Science Centres: Energy

Flaxroots approach to infrastructure

Inside the wharenui at Pōhatuiri Marae discussing renewable energy and efficiency options.

Last year, the Pōhatuiri Marae Trust approached NIWA about renewable electricity solutions for their marae near Waitomo. "We asked ’electricity for what?’," says NIWA energy research engineer Rilke de Vos. "The community realised they wanted to understand the implications of a more holistic solution that included electricity provision, clean water supply, and sewage treatment."

NIWA conducted a desktop review, creating three packages of options ranked as ‘most environmentally sensitive’, ‘moderately environmentally sensitive’, and ‘conventional design’.

The ‘most environmentally sensitive design’ included: passive lighting, good insulation, gas cooking, solar hot water heating, photovoltaic cells, stand-by generator, high efficiency refrigeration, rainwater collection & filtering, and composting/grey water toilets with 3–stage sub-surface irrigation sewerage treatment system.

In comparison, the ‘conventional design’ included: grid electricity, electric/gas cooking, electric water heating, a heat-pump, rainwater and trucked water, and standard toilets and infiltration sewerage treatment system.

The combined costs of the three packages were comparable.

Rilke de Vos says "Together, we’ve identified the tradeoffs, and the marae committee can now pick the options that best fit its budget and environmental objectives."