The Electric Grid

Sustainable development goals related to power system, and why do we have them?

Affordable clean energy, climate action, resilient infrastructure, and sustainable cities. Engineering needs actionable items

Wha are some priorities set by the US department of energy regarding sustainable electric grids?

New generation types (wind, solar), customer participation, infrastructure upgrades, advanced communication/control, and resilient and reliable grids

Threats to sustainable grids

Wildfires, severe weather, fuel volatility, cyber threats

What did the national academy of engineering name as the greatest engineering achievement of the 20th century?

Electrification

3 main sections of power grid?

Generation, transmission, and distribution

Electric generation related entities

Power producers

Electric transmission

Involves high voltage lines to move electricity long distances

Electric transmission related participants

Transmission line renters and auxiliary service providers

Electric distribution

Lower-voltage systems deliver power to homes / businesses

Electric distribution related participants

Utility (enabling power distribution) and customers (load or demand)

DER

distributed energy resource. A small scale energy resource connected close to where electricity is used, usually on distribution side of grid instead of large centralized power plants. This includes rooftop solar panels and small wind turbines, and also EVs

What is the issue with coordinating all the participants / entities involved in the power grid? (like power producers, distribution companies, end customers, transmission companies)

They all have different wants / needs. Generators want profit, utilities need reliability, customers want low prices, etc

System Operators

Organizations that coordinate large regional grids, balancing generation and demand. Act as a link between power producers / transmission companies and distribution companies / end consumers

Which entities are involved in the Electric Grid Transmission System (WHolesale of electricity)

Power Producers, Transmission Companies, Distribution COmpanies, System operators, NERC, FERC

Which entities are involved in the electric grid distribution system (Retail of electricity)

Distribution companies, End Customers, PUC

NERC

North American Electric Reliability council, set standards and protocols for system operators

FERC

Federal Energy Regulatory Commissions, makes rules and regulations for system operators

PUC

Public utilities commissions, set retail rates and design for distribution companies

What are some new trends in the modern grid?

Solar, batteries, EVs, and small wind systems. Now customers are also generating electricity and sending them back into the grid and EVs are changing the demand of electricity

What is stochasticity and how do EV charging / home solar generation influence it regarding the electric grid?

Stochasticity is randomness and unpredictability. Home solar can decrease electric grid power demand- as homes produce their own power (but depends on solar activity) however EVs increase demand on the grid. It creates many new variables

Price Volatility of electric grid because of renewables / EVs

Price fluctuate more because of laws of supply/demand, drop in renewable energy generation (if clouds, at night, etc) require expensive "at the moment" backup generation. Spikes in EV charging demand (when everyone wants to charge them after they get home from work) also requires “at the moment” backup generation

Why can EV charging overload equipment?

Many people charging simultaneously in the evening. This can also cause prices to rise because supply/demand

What is the revenue recovery challenge of utilities when people install solar?

Utilities spend money on maintaining infrastructure, but earn money from customers buying energy. If customers install solar they buy less electricity meaning infrastructure is less maintained, which leads to problems when solar can't be used (i.e. at night).

Benefits of DER

Low-cost energy, non-wire alternative, grid reliability [all needs research and innovation]

What is an infrastructure fee regarding DER and what are it's issues?

Some utilities propose to give solar users as they still use grid services (especially to sell back to the grid), but most utilities want it to be fixed, which is unfair to some solar panel users who generate less power (south facing panels generate more then north facing). It also lessens solar users’ returns on investment

What can DERs do during electrical emergencies?

When central power stations shuts down (like in Texas during that one winter), DERs still produce electricity and can provide a little to the grid and should be compensated by utility companies

On-arrival charging of EVs, what is it and is it good or bad?

It's when everyone charges EVs once they arrive home after work, it's bad because it can cause huge spikes in energy demand

EV charging schedules, what is it and is it good or bad?

Charging is staggered over time (different people are set to charge their EVs at different times). It's good because it prevents spikes in energy demand

Aggregator-based DER management

People that coordinate many DERs together, managing EV charging and scheduling distributed solar

Aggregator in grid structure act between what groups?

Act as bridge between utilities/distribution, consumers/prosumers (customers who both consume / produce electricity), and system operators

Traditional clustering

Users with similar energy demands are clustered together in an aggregator (homogeneity)

Context- Aware Heterogenous Clustering Algorithm (CAHC)

Intentionally combining households with different energy demands (heterogeneity) to one aggregator cluster because mixed behaviors smooth total demand. Helps in EV charging schedules

Where is coincident charging (when everyone charges at the same time, causing spike in energy demand) most problematic for EVs?

Rural areas, but optimal charging (charging schedules) help a lot

What was the problem in Ellis Kansas?

There was one aging transmission line to the town, causes power outage issues

EENS

Expected energy not served, measures how much energy customers lose during outages. Lower EENS = better reliability

What were the solutions to Ellis Kansas' transmission problem?

Building new transmission line (lowest EENs), building solar farm in Ellis to support transmission line (best benefit/cost ratio), and roof top solar

What are some changes in US energy mixes?

Wind and solar rising, less coal

What are some trends on the grid?

Transmission is expanding but more transmission needed

Trend in batteries and energy storage

Both growing (batteries price lowering)

What do future sustainable grid require?

+Coordination between Solar, EV, and battery storage

+Enhanced techno-economic analysis to capture locational impacts

+Coordinated processes and policy reforms (like using bottom-up approaches to change grids)

+Equity and social welfare driven investments

Bottom up approach and how does it influence sustainable grid

Future grids rely heavily on distributed customer participation, not only large centralized plants.