A microcontroller-based Active Solar Water HeatingudSystem for Domestic Applications

摘要

A potential solution to adequate and sustainable electricity supply problems in most developing countries isuddependent on proper harnessing of solar (radiant) energy. Owing to tbe over dependence on fossil-fuel based energy, tbere isudan exponential rise in carbon dioxide (C02) emissions into tbe atmosphere, thereby causing severe environmental degradationudand ozone layer depletion. This paper seeks to apply tbe readily available radiant energy source to solar water heating, andudestablish possible economic benefits to its use in domestic applications for residents of Covenant University campus. Theudmicrocontroller-based active solar water heating system (ASWHS) is designed to effectively absorb radiant energy using solarudcollectors, and store it as hot water in a water tank via a direct current (DC) circulation pump powered by a stand-aloneudphotovoltaic (PV) system. The design also incorporates an auxiliary electric heater which is put to use ou!y when tbere isudinsufficient radiant energy. A case study is reported to show tbe importance of tbe ASWHS for domestic water heating. Theudmaximum design efficiency and tbe expected energy output of tbe solar collector throughout its working life is 79.94% andud498,225kWh respectively. A reduced dependence on grid supply and/or fossil-fuel based generator sets during hot wateruddemand periods is recorded using tbe ASWHS witb a high payback period of 15 years; and a lower unit cost (US$0.01/kWh)udoftbe ASWHS makes it more economically viable as compared to tbe unit cost (US$0.18/kWh) oftbe grid supply fortbe sameudamount of energy consumed