The easiest way is to distribute that Thailand-sized area of solar panels around the globe, close to the point of use. This won't help Germany, which will still need either 2000-km-long transmission lines from Extremoduro or Algeria or something, or a lot more 10%-capacity-factor solar panels than they already have, but for electrical power in most of the world, photovoltaic power tends to decrease transmission losses (which are already included in the world marketed energy consumption numbers) rather than increase them. That's because thermal electric power plants tend to be in the 100MW–10GW range where they're most cost-efficient, while PV generation can be economically scaled down to 0.3 kilowatt at present.

Indeed, if the prices of modules and power electronics keep dropping as they have been, there's a point where it becomes uneconomic for most energy users to pay for offsite generation, transmission, distribution, and billing; around 02013 there was a lot of talk about the risk of a "utility death spiral" as more and more grid users deserted the grid for their own private PV farms, leaving the remaining grid users (steel mills, diamond foundries, Bitcoin mines, and the like) to pay higher and higher prices to maintain the stranded infrastructure. So far this has not materialized and probably will not.

However, of those 18 terawatts, about a third are transport fuels, mostly gasoline for cars and diesel for land shipping, but also passenger trains, bunker fuel for cargo ships, and jet fuel for airliners and air shipping. Although ships can plausibly tow their own PV rafts, the others will probably be the last strongholds of fossil fuels due to the low efficiencies of electrolysis (typically around 60%) and the Fischer–Tropsch process (typically 50%), which adds up to "transmission losses" of around 70%, relative to how they're measured in the IEA's report today. And if you're doing this to power your Antarctic research base's electrical needs, you lose another 60% (total losses: 88%) to Carnot.

The good news there, though, is that the electrical part of the equation gets a "Carnot boost": a kilojoule of coal or gas burned to generate electricity only yields 400 J of electrical energy. So we only need 400 W of PV generation to replace each kilowatt of coal mining for electricity!

Okay, I've answered three of your questions. Now it's your turn. How much are current transmission losses typically, and in maximal and minimal cases? How are they affected by transmission-line distance, and how much does the step-up and step-down equipment cost for different voltages? How does HVDC help? Are there better alternatives to water electrolysis followed by Fischer–Tropsch? How does the global distribution of current human energy use relate to the distribution of solar resource?