Distributed Generation with Heat Recovery and Storage

• Published in: Journal of energy engineering Vol. 133; no. 3
• Main Authors: Siddiqui, Afzal S., Marnay, Chris, Firestone, Ryan M., Zhou, Nan
• Format: Journal Article
• Language: English
• Published: United States 16.06.2006
• Subjects: 29; 32; CAPACITY; COMMERCIAL BUILDINGS; distributed generation heat recovery storage distributed energyresources combined heat and power; ELECTRICITY; ENERGY ACCOUNTING; HEAT RECOVERY; HEAT STORAGE; MARKET; POWER GENERATION; SCHEDULES; STORAGE; TARIFFS
• ISSN: 0733-9402; 1943-7897

Electricity produced by distributed energy resources (DER)located close to end-use loads has the potential to meet consumerrequirements more efficiently than the existing centralized grid.Installation of DER allows consumers to circumvent the costs associatedwith transmission congestion and other non-energy costs of electricitydelivery and potentially to take advantage of market opportunities topurchase energy when attractive. On-site, single-cycle thermal powergeneration is typically less efficient than central station generation,but by avoiding non-fuel costs of grid power and by utilizing combinedheat and power (CHP) applications, i.e., recovering heat from small-scaleon-site thermal generation to displace fuel purchases, DER can becomeattractive to a strictly cost-minimizing consumer. In previous efforts,the decisions facing typical commercial consumers have been addressedusing a mixed-integer linear program, the DER Customer Adoption Model(DER-CAM). Given the site s energy loads, utility tariff structure, andinformation (both technical and financial) on candidate DER technologies,DER-CAM minimizes the overall energy cost for a test year by selectingthe units to install and determining their hourly operating schedules. Inthis paper, the capabilities of DER-CAM are enhanced by the inclusion ofthe option to store recovered low-grade heat. By being able to keep aninventory of heat for use in subsequent periods, sites are able to lowercosts even further by reducing lucrative peak-shaving generation whilerelying on storage to meet heat loads. This and other effects of storageare demonstrated by analysis of five typical commercial buildings in SanFrancisco, California, USA, and an estimate of the cost per unit capacityof heat storage is calculated.