Hydrogen, wind, sun and a lake-sized battery
Wood, hydrogen and wind are all in the mix as alternatives to fossil fuels,
The energy sector is buzzing as New Zealand seeks to decarbonise by 2050. Projects are rolling out at pace and it’s clear there will be not one, but many options. New Zealand has long had a head-start on clean energy, with 81 per cent of the electricity sector stemming from hydro and geothermal.
But other energy sources have also been gaining traction. With the Government putting the clamps on oil exploration, the natural gas industry has reinvented itself, announcing it will use hydrogen to replace fossil fuel natural gas over the next 30 years.
In this new world, your car is almost certainly going to be electric by 2050, and hydrogen will probably be playing a key role in heavy transport.
Aircraft and ships will eventually be driven by biofuels, derived potentially from wood from our own forests.
But the most fundamental issue as New Zealand moves away from its coal-fired electricity plants is what to do in the dry years when our lakes are low, Greg Sise of consultancy Energy Link says.
Added to that is a huge projected jump in electricity use. Sise says that by 2050, demand could be 21⁄2 times higher as electric transport and hydrogen production kick in.
‘‘That’s a real challenge in itself. How do you build plants fast enough?’’
The Government has set an ambitious goal of fully renewable electricity by 2030.
But getting the right balance of supply is notoriously tough in the electricity industry, which spikes hour to hour and is vulnerable to low lake levels.
One radical idea to solve the dry year dilemma is being proposed by the $30 million New Zealand Battery Project, an initiative by the Ministry of Business, Innovation and Employment.
Its flagship idea, using Lake Onslow in central Otago as effectively a giant storage battery, is a big concept which left the industry gasping.
Unlike most hydro dams, the lake would pump water to an uphill storage pond, ready to flow back and generate power when needed.
Another idea for getting around dry years is to build a hydrogen plant in Southland which would soak up surplus electricity if and when the Tiwai aluminium smelter shuts. Electricity companies Meridian and Contact are busy investigating this.
According to the World Energy Council, the beauty of hydrogen is its potential to decarbonise sectors that are difficult or impossible to electrify, such as the steel, ammonia, and glass industries – big polluters.
It’s also particularly well suited to direct heat needs of certain industries and for gas cookers.
Hydrogen seems to have found a natural home in Taranaki, where energy contributes about a quarter of the local economy.
One of the most advanced projects is under way at Hiringa Energy, which is deliberately targeting the long-distance trucking industry for maximum impact.
The plan is three-fold: build a wind-powered green hydrogen plant, import trucks adapted to hydrogen and install a network of refuelling stations.
The plant is well on its way in partnership with fertiliser company Ballance at its south Taranaki factory.
For the rest, chief executive Andrew Clennett, a former oil and gas industry executive, is working with transport companies such as TIL Logistics, and fuel retailer Waitomo. They hope to have a network of 100 refuelling sites by 2030.
Clennett says it’s been easier to connect the supply chain dots for a hydrogen industry in New Zealand than in bigger countries.
Things could be speeded up if the Government follows through on its signalled mandate for blending biofuels into fuel.
The biggest challenge is that diesel is so cheap, Clennett says, but one day hydrogen will be cheaper.
TIL chief executive Alan Pearson says hydrogen won’t be the only tool to convert the trucking fleet but it has several advantages over electric batteries for truckers.
Quicker to refuel, hydrogen trucks are lighter and travel further. And crucially, the fuel cells don’t have to be shifted out of the way of the axles (New Zealand trucks need a higher number of axles).
On the downside, hydrogen trucks are still very expensive and Pearson believes the trucking fleet will take a long time to overcome its barriers.
‘‘We’ll probably be exporting hydrogen around the world before we’re fully able to do all the trucks and meet our requirements,’’ Pearson says.
Hydrogen is not just for trucks, but trains, buses, cars, coastal shipping and aircraft. Ports of Auckland has an electrolyser on site, and is working with Auckland Transport and KiwiRail as a fuel supplier.
Experts say the energy it takes to make hydrogen means it does not make much sense to use it when electricity may do.
But as a stored energy, it could definitely play a part, such as when wind turbines can’t operate or solar panels lose too much sun.
While petrol and diesel are expected to be around for some time, oil companies are mobilising. Z Energy in particular sees biofuels, electricity and potentially hydrogen in its future.
‘‘We can’t say with certainty how many petrol or diesel vehicles will still be in the mix by 2050,’’ chief executive Mike Bennetts says.
‘‘However, it may be that this will be the ongoing role of biodiesel or ethanol in the supply chain at that time, to support the remaining internal combustion vehicles that need liquid fuel.’’
Although Z has built a biofuel factory using tallow (currently mothballed), and Air New Zealand has dabbled in jet fuel made with algae, the focus is increasingly turning to making biofuels from wood.
This makes sense: the log industry uses only about 50 to 60 per cent of the tree, providing a plentiful source of material currently used for heating boilers and packaging.
And work is already under way, with Scion, the former Forest Research Institute, making biodiesel, marine and jet fuel.
However, biofuels are expensive to make, and a wood industry transformation plan due out this year is seeking to quantify whether it can be costeffective and attract investment.
Scion clean tech leader Dr Paul Bennett, who also chairs the International Energy Agency’s biofuels committee, says there has been a noticeable acceleration of interest in biofuels in the past year or so.
Biofuels are going to be ‘‘really important’’ for long-haul aviation and shipping, he says, which is why Scion has been working closely with the likes of Z Energy and Air New Zealand.
However, commercialisation will take time and New Zealand’s ‘‘old legacy fleet’’ still needs liquid fuel.
Both geothermal and wind energy are expected to pick up the pace over the next few years. Out of the two, however, geothermal can be overtaxed, while wind is fickle but plentiful.
Sise says individual wind farm projects have not always thrived because they need to be able to sell their power to one of the four big generators – Meridian, Mercury, Contact and Genesis – who prefer to build their own farms.
However, he says there are now signs that at least one company, Genesis, is talking to independents.
Solar is still a small component of the energy mix and relies on individuals not being put off by cost.
And though it’s an outlier, don’t count out wave energy as a technology. New Zealand is particularly suited, surrounded by ocean, the Cook Strait, French Pass and Foveaux Strait.
So far marine energy hasn’t amounted to much. However, Awatea, the Aotearoa Wave and Tidal Energy Association, says some work is under way and should be made public soon. Watch this space.