Slowly Solar, dual system - your opinion?

I've been looking over options for grid tied systems, and frankly, I hate the whole idea. My hope is to gain independence and some inflation-proofing of my energy needs, and the last place I trust to help me in that endeavor is APS! On the other hand there is my husband, who is interested in the idea of solar power, but worried about going "cold turkey".

Here's my idea: 1. I calculate the amount of electricity we'd need to be "totally safe" with an offgrid system. We currently use about 400 kWh a month. 2. Calculate the system requirements, except for the panels and batteries. What size and quality inverter, charge controller and so on. 3. Go slow! Buy panels and batteries to create 25 kWh per month, but buy the basic components like inverter sized to a much larger system. Wire this into one room of the house, using a completely separate system from our current house wiring (which is in deplorable condition anyway.) 4. Gradually add panels and batteries and wire up more rooms, until we've got a brand new system that covers our needs. 5. Say bye bye to APS, after we've done enough of a test run to convince ourselves that this is all working well.

these are the benefits I see:
at least some of our expense is spread out over time
we get comfortable with the system and do a learning curve that doesn't put us at risk
we don't violate any aps requirements, because our system has nothing to do with APS


I'm not entirely a newbie to solar power, and feel comfortable learning and doing, not just employing someone else to do all the calculations and work. I guess my questions for y'all are: 1. do you see any downside to this, other than the fact that we might save more money buying everything as a package, and 2. will using components designed for a much larger array work with just a few panels and batteries? I realize if I try to plug my clothes dryer into a 10000W inverter while it's connected to one golf cart battery it's going to run for about 30 seconds, but will I actually damage anything by overbuilding?

Comments

  • icarusicarus Solar Expert Posts: 5,436 ✭✭✭✭
    Re: Slowly Solar, dual system - your opinion?

    In short, grid tie will cost about 1/2 as much per watt as a off grid system. It will also operate more efficiently. The batteries have a high upfront cost, and a finite life, and need to be replaced regularly.

    With utility rebates, state rebates and tax incentives, as well as federal tax credits, the hardware gets cheaper on gird. With net metering payback can come quite quickly. If you have time of day metering you can do even better.

    While I understand giving the power company the boot, you money is much better spent on grid tie and conservation.

    Consider EVERY conservation measure you can do FIRST, before any PV solar installation. 400 kwh/ month will require a very big system, and if it is off grid it will be very expensive. If you can reduce your loads by half, you system can get that much smaller. I'm sure that Bill and others will chime in with some calcs, but here is my napkin calc.

    400kwh/mth= ~14kwh/day.


    To generate 14kw day, you will need a system, capable of generating ~21kw day with a battery system in rough numbers, taking into account battery efficiencies inverter efficiencies etc. Add in a factor for cloudy days, rule of thumb three days, makes a system ~63 kwh/day. Rough numbers 63 wh/6 hours=~10kw system! What is the going rate for off grid systems,,,$10/watt maybe, translates to a $100,000 system.

    Reduce the need for three days reserve by going grid tie, reduces the cost by more than 2/3. Reduce the load by half reduces the cost by a further one half, go on grid reduces it some more. Might come in $15-20k

    Tony
  • System2System2 Posts: 6,290 admin
    Re: Slowly Solar, dual system - your opinion?

    Icarus, I'm curious because that number comes up all the time: where does the half price for grid tied figure come from? My research isn't showing anything remotely like that: APS wants you to have a professional contractor install the system, they want you to use all new parts with the model and part numbers provided, they want you to have a separate meter, they want annual reporting, they want the right to do any in or out of house inspection they wish, they want they want they want. By the time I look at what I save in batteries, it's all been spent in required employment, admin and retail costs - and worse, all of these costs are directly tied to inflation.

    My feeling is that yes, if you were going with professional installation of all new equipment, the cost of batteries and associated peripherals would double the cost of installation. But in comparison to a homegrown homehammered system using some new and some used parts, no way.

    ETA: It's amazing, but although technology can create usable power from sunshine, APS hasn't figured out how to make a meter run backward. ;-) No net metering here, and the amount of power we currently use makes straight time billing a better alternative than time of day. Perhaps some of my annoyance is with our particular power company, which seems to be doing everything in its power to keep us all paying through the nose.
  • System2System2 Posts: 6,290 admin
    Re: Slowly Solar, dual system - your opinion?

    I appreciate the input, Icarus, but I'm still not convinced. ;) The point of my post was "going slowly". I believe with some lifestyle tweaking, here in southern AZ where I have yet to see three cloudy days in a row in ten years, I can get by with a system half the size of what you're recommending (the 400kwh was a max figure, our average is closer to 275); the idea is that by creating a dual system and remaining on the grid but not tied to it, I don't overbuild, I don't have to put up with APS BS, and I don't put myself at risk during the tweak period. Do you know the answer to my tech question: will temporarily underpowering a beefy system cause problems? (PS - hope you're still smiling, I do appreciate that someone's responding to my post!)
  • icarusicarus Solar Expert Posts: 5,436 ✭✭✭✭
    Re: Slowly Solar, dual system - your opinion?

    I'm sure others will chime in with better numbers, but a couple a major factors contribute to off grid costs.

    The first of course is batteries. Batteries, well designed, will have a life span of 7 10 years. In my little system, the batteries cost more than the panels, and have to be replaced every 7 10 years. The second is that batteries are less efficient. It takes ~ 125 amp/hours off charge to get ~100 amp/hours of load. Third is if you are off grid and want to build in a reasonable reserve you have to size the batteries properly. First, you should only draw down a battery to ~50%, (even better to only draw them down 20% (80%soc)) so you need a battery that is at least twice the size of the daily load, PLUS a reasonable reserve of say three days, makes the battery need to be 6 times the daily load,,,a big battery. Fourth, you will need a generator to back up your system somehow, both for emergencies, as well as battery maintenence. I suggest that you read the following links.

    http://www.batteryfaq.org/ http://www.rpc.com.au/products/batteries/car-deepcycle/carfaq4.htm#charge http://www.windsun.com/Batteries/Battery_FAQ.htm#Lifespan%20of%20Batteries

    Here is the bottom line in my opinion, if it were as easy as we would like, then everyone could/would do it. The reason solar is not on every roof is not because people are lazy or stupid, but because it is expensive, and requires some good conservation. When it gets right down to it, grid power is amazingly cheap given what it costs vs what it gives us. 24/7 365 relability at a very reasonable cost. (too cheap imho!)

    Tony
  • BB.BB. Super Moderators, Administrators Posts: 32,608 admin
    Re: Slowly Solar, dual system - your opinion?

    When all is said and done... Power to your "AC outlet" efficiency wise...

    77% from Panel to inverter to outlet with a Grid Tied system
    52% from Panel through charge controller, to battery to inverter to outlet with Off-Grid system

    Also, you add, very roughly, about 50% to your overall system cost for batteries and their replacements...

    Also, if you had net metering, the "Utility" is a one year storage batter with virtually unlimited capacity to store and supply electricity (for me, at $6.00 per month).

    With a home off-grid system... You can cost effectively store only about 3 days of electricity (cloudy weather and such)--so you cannot shift your excess generation energy from your summer months to your winter months... Depending on your usage profile, either your system is way over-sized for summer to make your winter numbers; or your system is sized for summer, and in winter you have to use a gas/diesel generator to make electricity--probably pretty close to $1.00 per kWhr for genset power for fuel, capital costs, and maintenance (you may be in Arizona--so your numbers will probably look better than others elsewhere).

    In the end, turnkey Grid Tied system will generate power for ~$0.25 per kWhr (assuming 20-25 year life, no property taxes or maintenance)... And Off Grid systems, very roughly, $1.00 per kWhr (when extra hardware, batteries, and replacement batteries, are included).

    Could you build and operate an off grid system for less--Yes... Finding panels on sale, using old forklift batteries, etc....

    If you can spend more money/time for conservation (energy star appliances, insulation, double pane windows, new A/C-Heater, etc.) and passive solar (and active solar hot water/heating)--you would probably get a better return on your money.

    Solar Grid Tie is what you would buy after you have done your "conservation"... Off-Grid solar PV is what you would probably do if you had to pay $50,000+ to run utility power to your property.

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • icarusicarus Solar Expert Posts: 5,436 ✭✭✭✭
    Re: Slowly Solar, dual system - your opinion?

    I don't mean to discourage you, by all means go forward, but go forward armed with the best info you can get. Here is one of the best sources out there. (Too many people succumb to the "ready, fire, aim" syndrome.)

    Do the math, do the math for your area. Clearly the kind of sun you get in Bisbee AZ is different from what you get in Seattle, or what we get in Northern Canada,,, but so are the loads, stresses on batteries etc. Do the math, look at your loads, your charging efficiencies, inverter losses etc. look at your hard costs as well as the depreciation of your batteries etc. After you have done all you homework, then you can make an informed choice in how to go forward. If your goal is to live cheaply, of grid is not the way to go IMHO. If, on the other hand you want to live off grid for other reasons then by all means go for it, but realize that it isn't going to save you any money,

    Tony
  • icarusicarus Solar Expert Posts: 5,436 ✭✭✭✭
    Re: Slowly Solar, dual system - your opinion?
    I appreciate the input, Icarus, but I'm still not convinced. ;) The point of my post was "going slowly". I believe with some lifestyle tweaking, here in southern AZ where I have yet to see three cloudy days in a row in ten years, I can get by with a system half the size of what you're recommending (the 400kwh was a max figure, our average is closer to 275); the idea is that by creating a dual system and remaining on the grid but not tied to it, I don't overbuild, I don't have to put up with APS BS, and I don't put myself at risk during the tweak period. Do you know the answer to my tech question: will temporarily underpowering a beefy system cause problems? (PS - hope you're still smiling, I do appreciate that someone's responding to my post!)


    I'm not sure what your question is, but if your question is, "will I hurt my system by under powering it?" the short answer is yes. If you chroniclly undercharge a battery you will shorten it's life considerably. Battery banks and panel sizes should be considered together. Elsewhere on this site are formulae for panel size vs battery capacity relative to charging capacity.

    The same is also true if you chroniclly over draw your battery system.

    As I suggested in a previous post, read the links re: battery info.

    Tony

    PS I'm still smiling. I don't care if anyone takes my advice or not, as I realize it is worth exactly what you pay for it! On the other hand I try to give my honest opinion formed from the school of hard knocks, as well as some practical experience.

    T
  • System2System2 Posts: 6,290 admin
    Re: Slowly Solar, dual system - your opinion?

    I ran completely offgrid solar for 2 years in a strawbale house near here, with seven 85 watt panels, ten golfcart batteries and a 1300W inverter. No stranger to hippie living OR battery maintenance! Frankly it boggles my mind that we've bloated our usage up to near 10 kWh a day.

    Here's my thought on cost, which is quite different from most people's. I live on a relatively fixed income generated from CD investments. So the question for me isn't necessarily when will this system pay for itself (I'm aware that the answer is, "probably never".) The question for me is, is it whether it will bring me greater happiness, peace of mind and potentially a hedge against inflation to invest $25,000 in a CD that will pay me $1,000 a year after taxes, and hand that over to the electric company, or to invest $25,000 in solar power and create the power myself. You can see I'm answering my own question? :roll:
  • System2System2 Posts: 6,290 admin
    Re: Slowly Solar, dual system - your opinion?

    Tony, here's an example of the imbalance I mean: I've got 1 100 watt solar panels, and I've got 2 golf cart batteries, and I run what I can comfortably run on that setup - a cf bulb light, my laptop, maybe a fan. All good. The imbalance part is that the rest of the parts in my system are designed for ten times as many panels and batteries, which I will add on eventually but not now. Provided I'm drawing down and recharging my batteries appropriately, does it matter what size my other components are?
  • icarusicarus Solar Expert Posts: 5,436 ✭✭✭✭
    Re: Slowly Solar, dual system - your opinion?

    I think I get it. In other words, if you have a 2kw inverter, a 80 amp charger etc, but you are powering it with a 100 watt panel and a 200 ah battery will you damage anything?

    If this is the question,,, you won't hurt anything, but all the hardware will be working at terrible efficiencies. The charge controller will have huge losses, as will the inverter. In this scenario, your system will perform even more poorly that it might other wise relative to a properly configured system.

    Also, if you read the links regarding care and feeding of batteries provided in a previous post, you will realize that you cannot add new batteries to an existing battery bank without doing long term damage to the new batteries. Batteries need to be of similar size and similar age in order to maximize longevity.

    I hope this was a clear answer,

    Tony
  • wxh3wxh3 Solar Expert Posts: 70 ✭✭✭✭
    Re: Slowly Solar, dual system - your opinion?
    I can get by with a system half the size of what you're recommending (the 400kwh was a max figure, our average is closer to 275);

    Just curious, do you plan on running air conditioning? I assume A/C is almost not an option in southern AZ. Even if you are only cooling a single room with a window unit I wonder what the monthly consumption would be in Arizona during the summer...
  • nielniel Solar Expert Posts: 10,300 ✭✭✭✭
    Re: Slowly Solar, dual system - your opinion?

    "whether it will bring me greater happiness, peace of mind and potentially a hedge against inflation to invest $25,000 in a CD that will pay me $1,000 a year after taxes, and hand that over to the electric company, or to invest $25,000 in solar power and create the power myself."


    karen,
    that is a tough question to answer being none of us can predict the future, including you. maybe another option would be to diversify into both. i do understand you as to not liking the red tape presented by yet another utility for grid-tie requirements and that you do you wish to be seperate from them and i can't blame you. it is possible to have a small system running specific things, but expansion is a delicate thing that takes much planning and, dare i say, engineering taylored to your wants and needs. you aren't a stranger it seems to doing either with your money and you'll have to decide how and what to be best for you.
    yes, take it slow and think things over and do this for some time while reading up here on the forum as aspects may arrise you may not have thought of, both good and bad. the battery bank is the toughest to expand on and is in need of a minimum charge rate. you could also supplement the charge with utility power until you obtain enough pvs to properly charge them and the agm type battery is expensive, but it is also the most efficient in charging and can take higher charge rates than normal lead acid batteries do. you have much to consider if you choose to do so with solar.
  • BB.BB. Super Moderators, Administrators Posts: 32,608 admin
    Re: Slowly Solar, dual system - your opinion?

    To continue that thought on how two different $25,000 systems would perform...

    $25,000 in solar power (the following numbers are really rough--just an example of how to look at "payback"):

    $5 per watt for solar panels
    $5 per watt for batteries over 20+ years
    $1 per watt for inverter
    $1 per watt for charge controller
    $1 per watt for frame/mounting
    $0 per watt for self install (professional install ~$2-$4 per watt)
    =========================
    $13 per watt (you could add another $2-$4 per watt for installation)

    5/13 * $25,000 = $9,600 for solar panels
    or 1/$5 per watt = 1,900 watts of solar panels

    Using this link for Tuscon Arizona, a 1,900 watt GT system (using 0.52 derating factor):

    You will generate (a maximum) of ~2,099 kWhr per year (remember can only store roughly 3 days of power)...

    If we take a typical GT system (remove the $5 for batteries and $1 for Charge Controller--say you need professional install and permits for a $10 a watt system cost), and using 0.77 derating factor..

    $5/$10 * $25,000 is $12,500 or 2,500 watts of solar panels...

    And from the above link, we get: 4,157 kWhrs per year (plus, a 1 year net metering account--I can store summer generation for winter use--or even the other way around--go negative in the winter and generate during the summer to make up the bill)...

    So, a GT system, with less maintenance, professionally installed, generates about 2x as much power per year as the homeowner installed (saved another ~$2-$4 per watt system by self installing) off-grid system...

    The numbers are very rough, and if the utility does not allow net metering or grid tied connections--there is only so much you can do.

    By all means, plug in real numbers from your own paper design/research. And see how things work out for you.

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • System2System2 Posts: 6,290 admin
    Re: Slowly Solar, dual system - your opinion?

    Aargh, I'd spaced out on the fact that you can't just add new batteries to old. So Niel, you're suggesting maximum battery power with high quality agm's from the get-go, and charging them on the grid until there's enough pv panels to power them, right? Sort of bass-ackward, huh, maybe I need to rethink the slow expansion. :p

    I've realized that the fridge, clothes dryer, electric stove, occasional space heaters, occasional high tool usage in the garage and, if we ever get one, recharge of electric car aren't conducive to off grid solar. I could see doing without every one of those things easily, but I'm part of a mainstream family now, soooo ... Our current lifestyle doesn't really allow for going entirely off grid, my idea is that I would prefer to keep two separate systems rather than grid tying. So little seems to be gained with grid tie here, as there is no net metering and the admin costs account for at least half our ele. bill. At least with two systems I have the illusion of control! :roll:

    whx3 - no, we don't have air conditioning. The house is well designed from a passive solar standpoint and we do have a "swamp cooler" (evaporative cooler), which uses much less ele. than an ac (but a lot of water). Most days a fan suffices just perfectly and keeps temps below 85. Surprisingly, we spend a lot more energy staying warm in winter.
  • nielniel Solar Expert Posts: 10,300 ✭✭✭✭
    Re: Slowly Solar, dual system - your opinion?

    karen,
    calm down as you can go with basic lead acid types and make them the cheaper walmart types so that in a few years you can upgrade to a larger battery bank with more pvs. you can do as you wish to and i did acknowledge that you wanted to power some things seperate from the grid as i never mentioned you being with a grid-tied system as everyone else did. i too power certain things with solar that aren't tied to the grid as i too don't want the hassles of the regulations and such. expansion isn't as easy as you think unless you have lots more $ to make these transitions often. it can be done, but you need to plan things out and know how you will do it and when, and that's if you decide to do it. it doesn't matter of the family way in doing this as it may be the best time to let them know conservation rather than grow to be power spoiled. don't be upset by what i say either as i am not the one to make the decision for you, but i'm just throwing some things out there. you can go small or large or not at all as it's for you to decide, but it isn't advisable to add batteries as you go for the newer battery(s) will be drawn down to be no better than the worst of the bunch when added later. please read up here on the forum rather than getting ready to kill the guy(s) with news you don't want or like to hear. don't kick the others either for their views on grid-tie as it is the most efficient use of solar power, but i can understand not when grid-tie has a hassle factor to it. you know doing this gridless is not hassle free either and adding expandability further adds to that.
    if you really only are interested in the safest bang for buck then invest in a painting or rare coins and put them in a safe as solar most likely won't have a big or quick return and other investments are so shakey right now. even my mother in law tried to pull some money out of her account and the bank told her she needs an appointment to do so. ps- this was also a bank mentioned for solar loans. citizens.
  • BrockBrock Solar Expert Posts: 633 ✭✭✭✭
    Re: Slowly Solar, dual system - your opinion?

    I don't think anyone here is saying you shouldn’t go off grid; we just want you to understand the differences between grid tied and off grid costs and maintenance.

    Personally I have a grid tied inverter with a battery backup. I did this mainly because the system is setup to act as a house backup in case of power failure. I don't have net metering on my system, still to small (1kw of panels) but everything else is setup up for 6 kw of panels, batteries, inverter charge controller (I would have to add a second one).

    But if cost is what you’re after you can't beat grid tie, if backup is what you’re after you need some batteries, if it's off grid, you need lots of batteries. Whatever it is you’re after or maybe even a mix of all these things come in to play as to how you want to proceed.

    I admit I did travel down the battery route because I didn't want to deal with our local utility (and my father still worked there at the time). I have heard since so many other people have gone forward it is much easier to do now. I also didn't want to be forced to use an "authorized" installer with "authorized" equipment, especially since none of the authorized equipment at the time had any option for battery backup. My understanding is now that has finally changed.

    I would strongly suggest looking for someone in your area that does installs or someone who has a grid tied system if you think you might want to go that way. See how they did it and who they worked with and talked to. Maybe if you find the right person at your utility it might make things better all around.
    3kw solar PV, 8 L16's, xw 5548, Honda eu2000i, iota DLS-54-13, Leaf EV, 4 ton horizontal geothermal, grid tied - Green Bay, WI
  • icarusicarus Solar Expert Posts: 5,436 ✭✭✭✭
    Re: Slowly Solar, dual system - your opinion?
    Aargh, I'd spaced out on the fact that you can't just add new batteries to old. So Niel, you're suggesting maximum battery power with high quality agm's from the get-go, and charging them on the grid until there's enough pv panels to power them, right? Sort of bass-ackward, huh, maybe I need to rethink the slow expansion. :p

    I've realized that the fridge, clothes dryer, electric stove, occasional space heaters, occasional high tool usage in the garage and, if we ever get one, recharge of electric car aren't conducive to off grid solar. I could see doing without every one of those things easily, but I'm part of a mainstream family now, soooo ... Our current lifestyle doesn't really allow for going entirely off grid, my idea is that I would prefer to keep two separate systems rather than grid tying. So little seems to be gained with grid tie here, as there is no net metering and the admin costs account for at least half our ele. bill. At least with two systems I have the illusion of control! :roll:

    whx3 - no, we don't have air conditioning. The house is well designed from a passive solar standpoint and we do have a "swamp cooler" (evaporative cooler), which uses much less ele. than an ac (but a lot of water). Most days a fan suffices just perfectly and keeps temps below 85. Surprisingly, we spend a lot more energy staying warm in winter.

    A couple more comments,

    First if you have as much sun as you think, why on earth would you need a dryer in AZ? Second, consider a gas stove with no electricity required. (Use no electric heating devices!) Consider hi-ef fridges or possibly propane.

    Now, if you consider being off grid, realize that you WILL need a generator. With that fact in mind, consider designing your system so that you use the generator for you large shop loads like power tools. It is way cheaper to run the generator for a bit than to size a system for that occasional use.

    You can also build an integrated system such that the generator and the batteries combine as needed to cover peak loads, but that too gets expensive and complicated.

    Please, please avoid the read fire aim!

    Tony
  • System2System2 Posts: 6,290 admin
    Re: Slowly Solar, dual system - your opinion?

    Oh, I'm not upset, just annoyed with myself for forgetting the basic solar no-no about combining batteries of different ages. Sorry if I came off angry.

    Keeping that in mind, it does seem like it would be more cost effective to just start out with a complete system, which is today's plan: figure out how much of our power is used by our on-grid guzzlers (which will remain on grid) and then design a "cute little system" :blush: for the rest of the electrical usage. I do hear you about being grid-tied, it's much more convenient and cost effective not to have batteries, and perhaps it's a good long run answer for sustainable electricity for all, as solar panels on every roof = much less "long distance" demand at the utility company. it just doesn't resonate with me, the queen of DIY.
  • BB.BB. Super Moderators, Administrators Posts: 32,608 admin
    Re: Slowly Solar, dual system - your opinion?

    Just as an FYI--Net Metering is a creature of government requirements... It does not make any business sense for the utility. If you take commercial power rates, roughly 1/2 of the cost of power is generation and the other 1/2 of the cost is distribution and transmission.

    And with Grid Tied Solar--because (in California) I "unwind" my meter by generating--that is a net loss for the utility. I am using their distribution system to pump power to other local users. And then, at night, I pull the power back in--again using their distribution system.

    So--in California, the government has but a cap on the amount of "small" grid tied power the utility has to let into the system... First it was 0.5% and now it is 1% of their total system load.

    And--there is a new metering system that we are probably (in California) only a few years from having implemented. It will be a real-time metering/billing system. Where your power usage and rates will be billed on a minute by minute (or whatever small time window they use) basis.

    I have no idea what it will be like--but my guess is that power from noon to 9pm will be pretty expensive... And for Grid Tied Solar--notice that it will be dark for much of the peak rate billing.

    For me as a GT consumer--that is not great (GT users may be forced onto this new system--regular residential users may not be--at least at first). With our current net metering / time of use billing, we push cooking dinner off until after 6pm during the week--not a big problem. But with real-time billing--watching rates and times which can change within 24 hours--boy what a hassle to explain to everyone in the home.

    As a utility, real-time billing is great... In California, at times, the daily peaks are after 6pm and represent the real cost of delivering power.

    The long way around--don't try and get too fancy in justifying a GT (or off-grid) system... Conservation, change in usage patterns, and grid/utility power is probably going to be cheaper for 99% of the people out there--now and for the foreseeable future. And predicting what government/utilities will be doing 10 years down the road is pretty difficult and would be hard to justify spending 10's of thousands of dollars on solar just hoping that things won't change.

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • System2System2 Posts: 6,290 admin
    Re: Slowly Solar, dual system - your opinion?

    Well, I got some interesting news - thanks for all that grid tied flag waving! ;) As of the beginning of this year Bisbee has started doing net metering and buyback programs, AND they will let us DIY if we wish, we just don't get a rebate from the power company for it ($3 per watt if we use an approved dealer & installer). This makes a big difference to me in choosing a tied vs. dual system, I feel like it puts the cost of our power more or less in our own hands even if we do remain grid tied.

    Tony, you're talking to the woman who takes her bath water and buckets it over to the washing machine to save on water and water heating. I moderate for the simple living network. :-) We have done some energy efficient things like installing an on demand gas water heater and buying a new efficient fridge (but not a $3,500 Sunfrost, I'm afraid), and most of the time we don't use the dryer and the other energy hogs, that's how we keep our electric bill around $45 a month. Nevertheless, we don't live an entirely alternative life, sometimes the convenience of being able to use the appliances we own overcomes the pride and pleasure of manual self-sufficiency. :roll:
  • BB.BB. Super Moderators, Administrators Posts: 32,608 admin
    Re: Slowly Solar, dual system - your opinion?
    ...(but not a $3,500 Sunfrost, I'm afraid)...

    Don't worry about things like that... We are a pretty practical group of people here---We would tell you to by a $500 Energy Star Fridge--which uses about the same amount of power as the SunFrost (per cuft of storage) and put the extra money in more solar panels (if needed to run the EStar fridge).

    Or, we would also tell you to buy a cheap chest freezer and a thermostat that you can set to 33-35F and use it as a "chest" fridge.

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • icarusicarus Solar Expert Posts: 5,436 ✭✭✭✭
    Re: Slowly Solar, dual system - your opinion?
    BB. wrote: »
    Don't worry about things like that... We are a pretty practical group of people here---We would tell you to by a $500 Energy Star Fridge--which uses about the same amount of power as the SunFrost (per cuft of storage) and put the extra money in more solar panels (if needed to run the EStar fridge).

    Or, we would also tell you to buy a cheap chest freezer and a thermostat that you can set to 33-35F and use it as a "chest" fridge.

    -Bill

    Agree once again with Bill.

    Consider solar domestic hot water before PV solar. If you've gone to demand hot water your 1/2 way there. In your climate you should be able to get virtually all you dhw from the sun with a pretty small initial investment.

    T
  • BB.BB. Super Moderators, Administrators Posts: 32,608 admin
    Re: Slowly Solar, dual system - your opinion?

    Once again I agree with Tony (this board becoming sickingly nice),

    For a "do it yourself" domestic hot water system--take a look at solarroofs.com

    One of the posters here (Solar Guppy) recommends these guys as good quality and easy to install yourself.

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
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