In the afternoon, young engineers from NetzeBW, a subsidiary of EnBW, the
utility based in Baden-Württemberg, described the research they have been
completing regarding (1) Project Grid-Control; and (2) E-Mobility Allee.
Project Grid-Control is focused on maintaining
a high quality, reliable supply of electricity while managing increasing
numbers of decentralized energy systems. Testing was conducted in Friamt, a
town with potential generation from installed solar photovoltaic (PV) systems
significantly higher than the maximum load. The traffic light model of
monitoring grid congestion was developed; green indicates no danger of too much
power on the grid; yellow indicates a prediction of too much power being generated,
leading to the utility constraining the sale of electricity from distributed PV
systems; red indicates too much power is being produced and the utility must
take emergency measures to curtail energy production. To implement this model,
homes were equipped with smart meters capable of monitoring and controlling the
movement of electricity. Additionally, substations were equipped with
monitoring and communication equipment. Three residential battery storage
systems and one neighborhood battery were also equipped with monitoring and
control systems. Results of the tests indicate that the system works
efficiently to control energy production, but additional technical upgrades of
the low voltage and medium voltage distribution systems are necessary.
E-Mobility Alley explores the effects on the
grid of charging increasing numbers of electric vehicles. Concern with
the ability of the low voltage part of the grid distribution system to handle
large numbers of electric vehicles (EV) charging at the same time led NetzeBW
to test EV charging in a single neighborhood under several conditions
instituted by the utility. With no constraints, the typical maximum number of
EV’s charging at the same time was three (out of 10). Over the course of a
year, the maximum ever charging at the same time was five. Storage batteries,
either in a consumer’s home or for the neighborhood, eased peak demand for
electricity. NetzeBW found that, since most consumers want their EV’s charged
for the morning, they are not concerned with limits on the rate of charging at
night, as long as their vehicles are charged by the morning. NetzeBW plans to
extend this testing to an apartment building in an urban area and to a rural
location to examine the potential different impacts in these environments.