Raising water temperature from 10 to 500 degrees requires about 500 calories/mm3. That’s 2 MJ/litre, meaning if you want to heat 1 liter/second you need 2 MW with perfect insulation, so a power plant of say 10 MW.

A post industrial world citizen could probably get by on 200 l/day (US averages about 300/day). That needs 2 kW/person/day.

Total global energy production is about 630 EJ which averages out at about 12 TW.

Meaning if the whole global energy production went to treat water in that way, we have enough clean water for about 6 million people.

I’m not sure what you mean is hard? Besides uprooting and establishing a new life in a different culture ofc.

To my country a travel visa of three months is automatic/not needed from the US.

A work visa requires proof of employment at a more than minimum wage job, something like a skilled chef, contractor or entry level college grad job qualifies. After two years you can job hop, four years you get a permanent visa, after five you can apply for citizenship.

Requirements at each of these steps is that you can show you have a valid passport, the means to support yourself (and family) financially, are following laws and regulations, and remember to file the paperwork. No tests, no language requirements, just bureaucracy, patience and making a new life.

If you’re in a high demand profession, a work visa takes 90 days to get and is valid for at least two years.

This is for my country, you can typically check with the consulate for whatever country you’re interested in and they will happily inform you.