SIX DEGREES
THE EFFORTS TO THWART GLOBAL WARMING ARE HEATING UP
TOP CLIMATE scientists predicted last year that the world is unlikely to stay within key targets to avoid dangerous climate change which could mean more extreme weather, disruption to food supplies and millions of climate refugees on the move around the world. There might be a climate sceptic in the White House but the New Zealand Government plans to put into law “net zero” carbon emissions by 2050.
BATTERY-POWERED
Renowned theoretical physicist and futurist Michio Kaku says new battery technology for storing renewable energy will radically improve the economics of moving away from burning fossil fuels. “The glimmer of hope is that the superbattery could be around the corner,” he said recently in New Zealand. “Prices are dropping seven per cent per year. So the solar revolution could become a reality with cheap, portable, durable storage batteries.” HOW CLEAN IS NZ?
New Zealand contributes 0.17 per cent of the world’s greenhouse gas emissions and while most of its electricity is generated from renewable sources (hydro and geothermal), the real challenge remains emissions from vehicles and cows.
Many New Zealanders are installing alternative energy systems to power homes and electric vehicles. Households are also generally buying less electricity and some are even selling surplus back to the grid.
Nelson-based alternative energy installer Brendon “Arny” Ahnfeldt of Current Generation, agrees that better batteries are the key to the uptake of micro solar, wind and hydro systems.
BACK- UP PLAN
Homes with self-generating systems that are on the grid don’t need batteries, but batteries allow storage of energy for use in the evenings or as back-up in power cuts. Arny says the biggest advance is the change from lead-acid batteries to lithium-ion batteries which last longer, need no maintenance and perform better. Batteries are the costliest element as photovoltaic solar panels have decreased in price rapidly. “It used to cost more than $10,000 to produce one kilowatt; the same cost now produces close to 10 kilowatts.”
GRID-LOCKED
On-grid systems cost an average of $8500 to generate 30 to 40 per cent of a family’s power and avoid the need for storage batteries.
It is more economical for on-grid households to consume the energy they produce, rather than export it to the grid. Feed-in tariffs, where energy companies pay for units of electricity produced from solar and other alternative means, have declined sharply to about 8 cents a unit (varying per retailer slightly) while purchased electricity costs about 28 cents a unit.
Arny says the costs were one for one and if they’d remained at that level there would have been a lot more uptake. A typical grid-tied system without batteries would pay for itself in eight to 10 years, while the addition of battery storage pushes that out to 15 to 20 years.
While Kiwis haven’t enjoyed subsidies for alternative energy systems and attractive feedin tariffs, this is a blessing in disguise, he says. “An industry that builds naturally is stronger than one built on the back of subsidies. We saw that in Australia where a lot of companies went tits up when the subsidies were pulled.”