AC vs DC wind turbines

theeostheeos Registered Users Posts: 1
edited September 1 in General Solar Power Topics #1
No doubt this discussion has been had many times on this site, but I still see a lot of questions from people who are less electrically oriented, meaning I have been working in electricity for about 33 years...
Here are some basic assumptions that will  help:

1. AC power is better for transmission, the nature of AC current means greater current can be sent over father distances more efficiently.
2. DC power is better for electronics and circuits since they all work based on continuous voltage.
3. Current Wind and Solar technology has not necessarily been developed on the basis of efficiency, but more based on business justification and development of technology.
 
So with that understanding in place, we can  talk about the most efficient way to build a system. According to my "perfect" understanding(just kidding) of how all this should play together, truth be told I am going to give you what I think is the best method to build a system and I would absolutely love to get your feedback on ways to make it better, I submit this to you without ego, just looking for everyone's solid experience to put together the best system.

Summary of overall system:
1. Wind Turbines 3 or so likely 5 blade with sealed windings or vertical spin turbines because they have natural resistance to over spin and AC output.  Minimum height of turbines should be 40 feet, if you can go higher then you will almost always have wind, unless their us none at all and will provide power at night. AC power would be brought to a rectifier input to clean it up convert to DC for the battery bank likely you will be at least 60-100 feet from your turbine when it all adds up. ( count 1 conversion) Their will be a water heater drop load(in winter) to provide additional heating to either your hot water heater or input water to radiation heating. That way it's not just wasted on a drop load when their is too much wind. The sky is the limit here on what you can do with that extra power in extremely windy conditions.
2. As a complement, will have 7-8 solar panels for direct DC generation and input into a regulator( count 1 conversion), between the two inputs, I should be able to provide enough electricity for pretty much a 6 bedroom house.( The normal water heater and stove will be gas/propane powered).
3. The battery bank will be either 48, 1Volt, 1000MHA or 24 2Volt, 1000MHA, will provide strong power, with the longest battery life running off a base of 48 volts, shortest down conversion delta from AC, and most efficient up conversion to house 120VOLT AC. New batteries of this type can easily last 20 or more years, with about 78-88% efficiency based on an almost continuous supply of power. Also they should be lead acid sometimes materials or acid is inconsistent, the acid can be replaced. (Someone brought up the idea of using catalytic caps to recover the hydrogen, this my be a costly feature and I would consider it only food for thought).
4. Sticking to the AC delivery system within your house and being compatible with most technologies. 
5. You should have redundant charge converts and depending on how much backup you want the possibility exists for a second battery array for those long days of not generating any power( its possible).
6. If you are connected to the grid, then you should definitely, feed your AC to your side of the power distribution and stop paying someone else for power. I like those quick connect UL approved devices, that isolate your power if the grid goes down, so you are not feeding the grid and electrifying the grid they may be working on. 
7. On the DC side use large conductors to reduce the LOAD that would otherwise use the power, on the AC side use small conductors, of course their is a formula on what size they should be, but that is a good general rule.
8. I cannot tell you about the inverter brands, but you should always be measuring  input, out put and system voltages. Your charge controllers should be able to detect battery issues.  You should be able to intake multiple sources of generation with minimal conversion loss with a 48 volt system I think it would be worth any extra cost.
9. Keep your battery bank in a climate controlled location, too cold will add maintenance costs quickly. Maybe use that dump load to heat the facility I recommend something like an Aircrete structure, very close to your house, but run your cables in a little tunnel, that you can access from the inside and you can have access from the outside. An underground structure will take advantage off the earths natural temperature and be easy to heat by heat exchangers in the winter or keep cool.

That's it for now, up coming topics will be Generators, propane and diesel, oil and fuel storage tanks 500-1000 gallon for remote users like myself.

Thanks

Comments

  • mike95490mike95490 Solar Expert Posts: 7,307 ✭✭✭✭
    theeos said:
    No doubt this discussion has been had many times on this site, but I still see a lot of questions from people who are less electrically oriented, meaning I have been working in electricity for about 33 years...
    Here are some basic assumptions that will  help:
    1. AC power is better for transmission, the nature of AC current means greater current can be sent over father distances more effeciently.
    2. DC power is better for electronics and circuits since they all work based on continuous voltage.

    Ah, both points 1 & 2 get a big disagreement from me,   The rest is so out of whack, I'm not even commenting on it,

    1) Neither AC or DC is better for transmission.  High Voltage is better. There are both AC & Dc high voltage transmission lines,

    2) DC is better for power supplies, maybe,   There is a LOT of electronics that uses AC to pass signals and power around, like the RF stages in a radio - are all AC.   They are Radio Frequency AC, not 120V household current AC.
    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 ,

  • jonrjonr Solar Expert Posts: 876 ✭✭✭✭
    There are very good reasons that AC is used for most utility grid transmission lines and yet high voltage DC is used for very long ones.

    https://en.wikipedia.org/wiki/High-voltage_direct_current

  • BB.BB. Super Moderators Posts: 26,872 admin
      Theeos,

    I too have different opinions on some (many) of your suggestions/observations. However, the post covers such a wide range of power systems--That I am afraid that we will have 27 "different conversations" in this one discussion and we will end up talking past each other.

    What segment of system design would you like to discuss first?

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