Off Grid Home Forums Technical Discussion Inverters for Computers Reply To: Inverters for Computers


I recently built a system using 6, 240watt panels and did a great deal of research before buying my inverter. Bottom line their is no black and white answer to which is better as for most things there are tradeoffs. Here is the pros and cons for each.

Modified Sign Wave


Low cost – a 400watt MSW inverter is about $40 at any Walmart.  Even a 2000watt inverter will cost around $200-$250

Compatibility – Almost anything will work with them. There are a few things that will have issues but not many. Some clocks have trouble as they use the 60 cycle from line current as a time base. And my Kill-O-Watt meter would not work.

The only real cons are that some CFL’s will hum as well as ceiling fans. But the biggest reason not to use one is that some items especially motors and other inductive loads will not run as efficiently requiring more power consumption and can shorten their lives somewhat.


Now the pure sine wave inverters are much more expensive. I recently bought a 1000watt PSW inverter because as a total solar home I wanted the highest efficiency I could get as power is at a premium for me. The cost was $450 so not only did it allow me more reserve power, but I didn’t have to listen to the ceiling fan complain all night while trying to sleep. Oh, and my Kill-O-Watt meter works with it.

However for the past few months I used a 400watt MSW inverter and powered my 15″ LED tv, media player, laptop, water pump and lights with no problems at all. So which is better? Well the Pure Sine of course, but the question comes down to what are your personal needs? You will not hurt anything by using the $40 inverter and will most likely never see any difference in most cases. If money is no object get the PSW, if price matters get the MSW and see how it works for you.