AC loads are more commonly available, require smaller wire size and are less expensive than their DC counterparts. DC can be favorable when you're looking to power lighting or small loads only.
What are AC and DC loads?
AC is an acronym used for Alternating Current. This is the current which is provided by the utility and is generated by using an alternating generator.
Loads that require AC power are commonly called AC Loads. Some common examples of AC loads are microwave oven, hair dryer, common lighting, etc.
On the other hand, DC stands for Direct Current. It is the current that is generated by energy generators such as solar panels and batteries. Loads that require DC Power are called DC loads. Some common examples are laptop batteries; cell phone batteries and DC powered LED lights.
AC can be transmitted over long distance
AC power can be transported over power lines with significant fewer losses than DC power. This is one of the reasons why most homes are equipped with AC power and therefore with AC appliances.
As solar panels generate DC power, it could be more efficient to use DC power, so you wouldn’t need an inverter to turn DC into AC power.
However one thing to keep in mind is that DC loads or appliances are more expensive and not easily available.
With the recent advancements in the inverter technologies, inverters have become more cost effective and have lower losses.
AC or DC ? Save on wiring with AC loads
Another major advantage of wiring your house for AC loads is the potential for significant savings over the cost of wiring used
A comparison:
For a 120 VAC circuit and a 12 VDC circuit carrying the same current, the voltage drop is much higher in the DC circuit. This means that by deploying AC wiring, you could use a smaller, more inexpensive cable, to carry the same power as you would by deploying DC wiring.
Conclusion
For the majority of households, AC wiring is the way to go when installing solar panels.
AC loads are more commonly available, require smaller wire size and are less expensive than their DC counterparts and this could result in significant dollar savings for you upfront, reducing your initial capital expenditure to install a solar power system.
Of course there are exceptions.
For instance when you’re powering a small home for lighting purpose, there’s no reason to convert the power generated to AC. You can simply store DC power in the batteries and then power DC LED lights.