13 Photovoltaics in the Future Energy System
337
Since then, a lot of research has been undertaken in order to identify, demonstrate
and implement much higher levels of PV penetration in the distribution grid. Over the
past decade, given the strong market development of PV in many countries, situations
of high PV penetration in electric grids have become a truly global issue in more and
more regions around the world. As an example, the state of Bavaria in Germany has
reached 15% average PV penetration.
Following the massive deployment of PV and other variable renewable energy
sources (RES)—mainly wind—in recent years, high penetration is no longer a local
distribution grid issue limited to a few regions or countries. Instead, today we are
talking about “RES-dominated” grids, where variable, non-rotating power generation
from renewable energy sources reaches levels of up to 100% of the load in the
transmission system during longer periods. While the technical system integration
of large amounts of PV capacity in a given electrical network is challenging and
therefore requires adequate solutions, it is by no means a barrier towards the future
large-scale deployment of PV as laid out in this chapter. New electrical network
management techniques, digitalization and smart grids will be decisive for balancing
load and demand in an increasingly decentralised electricity supply. Very high PV
penetration rates where the PV capacity may well exceed the grid capacity, will
require storage options and the coupling of different energy sectors (electricity, heat,
gas, etc.), thereby increasingly connecting different parts of the energy system such as
power generation, electrical grids, storage, including buildings and electric vehicles.
With the emergence of electric cars, a huge peak power and storage capacity will
become available for the grid in many countries. Heat or cold can be stored in fridges,
air-conditioning units, boilers, tanks, or in large underground caverns, even interseasonally (summer to winter). Hydropower, biomass, heat and cold generation are
options already used worldwide for long-term storage. With the expected ultra-low
cost of PV, the power-to-gas solution becomes an option, with the potential to compete
with the price of hydrogen or ammonia made from fossil fuels. If CO 2 sources are
available, synthetic methane can be produced, stored, and burned, ultimately in a
cycle where CO 2 is recaptured.
These developments underline that PV has definitely arrived in the energy
system. Today’s discussion is therefore no longer limited to the integration of PV
in the electricity grid but moves rapidly to the broader challenge of energy system
integration.
References
1. D.M. Chapin, C.S. Fuller, G.L. Pearson, J. Appl. Phys. 25, 676 (1954)
2. R. Vigotti, A. Claverie, in Proceedings of IEEE first world conference on photovoltaic energy
conversion, 2247 (1994)
3. T.D. Couture, K. Cory, C. Kreycik, E. Williams, A policymaker’s guide to feed-in tariff policy
design. NREL (2010)
4. Renewable Energy Sources Act, Federal Ministry for the Environment, Nature Conservation
and Nuclear Safety, Germany (2000)
337
Since then, a lot of research has been undertaken in order to identify, demonstrate
and implement much higher levels of PV penetration in the distribution grid. Over the
past decade, given the strong market development of PV in many countries, situations
of high PV penetration in electric grids have become a truly global issue in more and
more regions around the world. As an example, the state of Bavaria in Germany has
reached 15% average PV penetration.
Following the massive deployment of PV and other variable renewable energy
sources (RES)—mainly wind—in recent years, high penetration is no longer a local
distribution grid issue limited to a few regions or countries. Instead, today we are
talking about “RES-dominated” grids, where variable, non-rotating power generation
from renewable energy sources reaches levels of up to 100% of the load in the
transmission system during longer periods. While the technical system integration
of large amounts of PV capacity in a given electrical network is challenging and
therefore requires adequate solutions, it is by no means a barrier towards the future
large-scale deployment of PV as laid out in this chapter. New electrical network
management techniques, digitalization and smart grids will be decisive for balancing
load and demand in an increasingly decentralised electricity supply. Very high PV
penetration rates where the PV capacity may well exceed the grid capacity, will
require storage options and the coupling of different energy sectors (electricity, heat,
gas, etc.), thereby increasingly connecting different parts of the energy system such as
power generation, electrical grids, storage, including buildings and electric vehicles.
With the emergence of electric cars, a huge peak power and storage capacity will
become available for the grid in many countries. Heat or cold can be stored in fridges,
air-conditioning units, boilers, tanks, or in large underground caverns, even interseasonally (summer to winter). Hydropower, biomass, heat and cold generation are
options already used worldwide for long-term storage. With the expected ultra-low
cost of PV, the power-to-gas solution becomes an option, with the potential to compete
with the price of hydrogen or ammonia made from fossil fuels. If CO 2 sources are
available, synthetic methane can be produced, stored, and burned, ultimately in a
cycle where CO 2 is recaptured.
These developments underline that PV has definitely arrived in the energy
system. Today’s discussion is therefore no longer limited to the integration of PV
in the electricity grid but moves rapidly to the broader challenge of energy system
integration.
References
1. D.M. Chapin, C.S. Fuller, G.L. Pearson, J. Appl. Phys. 25, 676 (1954)
2. R. Vigotti, A. Claverie, in Proceedings of IEEE first world conference on photovoltaic energy
conversion, 2247 (1994)
3. T.D. Couture, K. Cory, C. Kreycik, E. Williams, A policymaker’s guide to feed-in tariff policy
design. NREL (2010)
4. Renewable Energy Sources Act, Federal Ministry for the Environment, Nature Conservation
and Nuclear Safety, Germany (2000)