A new Greenpeace
report on getting to 100% renewables globally by 2050 revisits the familiar
issue of scale: what’s the right mix of large-scale centralised and small-scale
local projects? It suggests a 70:30 ratio, arguing for mostly decentralised
power (i.e prosumer domestic PV projects and community scale distributed
generation), although it admits this will require more local capacity than if
more imports from more efficient larger projects elsewhere were allowed. It
does assume some are (e.g. from offshore wind and CSP), but not much: it’s keen
of to get the benefits of local control and ownership, and it also worries
about long distance transmission energy losses and grid cable visual impacts.
The issue of local control is an important
one, but over-reliance on small-scale local systems comes at a cost: not all
resources are even distributed. Surely
it is foolish to limit the use of efficient off-shore wind, wave and tidal
farms and CSP in desert areas? And
surely, even if they are more autonomous than now, there is nothing inherently
wrong with trading surpluses between communities? It depends on how the trade is done.
Technically, long distance transmission losses can be low (2%/1000km) and grid
impacts can be avoided (it’s easier to bury HVDV than AC grids), or reduced by
doubling up or replacing existing lines. But the other issue is that Greenpeace
want to avoid most biomass use (not biogas from wastes, but all biomass
imports). That means more electricity has to be produced for heating and
transport. A report from the German Federal Environment Agency, UBA, says that,
in this situation, even with a lot of Power to Gas/ Liquid conversion of excess
renewable electricity (as Greenpeace also suggests), Germany will have to
import a lot of green electricity from abroad, similar in scale (but not type)
to their fuel import level now: with biomass limited, there wouldn’t be enough
from local sources. www.umweltbundesamt.de/publikationen/germany-2050-a-greenhouse-gas-neutral-country
It does sound like you can’t avoid some
long distance transmission, and of course if you have it, although it opens the
door to centralised corporate power, it helps with balancing local variations
in supply and demand across wide areas, with differing resource availability.
So a 50:50 local/import ratio might make more sense, depending on location. Or,
of course, if you want more local power, again depending on location, you could
go for local biomass production and use. Forget about importing wood pellets,
and probably most biofuels for vehicles, but, in addition to AD of local farm,
food and home biomass wastes, surely some types of fast growing energy crops
for power and heat, like short rotation coppicing, can be acceptable in rural
areas, without land use or biodiversity conflicts?
Greenpeace is also nervous about hydro,
with large projects being seen as invasive, despite the fact that hydro
reservoirs can be used to help balance variable renewables, via pumped storage.
Some countries wont have much hydro capacity,
but if they have grid links to other countries with hydro projects they can be
used for pumped storage. That’s already done by Denmark, using Norwegian hydro
to store its excess wind derived electricity, for later re-import when Danish
wind is low and demand high. Once again it shows how useful grid links can be,
as in fact an earlier Greenpeace study of EU options had argued: www.energynautics.com/news/#GP_EU
The new Greenpeace report is very good,
arguing convincingly that, with proper attention to energy saving, supplying
100% of energy globally is possible using just renewables, and would not cost
more net, given the savings on the use of fossil fuel. But the issues touched on above are real
ones. Big hydro and large-scale biomass use do both open up many environmental
issues, so it may be that they have to be kept in check. Or at least be subject
to careful regulation. Similarly, there
are political issues related to trading energy, as we are well aware of with
fossil fuel and the power that has given to global energy corporations. We don't want to replicate that with
renewables. Surely we can come up with more democratic ways to manage energy
systems, even large systems, and avoid rip-off trade relationships? That's something that is currently a central
political issue anyway, with, in the UK, much talk of taming the Big 6 power
companies. It won’t be easy. Especially as we also need to reconfigure the
energy system overall.
However, as part of doing that, we have to
face the issues raised above. It will vary by country. But in general, trying
to duck these issues, by avoiding big hydro and biomass, and limiting
trade/transmission, would add costs and, arguably, make it harder to develop a
viable system. We need to decide what sort of system we need, how to link it up
effectively and equitably, what impacts we can accept and what trade-offs we
want to make between overall technical efficiency and community scale. Quite an
agenda! www.greenpeace.org/international/Global/international/publications/climate/2015/Energy-Revolution-2015-Full.pdf
An incremental
approach is to just focus of local energy and hope that it can expand: building
up from beneath. The rise of ‘prosumers’
and local energy co-ops in Germany suggests that this might be possible,
although it has occurred mainly due to favourable market frameworks provided by
the government – and that may change. Indeed it already is, with FiTs being
phased out, there and elsewhere. In the UK, the new Shadow Energy Secretary, Lisa Nandy,
has said Labour wants to ‘democratise rather than nationalise’ the energy
system. She told delegates at last years Labour party conference that every
community in the country should be able to own their own clean energy power
station. http://ow.ly/SPLVa That’s fine as far as it goes, but it probably
wont be enough to completely change the system. The Thousand
Flowers UK scenario produced last year by the transition consortium looked
to local councils playing a major role, and focused heavily on community-scale
biomass-fired CHP, and heat as well as power production. That might reduce some
of the power transmission issues: it would certainly be hard for the power grid
to cope with the electricity needed to meet all the UK’s heat needs. But would
there be enough biomass for that? And if so, would we be happy for it to be
used? The issues wont go away!
www.realisingtransitionpathways.org.uk/realisingtransitionpathways/news/distributing_power.html
All this and much more is discussed in my new IoP book
Balancing Green Power out later this year.
