Cairns’ warm climate can suit heat-pump or solar hot water systems, while electric storage and gas systems may also be appropriate depending on your home, budget and household usage. Humidity, water quality, available sunlight, installation space and cyclone-related considerations can affect the choice and ongoing maintenance needs. Ask a licensed local plumber to compare system sizes, running costs, warranties and installation requirements for your property. You can also check current energy-efficiency guidance on energy.gov.au before deciding.