Recommend me a system guys! Grid Tied? Battery? How many panels? Come on in!

C_HeathC_Heath Posts: 23Registered Users ✭✭
First let me say that I am a member in no less than 15 forums, maybe more and I have never had the hospitality as here. Ive had nothing but great help from great people. I came here in hopes of getting a little turbine to run my entire home and have no power bill. Man, that is now really funny! I have truly learned alot for sure. I have realized that solar is the way to go and that it would cost a small fortune to run my 2200 sf home with 4 females so I am searching for some more help in just what I need. First let me shed a little light on my situation......

Im in NW NC. We get the best of both worlds. 95 in July and 15 in January with maybe one snow per year at 3 inches. I live in the Appalachian wedge so we get screwed on the snowfall because it does not make it over and down to us at the foot of the mountain. As I get older, this is a good thing but as a kid it sucked. So anyway, I have a 34 year old Brick Rancher home with a East/West facing roof. I do have a front and rear porch with roof area facing south that will hold 5 panels each.

As of Feb 2013, I installed a wood burning furnace. Its plumbed into my existing heating ducts and provides plenty of heat. As far as the power suckers, I have the standard items, I fridge, 2 chest freezers, a 8 year old heat pump/Central Air Unit and a 15 year old 5000 watt Electric water heater. I do not have any gas and do not want any. I just dont want a gas bill thats all. We use the standard washer and dryer to do the clothes.

I started my conservation of power in Feb when I purchased the woodstove and immediately I saw a huge difference in power consumption. I went from 2000 Kwh to 1500 and then to 1000 last month. Going from $200 power bill for Jan to almost under $100 quickly got my wife involved. So, this month, I have installed timers on all outlets. DVR boxes, TV's, the Fridge and box chest freezer as well as the Water Heater.

My next DIY before I install anything solar at all is a Batch Water heater outside. I believe this is the cheapest way to see the largest benefit in my power bill and its simple to do.
Ok, so now you have some background, I would like to share my thoughts and ask you for advice on what I may need as far as a system. With 4 females in the home, Im not sure there is much more I can do short of burning candles and hanging clothes on a clothes line and let me be the first to say, I am OUT on that lol. I want to live just like I live now but have my frugalness in the back of my head so to speak.

In a perfect world, yes, Id love to have 50 panels up top Grid tied with 15000 watts of backup battery power just daring an ice storm to mess with me right? Well, yes but I am not a one percenter by any means and my blue collar salary wouldnt be able to absorb it anyhow. However, I really see the need for me to be able to feed back the grid AND have means to have power AT NIGHT when our power is out just in case. I know this is more expensive but Its something id like to have.

As far as size. I think that being able to run the essentials, fridge, lights, recepticals, one TV and DVR box so we wont kill each other in the event of an outage. One very helpful forum member here is adament that a 3.3 - 3.7 kwh system is perfect for my situation. I agree with him and this will help keep the cost down. I do have a 3000 watt honda generator so that may help your designing me a system lol.

As I said before. I want to be able to be conected to the system. I want to save power their as we are all gone during the day from 7 to 5. I think this would be a net time for my house. Also, even if small, id like to have some AGM batteries in case we lost power at night when the panels couldnt produce power.

With this said, tell me what you think. I am looking at the Sharp 235 watt panels that are 65x39. I like the Outback power systems equipment but am not opposed to other brands. I would like to keep my brands together and not mix and match. I will tell you that though Ive learned alot, I dont know much more than this....... Sun to the panel, power to the charge controller, power to the inverter, power out of the inverter to the breaker box. Really, I have not been around long enough to know alot more than that. Especially the parallel and series making it 12v 24v or 48v heck, Im lost there so bear with me.

Ok, guys, let me know what you think. You know what I want so go!

Thanks!
Chris

Comments

  • BB.BB. Posts: 27,904Super Moderators, Administrators admin
    Re: Recommend me a system guys! Grid Tied? Battery? How many panels? Come on in!

    To add--I am the adamant forum member that has been telling Chris to conserve and look at a smaller backup system + genset as a more cost effective backup power system (at least for now until he gets more experience).

    Chris, I think I suggested the GE Geospring hybrid water heater--That would be ideal (except for the 4 family member showers--it they take showers at the same time of night). You would either need a larger heat pump water heater, or a couple of them for water storage, or a larger hot water system (desuper heater on a new AC system and related heat exchanger+hot water storage tank--see your A/C guy).

    GeoSpring
    Hybrid-Electric Heat-Pump Hot Water Heater


    I would focus on reducing hot water costs next--I think that is your best bang for the buck investment here. And your "small" genset would be hard pressed to support a full electric 240 VAC water heater (cold showers anyone?). The Heat Pump water heater above takes around 500-600 watts (on heat pump only mode) so could easily be supported by the genset (if taking longer between showers/slower recovery time).

    In California, you cannot avoid low flow shower heads at ~2 GPM, yet one of my kids can still drain a 50 gallon natural gas water heater--The new low NOx emissions/"higher efficiency" water heaters have a smaller burner--around 35,000 BTU vs the >50,000 BTU water heaters I used to purchase--so that slows the recovery time a lot.

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • C_HeathC_Heath Posts: 23Registered Users ✭✭
    Re: Recommend me a system guys! Grid Tied? Battery? How many panels? Come on in!

    Maybe I should have posted this in the NON beginner area LOL. :confused:
  • C_HeathC_Heath Posts: 23Registered Users ✭✭
    Re: Recommend me a system guys! Grid Tied? Battery? How many panels? Come on in!

    C'mon guys ? 80 views? Anyone?
  • OffgridandlovingitOffgridandlovingit Posts: 38Solar Expert
    Re: Recommend me a system guys! Grid Tied? Battery? How many panels? Come on in!

    Since you are using ~33-34 kwh per day, I would say keep working on the conservation aspect. Might be worth looking at some kind of heat exchanger to connect to your woodstove to help reduce your hot water costs and supplement your batch water heater. I am not super familiar with those, but I am sure that there is a way to harness some of that wood heat to help. Looks like your biggest draw is easily the hot water heater, so once you get that out of the way, it will give you a much better idea of how much of a system you will actually need. Something else that you might consider would be putting those 2 chest freezers on a timer. They can hold the temperature down for a while without running, so maybe doing a 15 minute duty cycle every 3-4 hours, instead of leaving them running all the time could help. Extra insulation on those would also help pull the power usage from them down a bit further. If you have a basement, putting them down there, and possibly even turning one room down there into a "cold room" i.e. well insulated, no heat in that room, would also help them run more efficiently and require less power. Just a couple of thoughts based on the information you have given.
  • OffgridandlovingitOffgridandlovingit Posts: 38Solar Expert
    Re: Recommend me a system guys! Grid Tied? Battery? How many panels? Come on in!

    My apologies. I found your other conservation post, and it looks like you have already done most of what I suggested.
  • Eric LEric L Posts: 260Solar Expert ✭✭✭✭✭✭
    Re: Recommend me a system guys! Grid Tied? Battery? How many panels? Come on in!
    However, I really see the need for me to be able to feed back the grid AND have means to have power AT NIGHT when our power is out just in case. I know this is more expensive but Its something id like to have.

    One thing to look into is whether your utility supports net metering that basically allows you to offset your usage with pv production on a 1:1 basis (i.e., you are reimbursed at the retail rate for all kwh produced by solar). If it does, that's generally the most cost effective way to introduce solar, especially if there are additional rebates in NC. Just have a small generator for emergencies. Utilities in the Southeast seem to differ a lot on this issue: some of the Florida utilities have had pretty good grid-tie programs (FPL, e.g.), but others have not (like mine: Alabama Power).

    Going with a battery-based or hybrid system can work but it's a lot more money and effort, not just at the outset but for the entire life of the system.
  • nielniel Posts: 10,311Solar Expert ✭✭✭✭
    Re: Recommend me a system guys! Grid Tied? Battery? How many panels? Come on in!

    so far you are off to a great start and bill steered you well.

    for the most part a gt system is best, but you could opt for the gt with battery backup at less efficiency. this is great for those times that a smoother non interrupted transition of power take place and is especially good when one isn't home to turn on the generator. an automatic generator starter is ok, but not fast and not as reliable as things do happen with a higher degree of possibly going wrong with generators without people being presnt. the drawback is you need to design the battery bank so as to not be able to drain beyond 50% in your absence or outage allowance time.

    if you have room you could pole or ground mount some pvs as there's no rule or law that they must be on your roof, but even if all you can muster is 4, 5, or 6 on the roof area and go with it then it is certainly better than nothing. this could be upwards of around 5kwh per day from solar.

    a small dable in solar thermal for your hot water may be good too, but can get complicated at times for a simple thing in principle.

    btw this, "I have the standard items, I fridge, 2 chest freezers, a 8 year old heat pump/Central Air Unit and a 15 year old 5000 watt Electric water heater.", i would hardly classify as the standard items for most people. also don't be too rigid on propane for when the power is out it can save much wear and tear on solar needing to provide that much power for cooking.
  • PhotowhitPhotowhit Posts: 4,706Solar Expert ✭✭✭✭
    Re: Recommend me a system guys! Grid Tied? Battery? How many panels? Come on in!

    Here's a Federal site that gives most of the available Solar rebates and incentives. There is also the federal 30% tax credit for solar.

    As Eric said, your first stop should be to check with your electric company, to see what they are willing to do...

    I believe there are basically 2 hybrid solar/grid tied/battery backup systems, Xantrex and Outback. There is a minimum amount of battery needed for these systems, as I understand it, for them to work correctly.
    Home system 4000 watt (Evergreen) array standing, with 2 Midnite Classic Lites,  Midnite E-panel, Prosine 1800 and Exeltech 1100, ForkLift battery. Off grid for @13 of last 14 years. 1000 watts being added to current CC, @2700 watts to be added with an additional CC.
  • ggunnggunn Posts: 1,973Solar Expert ✭✭✭
    Re: Recommend me a system guys! Grid Tied? Battery? How many panels? Come on in!
    C_Heath wrote: »

    As I said before. I want to be able to be connected to the system. I want to save power their as we are all gone during the day from 7 to 5. I think this would be a net time for my house. Also, even if small, id like to have some AGM batteries in case we lost power at night when the panels couldn't produce power.
    Just so you know, if you want to have power during an outage, you'll need batteries whether the sun is shining or not. The only exceptions are DC pumps that run during daylight hours and the new SMA inverters which have a single very low powered outlet that runs directly off sunlight.
  • BB.BB. Posts: 27,904Super Moderators, Administrators admin
    Re: Recommend me a system guys! Grid Tied? Battery? How many panels? Come on in!

    More or less, a good starting point for a battery based system...

    At 48 volt bank, assume 100 AH per 1 kW of inverter rating (and, I would suggest for each 1 kW of solar array). For a 24 volt battery bank, 200 AH per 1kW inverter. And for a 12 volt bank, 400 AH per 1 kW of inverter.

    Obviously, if yo have a 1 kW inverter and never more than 500 watts of load (and 1 kW of surge), you could use a 1/2 sized battery bank.

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