Charted: Home Heating Systems in the U.S.

Published

on

By

Fossil fuel combustion for the heating of commercial and residential buildings accounts for roughly 13% of annual greenhouse gas emissions in the United States.

Decarbonizing the U.S. economy requires a switch from fossil fuel-combusting heating solutions to renewable energy sources that generate electricity.

Currently, the majority of new homes in the U.S. still combust natural gas for heating through forced-air furnaces or boilers. Just like cars need to be electric, homes will need to switch to electricity-powered heating systems that use renewable energy sources.

The graphic above uses census data to break down the different heating systems and fuels that are warming the 911,000 single-family homes built in the U.S. in 2020.

Most American homes use one of the following three heating systems:

U.S. home heating has been going through a transition over the last two decades. Electricity has steadily been replacing gas and biofuel/wood-powered home heating systems for new homes, and powers almost half of the heating systems in single-family homes built in 2020.

Here’s how the share of heat sources for new houses changed between 2000 and 2020:

Percentages may not add to 100 due to rounding.

While electricity’s share has grown since 2000, most American homes are still heated with gas largely because of the fossil fuel’s affordability.

According to the U.S. Energy Information Administration (EIA), households relying on gas for space heating are expected to spend an average of $746 over the winter months, compared to $1,268 for electricity, and $1,734 for heating oil.

Of the 911,000 new single-family homes, 538,000 houses installed forced-air furnaces. Of these, 83% or nearly 450,000 homes used gas as the primary heating source, with 16% opting for electrified furnaces. By contrast, 88% of the 353,000 homes that installed heat pumps relied on electricity.

Here’s how the heating systems and fuels break down for single-family homes built in 2020:

Percentages may not add to 100 due to rounding.

Fewer than 1% of new single-family homes used hot water or steam systems, and the majority of those that did relied on gas as the primary fuel. Around 1.3% of new homes used other systems like electric baseboard heaters, smaller space heaters, panel heaters, or radiators.

While gas remains the dominant heating source today, efforts to decarbonize the U.S. economy could further prompt a shift towards electricity-based heating systems, with electric heat pumps likely taking up a larger piece of the pie.

The Key Minerals in an EV Battery

Lithium Consumption Has Nearly Quadrupled Since 2010

How Clean is the Nickel and Lithium in a Battery?

Which Countries Are Most Reliant on Coal?

How Old Are the World’s Nuclear Reactors?

Life Cycle Emissions: EVs vs. Combustion Engine Vehicles

Ranked: The 20 Most Air-Polluted Cities on Earth

Mapped: Renewable Energy and Battery Installations in the U.S. in 2023

This graphic from Wood Mackenzie shows how nickel and lithium mining can significantly impact the environment, depending on the processes used.

Published

on

By

The production of lithium (Li) and nickel (Ni), two key raw materials for batteries, can produce vastly different emissions profiles.

This graphic from Wood Mackenzie shows how nickel and lithium mining can significantly impact the environment, depending on the processes used for extraction.

Nickel is a crucial metal in modern infrastructure and technology, with major uses in stainless steel and alloys. Nickel’s electrical conductivity also makes it ideal for facilitating current flow within battery cells.

Today, there are two major methods of nickel mining:

From laterite deposits, which are predominantly found in tropical regions. This involves open-pit mining, where large amounts of soil and overburden need to be removed to access the nickel-rich ore.

From sulphide ores, which involves underground or open-pit mining of ore deposits containing nickel sulphide minerals.

Although nickel laterites make up 70% of the world’s nickel reserves, magmatic sulphide deposits produced 60% of the world’s nickel over the last 60 years.

Compared to laterite extraction, sulphide mining typically emits fewer tonnes of CO2 per tonne of nickel equivalent as it involves less soil disturbance and has a smaller physical footprint:

Nickel extraction from laterites can impose significant environmental impacts, such as deforestation, habitat destruction, and soil erosion.

Additionally, laterite ores often contain high levels of moisture, requiring energy-intensive drying processes to prepare them for further extraction. After extraction, the smelting of laterites requires a significant amount of energy, which is largely sourced from fossil fuels.

Although sulphide mining is cleaner, it poses other environmental challenges. The extraction and processing of sulphide ores can release sulphur compounds and heavy metals into the environment, potentially leading to acid mine drainage and contamination of water sources if not managed properly.

In addition, nickel sulphides are typically more expensive to mine due to their hard rock nature.

Lithium is the major ingredient in rechargeable batteries found in phones, hybrid cars, electric bikes, and grid-scale storage systems.

Today, there are two major methods of lithium extraction:

From brine, pumping lithium-rich brine from underground aquifers into evaporation ponds, where solar energy evaporates the water and concentrates the lithium content. The concentrated brine is then further processed to extract lithium carbonate or hydroxide.

Hard rock mining, or extracting lithium from mineral ores (primarily spodumene) found in pegmatite deposits. Australia, the world’s leading producer of lithium (46.9%), extracts lithium directly from hard rock.

Brine extraction is typically employed in countries with salt flats, such as Chile, Argentina, and China. It is generally considered a lower-cost method, but it can have environmental impacts such as water usage, potential contamination of local water sources, and alteration of ecosystems.

The process, however, emits fewer tonnes of CO2 per tonne of lithium-carbonate-equivalent (LCE) than mining:

Mining involves drilling, blasting, and crushing the ore, followed by flotation to separate lithium-bearing minerals from other minerals. This type of extraction can have environmental impacts such as land disturbance, energy consumption, and the generation of waste rock and tailings.

Environmentally responsible practices in the extraction and processing of nickel and lithium are essential to ensure the sustainability of the battery supply chain.

This includes implementing stringent environmental regulations, promoting energy efficiency, reducing water consumption, and exploring cleaner technologies. Continued research and development efforts focused on improving extraction methods and minimizing environmental impacts are crucial.

Sign up to Wood Mackenzie’s Inside Track to learn more about the impact of an accelerated energy transition on mining and metals.

We look at carbon emissions of electric, hybrid, and combustion engine vehicles through an analysis of their life cycle emissions.

Published

on

By

According to the International Energy Agency, the transportation sector is more reliant on fossil fuels than any other sector in the economy. In 2021, it accounted for 37% of all CO2 emissions from end‐use sectors.

To gain insights into how different vehicle types contribute to these emissions, the above graphic visualizes the life cycle emissions of battery electric, hybrid, and internal combustion engine (ICE) vehicles using Polestar and Rivian’s Pathway Report.

Life cycle emissions are the total amount of greenhouse gases emitted throughout a product’s existence, including its production, use, and disposal.

To compare these emissions effectively, a standardized unit called metric tons of CO2 equivalent (tCO2e) is used, which accounts for different types of greenhouse gases and their global warming potential.

Here is an overview of the 2021 life cycle emissions of medium-sized electric, hybrid and ICE vehicles in each stage of their life cycles, using tCO2e. These numbers consider a use phase of 16 years and a distance of 240,000 km.

While it may not be surprising that battery electric vehicles (BEVs) have the lowest life cycle emissions of the three vehicle segments, we can also take some other insights from the data that may not be as obvious at first.

As we move toward a carbon-neutral economy, battery electric vehicles can play an important role in reducing global CO2 emissions.

Despite their lack of tailpipe emissions, however, it’s good to note that many stages of a BEV’s life cycle are still quite emission-intensive, specifically when it comes to manufacturing and electricity production.

Advancing the sustainability of battery production and fostering the adoption of clean energy sources can, therefore, aid in lowering the emissions of BEVs even further, leading to increased environmental stewardship in the transportation sector.

Ranked: The Top 10 EV Battery Manufacturers

Visualizing China’s Dominance in Rare Earth Metals

The World’s Top 10 Gold Mining Companies

The Key Minerals in an EV Battery

All the World’s Metals and Minerals in One Visualization

All the Metals We Mined in One Visualization

What is a Commodity Super Cycle?

How the World’s Top Gold Mining Stocks Performed in 2020