Energy saving is a journey
Start big or small, but start smart.
We want to empower you to make the best decisions for your home and budget.
We know energy. You know your home. Let us help you work out where to start?
Changing to solar hot water / heat pump will remove the biggest portion of the electricity cost in most households.
Payback 3-5 years
Useful Life 10-15 years
Many lights in living areas? You will save far more than you think by changing to LED.
Payback 1-2 years
Useful Life 3-5 years
Fix a portion of your electricity cost at below todays price for 25 years or more
Payback 6-9 years
Useful Life 20-25 years
Air-conditioning and refrigeration are very power hungry. Small improvements in efficiency can make major savings.
Payback – Maximises Payback
Useful Life – Extends Useful Life
How much can I save?
We have assumed between 40-75 litres of hot water per person per day. 40 for many people with a small bill, 75 for few people with a large bill.
We assume we heat water from 20 to 65 degrees and use 1 litre of hot for each litre of cold for a bath or shower. This will make for 42.5 degree bath water.
(200 (litres) x 4.18 (kilojoules required to heat 1 litre of water) x 45 (65-20 temperature change)) / 3600 (kilojoules per kilowatt hour) = 10.5 kWh electricity
Solar Hot Water
What to consider when choosing the right system
- Size really matters with Solar Hot Water systems and we work start with 50L per person per day.
- A shower can use anything from 10 to 15L per minute. A bath uses between 100L and 200L of water.
- Most geysers are set to heat water to 55 or 60 ℃. Most can only really tolerate water up to 46 ℃
- Your shower water is a mixture of hot (60 degree) geyser water and cold (20 degree) mains.
- (It is normally a 50:50 mix of hot and cold water.)
Solar Hot Water (SWH) systems are not complicated but they do need to be designed accordingly and installed correctly to ensure that you maximise their efficiency and your savings.
There are 2 basic configurations of SHW systems:
- Thermosiphon (solar collector and solar geyser on the roof)
- Pumped (solar collector on the roof with the solar geyser inside)
- There are a number of SANS standards that are required by law to ensure safety.
- There are also specific factors to consider to ensure maximum efficiency, safety and savings. It is therefore vital to conduct a site visit to determine your roof type, geyser size and location and to discuss your hot water requirements and usage patterns.
- Pumped systems will require slightly more lifetime maintenance than thermosiphon systems.
- Pumped systems also need electricity to work during the day, thermosiphon systems do not.
- Pumped systems use a small 40W pump to circulate the water.
- Thermosiphon systems use the law of Thermodynamics. (hot water rises, cold water falls)
- All SHW systems have back up elements so you always have hot water, even if there is no sun.
- Your current geyser can be connected (retrofit) to solar panels. The most cost effective option.
- When your geyser bursts you can upgrade to a solar geyser and, if needed, to a bigger volume.
- If you plan to increase your geyser size, it is important to choose its solar collector in advance.
- It is vital to get the size of your solar system in line with your hot water requirements.
- Your savings are compromised if you under-size your SHW system.
- You can also choose to place the geyser on your roof to reduce the risk of water damage.
- The orientation of the roof determines the type of collector used (in most cases)
- Flat plate collectors are used within 45 degrees of North
- Evacuated Tube Collectors (EVT's) are used outside 45 degrees of North
- Care must be taken with EVT collectors as they get very hot and can stress the solar system.
- Your collector must be at reasonable angle to the sun. We have flat roof stands if needed.
- (Collectors will need cleaning over time to prevent a drop in performance)
- Looks like an air conditioning unit but it works in reverse, heating water from ambient air.
- Is able to reduce your water heating bill by about 67% - 70%
- HP's are your best option when SHW is not practical OR when hot water is constantly needed.
- High water usage can affect solar systems but not heat pumps.
- The more you use the more you save.
- If roof access is difficult or the roof is considerably shaded, heat pumps can be considered.
- Sometimes it is not possible to achieve the correct hot water store, related to usage patterns.
- Heat pumps need annual servicing to maintain efficiency & lifespan.
- If the water quality is poor, they may need more regular attention.
- Has its own controller with a timer.
- Controls backup element on/off times and allows you to set your water temperature.
- Display unit allows you to manage and monitor your solar system and geyser manually.
- Vital for pumped systems as it controls the pump and circulates the hot water.
- Monitors the collector temperature in pumped systems.
- Has a holiday mode which cancels the back up element times while you are away.
- Reverse Thermosyphoning
- Only happens on a pumped system when the geyser is lower than the panel
- A key failure since your heated solar water flows in the wrong direction at night and is cooled.
- You essentially lose the solar energy and need electricity to make up the loss.
- You can check the panels at night to ensure they are not sitting at geyser temperature.
- Non-return Valve (NRV)
- This is used to ensure that there is no reverse thermosiphoning.
- It can get stuck (from dirty water) and will stop working, use your geyserwise to check at night.
- A quick service will address this.
- Pressure Reducing Valve (PRV)
- Used to reduce incoming water mains pressure down to the rated pressure of your geyser
- Also drips when the geyser is being heated to keep the pressure at the geyser rating
- Every geyser has a specific pressure rating. (100kPa, 200kPa, 400kPa and 600kPa)
- Steam Release Valve (SRV)
- Used only on pumped systems with Evacuated Tube (EVT) heat collectors
- When the geyser reaches 75 degrees the system stops circulating the water.
- Any water that is then left in the collectors turns to steam. This is released by the SRV
- If you collector is too big for your geyser, this valve will need replacing at regular intervals.
- The run off from this is extremely hot and needs to be channeled to a safe place???
- Lights use more electricity than you expect!.
- A single light, used regularly will pay off in less than 1 year if swapped to LED
- If your downlights are 12V then it is a bit more involved than simply swapping the bulbs, as we need to install separate 220v LED bulb holders.
- Key things to consider are the colour, brightness & warranty
- Are your lights dimmable? If so, you need dimmable bulbs and will may need to change your dimmer switches
If you have reduced you electricity use as much as you can, you are ready to generate your own power.
Rule 1: When power is generated, it has to be immediately used, stored, sold or wasted
Rule 2: You can never perfectly match power generation to usage, especially in a home
- Sun shines on Solar Panels (PV Modules) on your roof. This generates Direct Current (DC) electricity
- Your house & appliances run on Alternating Current (AC) electricity
- A solar Inverter converts the DC from the roof to AC for the house
- When power is generated it has to be immediately either
- If you want to store electricity you need a battery
- This is still relatively expensive, but prices will drop in the next few years
- If power security is an issue for you then batteries are the obvious solution
- If you want to sell the excess power, you need to be connected to the Grid (electricity network) and legally allowed to sell power to your provider.
- Sunlight is one of the few things that will always remain free.The sun is also pretty low maintenance!
- The cost of solar equipment has plummeted over the last few years. The cost of electricity is 4 times more expensive now (2016) than in 2007..
- Various municipalities have created tariffs that allow a household to sell excess power that they generate.
- It is already cheaper for many households to produce their own power than it is to buy it
- If electricity is not always available, you can use a system that includes batteries to protect you from power outages.
- Solar PV is a long-term investment. By investing in a solar PV system, you fix the cost per unit of electricity for a portion of your bill for the next 25 years or more.
- Solar PV is a long established, stable, low-maintenance technology. Once installed it will quietly generate electricity whenever the sun is shining.
Not only will solar save you a significant amount of money, but it will reduce your carbon footprint. Globally there is a huge move towards using renewable energy. Over 40% of power generated at power stations is lost by the time it is used in a home. Generating and using power locally avoids this loss.
There are solar options to suit most budgets and a system should be designed around your home specifically.
You can start with a small system and upgrade later if your budget is limited, or install an all singing, all dancing system and secure your energy costs for the next 25 years.
We are brand agnostic, we work with a range of tried and tested brands to ensure that we have a solution for most households. Different brands have different price points and value propositions. It is important to match these to your requirements.
There are a few main things to consider that will have a big impact on the type of system you require.
- Why you want Solar PV
- To save money
- To secure electricity supply (needs batteries)
- How much space you have for panels (on roof or ground or wall)
- This will affect which type of PV module (solar panel) you require
- Is there any shading where you plan to locate your panels?
- Who provides your electricity?
- Different providers have different rules, processes and tariffs
- Whether you have single or three phase power.
- What type of electricity meter you have.
- Your current meter will be either digital or mechanical.
- If you would like to to feed excess power generated into the grid:
- You have to pay to upgrade to a smart meter. This measures how much you buy and sell.
- You also have to sign up to the relevant tariff.
- This is done with your electricity provider. We will manage this process for you.
- If you do not want to buy a smart meter then you need to install additional equipment to ensure that you do not feed power back into the grid
- Whether or not it is financially viable to feed into the grid depends on your power provider as well as the size of your bill.
- If it does not make sense to sign up there are many other options that do make sense.
- How much you spend on electricity each month
- When you use your your electricity. I.e. how much you use in the day versus at night
Knowing the answers to these questions will allow you to define accurately to type of system that will address your requirements.
There are 3 main types of commonly used solar panels (PV modules).
- Polycrystalline Silicon
- Cheapest & most commonly used
- Good if you have lots of space
- Monocrystalline Silicon
- Most expensive.
- Most efficient. I.e. more power generated using less space
- Important when roof space limited
- Better where shading is an issue or where you have poor mounting angles
- Shading has a bigger impact than you would think. It is critical to cater for this correctly.
Things to consider:
- Your Roof
- Age, structure, direction and angle are important
- Do you have more or less usable space than you need to produce the power required
- Is there any shading that will affect any panels at any time of the day
- PV Modules
- Warranty offered and enforceable by the module manufacturer
- Speed and pattern at which the module efficiency drops over time
- Environmental specifics (close to coast, likelihood of impact, bird-poo etc.)
- Solar Inverters
- A solar inverter changes the direct current (DC) electricity generated by the panels into alternating current (AC) power that is provided by the Eskom and used by your appliances.
- A grid-tied (connected) solar inverter will only work when the grid is available
- This ensures that no power will be fed into the grid during maintenance
- A solar inverter will provide power only when the sun is shining!
- Battery Inverters
- A battery inverter changes the DC power from the battery into AC power to use in the house.
- Provide power when the grid is down
- Specific battery and solar inverters can be configured to work together to store additional power generated in the day for use at night
- Hybrid Inverters
- These inverters are relatively new and combine the solar and battery inverters into a single device.
- Typically cheaper than buying both a solar and battery inverter
- They will generate power even when the grid is down
- They are designed to allow you to store power from the day for use at night
- These inverters are relatively new and combine the solar and battery inverters into a single device.
- Historically batteries have been Lead based. These have a very limited lifespan.
- Battery technology is changing. The market is moving towards Lithium based batteries.
- The cost of this technology is expected to drop by 50-60% in USD terms over the next 3-5 years.
- Lithium batteries have a far longer lifespan than Lead-based ones
- The Tesla Powerwall is the most well known brand, but there are many others.
- Storing the power you generate in batteries for use at night is call Self-optimisation. This is done to maximise Self-consumption. I.e. use as much of the power you generate as possible
- Batteries for Self-consumption and batteries for Backup are two different requirements and require different approaches
- It is typically still more expensive to store power in batteries than to buy it, but there are many situations where the use of batteries is sensible.
In order to maximise your savings and returns it is important to match your electricity usage and generation as closely as possible.
Ideally you want to reduce night time consumption as much as possible and move usage to the day. Some of this can be achieved with no lifestyle changes. More can be moved if you are prepared to change how you live a bit
Typically we like to install and energy meter. This is simple to install and will measure how much power you use and when you use it.
- Simply by knowing how you use electricity it is possible to save money
- If you are not going to store power for nighttime use then you want to make sure that your system is sized to match your electricity use in the day
- If you want to install batteries to store power for nighttime use, then you need to know how much you use at night so you can store the right amount
- Legislation varies depending on who your provider is. Different providers have different registration processes and tariffs.
- It is important to ensure that your installation complies with all standards and is acceptable to your insurance provider.
- Currently all solar installations legally need a Professional Engineers sign-off.
- Legislation is new and changing as are the tariffs. It is important to understand your specific options when making decisions on how to proceed.
Did you know? There are around 2300 coal fired power stations in the world. Air-con, refrigeration, heating & cooling uses about 35% of all the worlds energy
It is often easy to improve efficiency by around 15% through good maintenance and servicing.
If this was done by everybody who owned an air-conditioned or fridge then you could close 120 power stations
- We all know roughly what an air-conditioner is. It cools or heats and removes moisture from the inside air and sends it outside. It does this using compressed gas and airflow.
- Air-conditioning is in fact the cheapest way to heat your house in South Africa. Cheaper than fire or heaters for the amount of air heated! With the rising cost of electricity this is clearly still an expense, but there are easy and sensible ways to minimise this cost.
- Typically you will have a unit mounted in the ceiling or wall inside the building and a compressor mounted on the wall outside. The gas is heated or cooled by the compressor and then run to the evaporator inside, to heat or cool the air as required.
- For air conditioners to work well, the airflow around the condenser outside needs to be clear. Very often the air filters & coil get dirty due to the air pollution and dust. Poor airflow decreases efficiency and increases cost.
- If there is too little gas then the compressor works harder than it should. This uses more electricity which means more cost.
- An air-conditioner should be serviced annually to maximise lifespan and minimise running and maintenance costs.
There are different brands at different price points. Probably the best known by consumers are Daiken, LG and Samsung, but there are a number of others that are also very good. All the top ones have similar excellent efficiency ratings, after sales part availability, service and warranty support is important .
The system efficiency (how much power it uses to create how much heating//cooling) is important when a system runs for many hours each day.
There are 3 basic configurations for an air-conditioning unit:
- Free-standing/portable units
- These are the cheapest and least effective
- These are not really cold anymore.
- If you have one of these it would be a good idea to learn how much it is costing you to run it and investigate replacing it
- Split units (evaporator in the room and condenser outside)
- This is the most widely used and most efficient set up
- The gas is moved from the unit in the house to the condenser. This is more efficient than moving the air.
You can have centralised units where you have a single condenser outside, running multiple evaporators (the bit in the room). We recommend units with one condenser to one evaporator for the following reasons:
- A single failure will not affect all units.
- These are also more efficient for the home as you only run the ones you need in the rooms you use.
There has also been a change to the motors used to drive the condenser unit. Old air-conditioners have a motor that runs at a single speed. This is either on or off. The new systems (called Inverters) use a variable speed motor. This runs only as much as is needed. The advantages of the new Inverter-type of air-conditioner are:
- Improved efficiency of between 30-40%.
- No temperature fluctuations = maximum comfort
- No voltage peak from the system
Air-conditioners have many moving parts. In addition there is a lot of airflow so a lot of dirt will get trapped by the filters.
It is important to have your system serviced once per year to keep running costs as low as possible and extend the useful life.
If your filters are blocked and the air does not flow properly, the system will work harder to achieve the same result. This causes more electricity usage and more wear and tear.
During a service the following should be done:
- Clean all air intakes & filters
- Clean other debris from around the unit
- Clean the coil to remove grease, carbon and other dirt
- Check the gas pressure
- Check all the warnings and settings
Sizing Your System
- The size of the system you need is determined primarily by the air volume of the room.
- Other factors include sunlight, insulation/airflow and ceiling height.
- If the room is heavily shaded, reduce capacity by 10 percent.
- If the room is extra sunny, increase capacity by 10 percent.
- If more than two people regularly occupy the room, add 600 Btu for each additional person.
- If the unit is used in a kitchen, increase capacity by 4,000 Btu.
- If you oversize a unit you get too much humidity as it will run for shorter periods which does not allow it to extract the moisture and you don’t get the oil back to the condenser efficiently.
- If you undersize it works too hard, the air gets too dry and you will have maintenance issues.
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Why Northface Solar?
GUARANTEED QUALITY AND 24/7 SUPPORTWe answer the phone day or night. 12 month warranty, call out service, technical support. Annual servicing.
EACH HOME IS UNIQUEWe individually review each home to ensure optimized savings now and for the future.
ENERGY EXPERTSOver our many years of experience in the home energy sector we have compiled a broad range of solutions to ensure we have the right solution for each customer.
YOUR BEST INTEREST AT HEARTWe make sure the system designed for you makes themost sense for your home and wallet. We are with you through the life of the system.
Free Solar Assessment
Each home is unique. We never underestimate the importance of gathering the correct information in order to provide the best possible service.
That is why we offer a free solar assessment, enabling us to recommend the best solar option for your needs. Please complete your details and we will contact you within 24hrs to discuss your options and arrange a free site visit. We are accredited installers with the City of Cape Town and provide up to date, objective and informative information to you so that you can choose the best system for your requirements.
We are accredited by City of Cape Town
Energy saving tips
Simple and effective ways to reduce your bill.