Definitions

Capacity factor - a measure of reliability

Carbon-free

the energy is produced by a resource that generates no carbon emissions, such as nuclear or large hydroelectric. For example, the waste produced by nuclear power plants needs to be safely stored long term, which can be cost-intensive. Additionally, the creation of dams to build new, large hydroelectric resources have lasting environmental impacts on the surrounding ecosystems.

Carbon-neutral

Carbon-neutral refers to balancing out the total amount of carbon emissions, net-zero carbon means no carbon was emitted from the get-go, so no carbon needs to be captured or offset. For example, a company's building running entirely on solar, and using zero fossil fuels can label its energy as zero carbon. Except that the carbon footprint of the construction and the materials used is not taken into account.

Life Cycle Assessments (LCA) and Carbon Footprints

The full carbon footprint of the life cycle of a product. It quantifies all inputs and outputs. All phases of a product are considered and analyzed, from raw materials, packaging, transport, retail, disposal, and recycling.

Renewables

A naturally replenishing resource that produces zero emissions. Renewable energy sources include solar, wind, geothermal, biomass and biowaste, and hydroelectric. It is important to note that these energy sources while producing no CO2 in operation require large amounts of fossil fuel produced energy during construction and decommissioning.

Carbon-free vs. renewables

While all renewable energy is carbon-free, not all carbon-free energy is renewable. Only naturally-replenishing sources are renewable.

Net zero-energy community

A net-zero-energy community (ZEC) is one that has greatly reduced energy needs through
efficiency gains such that the balance of energy for vehicles, thermal, and electrical energy
within the community is met by renewable energy. Past work resulted in a common zero-energy
building (ZEB) definition system of “zero energy” and a classification system for ZEBs based
on the renewable energy sources used by a building.