Committed To 100%

It is entirely possible to transition the energy system of the UK to one hundred percent renewables. Professor Mark Jacobson and team have developed individual roadmaps for 139 countries to transform the energy infrastructure each country uses for power generation, transportation, heating and cooling, to one powered by wind, water and solar. The roadmaps envisage eighty percent conversion by 2030 and one hundred percent by 2050.

Not only is it feasible for wind, water and solar power to replace fossil fuel power but there is also a huge dividend for doing so. Overall energy demand is reduced (by over forty percent globally!) as a result of the switch, in part because extra energy is no longer needed to extract, transport and process fossil fuels. Often overlooked, it’s a huge energy efficiency bonus that far outweighs the cost of anachronistic fossil fuel subsidies.

The main electricity-generating technologies are already commercially available: onshore and offshore wind turbines, concentrated solar power, geothermal heat and electricity, rooftop and utility-scale solar photovoltaics. The main electric technologies to replace the equivalent fossil fuel technologies are also commercialised on a large scale today, such as electric heat pumps for air and water heating, electric passenger vehicles, electric induction furnaces, electric arc furnaces, dielectric heaters.

A few of the electric technologies included in these roadmaps are still being designed for commercial use, such as current early stage electric aircraft and hybrid hydrogen fuel cell-electric aircraft, with the assumption that they would be ready for large-scale deployment before 2050.

The mix of renewable energy supplies in the UK roadmap is just one of many potential combinations of wind, water and solar power that can result in a stable, low-cost system of energy production, distribution and use. Each city or local region would rely on a unique mix of renewable energy sources as each geography and topology is different.

The relative merits of various eco-technologies are local decisions and the trade-offs are for people on the ground to make. The technical challenge in switching to renewables is not so much in choosing the appropriate mix but in managing a supply that inherently fluctuates: the electricity grid cannot store energy and so production and consumption must be equal all the time.

David MacKay has a wonderfully prosaic, no nonsense approach to such energy supply and demand challenges, and relishes replacing ill-informed opinion with realistic numbers in his book, Sustainable Energy Without the Hot Air. He looks at fluctuations in our renewable energy in two ways: short-term changes in either energy supply or demand that result in a slew of delivered power, and longer-term lulls when there is little renewable production.

In the UK, the slew rate when a strong wind stops blowing is no worse than in the mornings when everyone gets up, turns on the lights, and switches on the kettle. His point is that short-term fluctuations from renewables are a problem just like the problem of demand spikes that engineers have already solved. Similarly, long-term lulls can be addressed either by reducing demand during the entire period or by storing up the energy before the lull (or some combination). Again, the numbers stack up if the grid is smart enough to manage demand and to connect storage systems to the grid.

Some suggest that additional energy options such as nuclear power, coal with carbon capture and sequestration (coal-CCS), biofuels and bioenergy, should also play major roles in reducing carbon emissions. However, all four of these technologies represent opportunity costs in terms of carbon and air pollution emissions. Nuclear and coal-CCS may also represent additional opportunity costs in terms of their direct energy costs and their time lag between initial planning and becoming fully operational relative to wind, water and solar energy systems.

These roadmaps are consistent with conclusions drawn in previous studies: it is technically and economically feasible to transition to renewable energy for all uses; the main barriers are social and political. Citizens can use their power locally to break this logjam, by choosing renewable energy wherever it is available and supporting their local community energy co-ops.

Photo by Niclas Dehmel on Unsplash