Power systems based on 100% renewables is nor feasible or realistic

The approach is in direct opposition to those of most forecasters, such as the IEA and Intergovernmental Panel on Climate Change, who emphasise on a mix of technologies

The Sweihan solar power project in Abu Dhabi will be the world’s largest on a single site, with a capacity of almost 1.2 gigawatts. Costing about US$1.2 billion, it will cover an area four times the size of Downtown Dubai. Now imagine building almost three hundred such plants in the UAE alone.

This huge effort is one part of the sketches by the Stanford professor Mark Jacobson and his colleagues on how by 2050, the United States and the entire world could power itself solely with renewable energy – wind, sun and water (hydropower from rivers and tidal power from the sea). His team argues this is not just feasible and environmentally sustainable but, in fact, cheaper than our current system. And it has raised a strange controversy in the US – a controversy in which politics and public relations battle with engineering and logic.

A 100 per cent renewable targets are becoming increasingly popular for cities, countries and companies to adopt. Setting a vague political aspiration for three decades, and now politicians can quote scientific papers in approval.

But this approach is in direct opposition to those of most forecasters, such as the International Energy Agency and Intergovernmental Panel on Climate Change, who emphasise on a mix of technologies. Critics – many of them environmental and renewables advocates themselves – have pointed to errors and dubious assumptions in Jacobson's model.

Unlike many plans, his work looks not only at electricity, but at all energy use. So all industry runs on electricity, all ground vehicles are battery-powered and aircraft fly with hydrogen fuel made from renewable energy. There is no nuclear power, no biofuels (made from wood or crops), and of course no fossil fuels. He also does not use batteries, except in vehicles. So Jacobson needs extreme measures to match the intermittent and uncontrollable supply of solar and wind power until the time it is needed.

In Jacobson's world, there are no communities or environmental groups protesting against new dams and power lines, no shortages of scarce raw materials for solar panels or electric cars. Part of his dismissal of atomic energy assumes a nuclear war would be fought every 30 years, but no nuclear war has occurred in the past 70 years, and nuclear weapons do not require civilian nuclear power.

Three unproved technologies – hydrogen production for energy storage, hydrogen-powered aircraft and underground heat storage – have to be scaled up by hundreds of thousands of times in a few decades. US hydroelectric dams expand have to use hundred times the flow of the Mississippi River. Tiny Singapore, with its busy shipping lanes, has to install almost three times the offshore wind that the energy guru David Mackay calculated as the maximum plausible for the United Kingdom.

The time set, 2050, is now just 33 years away. In 1984, the global energy system – reliant on oil, gas, coal, nuclear and large hydroelectric power, and oil-powered planes, ships and cars – looked not that different from today’s. Indeed many of that era’s power plants and transmission grids still operate. The main difference now, along with steady improvements in efficiency, is the rise of solar and wind power in some places. Last year, renewable energy met 10 per cent of global energy demand, of which hydroelectric power was 7 per cent.

These and other objections suggest that, if anything, Jacobson shows that 100 per cent renewable energy by 2050 is not feasible or realistic. We might anyway ask why it should even be a target. Some use of fossil fuels by 2050 is still possible while meeting climate goals, particularly combined with carbon capture and storage. Nuclear power, at least existing plants, are reliable and cheap.

Claiming uncritically that renewable energy is ready to meet all our needs – and at lower cost with more jobs – is dangerous. It diminishes the urgency of the very real research and improvements we need. It leads countries such as Germany, South Korea and France to scale down or close successful nuclear power programmes – increasing greenhouse gas emissions now with no guarantee they will come down later. And it fixates politicians on backing perceived “winners”, such as ethanol from corn to fuel cars – putting money in the pocket of Iowa farmers at the cost of motorists, for little or no environmental gain.

The Arabian Gulf countries do have great potential to boost their use of renewable energy, particularly solar. Perhaps paradoxically, it may be easier for them to get to a high share of renewables than the US. Electricity demand, mainly for air conditioning, matches well with solar supply in summer. Large areas of sunny deserts give ample room for solar panels. Energy does not have be stored for months, as in Europe, heating and lighting homes on a chilly, dark and still winter evening.

Dubai’s latest world-record low bid, for a concentrated solar power plant which can store energy overnight, is further room for optimism. Other ingenious concepts include using desalinated water, ice and the batteries of electric vehicle fleets as ways of saving energy for when it is needed. Such approaches need rigorous development and deployment, not precisely wrong spreadsheet engineering.

It is time for urgent realism in energy policy: building the next Sweihan solar plant rather than dreaming of three hundred of them.

Robin Mills is the CEO of Qamar Energy, and author of The Myth of the Oil Crisis