146 Oscar Van Vliet
On intermittency, we find that Switzerland can phase out nuclear and switch
to renewables without risk of intermittency as long as we do not rely solely on PV,
even though there is sufficient space to put the panels (for more details, see Díaz
Redondo, van Vliet, and Patt, 2017). This is because Swiss hydropower can compensate for limited intermittency, but less so in winter when PV output is low and
Swiss rivers get limited water. Relying only on PV will require some seasonal electricity storage, which is currently prohibitively expensive due to the staggering
volume of electricity it would have to store for every winter. Wind power from the
North Sea is especially suited to the Swiss electricity system as it is more stable
than solar power and produces more electricity in winter.
Furthermore, both North Sea wind and North African CSP are likely to be
cheaper than using natural gas due to the rapid decline in installation cost for
renewables electricity. As a measure of this, we use the levelized cost of electricity (LCOE) that is defined as the cost of the entire electricity supply system,
including grid and backup plants to guarantee constant supply, divided by the
kWh of electricity it supplies (in Swiss francs per kilowatt hour). For example,
based on cost projections for wind and CSP from 2011 to 2016, replacing
nuclear with a combination of wind and CSP would cause an LCOE ranging
from about the same as using natural gas to almost twice as much. However,
using commercial costs for wind and CSP contracted in 2017 results in an
LCOE below these ranges. This showed that: (a) their model calculations were
outdated by the time they were published; and (b) that renewables have reached
‘grid parity’. The cost of generation is no longer a reason to avoid a switch to
renewables.
If Swiss utilities can invest in, buy a majority stake, or otherwise gain control
over one or two dozen wind farms and/or CSP plants abroad, this system would
insulate Swiss electricity supply from the intermittency of individual renewable
power plants and the resulting fluctuations in prices on power markets. This
would be a shift in policy for Swiss utilities: they already own stakes in power
plants in foreign countries (overwhelmingly in EU member states) but the electricity is sold on local markets, not imported back to Switzerland.
However, the second risk is that long power lines come with increased
chance of outages due to extreme weather, which currently accounts for almost
half of all grid outages. The magnitude of this risk depends on the grid: for a
future with a large share of imports, sufficient redundancy in transmission corridors, high- quality equipment, and best practices in grid management can
minimise the risk. Quantitative analysis and interviews with grid experts have
shown that grids can almost always be built to withstand the harshest conditions
in any given country. For example, the Finnish grid suffers more outages in the
comparatively mild summer than in the harsh Nordic winter. Exchanging best
practices would help transmission system operators (TSOs) prepare for changes
in weather conditions brought on by climate change. This can be organised
through existing organisations like ENTSO- E or Eurelectric. Furthermore, even
if the transmission grid breaks down due to weather or for other reasons, Switzerland has a large capacity for hydropower to provide some short- term buffer.
On intermittency, we find that Switzerland can phase out nuclear and switch
to renewables without risk of intermittency as long as we do not rely solely on PV,
even though there is sufficient space to put the panels (for more details, see Díaz
Redondo, van Vliet, and Patt, 2017). This is because Swiss hydropower can compensate for limited intermittency, but less so in winter when PV output is low and
Swiss rivers get limited water. Relying only on PV will require some seasonal electricity storage, which is currently prohibitively expensive due to the staggering
volume of electricity it would have to store for every winter. Wind power from the
North Sea is especially suited to the Swiss electricity system as it is more stable
than solar power and produces more electricity in winter.
Furthermore, both North Sea wind and North African CSP are likely to be
cheaper than using natural gas due to the rapid decline in installation cost for
renewables electricity. As a measure of this, we use the levelized cost of electricity (LCOE) that is defined as the cost of the entire electricity supply system,
including grid and backup plants to guarantee constant supply, divided by the
kWh of electricity it supplies (in Swiss francs per kilowatt hour). For example,
based on cost projections for wind and CSP from 2011 to 2016, replacing
nuclear with a combination of wind and CSP would cause an LCOE ranging
from about the same as using natural gas to almost twice as much. However,
using commercial costs for wind and CSP contracted in 2017 results in an
LCOE below these ranges. This showed that: (a) their model calculations were
outdated by the time they were published; and (b) that renewables have reached
‘grid parity’. The cost of generation is no longer a reason to avoid a switch to
renewables.
If Swiss utilities can invest in, buy a majority stake, or otherwise gain control
over one or two dozen wind farms and/or CSP plants abroad, this system would
insulate Swiss electricity supply from the intermittency of individual renewable
power plants and the resulting fluctuations in prices on power markets. This
would be a shift in policy for Swiss utilities: they already own stakes in power
plants in foreign countries (overwhelmingly in EU member states) but the electricity is sold on local markets, not imported back to Switzerland.
However, the second risk is that long power lines come with increased
chance of outages due to extreme weather, which currently accounts for almost
half of all grid outages. The magnitude of this risk depends on the grid: for a
future with a large share of imports, sufficient redundancy in transmission corridors, high- quality equipment, and best practices in grid management can
minimise the risk. Quantitative analysis and interviews with grid experts have
shown that grids can almost always be built to withstand the harshest conditions
in any given country. For example, the Finnish grid suffers more outages in the
comparatively mild summer than in the harsh Nordic winter. Exchanging best
practices would help transmission system operators (TSOs) prepare for changes
in weather conditions brought on by climate change. This can be organised
through existing organisations like ENTSO- E or Eurelectric. Furthermore, even
if the transmission grid breaks down due to weather or for other reasons, Switzerland has a large capacity for hydropower to provide some short- term buffer.