Absorption Chillers to Improve the Performance of Small-Scale Biomethane Liquefaction Plants

Biomethane liquefaction may help decarbonization in heavy transportation and other hard-to-abate sectors. Small-scale liquefaction plants (<10 ton/day) are suitable for small biogas plants located near farms and other agricultural activities. “Internal refrigerant” refrigeration cycles (e.g., Kapitza cycle) are often proposed for small-scale natural gas liquefaction due to their simplicity. An optimized Kapitza-based cycle is modeled and simulated, and then several modifications were studied to evaluate their influence on the energetic and economic performances. Results showed a specific consumption ranging between 0.65 kWh/kg and 0.54 kWh/kg of bio-LNG with no significant improvements by increasing cycle complexity. Instead, a reduction of 17% was achieved with the implementation of absorption chillers, that effectively turn waste heat into useful cooling energy. An economic assessment was finally carried showing that the Levelized Cost of Liquefation is more affected by electricity cost than additional CapEx.

Levelized Cost Based Economic Assessment of Waste-to-Energy Conversion Technologies in Pakistan

Regarding the bridging of the existing gap around the economic assessment of waste-to-energy (WTE) conversion technologies in Pakistan, this study performs a techno-economic assessment of energy generation through both the thermal and biochemical processes. The levelized cost of electricity (LCOE) serves as the fundamental parameter for analyzing the economic viability of these processes and their comparison with other energy generation processes. Based on the results, essential components of a bioenergy supply chain have been identified, through which the levelized cost can be lowered significantly. Furthermore, it has been defined as: What should be the role of key stakeholders for mobilizing the finance towards the bioenergy infrastructure development in Pakistan?

Analysis of the levelized cost of green hydrogen production for very heavy vehicles in New Zealand

<p>This study examined the feasibility of green hydrogen as a transport fuel for the very heavy vehicle (VHV) fleet in New Zealand. Green hydrogen is assumed to be produced through water electrolysis using purely renewable energy (RE) as an electricity source. This study chose very heavy vehicles as a potential market for green hydrogen, because it is considered “low- hanging fruit” for hydrogen fuel in a sector where battery electrification is less feasible. The study assumed a large-scale, decentralized, embedded (dedicated) grid-connected hydrogen system of production using polymer electrolytic membrane (PEM) electrolysers. The analysis comprised three steps. First, the hydrogen demand was calculated. Second, the additional RE requirement was determined and compared with consented, but unbuilt, capacity. Finally, the hydrogen production cost was calculated using the concept of levelized cost. A sensitivity analysis, cost reduction scenarios, and the implications for truck ownership costs were also undertaken. The results indicate an overall green hydrogen demand for VHVs of 71 million kg, or 8.5 PJ, per year, compared to the 14.7 PJ of diesel fuel demand for the same VHV travelled kilometres. The results also indicate that the estimated 9,824 GWh of RE electricity from consented, yet unbuilt, RE projects is greater than the electricity demand for green hydrogen production, which was calculated to be 4,492 GWh. The calculated levelized hydrogen cost is NZ$ 8.42/kg. Electricity cost was found to be the most significant cost parameter for green hydrogen production. A combined annual cost reduction rate of 3% for CAPEX and 4% for electricity translates to a hydrogen cost reduction of 30% in 10 years and more than 50% in 20 years.</p>

Analysis of the levelized cost of green hydrogen production for very heavy vehicles in New Zealand

<p>This study examined the feasibility of green hydrogen as a transport fuel for the very heavy vehicle (VHV) fleet in New Zealand. Green hydrogen is assumed to be produced through water electrolysis using purely renewable energy (RE) as an electricity source. This study chose very heavy vehicles as a potential market for green hydrogen, because it is considered “low- hanging fruit” for hydrogen fuel in a sector where battery electrification is less feasible. The study assumed a large-scale, decentralized, embedded (dedicated) grid-connected hydrogen system of production using polymer electrolytic membrane (PEM) electrolysers. The analysis comprised three steps. First, the hydrogen demand was calculated. Second, the additional RE requirement was determined and compared with consented, but unbuilt, capacity. Finally, the hydrogen production cost was calculated using the concept of levelized cost. A sensitivity analysis, cost reduction scenarios, and the implications for truck ownership costs were also undertaken. The results indicate an overall green hydrogen demand for VHVs of 71 million kg, or 8.5 PJ, per year, compared to the 14.7 PJ of diesel fuel demand for the same VHV travelled kilometres. The results also indicate that the estimated 9,824 GWh of RE electricity from consented, yet unbuilt, RE projects is greater than the electricity demand for green hydrogen production, which was calculated to be 4,492 GWh. The calculated levelized hydrogen cost is NZ$ 8.42/kg. Electricity cost was found to be the most significant cost parameter for green hydrogen production. A combined annual cost reduction rate of 3% for CAPEX and 4% for electricity translates to a hydrogen cost reduction of 30% in 10 years and more than 50% in 20 years.</p>

Measuring the impact of risk on LCOE (levelized cost of energy) in geothermal technology

Geothermal technology has a high level of uncertainty and, thus, requires thorough risk analysis for economic decisions. The levelized cost of energy (LCOE) is a basic economic analysis widely used in determining an investment or energy mix. Many reputable institutions and government agencies provide LCOE, to which they apply different levels of discount rates to reflect project risk. To this end, the weighted average cost of capital (WACC) is frequently used as a proxy for project risk-adjusted discount rate. However, whether using a higher discount rate for a riskier project is appropriate in calculating LCOE has not been scrutinized. The purpose of this paper is to propose a certainty equivalent method of LCOE as an alternative way for considering risk. We present a theoretical background and formula based on the utility theory, improving the probabilistic LCOE estimation methodology of previous studies. We also perform scenario analysis to show how the certainty equivalent model changes LCOE reflecting different level of risk of the individual variables, which traditional LCOE does not. Additionally, we suggest that the traditional LCOE should be used prudently, recognizing it can distort the result when an individual project has a different level of risk from the industry average.