Here comes the sun and the age of solar

An historic growth of solar power is changing the world and which, along with wind energy and electric vehicles, are collectively causing the greatest reductions in global carbon emissions. According to Climate Analytics, 2024 is likely to be the year that carbon dioxide emissions peak and start to fall.

The renewables revolution is well underway as illustrated by the world adding 50 percent more renewable capacity in 2023 than in 2022. Further, finance permitting, the next five years will see the fastest growth in renewables yet. It is possible that the worst of the impacts on global climate may be behind us.

There is good reason to be optimistic. The US, the world’s second largest carbon dioxide emitter, has already climbed down from its peak in 2005 and is continuing to reduce its remissions. (The caveat being that a Trump presidency could reverse the positive trend started by the present US administration.)

Even more significant is the report from Carbon Brief that China’s emissions are set to fall in 2024; as the world’s leading emitter, China could be promising a long-term decline in carbon emissions caused by the development of many clean energy renewable technologies in which China is a world leader, including solar and EVs.

The emissions of other potent greenhouse gases such as methane or natural gas (CH4) continue to rise, but an increasing number of governments – not including New Zealand! – are stepping up their efforts to reduce methane levels too. While the overall greenhouse gas emissions are on a plateau, the rate of renewables development suggests a turning point for all global greenhouse gas emissions may not be too far away.

The world is now on track to build enough solar, wind and other renewables over the next five years to power the energy demands of both the US and Canada. As recently described in an editorial in The Economist, solar will get cheaper and cheaper as an energy source, and make a leading contribution to the pursuit of zero carbon across the planet. Unlike the fossil fuel economy, the increasingly cheap and clean solar energy will democratise access to energy, making power accessible to impoverished countries and communities.

This is largely thanks to the crystalline silicon photovoltaic (PV) cell, a very reproducible unit. When the PV cell is exposed to sunlight, a surface charge develops which when drawn off by an applied voltage, generates several watts of electric power. Seventy billion of these PV cells are expected to be manufactured in the form of PV panels in 2024.

PV solar panels can be attached to almost any architectural structure as cladding to make the building energy independent. As silicon is one of the most common chemical elements in the earth’s crust, its global supply is virtually inexhaustible. Improvements in the materials science and design means that the trend towards increasingly efficient and cheap solar panels will continue for a long time to come.

Scaled-up solar energy has been deployed in China and India as massive PV farms occupying up to 60 square km of landscape – enough to power a city with clean, silent, sustainable energy. In Thailand, a PV array of 145,000 panels is floated on waterways to capture the solar energy during sunlight hours and then pumped off by turbines during the night. The cooling effect of the water makes the PV panels on such ‘floatovoltaic’ farms operate more efficiently.

As The Economist editorial notes, over the duration of 2023, solar energy produced about 1600 trillion hours of energy, which was 6 percent of global energy produced that year, and in a single day in 2024 the world is expected to produce about 700 times the quantity of solar energy produced in the year 2004. This astonishing rapid growth in cheaper clean energy indicates solar energy will outgrow and displace fossil fuel.

The silicon solar energy technology continues to present a variety of opportunities for higher efficiency arising from improved materials and clever designs that capture more sunlight. We are also seeing parallel improvements with wind turbines, so combining solar by day and wind by day and night will enhance both energy sources.

In New Zealand the advantages of solar energy begin with a direct reduction in the cost of household power. Adding solar panels and a battery to a home will add capital value to the property and make it more re-saleable. Including a solar battery will allow for us to manage power outages without needing diesel-powered generators and their associated health risks. Finally, using solar panels to provide power for an EV delivered via a home charger makes them very cheap to run compared to petrol cars, petrol hybrids or EVs powered by commercial fast chargers.

One barrier to broad public acceptance of climate change has been the apparent absence of an assured practical pathway to zero carbon. This age of solar is the first credible zero carbon pathway which together with wind, EVs and other renewables, will expand the genuine prospects of zero carbon over the coming decades.

Suddenly, finally, zero carbon seems an attainable goal, for New Zealand and the world.