Date posted: 22/04/2022 8 min read

The issue: Rewiring the nation

How do we slash global greenhouse gases by 2030? One idea is to electrify everything and run it on renewable power.

In Brief

  • Engineer Saul Griffith says that by electrifying all our machines and using renewable power, we can maintain our lifestyle but use half the energy and drive down carbon emissions.
  • Making electricity with wind, solar or hydroelectricity takes one-third the energy of making electricity with fossil fuels.
  • A home with a gas cooktop, gas heating and petrol car uses about 102 kWh of energy per day. A home with electric cooking, heating, home battery and electric vehicle can use as little as 37 kWh of electricity a day.

Compiled by Jo McKinnon

It may have been lost in the headlines last year, but there's a more pressing target than getting carbon neutral by 2050 – it’s halving greenhouse gas emissions by 2030. Scientists say it’s the only way to keep global warming to no more than 1.5°C and avoid catastrophic climate change.

Less than a decade away, it sounds daunting but it’s not impossible, says Saul Griffith, the Australian co-founder and chief scientist of R&D company Otherlab in San Francisco.

Griffith, an engineer and physicist who earned his PhD at MIT, says the world can decarbonise fast by electrifying everything we can – transport, industry and our homes – and powering it with energy from renewable sources. (Nuclear power, which doesn’t emit greenhouse gases, may also have a place. That’s a startling idea for us Down Under.)

Griffith says we should start with cars and households rather than leave it all to the industry sector. We should embrace electric vehicles, ditch our gas cooktops for electric and install heat-pump domestic water heaters and reverse-cycle air-conditioners.

He writes in his new book The Big Switch that: “Thermodynamics tells us that we can run the same country we do today using less than half the energy, just by electrifying all our machines.” Or in other words: “...doing things slightly differently (not shockingly differently) can make it all turn out OK.”

It sounds crazy-brave but Griffith, who has led projects for US agencies including NASA and the National Science Foundation, has done the numbers.

To electrify everything, the world will need about 10,000–20,000GW of electrical power, he calculates. At the moment, there is about 250GW of wind and 125GW of solar power generation installed around the globe, so it will take a determined effort to scale up. Or as Griffith puts it: “An emergency, wartime-style effort.”

To speed this transition, governments will need to fund pilot projects, eliminate green tape, and offer incentives, rebates and subsidies to develop the market. As more renewable energy set-ups and electric vehicles are made, prices will drop, but lower socio-economic groups may need targeted assistance.

As Griffith points out: “It’s not a fix if only the wealthy can afford it. This isn’t some bleeding-heart socialist observation. All the emissions have to stop, not just the rich ones.”

Four reasons to electrify your life

1. Making electricity with wind, solar or hydroelectricity takes one-third the energy of making electricity with fossil fuels, which waste two-thirds of their energy content. In many cases, renewable power is already cheaper to produce than fossil fuel.

2. An electric vehicle, regardless of size or type, will use about one-third as much energy as a petrol or diesel vehicle. Driving an electric car costs about half as much on the current grid, or about one-tenth if fuelled with rooftop solar.

3. For domestic hot water and heating our homes, a heat pump (on a water heater or reverse-cycle air-conditioner) needs only one-third to one-quarter of the energy to heat the same thing as fossil fuels.

4. For cooking, electric induction heating takes only half to three-quarters the energy as cooking with gas. When you heat a pot of water with a natural-gas burner, 90% or more of the energy in the natural gas gets converted to heat, but about 70% of that energy is lost because it heats the kitchen or room, not the water.

Sources: rewiringaustralia.org, The Big Switch (Black Inc.)

Household daily energy use

Conventional energy useSource: rewiringaustralia.org

The ‘conventional’ home has a gas cooktop, gas water heater, gas room heater, petrol/diesel car and electricity from the energy grid. It uses about 102 kWh of energy per day which produces about 11,000 kg of greenhouse gas each year.

Electrified energy useSource: rewiringaustralia.org

The ‘electrified’ home has rooftop solar panels, home battery storage, electric vehicles, efficient electric cooking, heat-pump water heating and reverse-cycle air-conditioning. It uses about 37 kWh of electricity each day.

Can rewiring the nation combat climate change?

That’s not a car, that’s a battery on wheels

Electric vehicles (EVs) are more than transport: they’re a movable battery. And because it has storage three to four times the size of a standard home battery, that EV in the garage can be used to feed in extra power to your home or to help stabilise the grid in times of higher demand.

To do this requires a bidirectional charger, which as well as charging can discharge energy from the EV’s battery, either vehicle-to-home (V2H) or vehicle-to-grid (V2G).

With a V2G system, compatible EVs (such as the Mitsubishi Outlander and Nissan Leaf plug-in hybrids) are plugged into the grid with bidirectional chargers.

Linked by software called a virtual power plant (VPP), during the day EVs charge their batteries on cheap solar or wind power. When demand for grid electricity is high, usually at night, the VPP directs the chargers to export that stored energy back to the grid.

The set-up can be used like a commercial-scale battery and is already running in the UK, where EV owners earn a tariff for power they deliver to the grid.

Global energy-related CO2 emissions by sector

Global energy-related CO2 emissions by sectorSource: International Energy Agency

A shift away from fossil fuels

The shift from coal, oil and gas and towards renewables is gathering pace. In 2020, the first year of COVID lockdowns, there was an overall 4.5% drop in energy demand globally, reports BP’s Statistical Review of World Energy 2021.

In 2020, OECD coal consumption fell to its lowest level since 1965. Global coal production reduced by 5.2%, natural gas consumption fell by 2.3% and oil consumption dropped by a record 9.1 million barrels per day, or 9.3%, to its lowest level since 2011.

In the same period, the share of renewables in power generation globally increased from 10.3% to 11.7%, while coal’s share fell to 35.1% – a new low in BP’s data set – and gas lifted to 24.7%.

Even in Australia, a fossil fuel stronghold, things are changing. Renewables produced just 5% of Australia’s power in 2008; in 2020 it was 24%, according to government figures.

In February this year, Origin Energy announced that in 2025 it would close Australia’s biggest coal-fired power station, Eraring Power Station near Newcastle, seven years earlier than first intended. The influx of wind and solar power to the grid had pushed down power prices and made the plant uneconomic to run, the company stated.

Read more

The Big Switch

Engineer and visionary Saul Griffith says by running our cars and homes on renewable power, an average household could save $5000 a year on energy bills and slash carbon emissions at the same time. “The Big Switch” is his playbook on how to do it. “The Big Switch” by Saul Griffith (A$24.99, Black Inc.) is available where all good books are sold.

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