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100% renewables - but slowly

A new multi-regional energy model attempts to identify the lowest costs energy transition path to 100% renewables by 2100. It is very different from most 100% scenarios. Renewables are not expanded much initially. And transport decarbonisation is left to the near the end of the century - after 2090!  So it’s a relatively delayed fossil fuel phase out programme compared with some other 100% renewable scenarios (e.g. LUT and Stanford's look to 2050), although the emphasis on efficient use of energy may reduce overall demand and emissions from the levels they might have reached. 

The new energy model makes use of three archetype regions, with Italy used as a case study- North (colder weather), Central small, largely populated, highly industrialized (mild weather) and South (warmer weather), with solar and also (oddly) wind seen as mostly in the large latter region.  But it doesn’t think long-distance ‘supergrid’ power transmission between these regions will be very prevalent due to its high cost. Some room for debate there, and also on the use of Italy as an example/test case ‘since it is a nation belonging to the temperate zone that well represent a Western World country’. Well maybe, but a central European country like Germany might have been more relevant. But then all the paper’s authors are Italian, although their aim is to provide more general guidelines, applicable to all Western countries.

While they say the details will vary in each region and area, overall they look to a multiphase transition based on the percentages of renewables proposed by the European Commission, although no nuclear in included, as is the case in Italy.  In the early stages of the transition, renewable capacity would expand, but only relatively slowly. Instead, they say ‘the reduction of the carbon footprint of the energy sector can be achieved just replacing boilers with heat pumps and without installing additional capacity of renewable systems. This action takes advantage of a more efficient production of the low-temperature heat, which leads to a lower fossil fuel consumption and, indirectly, to a higher renewable penetration for the same amount of energy demand.’ So it reaches 30%.

They say that ‘this strategy is preferred because, at this transition stage, it is less expensive than investing in renewable energy systems. Although this decision would imply a halt in investment in renewables, which is hardly feasible at present, it should be welcomed as a cue to review some decisions on energy policies’. Pretty controversial! 

However, in the subsequent step, with the renewables share increasing from 30% to 60%, installation of heat pumps instead of boilers to supply low-temperature heat continues, but they say that  ‘the installed capacity of renewable energy generation systems is also increased. In this way, the decarbonization is supported both by the efficiency increase of the system and by the conversion of the primary energy from fossil to renewable.’  Then ‘once the direct electricity and the low-temperature heat demands are decarbonized, the high-temperature heat has the priority. This phase of the transition (i.e., increase of renewable energy share from 60% to 90%) is based on the utilization of green gases in combustion processes’.

As a final step of the transition, the renewable share rises from 80% to 100%, with the transport sector being converted to renewables, that programme starting in 2090. ‘At First, green hydrogen is utilized for heavy-duty vehicles, then the light-duty vehicles are converted to electric and  finally, bio-fuels are produced for aviation.’

Overall it sounds a bit upside down- a recipe for delay! But they say ‘although the transition trend depicted here may appear remarkably different from most of the actual policies applied worldwide, it derives from relatively simple but accurate models of the physical/ thermodynamic processes occurring in the real plants and grids, and includes the cost projections of the most influential agencies’.  

Well that is debatable. Heat pumps can be very efficient in terms of meeting heat demand, but can be expensive to install, while renewable electricity is the cheapest power supply option now  across all sectors –  why not  start with that and get emissions down faster. Maybe they think there won’t be enough. Well that’s a matter mainly of politics, as is the cost-  renewables like wind and solar got cheap once the market for them was established. However this study doesn’t really take economic/technical system dynamics like that fully into account. It just looks at the cost data projected by ‘influential agencies’.  And that has sometimes been pessimistic on renewables, for example in the case of the IEA and PV solar, at least until recently. Especially when compared with the arguably unwarranted optimism that had been common from such sources about future nuclear costs.

While a focus on cost is understandable, cost projections, especially long-term ones, may be unreliable as guides to policy. This paper seems to assume that transport decarbonisation will be very costly. It may be that, tragically, transport will be politically hard to fully decarbonize. That’s is how it looks to some at present. So it will get left until last. But we don’t really know how things will pan out as climate change begins to impact, social views change and technology develops.  Ever optimistic, Stanford’s Mark Jacobson says we have the technology now to do it globally and fast (by 2050) in all sectors, including transport. Well let’s hope so. 2100 is too far off...For an update, see Jacobson’s contribution to a recent 100% renewables webinar, which also has contributions dismantling the case for nuclear, including SMRs. 

The Italian scenario looked at above apart, there are plenty of other fairly gloomy prognoses about global energy futures doing the rounds. Some are just anti-renewables polemics, but some are more thoughtful, focussing on what is politically realistic.  Although that opens up all sorts of possibilities, including for radical social and political change, potentially freeing up new avenues for technology-aided change and a transition to what some have called ‘eco-socialism’ via the adoption of ‘degrowth communism’. That may sounds scary to some, but then so may the sort of high-tech based capitalist growth proposed by some eco-modernists. There may be other options, but, given the evident failure of current ways of organising the world, one way or another, things seem likely to change dramatically - and long before 2100!

 

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