Designing a Hybrid Solar System From the Ground Up

Cool Breeze
Cool Breeze Registered Users Posts: 13 ✭✭
Hello from Beautiful Vancouver Island, BC!

I am purchasing a rural property that is on-grid, but has a somewhat unreliable grid in the winter, stormy months. My eventual plan is a fully automatic, hybrid on/off grid setup. After reviewing a number of threads on this forum I've decided to start my project with a generator. I already own a Honda EU2000i, which will be good in the future for short term charging of battery banks. I am in the process of deciding on a whole home generator to power the house and have enough extra to charge a future battery bank: see my post in the Generator Sticky.

The second component that has been recommended is the battery bank and charger/inverter. I'd like to go with a 48V battery bank and 240V coverage. I was thinking of 1.2-2V batteries in series: NiFe or SLA respectively. The only draw back is the price. What is the expert advice here? Do the benefits of 2V cells vastly outweigh a 6V series/parallel design? I was thinking of a Xantrex or Outback Radian unit for the inverter/charger.

The third and last component I was thinking of is the actual solar panels and charge controllers. I don't have a lot of south face roof space, so I was thinking of buying as high efficiency, mono panels as I can afford. I really like the SunPower units, and Outback charge controllers.

I'd like to size everything for future expansion. Meaning that I would like to have a bit more battery capacity, inverter size, and charge controller size so that I can start smallish and build out my solar capacity.

Thanks for your input!

Comments

  • Cariboocoot
    Cariboocoot Banned Posts: 17,615 ✭✭✭
    Re: Designing a Hybrid Solar System From the Ground Up

    Welcome to the forum and greetings from the smoke-filled Cariboo. *cough*

    Starting with a small generator is a good plan. Something to supply the essential power when the grid goes down. I think you'll be pleased with the Honda providing you don't have 'essential' needs in excess of 1600 Watts.

    The second ingredient would be an inverter and battery bank, yes. But you really need to know what amount of power you're going to have to supply first. If the plan is to go with grid-tie to maximize your investment (and you are aware BC Hydro pays practically nothing for purchased power) you will want a hybrid type inverter.

    Here's where it gets tricky. Your sell back to the grid is practically worthless so there is no point in going with the largest capacity possible; you won't have much ROI at ten cents per kW hour. So it would be best to size the system to meet your outages demands and consider any surplus sold as a small bonus.

    And before the Americans chime in, there are no tax incentives, credits, rebates, et cetera here. We are on our own and grid electric is extremely cheap. Couple this with higher-than-USA prices on equipment and you readily understand why despite abundant sunshine the GT installs aren't filling up the landscape.

    The only benefit of 2 Volt cells is more Amp hour capacity per cell. In terms of cost they're pretty horrible value. This is another reason to know exactly how much capacity you need before deciding; if you can get away with cheaper batteries do so. Also at 48 Volts you will need 100 Amp hours per kW of inverter power, so that sort of sets a minimum size for the inverter.

    Avoid Xantrex XW equipment whenever possible. Despite what the people who sell it or have been tricked into buying say, it is bug-laden and a real pain to get working. If you want an integrated system the Outback's works better than any other. Although in truth MidNite's charge controllers are the best. Again you can't pick the major components until you know what capacity you are going for.

    Your roof real estate may be an issue, but we're back at that "how much do you need?" question again. As it is there is a few percentage difference in efficiency between poly and mono, and the mono panels usually cost more per Watt. They may not be necessary or worth it for you.

    Expansion is not easy. You can't just add battery. If you start out with more than you need then you've already expanded and could have a value problem where you've invested in capacity you don't need. Since you have the generator you really only need a day's worth of stored energy. My advice is keep it small, as there will be no benefit from over-sizing at all but a significant extra expense. Any sell-back to the grid is going to be far less money than it costs to produce here.

    I can report some good news in that I was able to buy some name-brand panels recently @ $1.15 per Watt before taxes. Yeah, don't forget the taxes. Not like the government will let you.
  • Cool Breeze
    Cool Breeze Registered Users Posts: 13 ✭✭
    Re: Designing a Hybrid Solar System From the Ground Up

    Thanks for the reply.

    If I buy a generator, do I need an automatic transfer switch? Or can I buy a hybrid inverter(Radian) and have that act as the ATS?
  • Cariboocoot
    Cariboocoot Banned Posts: 17,615 ✭✭✭
    Re: Designing a Hybrid Solar System From the Ground Up
    Thanks for the reply.

    If I buy a generator, do I need an automatic transfer switch? Or can I buy a hybrid inverter(Radian) and have that act as the ATS?

    Any inverter-charger, including the Radian, has a transfer switch built in.

    You don't necessarily need a large generator, btw, as it really only has to supply charging plus average loads; the big loads only run occasionally on most systems and can be regulated. If you want really seamless operation you can get an inverter that does gen support: if the gen's limit is neared the inverter switches back to inverting and parallels with the gen (like stacking two inverters).
  • Cool Breeze
    Cool Breeze Registered Users Posts: 13 ✭✭
    Re: Designing a Hybrid Solar System From the Ground Up

    Which inverters with gen support should I be looking into? Brand/model?
    Any inverter-charger, including the Radian, has a transfer switch built in.

    You don't necessarily need a large generator, btw, as it really only has to supply charging plus average loads; the big loads only run occasionally on most systems and can be regulated. If you want really seamless operation you can get an inverter that does gen support: if the gen's limit is neared the inverter switches back to inverting and parallels with the gen (like stacking two inverters).
  • Cariboocoot
    Cariboocoot Banned Posts: 17,615 ✭✭✭
    Re: Designing a Hybrid Solar System From the Ground Up
    Which inverters with gen support should I be looking into? Brand/model?

    Outback's Radian and GVFX models will do this, so will the Schneider/Xantrex.Conext XW. Basically look at any 'hybrid' inverter; one that's meant for grid-tie with battery back up; they are likely to have the feature. You will need a good quality generator for this as well: the inverter-generators work, but the standard generators are more of a gamble because their output is not as tightly controlled (more variation in Voltage and frequency which can cause the inverter to drop the gen).
  • frank.thomson
    frank.thomson Registered Users Posts: 15
    Re: Designing a Hybrid Solar System From the Ground Up

    I would caution you against using Outback's Radian if you want Gen-support. It just doesn't work, period. You can check their own forums. Main reason I have been told is synchronizing the two inverter blocks inside to work with generator in parallel
    http://www.outbackpower.com/forum/viewtopic.php?f=40&p=42070



    Try to find a real life Radian that does this, you can't. Save yourself all trouble go with XW, peace of mind.

    -Frank
    Outback's Radian and GVFX models will do this, so will the Schneider/Xantrex.Conext XW. Basically look at any 'hybrid' inverter; one that's meant for grid-tie with battery back up; they are likely to have the feature. You will need a good quality generator for this as well: the inverter-generators work, but the standard generators are more of a gamble because their output is not as tightly controlled (more variation in Voltage and frequency which can cause the inverter to drop the gen).
  • Cool Breeze
    Cool Breeze Registered Users Posts: 13 ✭✭
    Re: Designing a Hybrid Solar System From the Ground Up

    After doing some research, I'm looking into a different area than I was before. Hopefully the experts here can give me some advice.

    What I'm thinking about now is a battery bank charged by an inverter/charger(Xantrex or Radian) that acts as my UPS in case of power outage. Then I use my Honda EU2000i to top up the batteries, or invest in either a Kohler 6kW generator (http://www.kohlergenerators.com/home-generators/products/6VSG) or a Generac 6kW EcoGen (http://www.generac.com/all-products/generators/home-backup-generators/ecogen-series/ecogen-series-6kw) to add automatic battery top up.

    This method allows me to get into the realm of solar (by starting to get the components), instead of just buying a generator for whole home support that may or may not have quality power generation, that may or may not work with an inverter/charger.

    Thoughts?
  • Cariboocoot
    Cariboocoot Banned Posts: 17,615 ✭✭✭
    Re: Designing a Hybrid Solar System From the Ground Up

    Try to find a real life Radian that does this, you can't. Save yourself all trouble go with XW, peace of mind.

    -Frank

    Oh yeah; the piece of mind of a bug-laden inverter that costs a fortune to upgrade and has lousy customer support.

    I suspect people trying to use gen support on Radians are about nil because it's not really an off-grid inverter. Any who tried it probably didn't bother to read the instructions.

    BTW, Outback "doesn't support" the function on the GVFX inverters but it works.
  • Cariboocoot
    Cariboocoot Banned Posts: 17,615 ✭✭✭
    Re: Designing a Hybrid Solar System From the Ground Up
    After doing some research, I'm looking into a different area than I was before. Hopefully the experts here can give me some advice.

    What I'm thinking about now is a battery bank charged by an inverter/charger(Xantrex or Radian) that acts as my UPS in case of power outage. Then I use my Honda EU2000i to top up the batteries, or invest in either a Kohler 6kW generator (http://www.kohlergenerators.com/home-generators/products/6VSG) or a Generac 6kW EcoGen (http://www.generac.com/all-products/generators/home-backup-generators/ecogen-series/ecogen-series-6kw) to add automatic battery top up.

    This method allows me to get into the realm of solar (by starting to get the components), instead of just buying a generator for whole home support that may or may not have quality power generation, that may or may not work with an inverter/charger.

    Thoughts?

    Are you saying you will have grid? Because using the inverter as a UPS implies a constant external AC source.

    This gets into a completely different realm, one often used in areas of undependable grid power. You can down-size considerably if all you need to do is keep the essentials running in the event of an outage. It does change the AC wiring a bit, and can eliminate the need for solar if the grid is at least reliable enough to keep the batteries up.

    Generacs, btw, are not highly regarded. Too much variation in quality from model to model and year to year.
  • Cool Breeze
    Cool Breeze Registered Users Posts: 13 ✭✭
    Re: Designing a Hybrid Solar System From the Ground Up

    I will have the grid available, but there can be frequent power outages in this neck of the woods. I'd like to start the project as a UPS, then move into the realm of grid-tie solar when I can afford to add in the panels.

    Understood about the Generacs. The Kohler unit that I quoted looks nice, but expensive. I'm not sure how the Kohler automatic battery charging feature would jive with the inverter/chargers gen support feature.

    Would my Honda EU2000i supply enough power to offset the UPS usage in times of power outage? It wouldn't be automatic. I'd have to roll it out and start it up whenever the power goes out, but then I don't need to buy a new, bigger generator right away.
    Are you saying you will have grid? Because using the inverter as a UPS implies a constant external AC source.

    This gets into a completely different realm, one often used in areas of undependable grid power. You can down-size considerably if all you need to do is keep the essentials running in the event of an outage. It does change the AC wiring a bit, and can eliminate the need for solar if the grid is at least reliable enough to keep the batteries up.

    Generacs, btw, are not highly regarded. Too much variation in quality from model to model and year to year.
  • BB.
    BB. Super Moderators, Administrators Posts: 33,431 admin
    Re: Designing a Hybrid Solar System From the Ground Up

    What you will your AC loads be on the inverter/generator?

    A Radian is something like 8 kWatt and the Honda eu2000i is just 1,600 Watts peak continuous.

    Add the size of battery bank needed to feed a fully loaded 8 kWatt AC inverter (something like 800 AH @ 48 volt battery bank minimum):

    800 AH * 59 volts charging * 1/0.80 charger derating * 0.10 minimum rate of charge = 5,900 VA minimum genset

    And you may even need a larger genset (the 80% charger derating is just a SWAG, and you might need an 80% derating on the generator output to avoid generator overheating).

    The 1,600 watt genset would be a drop in the bucket (1-2% of charging current).

    If, however, your loads would work with a much smaller AC inverter (say 1.5 to 2.0 kWatt)--Just enough to run a refrigerator, washer, lights, laptop computer, etc.--Then everything starts to look a lot less expensive.

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • Cariboocoot
    Cariboocoot Banned Posts: 17,615 ✭✭✭
    Re: Designing a Hybrid Solar System From the Ground Up
    I will have the grid available, but there can be frequent power outages in this neck of the woods. I'd like to start the project as a UPS, then move into the realm of grid-tie solar when I can afford to add in the panels.

    Okay, that is a workable plan.
    Understood about the Generacs. The Kohler unit that I quoted looks nice, but expensive. I'm not sure how the Kohler automatic battery charging feature would jive with the inverter/chargers gen support feature.

    It can work together; auto gen start (from the inverter) with gen support if the loads become too much. But you will not necessarily need gen support: many systems don't have it and work fine. Usually if the load demand is too much for the gen the inverter will drop it and take over seamlessly. Occasionally there will be a power blip when this happens; enough to reboot a computer for example. Whether or not it occurs depends on the equipment involved and how it is loaded.
    Would my Honda EU2000i supply enough power to offset the UPS usage in times of power outage? It wouldn't be automatic. I'd have to roll it out and start it up whenever the power goes out, but then I don't need to buy a new, bigger generator right away.

    That depends entirely on how much power you need to supply. For several weeks I was waiting for a missing part for my system back in '08 and use the generator as the only charging source available. It ran up a lot of hours but it worked. Not very efficient once the batteries get near full charge.

    You have to plan on what the average load is and add the max charging to that. For example average load here is <200 Watts and the max charging is 600 Watts; easily handled by a 1600 Watt generator.

    BTW the Outback chargers are better than the Xantrex or Magnum as the OB takes on the gen and switches the loads over, then ramps the charging up to sustainable level; giving priority to the loads. The other two start out with maximum charge capacity and then lower the rate to the set point, which causes a big hit to the gen to start with. Many have found this hard on small generators and you can have trouble getting it to work at all.
  • Cariboocoot
    Cariboocoot Banned Posts: 17,615 ✭✭✭
    Re: Designing a Hybrid Solar System From the Ground Up
    BB. wrote: »
    What you will your AC loads be on the inverter/generator?

    A Radian is something like 8 kWatt and the Honda eu2000i is just 1,600 Watts peak continuous.

    Add the size of battery bank needed to feed a fully loaded 8 kWatt AC inverter (something like 800 AH @ 48 volt battery bank minimum):

    800 AH * 59 volts charging * 1/0.80 charger derating * 0.10 minimum rate of charge = 5,900 VA minimum genset

    And you may even need a larger genset (the 80% charger derating is just a SWAG, and you might need an 80% derating on the generator output to avoid generator overheating).

    The 1,600 watt genset would be a drop in the bucket (1-2% of charging current).

    If, however, your loads would work with a much smaller AC inverter (say 1.5 to 2.0 kWatt)--Just enough to run a refrigerator, washer, lights, laptop computer, etc.--Then everything starts to look a lot less expensive.

    -Bill


    Bill;

    The charger on and Outback does not have to be set at maximum current for the batteries. This is exactly the situation I described in the last post: the Xantrex or Magnum will start with its maximum charge current and that would shut down a small gen like the EU2000i. The Outback starts at zero and runs up to the maximum set by the user.

    As such you can dial back not only the maximum AC input current but the maximum charge rate as well to suit the small gen. The other inverters can't do this. It is a big advantage.

    So instead of 80 Amps @ 48 Volts demanding 3840 Watts you can turn it down to 30 Amps and only need 1440 Watts. And yes I realize that is a very low charge rate, but at least it would do it.

    As yet we don't know what size inverter he'll need. It's amazing how much you can run off a small one when you leave off the inessentials.
  • Cool Breeze
    Cool Breeze Registered Users Posts: 13 ✭✭
    Re: Designing a Hybrid Solar System From the Ground Up

    I'm not sure exactly of my AC loads, as I haven't tested everything. Generally though it will be an occasional sump pump and well pump, then constant loads of lighting, cell and laptop chargers, fridge, freezer, and whatever phantom loads I can't track down and eliminate. I was thinking that the smaller 4000W Radian might be enough for my needs.
    BB. wrote: »
    What you will your AC loads be on the inverter/generator?

    A Radian is something like 8 kWatt and the Honda eu2000i is just 1,600 Watts peak continuous.

    Add the size of battery bank needed to feed a fully loaded 8 kWatt AC inverter (something like 800 AH @ 48 volt battery bank minimum):

    800 AH * 59 volts charging * 1/0.80 charger derating * 0.10 minimum rate of charge = 5,900 VA minimum genset

    And you may even need a larger genset (the 80% charger derating is just a SWAG, and you might need an 80% derating on the generator output to avoid generator overheating).

    The 1,600 watt genset would be a drop in the bucket (1-2% of charging current).

    If, however, your loads would work with a much smaller AC inverter (say 1.5 to 2.0 kWatt)--Just enough to run a refrigerator, washer, lights, laptop computer, etc.--Then everything starts to look a lot less expensive.

    -Bill
  • Cariboocoot
    Cariboocoot Banned Posts: 17,615 ✭✭✭
    Re: Designing a Hybrid Solar System From the Ground Up
    I'm not sure exactly of my AC loads, as I haven't tested everything. Generally though it will be an occasional sump pump and well pump, then constant loads of lighting, cell and laptop chargers, fridge, freezer, and whatever phantom loads I can't track down and eliminate. I was thinking that the smaller 4000W Radian might be enough for my needs.

    Of those:

    Well & sump pump have big start-up demand and large running demand but run briefly. Usually.
    Refrigeration equipment has big start-up demand, moderate running demand, and cycle periodically (often about 1/3 of the time they are on - varies with weather and how often they get opened).
    The other items lack any significant start-up demand, use little power when on, but tend to be on for long times.

    For example the computer stuff here is 50 Watts. But if I leave it on for all day and night: 1200 Watt hours, the same as the refrigerator which draws around 130 Watts but cycles on and off through the day.

    We have a well pump here; it is turned on only when the batteries are up and panels are still putting out or if the generator is running. It draws 800+ Watts, but usually only needs to run for 6 minutes to fill the pressure tank: 80 Watt hours. Likewise we have a septic pump that gets turned on once a day: 1200 Watt draw (soft start eliminates a monster start demand) and runs for about 30 seconds.

    If you're a good Watt juggler you can do a lot with a little.
  • mike95490
    mike95490 Solar Expert Posts: 9,583 ✭✭✭✭✭
    Re: Designing a Hybrid Solar System From the Ground Up

    Until I added a 3rd chilling appliance (21cf deep freeze, manual defrost) my normal base load was about 300 watts (2 fridges, 2 computers and lights.)

    In winter when solar is low, a 3Kw genset works just fine to keep batteries happy.

    Gen support with my XW works well, the SCP can modify the AC2 parameters to accept nearly any genset that works and has some regulation, a nice clean EU2000 should be no trouble. You may have to team up with solar to get enough amps to stir/de-stratify the electrolyte, but that's only 1x a week you need to worry about it.

    When running the genset and the toaster or blowdryer kick in, it just reduces battery charging till the heavy load is over.

    The XW inverters have a nice, efficient charger section in them, so you don't need a huge genset, just enough to top off batteries if the grid goes off for a long time
    Powerfab top of pole PV mount | Listeroid 6/1 w/st5 gen head | XW6048 inverter/chgr | Iota 48V/15A charger | Morningstar 60A MPPT | 48V, 800A NiFe Battery (in series)| 15, Evergreen 205w "12V" PV array on pole | Midnight ePanel | Grundfos 10 SO5-9 with 3 wire Franklin Electric motor (1/2hp 240V 1ph ) on a timer for 3 hr noontime run - Runs off PV ||
    || Midnight Classic 200 | 10, Evergreen 200w in a 160VOC array ||
    || VEC1093 12V Charger | Maha C401 aa/aaa Charger | SureSine | Sunsaver MPPT 15A

    solar: http://tinyurl.com/LMR-Solar
    gen: http://tinyurl.com/LMR-Lister ,

  • BB.
    BB. Super Moderators, Administrators Posts: 33,431 admin
    Re: Designing a Hybrid Solar System From the Ground Up

    My rough guideline (assuming LP, natural gas, oil, etc. for heating/hot water, etc):

    1 kWH (1,000 WH) per day == Small system to power lights, laptop computer, charge cell phone, small RV water pump
    3.3 kWH per day == Medium system, as above + refrigerator + washer + well pump + LCD TV--Lots of conservation for efficient home
    10 kWH per day == Large off grid system, more of the above--Near normal city life. Central Heat, kids, etc.
    33 kWH per day == Average north American Home (some A/C or Heat Pump)
    100 kWH per day == Texas/Florida A/C system, electric heat/hot water.

    The first three are "reasonable" for off grid solar power... The last two--Very expensive/large off grid solar power systems. Probably need a power engineer to design and install.

    Note that each is ~3x larger than the next--Including ~3x higher in costs and complexity. The first system--Very possible for a person that is handy with tools and a bit of electrical to install themselves. The 3rd--Probably would not recommend for a DIY first system.

    This also shows that "guessing" only gets you so far--You can easily be off by more than a factor of 1/2 or 2x and be in the next larger system (either because you underestimated your loads or over estimated them).

    We don't think twice when our power bill varies by a factor of 2 between summer and winter--You really do not have that luxury to bank summer production for winter use with an off grid/battery system.

    Another estimate... Your off grid power will cost you ~$1-$2+ per kWH (with much of the next decade's of costs due up-front for hardware and installation). Or roughly 10x a typical utility power bill. What would you do different if your power cost jumped up by a factor of 10 tomorrow?

    Power usage is highly personal. We will help you design the system that should support your power needs. However, conservation is usually the best first place to "invest" your money. It is almost always cheaper to conserve than to generate off grid power.

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • Cool Breeze
    Cool Breeze Registered Users Posts: 13 ✭✭
    Re: Designing a Hybrid Solar System From the Ground Up

    I'm going to say that the most I can afford at this point is a medium sized system. I may not be 100% off grid, but my footprint will be much lower and I will have some off-grid flexibility should we have a major outage.

    With a medium sized system (3000-4000 inverter W) in mind, what system voltage should I be thinking of running? 48V or 24V?

    I've been doing some calling around about batteries and found that Costco has probably the cheapest ones available. They are $119.99 CAD plus a $10 core charge, each. These are 220Ah @ 20 hr rating batteries. In comparison, the Interstate GC-2s were $179 each. Trojan and Surette would be even higher I'm sure. Now, I'm not all about the cheapest. I'm willing to pay for quality. But, I would prefer high 'Bang for my Buck' value. With Costco's warranty, there is added bang for the buck.

    I was thinking about two parallel strings of 8 to leave me with a 440 Ah battery bank at 48V. This would eventually be paired with a solar array to assist in the charging of the battery bank, with grid power supplementing any shortfalls. The goal would be never to go lower than 50% DOD in the battery bank during the day, and then use top up the batteries at night through the grid(as it is cheaper to utilize the grid during off-peak times). This method of using the battery power during the day also helps to shift the electrical load more towards off peak times where the energy is cheaper.
    BB. wrote: »
    My rough guideline (assuming LP, natural gas, oil, etc. for heating/hot water, etc):

    1 kWH (1,000 WH) per day == Small system to power lights, laptop computer, charge cell phone, small RV water pump
    3.3 kWH per day == Medium system, as above + refrigerator + washer + well pump + LCD TV--Lots of conservation for efficient home
    10 kWH per day == Large off grid system, more of the above--Near normal city life. Central Heat, kids, etc.
    33 kWH per day == Average north American Home (some A/C or Heat Pump)
    100 kWH per day == Texas/Florida A/C system, electric heat/hot water.

    The first three are "reasonable" for off grid solar power... The last two--Very expensive/large off grid solar power systems. Probably need a power engineer to design and install.

    Note that each is ~3x larger than the next--Including ~3x higher in costs and complexity. The first system--Very possible for a person that is handy with tools and a bit of electrical to install themselves. The 3rd--Probably would not recommend for a DIY first system.

    This also shows that "guessing" only gets you so far--You can easily be off by more than a factor of 1/2 or 2x and be in the next larger system (either because you underestimated your loads or over estimated them).

    We don't think twice when our power bill varies by a factor of 2 between summer and winter--You really do not have that luxury to bank summer production for winter use with an off grid/battery system.

    Another estimate... Your off grid power will cost you ~$1-$2+ per kWH (with much of the next decade's of costs due up-front for hardware and installation). Or roughly 10x a typical utility power bill. What would you do different if your power cost jumped up by a factor of 10 tomorrow?

    Power usage is highly personal. We will help you design the system that should support your power needs. However, conservation is usually the best first place to "invest" your money. It is almost always cheaper to conserve than to generate off grid power.

    -Bill
  • westbranch
    westbranch Solar Expert Posts: 5,183 ✭✭✭✭
    Re: Designing a Hybrid Solar System From the Ground Up

    You have ToD (time of day) hydro billing on V.I.? When did it kick in ?
     
    KID #51B  4s 140W to 24V 900Ah C&D AGM
    CL#29032 FW 2126/ 2073/ 2133 175A E-Panel WBjr, 3 x 4s 140W to 24V 900Ah C&D AGM 
    Cotek ST1500W 24V Inverter,OmniCharge 3024,
    2 x Cisco WRT54GL i/c DD-WRT Rtr & Bridge,
    Eu3/2/1000i Gens, 1680W & E-Panel/WBjr to come, CL #647 asleep
    West Chilcotin, BC, Canada
  • Cool Breeze
    Cool Breeze Registered Users Posts: 13 ✭✭
    Re: Designing a Hybrid Solar System From the Ground Up

    I thought it was so, but after doing more reading on the BC Hydro site, it looks like I was wrong. The only rate structure they mention is a two tier system:

    https://www.bchydro.com/accounts-billing/customer-service-residential/residential-rates.html

    I wouldn't be surprised if there was a transition to a TOD type of billing in the foreseeable future, especially now that we have the smart meters and consumption can be tracked much more timely.
    westbranch wrote: »
    You have ToD (time of day) hydro billing on V.I.? When did it kick in ?
  • Cariboocoot
    Cariboocoot Banned Posts: 17,615 ✭✭✭
    Re: Designing a Hybrid Solar System From the Ground Up

    4kW 48 Volt inverter with 440 Amp hours of battery: good combination. This makes it practical to expand the battery bank later if you need more stored capacity and starts you out with around 4kW hours @ 25% DOD.

    Starting out with Costco batteries isn't a bad idea either, as they are a good dollar value and you won't be out as much if you destroy them rather than some higher-priced brand. The first set is the most likely to suffer errors.

    I didn't know BC Hydro had TOU billing anywhere yet. But of course that's what the smart meters are for (that and eliminating the cost of meter readers). Are your rates above the ten cents per the rest of us get nailed with? Trapped over there on BC's version of Alcatraz I'm not surprised. :D
  • ZoNiE
    ZoNiE Solar Expert Posts: 100 ✭✭
    Re: Designing a Hybrid Solar System From the Ground Up
    Are you saying you will have grid? Because using the inverter as a UPS implies a constant external AC source.

    This gets into a completely different realm, one often used in areas of undependable grid power. You can down-size considerably if all you need to do is keep the essentials running in the event of an outage. It does change the AC wiring a bit, and can eliminate the need for solar if the grid is at least reliable enough to keep the batteries up.

    Generacs, btw, are not highly regarded. Too much variation in quality from model to model and year to year.

    X2 on Generac.

    My two cents on generators, If you want something in the 6KW range, consider a refurbished RV genset. They are more rugged. A good older 1800RPM Kohler or Onan or a newer Honda EV 4010 or 6010 are the most reliable. There are Pertronix Ingnition upgrades for the older Onan's. I have a 6KW that is more like a derated 7.5K. They were built tough as nails in the late 70's.

    I also have a Honda EV 4010, which is water cooled. I bought it used with 80 hrs on it for $900. They are getting harder to find, though.

    There is a company, Pinellas power, that refurbishes hondas, and has remote start kits for EU2000's as well. I have not used their stuff, but other RV'ers I know do. They will also help you over the phone or email when troubleshooting a problem. They helped me, and I am not even a customer.