A low-carbon built environment pursuit depends on deep de-carbonization of the energy supply and using renewable energy sources. While this is well-known in principle, a switch to all electric building systems as a strategy for de-carbonization is still a new concept. The concept simple enough, but we are now faced with an interesting transition period as technology and innovation lead to new models of electrification, distributed energy resources, and modernization of the utility grid. All-electric buildings can be designed to make best use of this electric infrastructure.
Wondering how? Read on.
Understanding the Need
To reduce carbon emissions globally, electric utilities across United States (and across the globe) have evolved with increasing percentage of renewable energy sources. In United States, the renewable energy penetration at utility scale has grown from 9 to 18% over the last 10 years. Renewable energy sources can be utility scale systems paired with storage, but there has been a surge in building level distributed energy systems. As utilities’ renewable energy portfolio and distributed renewable energy sources’ capacity continues to expand, the modern electric grid – aka grid of the future – is likely to provide electricity with significantly lower carbon emissions that support all-electric building designs.
Electric fuel mixes across regions currently vary greatly. A review of regional utility fuel mix is key in determining how much impact electrification of built environment may have on carbon emissions. Higher the penetration of renewable energy sources (or other carbon emission free fuels such as nuclear), greater will be the benefit of electrifying buildings. Comparing the national averages of some countries and regions in figure 2 below shows that generating 1,000 Btus of energy using electricity almost always leads to fewer CO2 emissions (ignoring demand side equipment efficiency such as using a heat pump or boiler). This is because most electric utilities use a mix of fuels – coal, natural gas, nuclear and renewable sources – that result in varying carbon emissions. The deep penetration of no-carbon fuel sources in utility fuel portfolio, in California for instance, helps greatly in making electricity a cleaner source of energy.
It makes common sense therefore, for buildings and communities to be equipped and designed to be able to take advantage of low carbon electric infrastructure. For distributed energy resources (DERs) such as PVs and electric storage, one can then argue that since the electric grid is likely to get cleaner, that it is better to wait for the cleaner electricity to become available instead of making expensive on-site capital investments. Need for frequency regulation, eliminating electricity transmission losses, increased resiliency provided by an all-electric infrastructure at building level are strong reasons for not just electrifying buildings, but also for future-proofing buildings with electrification and pairing with reasonable amount of on-site generation.