Transforming our energy systems
Posted on Tuesday, August 10th, 2021
Posted on Tuesday, August 10th, 2021
This diagram above is called an energy flow diagram or a Sankey chart. It illustrates the flow of energy from source (Total Primary Energy Requirement, TPER) to final consumption (Total Final Consumption). This view is developed annually for the USA by the Laurence Livermore National Laboratory and includes an assessment of energy use and waste at the final destination.
Because of the inefficiency of energy change particularly in thermal systems, two thirds of our energy is rejected or wasted into the ambient environment, including in the form of pollutants and climate-warming gases.
For example, an average home in a northern latitude climate with a natural gas boiler will use temperatures greater than 100 ºC to deliver space and water heating of 60 ºC or less. Much of that heat escapes through the walls, doors, windows and chimney, failing to do any work in keeping the inhabitants warm. Or consider an average vehicle powered by an Internal Combustion Engine (ICE) which uses only 25% of the energy generated by combustion to do work on the drive shaft. The rest is rejected through the exhaust tailpipe, through the cooling radiator or emitted as noise.
The figure illustrates the first challenge of any energy transition solution: how to most efficiently deliver the work required and only that. In other words, optimize the Energy Services block in the Sankey diagram. For homes this means effective heat transfer and insulation to use energy effectively and prevent waste. For industrial processes this starts with being absolutely clear on the minimum energy required to do the actual work (e.g. drying) in the plant.
The next opportunity is to use as much energy from the local environment, the direct opposite of many conventional systems in which we lose energy to the environment. For homes and other buildings, solar PV, solar thermal, air-sourced heat pumps and ground-sourced heat pumps are all ways to extract energy from the local environment to replace energy that would otherwise need to be transferred from distance in the form of electricity or natural gas in a grid, or trucked as propane, heating oil or coal.
Decarbonisation of the electricity grid is proceeding in many countries with the increasing penetration of renewable wind and solar. Decarbonisation of gas infrastructure is way behind that of electricity and is causing a huge debate in many jurisdictions about the role of hydrogen as an energy vector and storage mechanism.
CAUSEWAYGT’s technological model is the industrial version of the ground-sourced heat pump. We aim to supply much of industry and large commercial heating (and cooling) needs, currently provided by combustion of fossil fuels, by super-charging large-scale heat pumps with geothermal heat sourced from the earth. These Earth Sourced Heat Pumps tap deeper geothermal heat than ground-sourced heat pumps but similarly use clean electricity from the grid to amplify and boost the heat to the required temperatures, including raising steam.
Replacing fossil fuel heat with 100% clean geothermal energy amplified by low-carbon electricity from wind and solar promises to radically decarbonize many industrial and large commercial situations, addressing a sector that accounts for more than 10% of the world’s Green House Gas emissions.
A note on units
Quad, unit of energy equal to 1 quadrillion (1015) British thermal units (BTUs). The quad is a convenient unit for describing national and world energy resources. A quad is equivalent to 293 TWh and 25199577 tonnes oil equivalent (toe).