(184c) Evaluating Alternative Energy Sources
AIChE Spring Meeting and Global Congress on Process Safety
2024
2024 Spring Meeting and 20th Global Congress on Process Safety
Topical 16: Petrochemicals
Advances in Ammonia as a Fuel/Hydrogen Carrier
Wednesday, March 27, 2024 - 2:30pm to 3:00pm
Currently around 85% of the world’s energy is provided by fossil fuels: coal, oil and natural gas. The consequences to the climate of burning these fuels are increasingly serious and self-evident. Therefore, the process industries are under pressure to quickly transition to alternative, ‘clean’ sources of energy. (The year 2050 is frequently suggested as being a target for reducing greenhouse gas emissions to ‘Net Zero’.)
Proposed replacement energy sources include solar (photovoltaic and thermal), wind, nuclear (fission), hydrogen, geothermal, ocean (wave and tidal), biomass, and hydroelectric. Each of these energy sources has many positive characteristics. However, none of them offer the unique combination of features provided by the fossil fuels, particularly oil. (Hydrogen is not a source of energy, but it is included because its use as an energy carrier.)
This paper reviews the different energy sources, and assesses their strengths and limitations.
The Table provides a means of evaluating alternatives. The top row shows the energy sources. The first column in the Table lists the features of each alternative that can help assess its feasibility as a replacement for the fossil fuels.
| Oil | Nuclear | Solar | Wind | Hydrogen | Geothermal | Ocean | Biomass | Hydroelectric | |
| Energy Dense | Y | Y | N | N | P | N | N | Y | Y |
| Renewable | N | N | Y | Y | N | P | Y | Y | Y |
| Available | Y | Y | P | P | Y | Y | N | Y | Y |
| Dispatchable | Y | Y | N | N | Y | N | N | Y | P |
| Portable | Y | Y | N | N | Y | N | Y | Y | N |
| Safe | Y | P | Y | Y | P | Y | Y | Y | Y |
| Scalable | Y | N | Y | Y | Y | P | Y | Y | N |
| Petrochemical Source | Y | N | N | N | P | N | N | Y | N |
| GHG Emissions | Y | N | N | N | N | N | N | N | N |
| Environmental | P | N | N | P | N | N | P | N | P |
The first column lists the properties of each energy source. An evaluation for each energy type is then provided (Y is 'Yes', i.e., desirable, N is 'No', P is 'Partial').
Unfortunately, there is no single source of energy that offers the same combination of features as the fossil fuels, particularly crude oil. For example,
- Nuclear is not dispatchable (it cannot be ramped up or down quickly).
- Solar and wind are not always available (the sun does not shine for half the day, nor does the wind blow when wanted).
- Geothermal is not scalable ― there is a limit to how widespread its use can be.
- Biomass has a huge environmental impact because so much land is needed to grow the raw materials.
This means that the future energy grid will be more complex than today’s because there will be many energy sources. (The grid will also have to include energy storage.) The manner in which they can be fitted into an overall grid is discussed using the following sketch.