IEEE Power & Energy Magazine - November/December 2019 - 70

Load forecasts for systems with high penetrations of behind-themeter renewables can be susceptible to increased error, especially
when prosumers optimize their own consumption.

Sector Coupling Study Results
The higher the share of VREs, the more potential available for
sector coupling to open up new operational flexibility sources
and reduce carbon emissions in other sectors as well. Efforts in
coupling sectors can be seen at the research and development,
policy, experimental, and even commercial levels. All synergies
are designed to transition to decarbonize sectors at a reasonable cost without violating the adequacy or security requirements of systems.

Non-CO2 Other
Non-CO2 Agriculture
Residential
Tertiary
Transport
Industry
Power
Carbon Removal
Technologies
LULUCF
Net Emissions

5,000
4,000

MtCO2eq

increased error, especially when prosumers optimize
their own consumption.
Studies on high-share VRE systems usually focus on
supply-demand balancing with hourly resolution. Today,
additional concepts for sharing operational flexibility across
sectors and advanced methods for their investigation are
needed. Investigations of shorter operational time periods
have been intensified. It is hoped that these studies will
enable systems frequently dominated by inverter-connected
VRE production to manage increasing issues with stability,
frequency, lower inertia, and related matters that occur when
faults must be cleared. Table 1 outlines operational flexibility needs within the energy sector that span several time
horizons, from instantaneous to long-term disruptors.

3,000
2,000
1,000

Different Zero-GHG Pathways
Lead to Different Levels of
Remaining Emissions and
Absorption of GHG Emissions

MtCO2eq

by using smart grids/microgrids and storage at lower voltages and operating actions such as accurate forecasting and
demand-side management.
The challenges for electricity systems dominated by a high
share of wind and solar VREs can be described as follows:
✔ Regulation and reserves requirements: Since output
from VREs has the potential to lead to high ramps, additional regulation and flexible generation or reserves
may be required as well as flexible loads to handle unanticipated generation or load needs. Dispatch signals
to meet demand or prevent voltage issues can secure
the system in stressed situations such as correlated
sunset and evening peak.
✔ Foreseeing and mitigating transmission overloads:
Sudden changes in the VRE output can overload transmission equipment that requires immediate mitigation,
especially in situations with lines and transformers out
of service for maintenance.
✔ Load and VRE forecasting: Since output from variable renewables generally does not correlate well with
any traditional input variables for load forecast models (e.g., temperature, time of day, and day of week),
load forecasts for systems with high penetrations of
behind-the-meter renewables can be susceptible to

0
2005

2010

2015

2020

2025 2030
Year

2035

2040

2045

2050

figure 3. The pathway for sectoral GHG emissions in the EU Commission's 1.5 °C scenarios. LULUCF: land use, land-use
change, and forestry. (Source: EU Commission communication, "A Clean Planet for All," 2018; used with permission.)
70

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