Solar Home Power Supply System Model No.: SHS1206

This great new addition to the range of solar lighting kits now allows you to create a power solution to match your requirements.  Each system includes the solar panel, charge controller, solar battery, DC to AC inverter, cables & DC 12V lamps to complete your system.
The Model SHS1206 - 6W Solar lighting Kit gives you all the components needed to install a small lighting system in remote homes, caravans or wherever you need a reliable power source for lighting.

This Solar Lighting System consists of 3 LED lights & mobile phone charger as shown in the illustration.  The PV Solar panel has a maximum generating capacity of 6W and has an expected life cycle of approximately 10 years.   The three lights that are supplied with the Model SHS1206 consist of 2 pieces of 12V/3W LED bulbs and 1 x 12V/1W LED bulb.  The controller incorporates over-charging (14V) and over-discharging (10.5V) protection functions as well as short-circuits protection.  The battery is a 12V-4AH lead-acid battery with a rated charging current of 1Amp and a rated discharging current of 2Amps.

There is a no load loss of 8mA and a USB port current of 500mA.   The estimated full charging time with the solar panel is ten hours when clear sunny conditions are available.   Orientation of the 6V Solar PV panel in a direction facing towards the equator (North for Southern Hemisphere Countries and South for Northern Hemisphere Countries) will ensure maximum collection of solar energy each day.
An approximate lighting duration after the battery is fully charged of around 5 hours when the 3 lights are operated at the same time can be expected.

By Mel Peatey

Low Cost Solar Lighting Kits

In remote Regions of Developing Countries the people tend to use the traditional methods of either burning firewood, lighting candles or kerosene lanterns in order to provide lighting during the night time periods.  It is well known that candles and kerosene are expensive for these people as well as being harmful to the eyes - particularly when children are exposed to these types of lighting.   In addition, gathering firewood is heavy, hard work that is generally carried out by the women and sometimes the children of these communities and burning firewood can contribute to larger rural fires that can destroy large areas of vegetation.  Burning firewood is also not really environmentally responsible and could be considered to be somewhat of an unsustainable resource.  In many cases the remote Regions in Asia, Pacific Islands, and Africa are blessed with abundant amounts of solar energy which is freely available but is very much underutilized.  In order to overcome the problems with traditional lighting methods there has been a concerted effort to develop low cost, but effective solar lighting systems for these Regions.   The benefits of using the low cost solar lighting kits is that they are easy to install, are safe to handle, and simple to operate.  The solar PV lighting kits generate direct (DC) current which is totally safe to use unlike alternating current (AC) that is used in most developed world locations.   A NI-MH (Nickel Metal Hydride) rechargeable battery is used instead of lead-acid battery or NI-CD battery because of its long life, no memory effect, non-toxic, and is environmentally friendly.  Once the kit is installed, the sun will provide the energy needed to operate one 6V/1W LED lamp that is supplied with the Model SRY-001E (as illustrated above) for up to 8 hours after the battery is fully charged.   The expected life cycle of the Model SRY-001E lighting kit is approximately 10 years.  Over charging and discharging protection devices are incorporated into these lighting kits to simplify the use of the products.  Additional charging points are also available for other devices such as mobile phones.
 
Since the year 2009 over 100,000 pieces of the Model SRY-001E Lighting Kits have been installed in various parts of Africa and another 20,000 units have been sent to remote locations in South America.  The World Bank has recently conducted quality testing for the Model SRY-001E product and it has now been passed and has been accepted for their "Lighting Africa" Solar program.
There are a number of different Solar lighting kit models available in the range that are CE accredited and also include extra LED lamps and other charging options.  These kits have slightly larger solar panels that are capable of collecting the additional solar energy that is necessary to power the extra lights or charging points. 
 
By Mel Peatey

Solar Thermal Collectors Connected to Heat Pumps

There can be some advantages gained by connecting Solar Thermal Collectors to Heat Pump water heaters, but there are some important points to assess before this combination can be recommended.  The first point to consider is the economics of the project.   In other words will the addition of Solar Thermal Panels provide sufficient reduction in traditional energy use, which can then be calculated as a cost reduction when compared to the actual initial cost of supplying and fitting the Solar Thermal Collector Panels?

                                                              Schematic Image Only

There is an unwritten expectation for energy efficient products such as Solar Thermal and Heat Pump systems to provide a reasonable “payback” period, and this can sometimes be linked to the expected life cycle of the system or probably more closely linked to the warranty period offered for the products involved.   If the capital cost can be recovered within the warranty period then it is worth being given further consideration. However, when assessing the value of adding Solar Thermal Collector Panels to a Heat Pump installation it must also be remembered that during the daylight hours when the Solar Thermal Collector Panels could be contributing to the energy input of the system, that is also the period of each day that the Heat Pump units would be operating at their highest efficiency as well so the amount of purchased (input) energy for the Heat Pump units during the day time period could be between 3½ to 4.0 times less than the actual output that is produced in the form of hot water depending upon geographical location, ambient temperature and humidity.

The thermal contribution to a Heat Pump system from Solar Thermal Collector Panels is governed by the amount of radiation that is available at any given time and this can be intermittent because of varying weather conditions.   Therefore it is important to recognize that the Heat Pump units must be considered as the primary heat source and sized accordingly to be able to meet the total hot water requirement of the project due to the reliability of Heat Pumps being able to produce energy efficient hot water in all conditions including daytime, night time, as well as cloudy or rainy periods.  The Solar Thermal collectors will therefore only provide supplementary energy input during periods when there is a favorable level of radiation available for collection.  A number of factors can influence the decision to add Solar Thermal Collectors to a Heat Pump installation or not, but generally it has been found that in Regions where Government or Utility incentives are offered for the inclusion of Solar Thermal Collector Panels and the value of that incentive covers the cost of the Solar Thermal Collector Panels then obviously the economic equation is positive however, when no incentives or subsidies are available then there are some questions that need to be asked as to the added value of the Solar Thermal Collector Panels fitted to Heat Pump Units.

By Mel Peatey

Water to Water Heat Pumps

Another option for Commercial/Industrial Heat Pump water heaters is the Water to Water - or hydro sourced Heat Pump.   Water source heat pumps (WSHP) are specialized types of heat pumps that can also be used as reverse cycle or multi function units that use water as a heat source when in the heating mode and as a heat sink in the cooling mode. In the Water to Water HeatPump, heat is absorbed or rejected in a fluid medium rather than from the ambient air. Water loop heat pumps (WLHP) use a circulating water loop which could be from a chiller/cooling tower system as the primary heat source for the liquid refrigerant causing it to vaporize before moving it to where it is upgraded by an electrically-driven compressor and is then subsequently delivered at a useful super heated temperature for heating potable water via a suitable heat exchanger.

A typical schematic of a multi function Water sourced Heat Pump shown above indicates how in some cases a single Water to Water Heat Pump Unit can be used to provide hot water, air conditioning, as well as under floor heating if required.   In the schematic layout above the primary heat source can be provided by any medium (ground, lake, sea water or hotel cooling tower circuits) where heat energy can be captured (transferred) in the primary evaporator in the Heat Pump Unit.   These types of Heat Pumps can also be used very effectively for just the hot water output function depending upon the project requirements and still have the capability of delivering a very high Coefficient of Performance (COP) outcome of over 370% more than the actual energy consumed.   However, when used as a multi function unit for example, delivering hot water and air conditioning in an ambient temperature environment of around 24ºC the combined COP’s for both functions can be as high as 700% more than the energy consumed for the operation of the system.

By Mel Peatey.

Difference between Heat Pumps and Diesel or Gas Fired Boilers

In years gone by heating sources for large volume Commercial/Industrial Water Heaters have mainly been in the form of diesel or gas fired boilers.   These systems have always been afflicted with some disadvantages such as heating inefficiencies and the rising cost and the vulnerability of supply in some cases for these fuel types.  In addition there has also been a need to duplicate these systems with stand-by units to ensure continuous operation in the event of a breakdown or maintenance requirements.   The heating inefficiencies are caused – because only a low percentage of the gross energy that is produced from “burning” the diesel or gas, is actually transferred to the water or other fluid that is being heated.   This percentage of energy input can be between around 75% for new systems down to as low as under 50% for older systems.  The main cause of energy inefficiency in diesel or gas fired systems is that a good proportion of the heat that is generated through the burning process of these fuel sources is dissipated into the atmosphere through the flue pipe or chimney.   Further inefficiencies (up to an additional 30% reduction) can be experienced if the diesel or gas fired systems (in a Hotel for example) are required to heat the water to steam (100ºC) and then that steam is directed to a calorifer type storage tank to produce potable water at 60ºC for circulation to the various fixture points.    
In most cases when a diesel or gas fired boiler is initially installed it has to be duplicated with at least one additional identical system as a stand-by unit that will be able to handle the full hot water load requirement when the primary system requires repair or maintenance.   During these repair or maintenance periods the complete diesel or gas fired system is totally shut down and cannot contribute in any way to the heating requirements of the project; therefore the need for a stand-by unit.   However, the larger Commercial/Industrial Heat Pump products that are now available are normally fitted with multiple Heat Pump modules in the one unit that are digitally controlled in such a way that they can operate individually or together at any given time.   Provided the Heat Pump daily run cycle design is done correctly for each project there is usually no requirement to include any stand-by units thereby contributing positively to the reduction in capital cost and subsequently having a positive effect on the ROI equation.   The design of the system is critical in order to maximize the daily run cycle and at the same time keeping the daily run cycle at a suitable operational percentage that will allow the system to still contribute effectively even if one of the Heat Pump modules is isolated for service or maintenance at any time.  The non requirement of stand-by units for the Heat Pump alternative also reduces the amount of occupied floor space required in the building to house the heating systems.
Finally, a Heat Pump solution also provides a positive effect on the operating cost due to the energy efficiency of its design.   Whilst diesel or gas fired boilers produce a negative Coefficient of Performance (COP) because of the various heat losses that are experienced during their operation, a Heat Pump will actually produce a positive COP that provides a heating output in the form of hot water of somewhere between 360% to 400% more than the energy that is actually consumed by the system depending upon regional ambient and humidity weather conditions.   Heat Pumps are also capable of operating effectively in most areas of the World during the daytime, night time, or rainy and cloudy periods.  
By
Mel Peatey

Heat Pumps compared to Solar Water Heaters

An Air to Water Heat Pump provides an ideal energy efficient hot water system alternative for both domestic household use, or for larger Commercial applications.  In reality a Heat Pump provides slightly less energy savings when compared to a domestic solar water heater, but there are a number of other significant advantages associated with the use of an Air to Water Heat Pumps.

One major advantage of the Heat Pump is the aesthetic appearance that is gained by not needing any thermal solar panels and in some cases a storage tank on the roof of the building to ensure efficient operation.  In some cases roof structures may have to be reinforced when they are required to support the weight of a domestic sized solar storage tank that can weigh in excess of 400 kg.  In addition, the installation cost of an Air to Water Heat Pump is very simple compared to the installation cost of a solar water heater, and this significantly lower installation cost for the Heat Pumps should also be taken into consideration when assessing the overall installed cost of either product alternative.

Another advantage of the Air to Water Heat Pump is the low energy input from the electricity supply that is required to operate the system, while at the same time producing an output of around 3 times more than the actual electrical input, when operated in average ambient temperatures of 20 degrees Celsius.  This results in an energy saving (reduction) of approximately 75% when compared to traditional electric water heaters.  In Regions where the average ambient temperature is higher than 20 degrees Celsius the actual energy savings can be higher due to the extra heat energy that is available from the ambient air in these locations.  Air to Water Heat Pumps do not require direct sunlight to operate efficiently because they collect free energy from the ambient air.    Contrary to popular belief, a solar water heater does requires back-up electrical energy to operate the booster element during periods of inclement weather, low radiation periods, and at night time when there is a need to supply hot water during those times.  When comparing similar volumes of hot water delivery the annual booster or back-up energy needed to ensure solar thermal water heaters provide a continuous supply of hot water during all weather conditions, or if hot water is needed during the evening period, is similar to what is expended annually for a Heat Pump to drive the evaporator fan and compressor.   A domestic sized Heat Pump could, in some cases, operate from Photovoltaic (PV) solar cell system due to the low energy input needed when compared to the actual output that is delivered in the form of hot water.  This makes the Heat Pump products ideal for isolated and heavily forested locations such as remote Eco Resorts.

By Mel Peatey.

Benefits of using Integrated Heat Pumps for Small Commercial Installations

Integrated Heat Pumps that are designed with a storage tank and heat pump module in one unit can definitely be an economically viable option to provide hot water for small commercial installations such as single block multiple level hotels with up to 100 accommodation rooms or in some cases even up to 150 rooms.    Provided there is sufficient floor space to locate the Heat Pumps and the proposed design (number of units) is correct the integrated models can provide a complete solution of hot water storage capacity as well as multiple heat pump modules that allow flexibility to maintain total hot water load requirements to be maintained even during periods when some units could be undergoing servicing or maintenance.
 
For example if a quantity of integrated systems were designed with sufficient units to meet all of the hot water demand criteria for a particular project and based on a 70% daily run cycle it would mean that the total heating capability of the combined units would be 30% above what is actually required on a daily basis.   Therefore the equivalent number of integrated heat pumps that represents 30% of the total could be isolated for a period of time while servicing or maintenance was carried out and the rest of the integrated heat pump units could still meet all of the daily hot water requirements for the project.   This design also removes the requirement to install additional stand-by units therefore reducing the capital costs and subsequently improving the return on investment (ROI) for the installation.
 
The plumbing pipe work connection design for multiple integrated heat pump installations is simple and straight forward with the main considerations being the use of reverse return pipe work which basically means that the first integrated heat pump unit that the cold water supply pipeline is connected to should be the last unit that the hot water delivery is taken from.   In addition the geometry as well as the length of branch connections off the main header pipe line to each integrated heat pump unit should remain the same in order to provide a balanced cold water flow and hot water delivery and ensure that each integrated heat pump unit contributes equally to the overall hot water requirement.  
 
By  Mel Peatey