Some thought on New Zealand
Energy. New Zealand still has a massive untapped hydroelectric potential of course the environmentalists won't let further development happen without a massive fight, but there was a report done in the 70's (oil shock) that I read that documented all the significant potential hydroelectric sights in New Zealand, and there is a massive untapped potential.
There are massive coal reserves in New Zealand that were mapped in the 70's (oil shock) much of it is low quality, and or under crown owned protected land.
Land. Nearly 30% of New Zealand is publicly owned protected land.
People. If you want to boost the population then there are a number of historical changes that could be taken.
Allowing Chinese immigration during the gold rushes, large numbers of Chinese men worked on the gold fields but very few Chinese Woman were allowed, and the Chinese faced massive legal discrimination, and very few stayed after the gold run out.
Encourage settlement of British returned service men post WW1, and WW2.
Encourage Indian immigration, during and after Independence/Partition of India. New Zealand restricted the immigration of Indians during this period, due to them being non-white.
Allow more Pacific immigration, and make it easier for them to stay. The dawn raids and deportation of the 80's come to mind.
While New Zealand has historically encouraged and subsidized the immigration of whites it's polices have been to discourage other races.