An Auckland plant nursery says ditching its gas-fired boiler – as part of a pilot scheme – for an electric heat pump has cut its energy use by 61%.

Van Lier Nurseries, which grows plants and flowers at Riverhead, says it has used a one-megawatt (MW) low-emission heat pump for the past year to grow its range of plants and roses.

The nursery’s glass house was previously kept warm with a gas-fired boiler.

The reduction in energy use, equating to 9295 gigajoules, meant its carbon emissions dropped by 88%, or 773 tonnes.

The timing of the pilot meant Van Lier Nurseries avoided the very high gas prices seen early this winter, which were caused by declining gas supply.

Van Lier Nurseries chief operating officer Joanne Hurley said the conversion meant the nursery had access to sustainable heating to produce blooms – at a temperature of 16C – over the last 12 months.

Genesis provided the design integration, procurement and project management for the heat pump’s installation, while the Energy Efficiency & Conservation Authority (EECA) and NZ Green Investment Finance (NZGIF) helped fund the conversion.

The generator-retailer’s senior manager of commercial and industrial partnerships, Patrick Dempsey, said a heat pump conversion could be considered by other companies looking for a more environmentally friendly, affordable and reliable source of energy.

Genesis and NZGIF provided the heat pump to Van Lier Nurseries on a lease-to-own arrangement, enabling the nursery to spread the cost of the heat pump while receiving engineering and maintenance support from Genesis, along with certainty of energy cost and supply through a long-term electricity agreement.

“This heat pump solution could make a lot of sense to many operators who want to focus on their core business without having to commit a large amount of upfront capital, and to avoid the hassle of owning and operating kit like heavy-duty boilers,” he said.

Genesis chief transformation and technology officer Ed Hyde said companies requiring process heat were among the largest contributors to New Zealand’s energy carbon emissions.

He said lessons from the pilot would help to refine offerings to other business customers.

Van Lier Nurseries is a family-owned business that has been producing and selling flowers and plants to the New Zealand and international wholesale markets for over 50 years.

The business has about 1.5ha of glasshouse planted with over 30 varieties of roses.

Jamie Gray is an Auckland-based journalist, covering the financial markets and the primary sector. He joined the Herald in 2011.