Technology-rich modelling of micro combined heat and power for economic, environmental, and policy assessment

Imperial Users onl

Performance assessment of tariff-based air source heat pump load shifting in a UK detached dwelling featuring phase change-enhanced buffering

Using a detailed building simulation model, the amount of thermal buffering, with and without phase change material (PCM), needed to time-shift an air source heat pump's operation to off-peak periods, as defined by the UK 'Economy 10' tariff, was investigated for a typical UK detached dwelling. The performance of the buffered system was compared to the case with no load shifting and with no thermal buffering. Additionally, the load shifting of a population of buffered heat pumps to off-peak periods was simulated and the resulting change in the peak demand on the electricity network was assessed. The results from this study indicate that 1000 L of hot water buffering or 500 L of PCM-enhanced hot water buffering was required to move the operation of the heat pump fully to off-peak periods, without adversely affecting the provision of space heating and hot water for the end user. The work also highlights that buffering and load shifting increased the heat pump's electrical demand by over 60% leading to increased cost to the end user and increased CO2 emissions (depending on the electricity tariff applied and time varying CO2 intensity of the electricity generation mix, respectively). The study also highlights that the load-shifting of populations of buffered heat pumps wholly to off-peak periods using crude instruments such as tariffs increased the peak loading on the electrical network by over 50% rather than reducing it and that careful consideration is needed as to how the load shifting of a group of heat pumps is orchestrated

MEASURING NET BENEFITS RESULTING FROM UNIVERSITY-INDUSTRY COLLABORATION: AN EXAMPLE FROM THE NEW MEXICO CHILE TASK FORCE

Research and Development/Tech Change/Emerging Technologies,

Finding the "Early Medieval" in South Asian Archaeology

The concept of an “early medieval” period (c. 600–1300 c.e.) in the study of South Asia’s past is well established, yet remains ill defined and poorly understood. As a result, debates regarding grand explanative frameworks, not to mention the meaning and use of the term medieval, have dominated the study of the period. Important though these concerns are, what underpins them, and something that is rarely considered, is how sources and methodologies affect the study of the period. Historiographic review of scholarship on the early medieval reveals that from its inception, the period has been studied exclusively through the examination of documentary sources and monumental remains within the fields of history, literary and religious studies, and art history. Archaeology has been used to support historical theories, largely in order to provide further empirical “proof ” of a perceived decline in trade and urbanism. The continued use of archaeological evidence in this way has meant that the full potential of archaeological inquiry has not been fulfilled, and the impetus for new archaeological research has been stifled. As a result, the early medieval is arguably the most poorly represented period archaeologically in the entire subcontinent. Critical assessment of the limited amount of archaeological evidence that does exist reveals a number of methodological and theoretical concerns that bring into question its applicability and use. These shortcomings not only force one to question historical interpretations, but also limit what can be said, archaeologically, about the period. It is argued that many of the wider uncertainties surrounding the definition and meaning of the early medieval stem from this absence of archaeological research. What is urgently needed is a revitalization of the archaeological approach to the study of the period; some ways are suggested in which this might be achieved in terms of methodological approaches, and questions that could be asked