Bryn Baker, WWF, coauthored this blog.
Renewable energy for heating and cooling applications has received relatively little attention compared to renewable electricity, despite large and growing demand for renewable thermal solutions. The Renewable Thermal Collaborative (RTC) is putting greater focus on this topic, led by companies like Mars, P&G, and General Motors and cities like the City of Philadelphia.
Energy used for heating and cooling makes up approximately 50% of total global final energy demand and 39% of energy-related CO2 emissions. In the US, industrial manufacturing, which mostly consumes thermal energy, accounts for one-third of the nation’s total energy use. In the European Union, heating and cooling accounts for half of the total energy consumption, and within the industry accounts for over 70%.
The carbon reduction potential is significant. This, together with thermal users setting goals to cut emissions and shift to renewable energy, makes the call for clean thermal solutions imperative.
The First Barrier
The inconsistencies around the accounting methods used to assess the emissions impact of renewable thermal projects is slowing deployment and impeding decision-making. The lack of consensus around which methodologies to use is leading to confusion by users and incomplete assessments of the emissions and emissions inventories.
A new Navigant report, Renewable Heating and Cooling for Industrial Applications: Guidance for Carbon Accounting, developed with the RTC, reviews the methodologies for six project types (see table below) and recommends a single methodology for each type to simplify guidance for end-users. The report finds that some distilling of the range of methodologies is possible, but that significant gaps remain in accounting for bioenergy projects.
For four bioenergy project types—ranging from burning biomass waste and residues, virgin wood, or biogas—the report recommends one methodology (BioGrace-II) that is the most comprehensive compared to others but it excludes a calculation for three categories of emissions: 1) biogenic emissions, 2) conversion of natural forest to plantations, and 3) indirect land use change, which could result in a significant underestimate of emissions.
These three gaps indicate where work is needed to develop methodologies and build consensus around how users treat these emissions. This is important both to facilitate informed decision-making about the emissions impact of projects and to create a complete emissions inventory.
The report recommends using bioenergy from residual sources instead of virgin materials as the methodological caveats are most relevant for the latter. Navigant and RTC’s report is the first step in clarifying methodologies and identifying ways to provide clarity and guidance going forward.
The RTC is now working to assess approaches for accounting for biogenic emissions from a user perspective and making recommendations that can be adopted into accounting processes. Other stakeholder groups are addressing the gaps around land use change and the RTC will support these efforts.
Beyond bioenergy projects, two project types—ground source heat-pumps and waste heat recovery (from burning fossil fuels)—have either a consensus methodology or an uncontroversial calculation method that can be used. For recovered heat, a straightforward method was proposed, though no widely accepted methodology exists. Therefore, consensus was more clear-cut for these project types.
Recommended Methodologies by Project Type
(Source: Navigant and Renewable Thermal Collaborative)
The Next Frontier
In the not too distant future, candy, paper products, and cars may be made in factories that no longer rely on fossil fuels for process heat. The same shift is coming for cities, hospitals, and universities. Renewable thermal represents another frontier in the low carbon transition where stakeholders are joining forces to pioneer solutions. Getting the emissions accounting right is an important first step on that journey.