It probably is the same, as they share energy market. In both cases it is also because of lackluster transmission capacity to the rest of the continent, that shields Spain and Portugal from the German market. Sweden has plenty of transmission capacity, so we pay German prices in the south of Sweden.

As for “not using fossil fuel for electricity”, in 2022 the Swedish oil fired power reserve was used for 72 to stabilize the polish market, due to all nuclear reactors shutting down simultaneously. Yet Swedish electricity price is still tied to the cost of oil. That transmission capacity has its drawbacks…