In summer, it is possible to heat all the water you need with solar energy. In winter, or cold and cloudy days, solar water heating to meet part of its hot water needs - you will also need a little additional reinforcement system heating.
The exact amount you save heating solar water depends on a wide range of factors, including the amount of hot water that uses the system of water heating solar install, and the quality of the installation. However, it has been estimated that you for an average household, an effective system will do the following:
Provide between 50 percent and 75 percent of annual hot water needs.
Cut on 2200kWh of annual electricity use.
Provide a savings of $350-$450 per year (depending on the cost of electricity or gas).
If you install solar water heating, you will be helping to reduce New Zealand dependency on non-renewable energy sources, and you'll be helping to reduce greenhouse gas emissions.
Each residential solar system installed water heating is estimated to save, on average, around 1.4 tons of carbon dioxide a year (assuming a mixture of coal and electricity generation, gas fired avoided).
Since each installation is different, solar water heating costs can vary widely. Currently, the solar water heaters (including cylinder) typically cost between $4000 and $8000 installed.
In general, it is more expensive to install solar water heaters in a house in a new home. This is because, in an already existing House:
You may need to add the pipes in some parts of the House that are difficult to access.
You might need to add structural roof frame that can support the weight of the solar water heating cylinder - if you decide to have the cylinder on its roof.
You may be eligible for assistance from the public finances.