Heat pump vs solar energy- here's which saves you the most money.

In a post load-shedding world, the South African market has settled on heat pumps and solar water heaters to fight increasing electricity tariffs, according to Cala van der Westhuizen, head of marketing at Energy Partners South Africa.

Speaking to Property Wheel, van der Westhuizen noted that water heating accounts for as much as 50% of a household’s electricity use.

“Replacing a home’s conventional geyser with a renewable energy alternative is one of the first steps to drastically reduce an average home’s monthly electricity spend, said van der Westhuizen.

“The current renewable energy powered water heating options available to home owners are heat pumps and solar water heaters.”

While both heaters do fundamentally the same thing, a heat pump uses energy from the surrounding air to heat water, while a solar water heater relies on the sun for power.

Pricing compared

According to van der Westhuizen, a solar heater is traditionally much easier to install than a heat pump, with the the total cost of an average 200 litre system costing around R26,000.

He notes that in the short-term, this is cheaper than an average heat pump with a 300 litre efficient tank system, which costs around R35,500.

They will also typically last for over 10 years, while heat pumps generally need to be replaced after five to ten years, he said.

However, despite initial the steep up front costs, heat pump systems have significant advantages over solar heating, van der Westhuizen said.

“A solar panel needs to be oriented towards the sun to operate at maximum efficiency, and when there is no direct sunlight on the system, like at night or on an overcast day, the system relies on a regular geyser element.”

“As a result, the efficiency of a solar heating system fluctuates between 45% and 70%. This comes down to an average drop in energy costs by approximately 54% over the course of one year.”

In contrast, a heat pump system is only slightly affected by variations in temperature, and therefore it runs efficiently at any time of day, said van der Westhuizen.

“It requires approximately one-third of the energy of a conventional geyser to heat the same amount of water, resulting in an average energy saving of up to 70%.”

“This results in a cumulative cost saving of around R62,500 for a standard four member household using an average of 52 litres of warm water per person over a ten year period.”

“By comparison, a solar heating system achieves around R59,500 in savings under the same conditions,” he said.