Factors Affecting Feasibility
Evaluating the feasibility of waste heat recovery requires characterizing
the waste heat source and the stream to which the heat will be transferred.
Important waste stream parameters that must be determined include:
- Heat quantity. A large and constant volume of heat is ideal,
although there are options for smaller heat quantities.
- Heat temperature/quality. A high-temperature heat source can
yield greater outputs, although the temperatures can also affect what
materials are used in the equipment design of heat exchangers and
- Composition. A heat source free of corrosives or particulates
is best; otherwise, more expensive heat exchangers and maintenance
increase the costs.
- Minimum allowed temperature. Too cool a temperature can cause
the water vapor in exhaust gas to condense and deposit corrosive
substances on the heat exchanger.
- Operating schedules, availability, and other logistics. For
example, it is important that the schedule of the heat source match the
schedule of the heat load. It is also important that the recovery not
interfere with the industrial process that is the source of the waste
- Location. When generating electricity, a close proximity to
the electric grid (and ideally a transmission line) is preferable.
- Economic Incentives. Some states offer tax credits, grants,
and/or eligibility in renewable portfolio standards, any of which help
the economic feasibility.