100 per cent renewable energy globally by 2050

The world could be fuelled by 95 per cent renewable energy by 2050, according to a report by WWF, while maintaining rates of economic growth and with small lifestyle changes.

“The Energy Report 100% Renewable Energy By 2050” was produced by WWF in collaboration with the energy consultant EcoFys and the Switzerland-based OMA, Office for Metropolitan Architecture.

It comes in two parts, the first more qualitative and inviting discussion, the second a full energy balance from EcoFys.

The scenario projects a 2050 world with no fossil use for electricity, transport and buildings, and for more than an 80-per-cent cut in fossil energy use in industry, where some coke use in the steel industry remains.

Nuclear is ruled out for several reasons. Carbon Capture and Storage is not dismissed, but is not credited “primarily because it is expected to mature too late, by 2025–2030. By the time CCS could then be deployed on a large scale, the use of fossil fuels will have declined so heavily that investments would not be likely to yield the required returns.”

This may seem a pretty devastating critique, but the report hastens to say a few favourable words about CCS, such as bio-CCS and its use for industrial processes. (Maybe it would have been simpler to state that the report authors have different views.)

The quote also shows that the scenario is not only a 2050 scenario. It is not a case of a perfect, but distant world. There is a dotted line through 2020, 2030 and 2040, and the scenario does not make any heavy bets on unproven technology.

But to see the broad picture, with a manageable amount of figures, Table 1 summarises the use in 2010 and 2050.

As seen, efficiency plays a large part. Energy use is projected to shrink some 15 per cent despite two billion more people and world GDP that is more than doubled.

An important part of this increased efficiency comes from retrofitting 2-3 per cent of the floor area of existing buildings every year. Such a level of renovation has already taken place in Germany, according to the report.

Table 1. Global energy provided by source and year (EJ/a).

The biggest contribution to renewables comes from biomass. This suggests a need for “250 million hectares for bioenergy crops, equal to about one sixth of total global cropland”. To achieve this without deforestation or food and water shortages is admittedly “no easy challenge”.

However an honest effort to reconcile different land use stakeholders is presented in the report. It does not use inflated figures for available land, and subtracts more protected land and all land now used for food from the potential area available.

The problem is not that very large amounts of sustainable biomass production is impossible in principle; it is that that we live in an imperfect world where things often go wrong, as already happens. It is commendable to state that “land-grabbing” – when rich countries buy or lease large tracts of land, especially in Africa, to grow biofuels or food – should be outlawed.

But how can you create enough strong incentives for bioenergy crops without also creating incentives for abuse?
Some of the biomass potential is not so controversial however.

Traditional biomass for cooking etc. in poor countries, often unsustainable, is projected to decrease substantially, taking stress off some land.

Residues and waste from food and agriculture should be used more widely and more efficiently, as should felling waste and other by-products from sustainable forestry.

Algae is an additional resource, though not yet a proven technology.

Other routes to sustainability include very large lifestyle changes. This report assumes fairly mild and slow changes of this type.

World GDP is (by convention) expected to grow by more than 100 per cent from 2010 to 2050.

Though no austerity is assumed, some lifestyle changes are seen as necessary. “If people in the developed world ate half as much meat as they do today, we would need less land for growing animal feed and grazing.”

Personal mobility is also predicted to rise by 2050. Projections show the overall distance people travel will increase by half in OECD countries, and treble in the rest of the world. Ecofys “suggests we can manage these increases if we move towards more efficient forms of transport – walking or cycling short distances, taking buses, and taking the train instead of flying.”

1.4 billion people are not connected to the electric grid today. This is one reason why global electricity use more than doubles. The other reason is of course that much of the near-term energy technology produces electricity: wind, hydro, photovoltaics and concentrating solar thermal power produces nothing else. Geothermal energy is used both for direct heat (11.3 EJ) and for power (4.9) by 2050.

Biomass is projected mainly for transport and industry use, but a minor part of it is used for power production.

Concentrating solar thermal, considered for deserts, can store some energy as heat, so electricity production can continue through the night, but not for cloudy days. Photovoltaics and wind and wave power, on the other hand, have a big problem with variability. Hydro and biomass can mitigate, as can demand side management.

Table 2. Efficiency and fuel shift assumptions for all transport modes.

The report assumes that for 60 per cent wind and photovoltaics, “full use of all of the following four levers are needed”:

  • Grid capacity increase
  • Demand side management, first for wholesale customers but then also for individuals
  • Storage as pumped hydro, centralised hydrogen storage and heat storage
  • Excess electricity is used for hydrogen production for use as a fuel in specific applications.

Hydrogen is given a limited role in the scenario, due to huge research, development and infrastructural demand. It is mainly projected for use near production, as an industrial fuel or high temperature source, not for example for cars, but plays a minor part as fuel for ships.

In this electricity-dependent world, cars have to be overwhelmingly electric, either alone or as plug-in vehicles. Electrification degrees are given as follows from

It can be done, but it won’t be easy. One of the non-climate objects is equity, i.e. to end energy poverty and to give access to electricity to everybody. Anything else would be unfair, and this probably calls for some economic growth. Historical data at least tells us that in poor countries, there is a strong correlation between economic growth and life quality.

But is a doubling in global GDP really necessary or, for that part, likely? It could be argued that slower growth would make it simpler to make ends meet.

Fredrik Lundberg

The report can be downloaded here.

In this issue