Market Power with Combined Heat and Power Production in the Nordic Energy System

The trend toward increasing energy efficiency and variable renewable energy (VRE) production has implications for combined heat and power (CHP) plants, which operate in both the price-driven power market and the district heating (DH) sector. Since CHP will be important in VRE integration, we develop a complementarity model to analyze CHP producers' roles in integrated markets. We use a Nordic case study to gain insights into (i) the effect of the link between CHP and DH on market power and (ii) market power's impact on operations in the DH sector. The results indicate that (i) the link of CHP to DH supply can increase market power and (ii) market power can induce shifts in DH production from heat-only to CHP

Evaluating consumer investments in distributed energy technologies

The adoption of solar photovoltaic and electrical energy storage by end users depends on their economic attractiveness, which is typically assessed with metrics of future cash flow such as Net Present Value (NPV). Yet analyses using NPV typically do not account for the evolution towards low-carbon electricity systems in the short and long term. We show this to be of critical importance for accurately calculating the profitability of these technologies. By linking an energy system model with a power system model, we observe substantial differences between NPV estimates calculated with and without representing potential evolutions of the electricity system. Our results suggest that not accounting for short- and long-run changes in the electricity system could underestimate the NPV of an investment in photovoltaic and storage by around 20%, especially in scenarios with high levels of renewables, moderate flexibility, and high electrification in the energy system. Using system-dependent cash flow metrics can have a major impact on end-users' energy technology profitability

Evaluating consumer investments in distributed energy technologies

The adoption of solar photovoltaic and electrical energy storage by end users depends on their economic attractiveness, which is typically assessed with metrics of future cash flow such as Net Present Value (NPV). Yet analyses using NPV typically do not account for the evolution towards low-carbon electricity systems in the short and long term. We show this to be of critical importance for accurately calculating the profitability of these technologies. By linking an energy system model with a power system model, we observe substantial differences between NPV estimates calculated with and without representing potential evolutions of the electricity system. Our results suggest that not accounting for short- and long-run changes in the electricity system could underestimate the NPV of an investment in photovoltaic and storage by around 20%, especially in scenarios with high levels of renewables, moderate flexibility, and high electrification in the energy system. Using system-dependent cash flow metrics can have a major impact on end-users' energy technology profitability

Achieving fruit, juice, and vegetable recipe preparation goals influences consumption by 4th grade students

<p>Abstract</p> <p>Background</p> <p>Including children in food preparation activities has long been recommended as a method to encourage children's consumption, but has not been evaluated. Goal setting is also a common component of behavior change programs. This study assessed the impact of attaining goals to prepare fruit-juice or vegetable recipes on student fruit and vegetable consumption as part of a 10-week fruit and vegetable intervention for fourth grade students.</p> <p>Methods</p> <p>At six of the 10 sessions, students (n = 671) selected a fruit-juice or vegetable recipe to prepare at home before the next session. Students returned parent-signed notes reporting their child's goal attainment. Baseline and post consumption were assessed with up to four days of dietary recalls. Analyses included regression models predicting post consumption from the number of fruit-juice or vegetable recipe preparation goals attained, controlling for baseline consumption.</p> <p>Results</p> <p>In general, girls and Hispanic students achieved the most recipe preparation goals. For students with highest baseline fruit-juice consumption, post fruit-juice consumption was higher by about 1.0 serving for those achieving 2 or 3 fruit-juice recipe preparation goals. Post vegetable consumption was highest for students reporting the highest baseline vegetable consumption and who achieved two or three vegetable recipe preparation goals. In general, recipe goal setting was a useful procedure primarily for those with high baseline consumption.</p> <p>Conclusion</p> <p>This is one of the first reports demonstrating that home recipe preparation was correlated with dietary change among children.</p

Impacts of Trade Friction and Climate Policy on Global Energy Trade Network

The trade impacts of the COVID-19 pandemic and the Russian invasion of Ukraine have raised questions about the role of trade and climate policies in energy security and global emissions. This study updates a widely used integrated assessment model (IAM), MESSAGEix-GLOBIOM, to represent complex trade networks to explicitly draw energy flows from their origins to their destination. It then examines the effects of (1) energy trade tariff policies, such as import tariffs, as a proxy to represent an unfriendly trade environment and (2) a global carbon emissions tax on the global energy trade network. Results indicate that trade tariff policies have marginal effects on the trade network, i.e., the size of trade and importing-exporting regions do not change significantly. While high import tariffs significantly reduce emissions due to reduced fossil fuel imports in the importing region, this effect does not translate to significant emission reductions globally, as trade policies only impact downstream of the energy supply chain. However, a carbon emission tax dramatically alters the trade network, by (1) reducing its size by up to 50% and (2) forming trade linkages that allow for a more complex and diverse network of suppliers. This diversity under the emissions tax scenario improves the energy security of major energy-importing regions. Moreover, under an emission tax scenario, a friendly trade environment reduces the energy system costs globally. However, trade friction, such as sanctions or high import tariffs, will increase the energy supply cost significantly, especially for energy-importing regions such as Europe, East and South Asia

Gastric Fistula in the Chest After Sleeve Gastrectomy: a Systematic Review of Diagnostic and Treatment Options

This study aimed to establish the optimal diagnostic and treatment algorithm for the management of gastric fistula in the chest (GFIC) after sleeve gastrectomy (SG) through a systematic review of published cases. A multi-database search was performed, which produced 1182 results, of which 26 studies were included in this systematic review. The initial presentation included subphrenic collections, leaks, or (recurrent) pneumonia with associated symptoms such as persistent cough, fever, and/or dyspnea. Computed tomography (CT) scan in combination with either upper gastrointestinal (UGI) series or an esophagogastroduodenoscopy (EGD) was used to adequately diagnose the fistulas. Initial treatment was either with clips and/or clips and stents that were placed endoscopically. When unsuccessful in the majority of the cases, the surgical treatment consisted of total gastrectomy and Roux-en-Y esophagojejunostomy in a laparoscopic or open fashion

Synergies between energy arbitrage and fast frequency response for battery energy storage systems

Energy storage can make key contributions to balancing future low-carbon energy systems by providing a variety of energy system services, with batteries expected to be widely deployed as costs fall with innovation. This paper assesses whether synergies exist between two of the most significant of these services, fast frequency response and energy arbitrage, if a battery energy storage system (BESS) is used to deliver both. A techno-economic model is developed to simulate 600 possible fast frequency response availability windows. Results show that two distinct synergies exist between the two services. The first synergy accounts for the possibility of charging outside the deadband for delivering fast frequency response. We propose an innovative state-of-charge management strategy to exploit this synergy. The second synergy results from energy arbitrage revenues being highly concentrated around peak times, which can enable a battery system to capture most of the arbitrage revenues without an excessive reduction in revenues from capacity provision with enhanced frequency response. The combination of these two synergies means that a battery system could increase its operating profits by 25% by delivering arbitrage and frequency response alternately. This result is shown to be statistically robust using historical data. A battery system able to discharge for 1.5–2 h at its full power rating will most most likely optimise these synergies

Hydrogen Deep Ocean Link: a global sustainable interconnected energy grid

The world is undergoing a substantial energy transition with an increasing share of intermittent sources of energy on the grid, which is increasing the challenges to operate the power grid reliably. An option that has been receiving much focus after the COVID pandemic is the development of a hydrogen economy. Challenges for a hydrogen economy are the high investment costs involved in compression, storage, and long-distance transportation. This paper analyses an innovative proposal for the creation of hydrogen ocean links. It intends to fill existing gaps in the creation of a hydrogen economy with the increase in flexibility and viability for hydrogen production, consumption, compression, storage, and transportation. The main concept behind the proposals presented in this paper consists of using the fact that the pressure in the deep sea is very high, which allows a thin and cheap HDPE tank to store and transport large amounts of pressurized hydrogen in the deep sea. This is performed by replacing seawater with pressurized hydrogen and maintaining the pressure in the pipes similar to the outside pressure. Hydrogen Deep Ocean Link has the potential of increasing the interconnectivity of different regional energy grids into a global sustainable interconnected energy system