Space cooling constitutes >10% of worldwide electricity consumption and is anticipated to rise swiftly due to intensified heatwaves under emerging climate change. The escalating electricity demand for cooling services will challenge already stressed power grids, especially during peak times of demand. To address this, the adoption of demand response to adjust building energy use on the end-user side becomes increasingly important to adapt future smart buildings with rapidly growing renewable energy sources. However, existing demand response strategies predominantly explore sensible cooling energy as flexible building load while neglecting latent cooling energy, which constitutes significant portions of total energy use of buildings in humid climates. Hence, this paper aims to evaluate the demand response potential by adjusting latent cooling energy through ventilation control for typical medium commercial office buildings in four representative cities across different humid climate zones, i.e., Miami, Huston, Atlanta, and New York in the United States (US). As the first step, the sensible heat ratio, defined as sensible cooling load to total building load (involving both sensible and latent load), in different humid climates are calculated. Subsequently, the strategy to adjust building latent load through ventilation control (LLVC) is explored and implemented for demand response considering the balance of energy shifting, indoor air quality, and energy cost. Results reveal that adjusting building ventilation is capable of achieving 30%–40% Heating, Ventilation, and Air-conditioning (HVAC) cooling demand flexibility during HVAC operation while among this, the latent cooling energy contributes 56% ~ 66.4% to the overall demand flexibility. This work provides a feasible way to improve electricity grid flexibility in humid climates, emphasizing the significant role of adjusting latent cooling energy in building demand response.
more »
« less
Providing Grid Services With Heat Pumps: A Review
Abstract The integration of variable and intermittent renewable energy generation into the power system is a grand challenge to our efforts to achieve a sustainable future. Flexible demand is one solution to this challenge, where the demand can be controlled to follow energy supply, rather than the conventional way of controlling energy supply to follow demand. Recent research has shown that electric building climate control systems like heat pumps can provide this demand flexibility by effectively storing energy as heat in the thermal mass of the building. While some forms of heat pump demand flexibility have been implemented in the form of peak pricing and utility demand response programs, controlling heat pumps to provide ancillary services like frequency regulation, load following, and reserve have yet to be widely implemented. In this paper, we review the recent advances and remaining challenges in controlling heat pumps to provide these grid services. This analysis includes heat pump and building modeling, control methods both for isolated heat pumps and heat pumps in aggregate, and the potential implications that this concept has on the power system.
more »
« less
- Award ID(s):
- 1711546
- PAR ID:
- 10177153
- Date Published:
- Journal Name:
- ASME Journal of Engineering for Sustainable Buildings and Cities
- Volume:
- 1
- Issue:
- 1
- ISSN:
- 2642-6641
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
More Like this
-
-
Pumps in drinking water distribution networks can be controlled to participate in demand response programs. In this paper, we estimate the demand response potential of water distribution networks based on actual network data. We calculate the power and energy capacities of community water systems within Wisconsin and Arizona, drawing on publicly available data of consumer water demand, population served, storage tanks, and pump specifications. We then extrapolate this data to get an order-of-magnitude estimate for the entire United States. Overall, we found that water distribution networks are sizable demand response assets with an estimated power capacity of 13 GW and energy capacity of 750 GWh in the United States. We also found that large and very large utilities may be the best demand response candidates. This paper also discusses factors impacting water supply flexibility and future research directions.more » « less
-
Elsevier (Ed.)Electrification of buildings through deployment of heat pumps requires innovative design and control strategies to reduce their energy demands on the grid. Instead of the sequential approach of optimizing the design specifications and control strategies, this paper considers the benefits of the combined and simultaneous optimization of design capacities and control settings for heat pumps when specified for US residential buildings. A Genetic Algorithm optimizer is used to simultaneously adjust the main and supplementary coil capacities for the heat pump as well as the indoor temperature setpoints to minimize annual heating and cooling energy needs as well as occupant thermal discomfort levels. In comparison to design and control baselines, it is found that simultaneous optimization can achieve 21% and 7% reductions in heating and cooling annual energy consumption for the cases of variable speed and single speed heat pumps. Moreover, the analysis results indicate that these reductions are nearly double the savings obtained when design only and control only based optimizations are considered. The presented combined design and control optimization approach could potentially provide an effective paradigm shift in specifying heat pump systems for residential buildings.more » « less
-
Background and Situation AnalysisThe importance of Water Sanitation and Hygiene (WASH) projects for the protection of health is embedded in the sustainable development goals. However, within the development and humanitarian fields sustainability of WASH projects is still a challenge with 30–50% of projects failing within two to five years of implementation. Though failure is not linked to any one source, a common theme speaks to a greater need for community engagement and integration of the wants and needs of the end-user in the design process. Social marketing, with its focus on the consumer and use of commercial marketing strategies to achieve behavior change is a promising approach that can be integrated into ongoing WASH initiatives to meet program outcomes and to achieve long-term sustainability. Priority audiencePrimary audience includes technicians who manufacture and repair pitcher pumps. Secondary audience includes community members in Toamasina, Madagascar, who will experience a decrease in exposure to lead through their water supply. Behavioral objectivesDecrease exposure to lead (Pb) introduced through the use of a decentralized, self-supply water system, the pitcher pump. Specifically, decrease use of leaded components in the manufacturing and repair of pitcher-pumps Strategy/InterventionDevelopment of the intervention followed the social marketing process including conducting a situational analysis, identification and selection of a behavioral focus and priority population, formative research, development of an integrated marketing strategy, pretesting the strategy, followed by campaign implementation, and monitoring and evaluation. An intervention focused on building a sense of community and introducing the element of professionalism for the pump manufacturers was developed, consisting of personalized one-on-one outreach to raise awareness of the health topic, followed by skill building trainings on how to make the switch to non-leaded components. This was coupled with tangible products that created a new professional network, documentation of work, and backing of work by trusted government entities. Evaluation Methods and ResultsUsing the theory of planned behavior, a pre/post-test summative evaluation was developed. Preliminary results indicate that pump technicians no longer use lead in pumps unless specifically requested by the pump owners. These results indicate a positive shift towards the use of lead-free components with project follow-up and analysis ongoing. Recommendations for Social Marketing PracticeUse of social marketing within the WASH sector is lacking. This paper demonstrates the integration of social marketing in an ongoing WASH project. Through a description of each step of the process, our experiences in implementing it and the lessons learned, we hope to guide future integration. Additionally, this paper demonstrates the convergence of engineers and social marketers working collaboratively on an interdisciplinary team and how this served to enhance project understanding, aid in building local partnerships and help with long-term sustainability.more » « less
-
Climate change is expected to intensify the effects of extreme weather events on power systems and increase the frequency of severe power outages. The large-scale integration of environment-dependent renewables during energy decarbonization could induce increased uncertainty in the supply–demand balance and climate vulnerability of power grids. This Perspective discusses the superimposed risks of climate change, extreme weather events and renewable energy integration, which collectively affect power system resilience. Insights drawn from large-scale spatiotemporal data on historical US power outages induced by tropical cyclones illustrate the vital role of grid inertia and system flexibility in maintaining the balance between supply and demand, thereby preventing catastrophic cascading failures. Alarmingly, the future projections under diverse emission pathways signal that climate hazards — especially tropical cyclones and heatwaves — are intensifying and can cause even greater impacts on the power grids. High-penetration renewable power systems under climate change may face escalating challenges, including more severe infrastructure damage, lower grid inertia and flexibility, and longer post-event recovery. Towards a net-zero future, this Perspective then explores approaches for harnessing the inherent potential of distributed renewables for climate resilience through forming microgrids, aligned with holistic technical solutions such as grid-forming inverters, distributed energy storage, cross-sector interoperability, distributed optimization and climate–energy integrated modelling.more » « less
An official website of the United States government

