Smart Grids, Electric Vehicles, and Net-Zero Energy Buildings

Posted on Dec 12, 2024 in Electronics

Smart Grid Concept

A smart grid is an electrical network with a two-way flow of electricity and data. With digital communications technology, it can detect, react, and proactively respond to changes in usage and multiple issues. It features self-healing capabilities and enables electricity customers to become active participants.

Objectives of Smart Grids

  • Environmental impact: Reduce consumption peaks with Energy Storage Systems (ESS), integrate renewable energies, and improve efficiency.
  • Control systems integration: Implement centralized control systems.
  • Security: Utilize isolation systems, such as converters and transformers.
  • Flexibility: Enable bidirectional energy flow.

Benefits of Smart Grids

Environment:

  • CO2 emission reduction
  • Reduced environmental impact of electricity supply
  • Delay of new power plant infrastructure for peak hours
  • Improved efficiency, reduced generation for the same consumed kWh

Users:

  • Greater participation
  • Increased knowledge, enabling informed consumption decisions
  • Improved comfort and living conditions
  • Long-term savings

Companies:

  • Easier management due to increased data availability
  • Large market space
  • Fraud detection
  • Peak reduction

Challenges of Smart Grids

  • Communications
  • Demand response
  • Security
  • Privacy and ensuring public trust
  • Integration of renewables (inertia loss)
  • Initial cost

Electric Vehicles

We define electromobility as a road transport system based on vehicles propelled by electricity.

Some road vehicles are equipped with technologies that enable them to produce their own electricity (e.g., hybrid electric vehicles). Others use energy supplied by an external source of electricity, usually the electric grid. This definition applies to battery electric vehicles and vehicles that do not store electrical energy, such as trolleybuses.

Hybrid Propulsion

  • Parallel hybrid: Both prime movers operate on the same drive shaft, so they can power the vehicle individually or simultaneously.

  • Series hybrid: The electric motor alone drives the vehicle. The electricity can be supplied either by a battery or by an engine-driven generator.

The efficiency of parallel and series hybrids varies according to the driving conditions. According to the Hybrid Center, the composition of parallel hybrids makes them more efficient for highway driving at higher, more constant speeds. However, series hybrids are more efficient for city driving because their drivetrain structure reduces the strain on the engine in stop-and-go situations.

Desirable Properties of Electric Vehicles

  • High energy density: Long range
  • High refueling power: Fast refueling
  • Simple refueling
  • Low environmental impact (health aspects, recyclability)
  • Easy infrastructure to implement (replacements)

Net-Zero Energy Buildings (NZEB)

A net-zero energy building (NZEB) is defined as a building that, on average, produces as much energy (electrical plus thermal) from renewable energy sources as it consumes annually.

NZEB

An NZEB produces as much energy annually as it consumes. Design and engineering usually involve energy-efficient technology and renewable energy sources to achieve zero net energy use throughout the year.

Even if a building is not designed for optimal energy efficiency, it could be classified as net-zero if it generates sufficient energy to compensate for those deficiencies.

Passive House

A passive house is a highly engineered structure focused on energy efficiency and a design standard that uses environmental factors to minimize energy use.

It’s a voluntary standard aimed at maximizing comfort and affordability while minimizing the ongoing environmental impact.

Main Goals of Passive Houses

1. Reduce consumption by:

  • Passive use of solar irradiation (building architecture)
  • Strategic use of shading
  • Elimination of thermal bridges
  • Use of high-performance, energy-efficient windows

2. Create renewable energy production:

  • Direct solar irradiation: Thermal and photovoltaic panels
  • Indirect solar irradiation: Wind power (Eolic)

Grid-Connected NZEBs

  • Able to inject or draw energy from the grid.
  • More reliable than isolated systems: If your energy system fails, you can rely on the grid, and vice versa.
  • More complex control.

Island Mode NZEBs

  • No connection with the grid.
  • Requires an energy storage system or secondary generators to operate.

Connectivity in Smart Buildings

  • Connection between all equipment and systems in a building.
  • Sharing information to optimize overall building performance (incorporating some form of intelligence).

Adaptability in Smart Buildings

  • By reading the electricity market and adjusting usage accordingly, a smart building ensures the lowest possible energy costs. This includes the use of smart appliances.

Consumption measurements are necessary to control and optimize the system.

Benefits of Smart Meters

  • Faster problem-solving: Easier identification of supply problems, leading to shorter power outages.
  • Easier power supply adjustments: Remote adjustments eliminate the need for technician visits.
  • Accurate readings: Real-time usage data replaces estimated readings.
  • Tamper-proof: Constant monitoring prevents manipulation.