If you only look at the Inverter losses you would lose about 30% in a 95% efficiency inverter. This is because a 95% efficiency inverter has a MAXIMUM efficiency of 95% only if the load and the input power and ALL parameters are perfectly matched. It can be as low as only 5% efficiency at night lighting up 1 light bulb and efficiency will always be less than95%.

If you look at the total energy lost due to using an inverter, then total losses are on average 75% from using an inverter. This is due to modern appliances all running on DC power. Take your 36 Watt, laptop computer as an example. Using a 5Kw inverter you have 40% losses in converting the solar DC into Mains AC power. Then you put the AC power into the mains cable of the laptop computer which has an AC to DC converter in it. This converter converts the AC back to DC with as much as 75% losses. Total loss in the conversion process, from DC to AC back to DC is 115%.

A much more sensible way would be to put the solar panels on the roof, close to your computer room, connect the 12v solar controller to the laptop, using the Car cigarette lighter adapter for your computer and save 114% losses.

Washing machines save energy by using DC inverter technology. Fridges use DC inverter technology. Panasonic just released a DC ceiling fan to save energy. Modern LCD TV uses only DC power. There is no need for an inverter any more.

Modern solar power systems come as dedicated packages which include the appliance as well as the PV system. This allows you to buy 1 appliance at a time at a cost less than 50% of existing PV systems with inverter and you get a FREE appliance included in that price.