You can get much bigger inverters on 24V or 48V than 12V. There are a number advantages in opting for a higher DC supply voltage.
&#; For any given load, half the DC current and losses are down by ¼. Reduced fire risk.
&#; Better input regulation. 0.5v line drop at 12v = 4.6% supply drop whereas 0.25 v line drop at 24v = 1.04% drop.
&#; Better inverter efficiency and regulation. i.e. Less losses converting to 240 VAC. An inverter doesn&#;t have to work as hard to keep its AC output constant.
&#; Larger usable operating voltage window (for acceptable DOD) available from batteries.
Up to 3kW max demand a quaility 24 volt inverter would still be ok.. the rule of thumb is max current demand from inverter should not be over 120-140amps. If over 3KW indeed go for 48 volt system. 150 amps is the limit for cost effective cabling, switching, breakers & fusing.
In short, your energy consumption should determine the voltage of your solar power system. You should not have continuous currents greater than 100 Amp.
Power &#; Current &#; Voltage
1,000 Watt = 83 Amp @ 12 Volt
2,000 Watt = 83 Amp @ 24 Volt
4,000 Watt = 83 Amp @ 48 Volt
20,000 Watt = 83 Amp @ 230 Volt
The higher the current (measured in Ampere or Amps) the bigger the components need to be. High currents require large diameter cables and fuses, both of which are expensive. By doubling the voltage you get double the power (Watt) at the same current.
Dealing with currents over 100A is costly (and therefore inefficient) and potentially dangerous. A perspective: a standard household extension cord is rated at 10A max. current. 100A would probably melt it and could start a fire!
Industry Standard
12 Volt used to be a standard for extra low voltage solar power systems. Today, most systems are 24V or 48V and include a 230V AC inverter. This means the wiring of the house does not have to be different from any other grid-connected household and cabling cost is greatly reduced.
We advise that you get an electrician to wire your house for 230V AC. This way you can use standard AC appliances and lighting, most of which are a lot cheaper to buy and many are becoming quite efficient.
Solar Power System Size
In the past we tried to reduce the cost of an off-grid system by limiting its size. This was achieved by using 12V or 24V appliances & lighting that do not require an inverter. In recent years, inverters and solar panels have become more efficient and a lot more affordable. In addition, most customers seem to want more power over the years. A 12V DC system with a tiny inverter is difficult if not impossible to upgrade/upsize. Not to mention that only very few companies sell extra low voltage appliances or lighting.
You will get efficient and thoughtful service from Sino Air Conditioner.
another calculator online: see http://www.rapidtables.com/calc/electric/ohms-law-calculator.htm
It&#;s mostly a matter of distribution. You can use smaller cable to distribute the same power using higher voltage. So, if you have a big DC motor to run, or want to run something a long way away from the batteries, 24v will allow you to get power there using smaller cable. In some installations this can be a big money saver, or allow larger services, but it&#;s not always better. You will also need more batteries with higher voltage, so it&#;s not a magic bullet for a less expensive system.
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Just looked at the board and see 1 NEW post and 4 older posts of my AC generator is not working right! "need help setting up mate for genset" This is why DC gensets are SO NICE!Just a note that if you do purchase one of these units make sure it has FILTERED output if you intend on running it thru a devise like the MX60.Things I have learned about my unit (ALPHAGEN)1) Due to codes it has a fan that runs 24/7 to keep gas vapors from building up and causing the gas detector to disable the unit. The fan is 12 volt and runs off of the starting battery. It consumes 10 watts and will cause the 48VDC to 12VDC charger to activate ALOT.2) Cold weather starting is non-existiant without a cold start kit, which is basically a solonoid attached to a flap for a choke.3) To date it has only been used a couple of times for 4 to 6 hours and I am not sure it would be worth $ if that is what I had to pay, it IS worth the $800 I spent for it brand new4) It does not temp compensate battery bank but it does temp compensate the starting battery. Starting battery charger is ALWAYS on below 50 degrees F which eats up watts too13.8 VDC at 7 amps.5) I have NEVER had an issue with compatability with GVFX inverters. Everything works very nicely togather.6) I have a gallon propane tank that is hooked to the unit. I noticed that minor leakage occurs at the carb. So I split the propane input line and installed a BBQ cylinder too. Now the unit is supplied 24/7 by the BBQ tank and if I have a long outage I can turn a valve and run unit off gallon tank. Its much easier to refill a BBQ tank and I do not have the condensation from the propane line from house out to the unit.7) Generator starts itself once a month. Problem is that it just idles because batteries are always charged or it just takes a couple of seconds at 100 amps to get voltage up above 52. Its good to set sellre to less than 52 VDC and sell the generator for about 30 min. This allows the generator to be loaded and help seal and lub everything.
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