are fridges that run on that fuel. there might even be propane fridges that also use solar heating to run.

    Invest in insulation, as that will reduce heating and cooling demands. Even look into solar thermal storage like used in a passivehaus.
    Passive House Institute US (PHIUS)
     
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  7. MMBH

    MMBH Member

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    Apparently that was a typo for the average daily usage: it was 19799 kWh usage Jan 2019-Nov 2020, as per my utility bills. So if I divide 19799 by 699 days calculated, it comes up to just shy of 28 (not 39) kWh daily …. but there were days that were that high or higher if I use the highest monthly usage noted divided by the number of days for that month… and the usage was higher last year when I was plugging it in daily. Since I haven't been using its very much since March due to the pandemic, it's been unplugged more times than not this year. But from my account usage for the last 23 months, the highest monthly usage was a high of 1494 for May 2020 and a low of 325 for March 2020 (actual vs estimate; as they estimate it every other month and then read it the following month.)

    Yes, thanks, I do realize that I need to know how much energy the various items we would consider taking with us would be using energy wise. But I was trying to get an idea how big of one I need just for the Prime to be charged. I also think a lot of the energy difference being used has been for charging the Prime. I also haven't had it plugged in consistently the last 4 months or so, and I do see a difference in the average amounts between this year and last and have been working from home too, so I may be adding to the daily usage on the other side of the coin as well (plus, it was interesting that the most extreme differences seem to have been this year vs the prior year. I also know that our prior house which was electric everything, used less electric than we seem to be using here in this house we moved into back in 2014. We had figured out we could get away with a 4.5 K system back then, and that was with electric heat backup to our wood stove, electric water heater, electric stove, electric dryer (which we didn't use it all that much because we like to hang them out on the line whenever it's possible, and also hang them out here as well); but we probably do use the dehumidifier here more than in the first house, as this one has a dampness/humidity issue.)

    So that said, I know we will have different energy consumption and will need to utilize more of it during the day if we are overproducing what we are storing, or conserve energy when it is not as sunny out or producing as much. I also am aware that we should try to match production to consumption as closely as necessary and that we can afford, to avoid having to run a generator, but I am not against using a generator, but would like to limit it as much as that will be possible. It's all going to depend on cost of system which depends on the size needed and that we can afford.

    The other unfortunate issue is that the solar incentive decreases next year and then if I understand it will be phased out. so we really have to get it started and installed next year, otherwise we might have to skip the off grid build, sell the property and buy something elsewhere.

    Thanks again for your input!!! :)
     
  8. MMBH

    MMBH Member

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    *****************************************************************************************************************************************************
    We do have the Kill A Watt!

    We dug it out of storage and are working on getting a better idea of the appliance usage for the usual culprits.
    Although, I'm confident there's vampire draw going on as well too that we will need to resolve with power strips and such eventually here!

    Also, correct, it will be a well as well there! I am open to the idea of using a holding tank, but not so sure my hubby will be, as he loved the well water at our original house (as did I too) plus, it was always cold!

    I will definitely check out the links you included!

    Thanks so much!!!
     
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  9. MMBH

    MMBH Member

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    True! We are already considering propane for water heater and cooking, as well as to supplement a wood stove for heat!

    We will need to look into what options will work best overall for the freezer and refrigerators.
     
  10. ForestBeekeeper

    ForestBeekeeper Active Member

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    We have 4400 watts of photovoltaic panels, our battery-bank is 48vdc @ 600ah.

    We found that starting at 8am we could power every power tool and every kitchen appliance we owned and still put a charge on the battery bank. But once the sun goes down even the electric coffee maker was too much of a load.
     
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  11. MMBH

    MMBH Member

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    Q3 -

    Did you go with LIFePO4 batteries, AGM or plain old auto-type batteries?

    Also, did you install the PV and battery system yourself?
    If so where did you purchase through? or...
    If not, who did you use as the installer?
    (We are in NY but possibly they would be willing to consult, etc and work with a local electrician here.)

    Thanks again for all of the info!

    PS- I attempted beekeeping myself about 15 yrs ago, and had kept them alive the first few years, but I never seemed to have much success - probably because I didn't treat them… Although, I will say that the flow hive frames were a great invention and I did finally get some honey harvested after I started using those! So maybe in retirement I will be able to have time to get back into it and build back up beyond the single hive we have currently (which were free, as a swarm moved into a hive in May that had died out over the winter the year prior.)
     
  12. ForestBeekeeper

    ForestBeekeeper Active Member

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    We are using lead-acid deep-cycle marine-grade batteries.

    I installed everything myself.

    I sourced our panels from SunElectric. Sun Electronics &#8211; World&#039;s Lowest Solar Panel Prices

    And the Charge-Controller / invertor from WholeSaleSolar.

    Honeybees have a lot of problems, a wide array of diseases and pesticide overuse. The 'flow hives' look real cool, but they do not address any problem that honeybees have. I have heard of them compared to installing a boat anchor on your car.
     
  13. Salamander_King

    Salamander_King Senior Member

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    As far as your question about the size of the PV system, you just need to add ~6kwh of energy per charge to your system. If you are currently charging your PP, then you already know the amount of kWh electricity usage for each month including the charging PP.

    I have been thinking of installing PV panels on our roof mainly to save money but also to be more energy independent. However, the more I research and crank up the numbers, the harder it becomes to justify investing in solar panels at least in my situation. For our climate and for our current household electric usage, the cost of solar panels to provide 100% of our usage installed by a professional installer would be high enough so that the payback period is 13-15 years. If I opt for DIY installation, which I am probably not capable of but just for the sake of comparison, the cost would be about half, and the payback period is also cut in half. This is for a grid-tied system. If I want either off-grid or grid-tied with a battery back-up system, then the cost would double and I would have a much more complicated battery charging system to maintain. Now, instead of using the money for PV, if I put the money in an investment account and let the money earn at a very doable 7% return, no matter how long I keep the solar system and even years after the payback period, the saving the PV provide would never catch up the hypothecal investment account. I even did this calculation at a 4% return, and saving by PV will not catch up to the investment account for the first 30 years. By then I may be dead or even if I am still alive the PV system may need to be replaced. The point is unless the upfront cost of installation of PV panels gets more affordable, it makes no financial sense to invest in my own PV panels.

    After all the calculations, I am now leaning toward saving the money in an investment account and signing up for a community solar farm share instead of having my own panel. That way, I will be contributing to renewable energy development without using my money and I get a discount on my electric bills. With the money saved, I can build an off-grid tiny house with a much smaller system when I retire. And who knows, in 10-15 years, PV system may become so popular, that it may cost a fraction of the current cost.
     
    #13 Salamander_King, Nov 14, 2020
    Last edited: Nov 15, 2020
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  14. MMBH

    MMBH Member

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    THANK YOU for this info!!! It's extremely helpful!!!
     
  15. fuzzy1

    fuzzy1 Senior Member

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    That is just over 10,000 kWh/year, almost what my house was burning before serious conservation began (10,600 over a long period, 11,000 over a shorter period.) But serious conservation efforts cut that to just over 5,000/year, and now my PV produces 6,000/year.

    If your next house will be custom built, you can design and build it to much better efficiency and comfort standards than your previous houses, saving considerable energy.

    You don't show a location. Needed solar capacity will be a very strong function of local climate. I.e. to reach year-round net-zero energy consumption, i.e. I need significantly more capacity at my metro-Seattle location than someone in sunny Arizona would need. And full off-grid solar here would be insane due to the large capacity needed to get through winter, as shown by the seasonal variation of my own production (full capacity not installed until summer 2015):
    upload_2020-11-14_22-1-42.png

    If you are going off-grid, don't use electric resistance heat, that requires far too much production and storage capacity. Instead, consider some form of gas, or more efficient forms of electricity such as heat pumps for space heat, hot water, possibly even the clothes dryer. The first two are excellent now, but the clothes dryers might might not yet be mature enough for your needs/wants.

    My grid-tie solar system was completely DIY design and install. It helped to be a retired electrical engineer, with a bit of electrician skill too (they are not the same), and even did some solar energy harvest investigation for a proposed project on my last contract before retirement.

    Re: payback time

    I went for a solar system sized for Net Zero Energy Consumption (after serious conservation measures) not for financial return reasons, but rather to put my money where my mouth is towards dealing with Anthropomorphic Climate Change.

    Payback time is difficult to figure due to varying incentives and tiered energy rates. Very roughly, tax incentives have paid back about 40% of the installed cost, production incentives (expired June this year) paid about 20%, and eliminated energy bill (except fixed account charge) paid back about 20%. The remaining 20% will be paid back solely by the eliminated energy bill, likely 7-10 more years. Note that this is a solar-unfriendly climate, and I am working with significant neighboring tree interference. Friendlier climates without obstructing trees will pay back faster, but I'm helping prove that it works even in Seattle!
     
    #15 fuzzy1, Nov 15, 2020
    Last edited: Nov 15, 2020
  16. ForestBeekeeper

    ForestBeekeeper Active Member

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    That is interesting, thank you for sharing.

    We do not have tiered energy rates here in Maine. The power grid is either up and you pay for it, or else it is down so you wait a few days as they make repairs.

    Our electric bills are divided in two parts. First is how much power you have consumed, and second is the Transmission charges. Both of these two parts have taxes added on.

    Net-Metering systems here, pay for any power they consume and that power is taxed, and when they put power onto the grid they pay the transmission fees on that power and the taxes on that.

    I am curious though, if you were to depreciate your solar power system completely over 7 years, how much would that change your projected payback?
     
  17. Trollbait

    Trollbait It's a D&D thing

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    The cable TV set top box and cable company supplied modem/router are a likely culprit. The company isn't paying for the electric, so they get cheap, inefficient models. Then that set top box, DVD player, game console, TV streaming device, and even the TV, may not actually be turning off, but just going into a sleep mode.
     
  18. fuzzy1

    fuzzy1 Senior Member

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    We don't have separate transmission charges, it is all rolled into the energy charge. We are still under monopolies here, not a competitive choice market, so there is no need yet to separate those charges.

    The legislature set fixed solar production incentives, but the program was capped. My area's solar installations surpassed the cap, so the incentive rate had to be reduced, pro-rated. The legislature established a second incentive program for later solar adopters, but that hit program its cap almost immediately. Bad for people looking for fast payback, but a great sign highlighting the rapid movement to non-carbon energy.
    If we had business depreciation available, it would shorten 'payback' only a little, depending on tax bracket. As in-between retirees, post-paycheck but pre-pension, we are in a low bracket. Note that depreciation would guarantee a 7 year payback only in a 100% tax bracket, which doesn't currently exist.
     
    #18 fuzzy1, Nov 15, 2020
    Last edited: Nov 15, 2020
  19. MMBH

    MMBH Member

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    Trollbait- Totally Agee! The current TV is new (and ‘sleeps’ but is always on so at avoid dreaded delays/repeat setups) and there was an old DVD player that we did not have at our first residence which may be contributing to new Vampire draws we did not have in our prior home. (Our first home was newer and built with electric heating in mind. Plus it also benefited by passive solar (more by accident than design though.) So I unplugged the DVD player today as it does not need to be plugged since it’s rarely used.

    [The only plus to moving here was the school district; and in hindsight I’m now kicking myself for selling it at a loss (as it was quieter, more energy efficient and our first home. But.. everything happens for a reason I guess. Just haven’t figured it out as of yet.]
     
  20. MMBH

    MMBH Member

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    Agree! Our prior residence had baseboard electric heat. We installed a wood stove after that initial winter season! While designed for efficiency, wood was plentiful, more efficient as well as preferable.
     
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