SOLAR WATER HEATING
Battery World is proud of its record and leadership role in the development of the solar water heating industry in East Africa and beyond. Since inception, Battery World has supplied thousands of solar water heaters nationally and has supported 100’s of plumbers in the development of solar skills. Additionally we have been responsible for the supply, installation and commissioning of thousands more low pressure solar water systems for various mass roll outs in East Africa. During these projects Battery World has trained in excess of 450 local people in basic plumbing and solar installation techniques.
There are core elements to our solar business – the supply of solar water heating technology to commercial developers, builders, resellers, turnkey contracts, delivery to government, state-owned enterprises and municipalities.
WHAT IS A SOLAR WATER HEATER?
A solar water heater consists of a collector to collect solar energy and an insulated storage tank to store hot water. The solar energy incident on the absorber panel coated with selected coating transfers the Heat to the riser pipes underneath the absorber panel. The water passing through the risers get heated up and is delivered the storage tank. The re-circulation of the same water through absorber panel in the collector raises the temperature to 800C (Maximum) on a good sunny day. The total system with solar collector, storage tank and pipelines is called solar hot water system.
Battery World Solar thermal systems use sunlight to heat water — for domestic use, swimming pools and more. A typical direct solar thermal system consists of collector, pipes and an insulated tank.
A typical 100 LPD (liter per day) system is sufficient to provide approximately 100 liters of hot water at an average temperature of 65°C every day on all sunny days. This helps save approximately 4 units of electricity daily. Battery World Solar Water Heaters are available in scalable multiples of 100. Large scale installations, for special applications involving heat transfer can also be engineered.
HOW DOES A TYPICAL SOLAR SYSTEM WORK?
- When the sun’s rays fall on a solar water heater collector, made of either an Evacuated Vacuum Tube system (EVT) or Flat Plate Collector system (FPC), the solar radiation heats up the water present in glass tubes (in EVT) / metal tubes (in FPC) due to high transmittance of the covering glass medium.
2.The heated water, now less dense, rises in the various tubes eventually reaching the tank at the top.
3. The relatively colder and denser water in the tank descends into the tubes, in turn getting heated — this cycle continues. The Thermosiphon effect ensures the movement of hot water upwards into the tank because of difference in density, eliminating the need for an external pump. The insulated tank ensures that the hot water remains hot for a long time.
Battery World Solar water heating systems are of two categories.
1. Closed loop system: Heat exchangers are installed to protect the system from hard water obtained from borewells or from freezing temperatures in the cold regions.
2. Open loop system: either thermosyphon or forced circulation system, the water in the system is open to the atmosphere at one point or other.
The thermosyphon systems are simple and relatively inexpensive. They are suitable for domestic and small institutional systems, provided the water is treated and potable in quality. The forced circulation systems employ electrical pumps to circulate the water through collectors and storage tanks. The choice of system depends on heat requirement, weather conditions, heat transfer fluid quality, space availability, annual solar radiation, etc. The Battery World Solar Water Heating Systems are economical, pollution free and easy for operation in warm countries like ours.
- Batch collectors, also called Integrated Collector-Storage (ICS) systems, heat water in dark tanks or tubes within an insulated box, storing water until drawn. Water can remain in the collector for long periods of time if household demand is low, making it very hot. A tempering valve is your protection from scalding at the tap. The tempering valve mixes in cold water to decrease the water’s temperature before it’s delivered to the tap.
Batch collectors are incompatible with closed-loop circulation systems. Thus, they are generally not recommended for cold climates.
2.Flat-plate collectors typically consist of copper tubes fitted to flat absorber plates. The most common configuration is a series of parallel tubes connected at each end by two pipes, the inlet and outlet manifolds. The flat plate assembly is contained within an insulated box, and covered with tempered glass.
Flat plate collectors are typically sized to contain 40 gallons of water. Two collectors provide roughly half of the hot water needed to serve a family of four
3. Evacuated tube collectors are the most efficient collectors available. Each evacuated tube is similar to a thermos in principle. A glass or metal tube containing the water or heat transfer fluid is surrounded by a larger glass tube. The space between them is a vacuum, so very little heat is lost from the fluid.
These collectors can even work well in overcast conditions and operate in temperatures as low as -40°F. Individual tubes are replaced as needed.
Battery World has five types of solar water heating systems as here below to choose from:
1. Thermosiphon Systems. These systems heat water or an antifreeze fluid, such as glycol. The fluid rises by natural convection from collectors to the storage tank, which is placed at a higher level. No pumps are required. In thermosiphon systems, fluid movement, and therefore heat transfer, increases with temperature, so these systems are most efficient in areas with high levels of solar radiation.
2. Direct-Circulation Systems. These systems pump water from storage to collectors during sunny hours. Freeze protection is obtained by recirculating hot water from the storage tank, or by flushing the collectors (drain-down). Since the recirculation system increases energy use, while flushing reduces the hours of operation, direct-circulation systems are preferable in our climate where it rarely freezes.
3. Indirect/ Closed Loop Water-Heating Systems. In these systems, freeze-protected fluid is circulated through a closed loop and its heat is transferred to potable water through a heat exchanger with 80 to 90 percent efficiency. The most commonly used fluids for freeze protection are water-ethylene glycol solutions and water-propylene glycol solutions.
4. Drain-Down Systems. These systems are generally indirect water-heating systems. Treated or untreated water is circulated through a closed loop, and heat is transferred to potable water through a heat exchanger. When no solar heat is available, the collector fluid is drained by gravity to avoid freezing and convection loops in which cool collector water reduces the temperature of the stored water.
5. Air Systems. In this indirect system the collectors heat the air, which is moved by a fan through an air-to-water heat exchanger. The water is then used for domestic or service needs. The efficiency of the heat exchanger is in the 50% range. Again, this is not common for our African Climate but common Mostly in the USA
10 year warrantee – Battery World’s Solar Water Heaters have a standard 10 year warranty. Due to our glass-to-glass vacuum sealing techniques for the Tube Collectors and high quality material, our products have a life expectancy of more than 30 years.
Quality management is an important compliance component for undertaking large contracts and Battery World meets this in compliant to our Quality Management Policy.
Battery World solar collectors have survived rigorous testing by International bodies i.e. the SGS and Intertek, and in East Africa we are fully compliant to Kenya Bureau of Standards (KEBS), Uganda National Bureau of Standards (UNBS) and Tanzania Bureau of Standards (TBS) to ensure Pre-Export Verification of Conformity to Standards (PVoC)
Battery World also helps with saving environment, by reducing carbon emissions.
Solar Thermal-Solar Water Heating System
Heat water for your home using energy from the sun for FREE! Solar heating systems use the suns radiation to warm your residential hot water. Our solar heating systems use solar panels or collectors that are fitted to your roof. These collect the suns radiant heat and use it to heat the water which is stored in a hot water tank. There are two types of solar water heating panels; Evacuated tubes and Flat plate collectors. Flat plate collectors can be fixed on the top of your roof tiles. Electricity can be used as a back up to heat the water to reach the temperature set by the heaters thermostat when the solar water heating system does not reach the required temperature.
THE BENEFITS OF USING SOLAR WATER HEATING
- Hot water throughout the year: the system works all year round thanks to our sunny African climate.
- Cut your bills: sunlight is free, so once you’ve paid for the initial installation your hot water costs will be reduced.
- Cut your carbon footprint: solar hot water is a green, renewable heating system and can reduce your carbon dioxide emissions. It will also save up to 580kg of CO2 emissions.
- Our competent accredited nationwide installers will be able to assess your home and help you choose the best set-up for the most efficient use of Solar Energy. Maintenance costs are generally very low. Once fitted we shall leave written details of any maintenance checks that you can carry out from time to time, ensuring everything is working properly.