* Any views expressed in this opinion piece are those of the author and not of Thomson Reuters Foundation.
Solar panels and wind turbines can take more space than fossil fuel power – but they can double up with other uses and bring big benefits
Paul Behrens is an assistant professor of environmental change at Leiden University’s Institute of Environmental Sciences and the author of The Best of Times, The Worst of Times: Futures from the Frontiers of Climate Science
To have a fighting chance of limiting global warming to 1.5 degrees Celsius, emissions must drop by at least 40-60% by 2030. Richer nations, having put most of the excess carbon in the atmosphere in the first place, should be aiming even higher.
Because so much needs to be done in such little time, we must rely primarily on technology that already exists. This includes a massive expansion in low-carbon energy generation, and improving energy efficiency through, for example, national building insulation schemes.
What needs to happen might sound daunting, but we already have the technologies to hand.
Studies show that at least 70% of all energy use can be easily electrified and that this electricity can come from renewables or nuclear. It helps that solar energy is now the cheapest electricity in human history and that, in many places, it is already cheaper to build new solar or wind than to continue running paid-for coal or gas power plants.
But given the need for speed, we’ll have to build vast amounts of renewables very quickly. and there are concerns regarding the amount of space that will be required.
It’s true that, watt for watt, renewables can use 10 to 100 times more space, but this is not the problem it seems to be, for five main reasons:
With renewables, land has multiple uses. Roofs don’t just keep the rain off; with solar panels, they can quietly generate energy year after year. Solar panels can also be fixed over crops and greenhouses, optimizing the land in so-called agrivoltaic systems.
Wind turbines spin just as well over fields of barley. There are even floatovoltaics: solar that floats on water.
One study found that floatovoltaics on just a quarter of man-made reservoirs in the United States could produce 10% of national energy requirements while saving water. It’s not just solar that can find a home on water. Wind power can sit offshore too.
Systems that run on electricity are far more efficient. A gasoline-powered car wastes around 70% of the gasoline energy in heat and noise. An electric vehicle wastes less than 23% of its electricity.
An electric vehicle charged by solar represents huge cuts in the energy and land needed in the first place. Solar-powered electric bikes are even better.
The high estimates for renewable space requirements come from biofuels. Plants are terrible at converting solar energy. Solar panels convert energy 10-20 times more efficiently, and straight into electricity. Choosing more solar and wind power over biofuels means the upper end of land-use estimates can be avoided.
Fossil fuels can pollute land and oceans for the very long term. Once the mines and wells are exhausted, it can take decades for the land to recover, if it ever does. The stretches of polluted land are increasing each year as Canadian tar sands and US shale gas operations expand.
Care needs to be taken to ensure we don’t see the same problem with the mining materials for renewable energies. But, overall, the potential for pollution is much lower than oil spills and mine tailings from coal.
In a warming world, we will see an increasing risk of extreme events. Repeated disasters like flooding and wildfires can threaten both fossil fuel and nuclear infrastructure.
Renewables, especially solar, can be moved and re-sited quickly. Renewables also don’t pollute the environment if flooded.
Policy makers still need to take care and empower communities in renewable energy developments. But given the speed of transition required, space is not a significant reason for concern or delay.
If we don’t reduce emissions dramatically this decade, we may need large-scale carbon capture in the future, either by growing plants and burying the carbon they use to grow or through devices that physically scrub the atmosphere of carbon.
If we grow plants for this or use renewables to power the scrubbers, we may see increasing land tensions. But this is just one more reason to focus on lightning-fast emission reductions now, so we need less of this scrubbing later in this century. In any case, we don’t yet have this technology at scale.
We might see more evidence of our energy use around us: solar panels on our roofs and wind turbines in our fields. But is this really such a bad thing? It beats the invisible fossil-fuelled air pollution that kills millions each year.
People in higher income nations use so much energy that if you had to replace the fossil fuels and renewables with human labour, each European would need 100-150 energy servants working for them 24-7. This might be a shocking statistic. But by seeing the source of our energy, perhaps we’ll be encouraged to find ways to use less of it.