2,239 research outputs found
Sustainable tourism development : a critique
Sustainable tourism has become an increasingly popular field of research since the late 1980s. However, the sustainable tourism debate is patchy, disjointed and often flawed with false assumptions and arguments. This paper is a brief critique of some of the weaknesses in the sustainable tourism literature. In particular, it explores six issues that are often overlooked but must be addressed in research: the role of tourism demand, the nature of tourism resources, the imperative of intra-generational equity, the role of tourism in promoting sociocultural progress, the measurement of sustainability, and forms of sustainable development. Finally, it is argued that in order to transform research on sustainable tourism to a more scientific level, a systems perspective and an interdisciplinary approach are indispensable
Harnessing Flexible and Reliable Demand Response Under Customer Uncertainties
Demand response (DR) is a cost-effective and environmentally friendly
approach for mitigating the uncertainties in renewable energy integration by
taking advantage of the flexibility of customers' demands. However, existing DR
programs suffer from either low participation due to strict commitment
requirements or not being reliable in voluntary programs. In addition, the
capacity planning for energy storage/reserves is traditionally done separately
from the demand response program design, which incurs inefficiencies. Moreover,
customers often face high uncertainties in their costs in providing demand
response, which is not well studied in literature.
This paper first models the problem of joint capacity planning and demand
response program design by a stochastic optimization problem, which
incorporates the uncertainties from renewable energy generation, customer power
demands, as well as the customers' costs in providing DR. We propose online DR
control policies based on the optimal structures of the offline solution. A
distributed algorithm is then developed for implementing the control policies
without efficiency loss. We further offer enhanced policy design by allowing
flexibilities into the commitment level. We perform real world trace based
numerical simulations. Results demonstrate that the proposed algorithms can
achieve near optimal social costs, and significant social cost savings compared
to baseline methods
Incentivizing Reliable Demand Response with Customers' Uncertainties and Capacity Planning
One of the major issues with the integration of renewable energy sources into
the power grid is the increased uncertainty and variability that they bring. If
this uncertainty is not sufficiently addressed, it will limit the further
penetration of renewables into the grid and even result in blackouts. Compared
to energy storage, Demand Response (DR) has advantages to provide reserves to
the load serving entities (LSEs) in a cost-effective and environmentally
friendly way. DR programs work by changing customers' loads when the power grid
experiences a contingency such as a mismatch between supply and demand.
Uncertainties from both the customer-side and LSE-side make designing
algorithms for DR a major challenge.
This paper makes the following main contributions: (i) We propose DR control
policies based on the optimal structures of the offline solution. (ii) A
distributed algorithm is developed for implementing the control policies
without efficiency loss. (iii) We further offer an enhanced policy design by
allowing flexibilities into the commitment level. (iv) We perform real world
trace based numerical simulations which demonstrate that the proposed
algorithms can achieve near optimal social cost. Details can be found in our
extended version.Comment: arXiv admin note: substantial text overlap with arXiv:1704.0453
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