Business Scoop

Green The Grid? No, Use Mixed Energy Sources To Reach True Carbon-zero

Press Release – Molly Melhuish

Labours plan to green the grid is all about electricity. It relies on the analysis promoted by Transpower in 2018, proposing to build an electricity empire twice the size of ours today. Labours Lake Onslow scheme to provide electricity in dry hydro …

Labour’s plan to green the grid is all about electricity. It relies on the analysis promoted by Transpower in 2018, proposing to build an electricity empire twice the size of ours today.

Labour’s Lake Onslow scheme to provide electricity in dry hydro years is costed at a likely $4 billion and would create some 4,000 jobs during construction of the new hydro scheme.

Instead if New Zealand used the most cost-effective energy options for households, retail and industry, the initial cost would be reduced and the ongoing costs would be much lower. EECA found that a whole suite of energy efficiency improvements would cost half that of new energy supply.

Government has allocated $30 million to develop a business case “for a solution to address New Zealand’s dry year storage problem”. They favour the Lake Onslow scheme but also mention alternative pumped storage options and “alternative technologies”.

Sustainable Energy forum’s hydro expert, Alastair Barnett, estimates that the Onslow scheme could provide 5000 gigawatt-hours storage. But a simpler pumped storage system between Lake Tekapo and Lake Pukaki could provide over half Onslow’s dry-year storage with minimal construction cost – the two lakes were originally designed to do exactly that.

That scheme was precluded by the separation of ownership within the Tekapo-Waitaki hydro scheme. Genesis owns and manages Tekapo, Meridian owns the power stations below Tekapo. Each gentailer manages their part of the resource to maximise profit and shareholder value, not to minimise financial or environmental cost.

Transpower’s vision is all about economies of scale. Instead, we could choose local energy options, typically community-based, which show “economies of scope”. That means one energy solution produces several benefits.

Most important, as the climate emergency intensifies, is resilience. Climate-caused outages can be survived by individual households if they can get sufficient warmth, cooking and water heat. A barbecue generally offers only cooking, though water can be heated with a pot on the stove top.

Emergency centres – maraes , schools or community halls – can offer warmth, water heating and cooking with new-technology wood gasifiers, or simpler down-draft burners. At present most of these use electric or bottled gas cookers. Most use electric hot water which is slow to heat up (for occasional use), and wasteful of stored heat once the emergency is over.

The Onslow pumped hydro scheme provides around four thousand jobs. Retrofitting even half of the half-million presently underheated homes must offer ten thousand jobs or more. Community energy schemes could cover far wider services than just retrofitting cold damp houses, and offer many and varied jobs.

Fuel from wood – both grown for purpose and waste wood – is the most important means of providing extra energy in dry years. I believe that the wood gasification appliances being designed by Ian Cave – which are not only smokeless but which can burn either dry or green wood and emit no nitrogen oxides – are ideal as flexible resources to be used in conjunction with heat pumps for space and water heating. The burners now being trialled are sized for household use, but easily scaled up for schools, rest homes, and agricultural or industrial uses.

A significant proportion of the $30 million allocated by Labour to develop a business case for dry year energy must therefore be spent comparing the Lake Onslow scheme to:

  • alternative pumped hydro schemes, especially Lake Tekapo-Lake Pukaki
  • energy efficiency projects designed to reduce overall energy use, which will incidentally reduce peak electricity demands
  • development and widespread use of truly smokeless wood burning appliances in houses, schools and hospitals and rest homes, which reduce peak demands
  • coordinated use of heat pumps and wood burning appliances, the latter used when heat pump performance falls, e.g. when outdoor temperature is less than 10 degrees Celsius.

Despite my strong submissions to the Interim Climate Change Committee, they refused to include an electricity scenario that included any such options. They used the same electricity-centric advisers that were used by the Electricity Price Review.

True 100% renewable energy systems need energy that can be stored, and need electricity pricing that charges extra when electricity is scarce and/ or carbon emissions are high. Today’s pricing system is perverse in that gentailer profits increase when coal is the marginal fuel.

Pricing needs to reward consumers who save energy when supply is scarce. Perversely, lines companies are lobbying to set very high fixed daily charges, so they can reduce per-kilowatt-hour charges. That would make home insulation and solar rooftops take longer to pay back.

Each of the above policies that reward investment in local and community energy has been cut from the energy scenarios used by Government and industry to plan for the future. Yet only local and community energy can bring us to 100% renewable at a reasonable price.

At the very least, the $30 million feasibility study of replacing thermal generation with pumped hydro needs to be widened to incorporate energy efficiency and biomass energy that can be stored until needed.

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