Global Energy Use and Climate Change
In 2024, global energy demand rose by what percentage, nearly double the decade’s average?
2.2%
Embodied energy includes energy from which three processes before a building is occupied?
Mining & manufacturing, transportation, and construction
What is the theoretical maximum efficiency (Betz Limit) for wind turbines?
~59%
Passive solar design can reduce heating and cooling costs by up to what percentage?
85%
Buildings account for approximately what percentage of global energy consumption?
About 40%
What is the key difference between net zero energy and carbon neutral design?
Net zero focuses on energy balance, while carbon neutral includes the entire carbon footprint (including materials and construction)
What share of global energy consumption still comes from fossil fuels in 2024?
Around 70%
Which building material has the highest embodied energy, at 227 MJ/kg?
Aluminum
Hydroelectric power provides about what percentage of the world’s electricity?
About 15%
What are the five key elements of passive solar design?
Aperture, absorber, thermal mass, distribution, and control
Which system typically consumes nearly 50% of a building’s energy use?
Heating & cooling (HVAC)
Buildings account for nearly what percentage of global carbon emissions?
Nearly 40%
Energy production and use account for what percentage of global greenhouse gas emissions?
Over 70%
Operational energy continues throughout a building’s life. Name three examples of where it is used.
Heating/cooling (HVAC), lighting, appliances/electronics, hot water systems, elevators/escalators
Ground source heat pumps can reach what efficiency range?
300–500%
In the Northern Hemisphere, buildings should face within how many degrees of true south for optimal orientation?
Within 15°
What does R-value measure in insulation?
How well insulation resists heat flow (thermal resistance)
Name two passive strategies that help reduce energy use before mechanical systems are added.
Solar orientation, insulation & air tightness, natural ventilation, shading/landscaping
Which country’s per capita emissions are now 16% higher than advanced economies?
China
At what point in a building’s lifecycle does operational energy typically surpass embodied energy?
After 20–30 years
Biomass energy can be produced from which common agricultural or organic materials? (name two)
Crops/residues, wood/forest residues, animal waste, food waste, municipal organic waste
Which material has the highest heat storage capacity for thermal mass?
Water
How efficient can heat pumps be compared to the electricity they consume?
300–400% efficient
What system recovers 80–90% of heat from exhaust air to pre-warm incoming fresh air?
Heat recovery ventilation
Which two renewable energy sources added nearly 700 gigawatts of capacity in 2024?
Solar and wind
What percentage of global energy use and carbon emissions do buildings account for?
Nearly 40%
Which renewable energy source prevents ~4 billion tons of CO₂ emissions annually?
Hydroelectric power
Name one real-world passive solar design example (system or feature).
Trombe wall, sunspace/solar room, or direct gain system
What is the highest LEED certification level, requiring 80+ points?
LEED Platinum
This building was highlighted for producing 60% more energy than it consumes.
The Bullitt Center
What design strategy involves considering emissions across a product’s entire journey from beginning to end?
Life cycle thinking
In the Oakridge High School case study, how much of the existing structure was reused to save embodied energy?
75%
Name one innovative renewable energy trend expected in the near future.
Floating solar farms, offshore wind, advanced energy storage, smart grids, AI energy management, building-integrated PV, or green hydrogen
What building feature blocks high summer sun but allows low winter sun to enter?
Roof overhangs
The Bullitt Center in Seattle generates what percentage more energy than it uses?
60%
What is one career path in net zero building design?
Sustainable architect, energy engineer, HVAC specialist, or renewable energy technician