S OLAR W ATER H EATING A renewable energy resource that consists of transmitting solar energy into heat energy to warm water.

D IFFERENCE BETWEEN SWH AND SPV Solar photovoltaic Converts sunlight into electricity Only 20% of the energy is converted into electricity Produces 15,000 megawatts worldwide Solar water heating Direct heating of water usage by solar heat Heat is stored in tanks for day/night use 60% of the energy is converted in heat energy Produces 450,000 megawatts worldwide

T HE HEATING SYSTEM There are dominant heating systems, which include: ACTIVE Direct and Indirect PASSIVE Integral and thermosyphon

H OW IT WORKS - A CTIVE Pumps heat transfer fluid through collector s to heat exchanger.

S TEP 1 A pump circulates water or HTF between the collector and the tank. The direction in which water is circulated is anti- clockwise if direct system is utilized.

S TEP 2 The pump will only pump water when the water in the collector is warmer than the water in the storage tank. A controller is used to turn the pump on and off.

S TEP 3 As the collector retrieves light energy, this energy is transformed to heat energy in the collector which then heats the water making it warmer, as a result the controller signals pumper to pump water to tank. This thermal energy is transported to tank where it is stored for consumer. …And there you go! Your hot water bath awaits!

H OW IT WORKS - P ASSIVE Here the tank acts as both a collector and storage tank.

P ASSIVE H EATING S YSTEM This is seldom used as it is more pricey. The dominant difference between the passive and active is the fact that the passive system has a two in one. The tank is its collector as well as storage.

C OSTS & W ORLD U SAGE Costs and payback periods assuming a household electricity savings of 140 kW.h/month due to SWH (using 2010 data) CountryCurrency System cost (in currency) Subsidy (%) Effective cost Electricity cost/kW.h Electricity savings/ month Payback period(y) Australia $Aus5000 [49] [49] 40 [50] [50] [51] [51] Belgium Euro4000 [52] [52] 50 [53] [53] [54] [54] Brazil Real2500 [55] [55] South AfricaSouth Africa ZA Rand [56] [56] United KingdomUnited Kingdom UK Pound4000 [57] [57] 10 [58] [58] [59] [59] United StatesUnited States US$5000 [60] [60] 30 [61] [61] [60] [60] The calculation of long term cost and payback period for a household SWH system depends on a number of factors. Some of these are: Price of purchasing solar water heater (more complex systems are more expensive) Efficiency of SWH system purchased Installation cost State or government subsidy for installation of a solar water heater Price of electricity per kW.h Number of kW.h of electricity used per month by a household Annual tax rebates or subsidy for using renewable energy Annual maintenance cost of SWH system Savings in annual maintenenance of conventional (electric/gas/oil) water heating system

I MPACT ON ENVIRONMENT No daily impact on environment as the fuel is the sun; a renewable resource. The construction of the devices utilized, obviously impacts the environment negatively. Mining has to occur to retrieve components. R ELIABILITY It is reasonably reliable in places that are located near line of Equator, such as: North of Brazil, Egypt, Indonesia and so forth. It is evident that it isn`t a reliable source at night time specifically and in Autumn and Winter seasons. This problem has, however, been overcome by storing it when resource is available. This energy resource is improved throughout the years….

T HANK YOU Your attendance is much appreciated!!!