Decarbonization is becoming an increasingly common goal within industrial facilities. Without proper thought, simply replacing fossil fuels with electricity likely results in higher operational costs and may even increase emissions in the short term. In industrial facilities, electrification alone is not synonymous with carbon reduction. For example, Figures 1 and 2 below show the emissions for a facility considering electric boilers. Figure 1 shows the current operation, with steam generated via natural gas boilers and a cogeneration unit. Figure 2 shows the electrified system, with replacement electric boilers. When emissions for electrical generation are included, the overall emissions increase substantially. The critical assumption here is that all electricity supplied is from a natural gas power plant; local electrical generation profiles must be considered to accurately assess the carbon emission impact of electrification.
Thus any electrification at a facility must coincide with a greater effort by state and federal governments along with local utilities to supply energy from green or low carbon sources. How can electrification be done in a way that benefits the facility and the environment, without relaying heavily on government entities or local utilities? Strategic or beneficial electrification is defined as the reduction of emissions and cost through replacement of fossil fuels with electricity.
Kinergetics believes that strategic electrification should be approached in a manner which leverages waste heat when available, and followed by renewable energy when practical, to reduce electricity requirements and related GHG emissions. In general, this can be broken into three stages:
- Conventional heat recovery – High grade waste heat should be recovered as a first step whenever possible. Examples may include high temperature wastewater, air compressor waste heat, process cooling applications, etc. This form of heat recovery will be the cheapest to implement with most projects attaining a justifiable return-on-investment. In the context of an electrification road-map, it reduces the total load required. As a result, operational and capital costs for future steps are reduced, potentially eliminating the need for new substations.
- Strategic electrification – This step will focus on recovering low grade waste heat to offset fossil fuels, which is often accomplished with a heat pump. Any available waste heat is leveraged in a manner that requires far less electricity than the equivalent heat from an electric boiler. These projects often reduce operational expenditure as electricity is efficiently used to offset fuel requirements. While many projects fail to provide an attractive return-on-investment with current fossil fuel prices, the economics shift to favorable when full decarbonization is the true end-goal of a facility.
- Electrification – In most cases, some amount of energy requirement will remain and need to be replaced with other carbon-free options like electric hot water heaters or steam generators. Options like biomass, biomethane, or green/blue hydrogen may exist for some facilities, however they are often more expensive to operate (at present) unless special circumstances exist. All of these options, including electric, will almost certainly increase operational expenditure. Additionally, overall emissions may increase, depending on how electricity is generated, unless a rapid large scale decaronization of the power grid is undertaken.
Many companies purchase unbundled renewable energy credits, or RECs. Unbundled RECs are sold separately from the electricity generated from a renewable source. This allows facilities which do not have access to renewable energy to purchase the rights to emission free energy. When developing a decarbonization roadmap, it is Kinergetic’s view that RECs should be used in conjunction with long term planning, strategic use of electricity, and local electrical grid decarbonization.