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The next generation radar suite will include a radar that has sensitivity far greater than shipboard radars in use today. Most likely the radar will be a multi-faced, solid state, phased array system with each array consisting of thousands of individual radiating elements powered by transmit/receive (T/R) modules. It will likely need to be large, and the demands it makes on ship services will be unprecedented. Its electrical power demands could be larger than the total ship's load for present-day ships. Array size could significantly impact topside design. This paper examines top-level radar system design choices and illustrates the trends in the ship impact of those choices. Radar design options considered are aperture size and shape, coolant operating temperature, number of array faces, and power system architecture. These design options have an effect on the radar system's weight, footprint, power demand, and cooling load. The effects on ship design can be significant. The ship impact analyses consider a radar system that includes ship-provided equipment such as electrical power distribution equipment and chill water plants. An analysis of radar systems, all with the same performance, shows that radar system power demand can change by as much as four megawatts for a notional surface combatant depending upon the radar designer's configuration choices. Radar system weight can vary by more than 100 metric tons. There is a cubic relationship between T/R module power and array face area for a constant sensitivity radar system. This relationship is examined to show that there is often a choice of T/R module power that minimizes radar ship impact. The exact choice of T/R module power depends upon the customer's preferences, the manufacturer's capabilities, and choice of vendors. This paper does not convey any official US government position or US Navy endorsement of any particular radar architecture or design approach. [ABSTRACT FROM AUTHOR]

• Backup capability of solar and storage differs by region in the U.S. • Small batteries can meet a limited set of critical loads in most counties. • Electric cooling and heating loads are typically hardest loads to backup. • Household building attributes like efficiency can impact results up to 20% • Resiliency value needs to be high to motivate adoption of solar-plus-storage. Customer concerns over electric system resilience could drive early adoption of behind-the-meter solar-plus-storage (BTM PVESS), especially as wildfire, hurricane, and other climate-driven risks to electric grids become more pronounced. However, the resilience benefits of BTM PVESS are poorly understood, especially for residential customers, owing to lack of data and methodological challenges, making it difficult to forecast adoption trends. In this paper, we develop a methodology to model the performance of BTM PVESS in providing backup power across a wide range of customer types, geography / climate conditions, and long duration power interruption scenarios, considering both whole-building backup and backup of specific critical loads. We combine novel, disaggregated end-use load profiles across the continental United States with temporally and geospatially aligned solar generation estimates. We then implement a PVESS dispatch algorithm to calculate the amount of load served during interruptions. We find that PVESS with 10 kWh of storage can meet a limited set of critical loads in most United States counties during any month of the year, though this capability drops to meeting only 86% of critical load, averaged across all counties and months, when heating and cooling are considered critical. Backup performance is lowest in winter months where electric heat is common (southeast and northwest U.S.) and in summer months in places with large cooling loads (southwest and southeast U.S.). Winter backup performance varies by roughly 20% depending on infiltration rates, while summer performance varies by close to 15% depending on the efficiency of the central air-conditioning system. Differences in temperature set-points in Harris County correspond to a 40% range in winter backup performance and a 20% range in summer performance. Economic calculations show that a customer's resilience value of PVESS must be high to motivate adoption of these systems. [ABSTRACT FROM AUTHOR]

The prescriptive path is the most widely used approach for commercial code compliance in the United States. Though easy to implement, prescriptive approaches do not typically discriminate between minimally compliant, high-performing and poorly performing HVAC system configurations. Hence, to meet aggressive energy and carbon reduction goals, it is clear that energy codes will need to transition from prescriptive to performance-based approaches, a transition that is riddled with several challenges. This paper discusses a new HVAC system-based performance approach (HVAC System Performance) which provides a simpler solution to HVAV system evaluation compared to whole building performance, while keeping tradeoffs limited to specific building systems. The Total System Performance Ratio (TSPR) is a metric for evaluation of overall system efficiency instead of individual component efficiency, a solution which could also eventually facilitate the transition to a 100% performance-based code structure. TSPR is a ratio that compares the annual heating and cooling load of a building to the annual energy consumed by the building's HVAC system. A calculation software tool has been developed for determining a building's TSPR. Already incorporated into the 2018 Washington State Energy Code, this approach is also being evaluated by ASHRAE Standard 90.l Project Committee and has the potential to provide a comprehensive performance-based approach for HVAC system evaluation and analysis. [ABSTRACT FROM AUTHOR]

This paper presents an energy dispatch algorithm for real-time topping cycle cooling, heating, and power (CHP) operation for buildings with the objective of minimizing the operational cost, primary energy consumption (PEC), or carbon dioxide emission (CDE). The algorithm features a supervisory feed-forward control for real-time CHP operation using short-term weather forecasting. The advantages of the proposed control scheme for CHP operation are (a) relatively simple and efficient implementation allowing realistic real-time operation, (b) optimized CHP operation with respect to operational cost, PEC, or CDE, and (c) increased site-energy consumption resulting in less dependence on the electric grid. In the feed-forward portion of the control scheme, short-term electric, cooling, and heating loads are predicted using the U.S. Department of Energy benchmark small office building model. The results are encouraging regarding the potential saving of operational cost, PEC, and CDE from using the control system for a CHP system with electric and thermal energy storages. [ABSTRACT FROM AUTHOR]

Undisturbed ground temperatures are often required for engineering applications, such as analyses of building heating and cooling load calculations and design of ground heat exchangers. In two companion articles, an automated procedure for generating a world-wide dataset of typical year ground temperatures has been developed and validated against measured results at 19 Soil Climate Analysis Network sites. This procedure relies on a two-harmonic relationship and five weather-related constants—annual average ground temperature, two temperature amplitudes, and two phase lags—to predict the undisturbed ground temperatures. These constant values generated for 4092 sites world-wide covered by short and tall grass are summarized in Appendix A and B in this article. In the United States, a one-harmonic model which relies on three constant values to estimate the ground temperatures is commonly used. The ASHRAE Handbook and ASHRAE District Heating Guide provide these constant values in North America and in a world-wide range, respectively. The estimated typical year ground temperatures using the Xing and Spitler procedure are compared to the measured results at the 19 Soil Climate Analysis Network sites, it shows the mean root mean square errors of all sites are within 1.3°C–1.6°C (2.3°F–2.9°F) at 5–100 cm (2–40″) depths, which are 0.7°C–1.4°C (1.3°F–2.5°F) lower than the root mean square errors given by the commonly used procedures in United States. Estimations of the peak (maximum/minimum) ground temperature over multiple years are also important. Thus, a correction factor β is introduced in the two-harmonic model, the newly developed simplified design model could now be used to predict typical year ground temperatures and peak ground temperatures of multiple years. For a typical year, the correction factor is set to be 1. It is suggested that the correction factor of 1.6 to be chosen, so as to use the simplified design model to estimated maximum/minimum ground temperatures of multiple years. [ABSTRACT FROM PUBLISHER]