Efficient, cheaper heating more expensive to install

By BRIDGET CARTER

A Consumers' Institute survey finds alternatives to electricity may be cheaper, but switching to another energy source can take time to pay off.

The study conducted last year shows that the most efficient heating is often the most expensive. Others might be cheaper, but have a long pay-back period.

Fixed charges for electricity range between 60c and $1 a day.

The most efficient electric heaters are the most expensive to install. For example, a heat pump costs from $3000 for a 2.5kW model, including installation and costs around 7c a kilowatt hour to run in most places. To get the most benefit from a heat pump, a house must be well sealed and insulated. They can also be used for cooling in the summer, but not in winter.

So for anyone at home during the day and with cheaper night tariffs for electricity, a night storage heater might be a better option.

It stores heat from cheaper off-peak night power and release it during the day.

But they do sometimes waste energy by producing heat when it is not needed, and cost between 8c and 15c per kWh to run.

Plug-in heaters are generally the most expensive to run - between 10c and 16c per kWh, but are highly efficient.

The familiar bar heater and fan heaters are good for a quick warm-up and oil-filled column heaters are a good choice for a moderate-sized room.

Many New Zealanders can be connected to gas for free, but others pay a daily fixed charge of about 40 cents.

Gas fireplaces are expensive - $2000 to $4000, including connection and installation; and lower-cost flued heaters start at around $1000.

Unflued heaters or LPG can make the house damp, and they also put carbon dioxide and small amounts of carbon monoxide into the room.

It defeats the purpose of a heater a large amount of ventilation is needed to get rid of the waste products.

Enclosed woodburners generally offer the cheapest option, from around 8c a kWh in Auckland to a mere 3c in Greymouth. They give rapid warmup and plenty of heat for very cold snaps. But the cost is also high - from around $1200 to more than $2000, depending on the size of the burner.

It can be cheaper to burn firewood in a efficient woodburner than to pay for electric or gas heating.

Woodburners are often suitable for large open-plan homes of 150 to 200 sq m. However, a well-insulated house is tricky to heat with a woodburner as it is likely to operate at a slow-burning, highly polluting level.

The condition of the wood is important. It should be well-seasoned, and stored under cover.

Woodburners can be equipped with a wetback, which heats household water. This can complement a solar water heating system, to make up for the short-fall in the sun's heat during winter months.

Another option is solar heating, but it is expensive to set up.

A solar PV system costs around $24,000. The panels are guaranteed for 25 years and have a life expectancy of 50 years.

Feature: Electricity

Energy Efficiency and Conservation Authority