Future Grids: challenges and opportunities

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Future Grids:

challenges and

opportunities

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Sistemi e strumenti per l'automazione A. Flammini, AA2011-2012 1

Energy Distribution Today

• It is common believe that AC distribution is the most economic

approach:

•Transformers as key technology

• It is more convenient to concentrate generation in large power •plants

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Characteristics of Present and Future Energy

Grids

• Generation highly

concentrated

• System is quasi-static

• Generation is “totally” under

control

•Load are statistically

predictable

• Flow of energy from

transmission to distribution is unidirectional • Distribution is a totally passive system •More distributed generation

•Renewable sources are

not totally predictable (uncertainty) and not under our control

• Power injection happens

also at distribution level

• The system is

characterized by higher dynamics, e.g. wind puff

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Summarizing the changes

•Growing presence of renewable sources • Solar

• Wind • Waves

• Geothermal

• Growing attentions at the environment even for what it

concerns the infrastructures

• It is becoming less and less likely that new transmission lines

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Photovoltaic Home Systems

1. PV Panels 2. Switching Gear 3. DC Cabling 4. Inverter 5. Energy Meters

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Wind Energy Systems

•Now a mature technology •Widely Spread in Germany •Off-shore windfarms

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Wave Energy

•Total Estimated: • Shoreline 1 TW • Offshore 10 TW

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Geothermal Energy

•Among the first real renewable applications •First industrial plant in Italy at Lardarello •Active research for wider application

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Challenges for the Distribution Grid

•Aims of CO2 reduction can only be achieved

by restructuring the electricity grid

•Power Generation has to be substituted with

Renewables and Distributed Generation (Wind,Solar, CHP)

•High penetration of Renewables in the

network requests a compensation of its fluctuating power input

•Current power plants have a low efficiency

while working outside their designed operation points

•Decentralized Power Generation is suitable

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Challenges for the Distribution Grid

• The Electrical energy system must be constantly balanced

•if the sources are less predictable the balance is less predictable

•if more sources are present and decentralized (not under the authority of

one or very few companies) the balance becomes more complex

•The Distribution system is not ready for automation

•Very limited monitoring

•Protection designed for unidirectional flow of power

•The operation of the system are designed under the assumption of

low dynamics

•Control rooms still have man in the loop •Data refresh is in the order of seconds

•Possible impact at transmission level if large renewable plants are

used

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A Pathway to Smart Grid

•Transmission Level

•Partly already smart

• Power Electronics (FACTS) can make routing more efficient

• Distribution Level

•Full deployment of automation

•State Measurement at Medium Voltage Level using

• First level of involvement of the customers: Peak Shaving

• Second level of involvement of the customers: Generation (VPP) • Third level of involvement: Storage

•Home Level

•Smart Metering

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Open Questions

•What is the limit of stability of the

grid with distributed resources?

•How much renewables is the grid

ready to absorb?

•What kind of architecture should

be adopted for the control of distribution?

•Role of Communication

Infrastructure in the automation

•How to address the new

challenges in terms of complexity?

•How are we going to approach the

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New Solutions .... New Problems

•Generation is less predictable.

•Stability of the network becomes more complicated

•Energy Storage is becoming more and more important •We need to update how we control the energy flow

•One more option ….ÆChange the relation with the user!!! •Smart Metering

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Conclusions

• The Grid is going through a significant redesign and Home

Energy

• Systems are supposed to play a significant role in this process • The evolution toward more decentralized energy sources is

pushing in the same direction

• Many technology insertion opportunities are supposed to play a

role

• However significant uncertainties still affect the scenario

definition making the industrial progress not as fast as it could be

• Standard at every level and in every domain are a key enabler