Follow on to my post in Greetings from Norway re;Longyearbyen today:
The other major settlement on Svalbard is the Russian mining town Barentsburg, which is also slowly changing into a tourist and research centre. Both places have coal fired powered plants at the moment.
The present power station in Longyearbyen will be shut down in 2023 and the Russians are planning to upgrade the one in Barentsburg:
The plan for Longyearbyen is to operate a diesel driven power station initially, until a more permanent solution is found.
Green Ammonia from Finnmark is a likely energy source in the future: