- Understanding Solar Photovoltaic Solutions
- The Rural Application (Domestic)
- The Urban Application (Domestic)
The idea of free energy appeals to most people but once the costs are unpacked and they roll into hundreds of thousands most clients call it a day. There are many 'boer maak 'n plan' concepts and the tolerance around these products to the home owner and designer are flexible but when one designs a system to seamlessly integrate into a specific solution the scope of work changes. Ironically the big systems are easier to design and install than the domestic applications, providing an explanation why so few companies are actually able to take on domestic solar PV solutions. KZN Solar has approached the subject tentatively fully aware of the risks associated with doing these types of installations but after having done the necessary groundwork finally feel comfortable in bringing solutions to the market.
Grid independence is the desired result but as you will read later may not always be the right approach. The absolute goal shared by all is cost saving and a financially viable proposition.
In some instances, the client may be guided toward maximising the amount of solar energy generated during the day without any battery backup but with a generator as primary source of backup in the event of power failure. Certain customers are however set on having a permanent source of battery backup in order to have free energy at night and are willing to incur extra costs by adding a battery backup component, but still keep an open municipal supply. Farming communities vulnerable to cable theft and also sensitive to crime prevention want a totally “off grid” solution.
Regardless of requirement and budget, the consumption patterns are a critical component. Other items to consider are the roof orientation and shade. Our broad focus in this document is on urban and rural applications.
Connectivity fees in some rural areas are in excess of R3000 per month, excluding the KW Hour consumption cost. We often experience customers from the rural areas calling in with electricity bills exceeding R6000 per month. The rural power supply is often susceptible to theft and/or poor infrastructure, resulting in a discontinuation of supply either temporarily or for sustained periods in certain areas.
The combination of excessive costs, threat of service discontinuation and security consciousness present photo voltaics as a good solution in these areas.
The key consideration is belief. Our client’s need to know that the system will perform, the investment makes sense and that the company doing the installation is committed to a successful model.
The independence associated with the rural application is only a portion of the success. The return on investment is by far the biggest motivation to convert to photo voltaics in the rural area. Typically most rural solutions where we are providing 10 Kw solutions (single phase) or less can be amortized in 6 years or less. Rural applications often result in a discontinuation of Eskom supply. The generator is a key component in this configuration.
Attention to hot water storage and capacity as well as the prospect of wind turbine technology plays a big part.
Generally the clients interested in the domestic solar PV solutions are people who are fiercely independent and financially strong enough to pursue the PV option. They do this notwithstanding the fact that the grid supply is secure and relatively inexpensive.
Convincing these people to stay connected to the grid is sometimes difficult but the right thing to do. Having Eskom as a backup is a good option, especially when you want to avoid the cost of batteries and you are able to eliminate a large amount of evening consumption to the bare minimum. Our strategy in this sector of the market, is to provide a component of electricity as close as possible to the client’s requirement on a daily basis, but only put in batteries if the client insists on an “off the grid” solution.
The idea is to reduce the bill and fully utilise the solar portion generated but not to pay for solar contribution that cannot be used. We accomplish this by addressing consumption patterns through replacing older, less technical energy consumption items with new appliances that are far more energy efficient.
The remaining energy consumption is assessed and a photo voltaic system suited to the consumption is then designed. This system is commonly referred to as a “grid tied” solar PV solution but it doesn’t have the capacity to feed energy into the national grid. Should the client require battery backup but still require a dependency on the grid an alternative system will need to be designed, in which bi directional inverter is included in the mix.
The configurations available are numerous and challenging, but with careful consideration and customer needs analysis the right system can be designed.
The inverter and solar (MPPT) Controller are the two key components in any solar PV system given the requirement for PV panels and batteries. These components linked to the integrating dynamic and needs analysis interpretation is what contributes mostly to a successful installation. In the critical areas KZN Solar uses Micro Care products, primarily because the parts are freely available, they also understand the Eskom legislation, we speak the same language and problems are resolved quickly when they arise. Our panels are sourced on the basis of price, guarantee and specifications. Importantly, they always carry the market related guarantees (20 years), where loss of efficiency over the 20 year period plays an important role in our decision making around the choice of panel.
'Grid tied' and any terminology inferring a grid connection is a red flag to the authorities. Installations that present solutions around grid supply need to be authorised by either the local municipality or by Eskom. Unauthorised supply of electricity onto the grid is subject to a fine and disciplinary procedures.
At this point in time none of our systems have the capacity to feed the grid. The incentive to sell power back to the grid at a price comparative with what the Municipality is paying from Eskom direct, is highly unlikely.
The photo voltaic conversion is one that is done on the basis of belief. The Client needs to believe in our company’s ability to make the system perform. They need to trust us in delivering the right solution and they need to know that the real measurable benefits will only come into being roughly 60 months from now when their systems have been paid off and amortised overall.
An amount of between R150 000 and R300 000 is generally required to have a meaningful shift in energy costs. If the focus is on investment opportunity and containing costs, photo voltaics present an excellent opportunity.
Prior to commencing with any PV installation, attention will need to be given to the performance of household appliances currently in use, relative to new technology readily available.
Appliances to consider would include:
- Air Conditioning Unit
- Tumble Dryer
- Hair Dryer
- Washing Machine
- Vacuum Cleaner
Primary focus should be on the geyser, stove, air conditioning, tumble dryer (if used frequently). Cooking on gas is also a good option and conversion to LED lighting essential.
Keep in mind that the most cost effective solutions (grid tied systems) where there is no battery backup, will require sundown time to be a time of bare minimum electrical activity.
Invariably an element of inconvenience needs to be catered for during the process of conversion. Teething problems are unavoidable and need to be anticipated. They are however overcome once the consumption patterns are clearly identified and spread.
An agricultural system consisting of a single phase supply with 10 Kw capacity, battery backup of 1600 amp hours with lead crystal batteries and a suitable generator feed will cost roughly R300K
Grid Tied System with Generator
A grid tied system with a 5 Kw solar generation capacity, where there is no battery backup, including a generator as backup in the event of power outages will cost roughly R160K
Grid tied with Battery backup and Generator
A grid tied system with 5 kw solar generation capacity, 800 amp hours battery backup, in which we have both grid tied and bi directional inverters with dedicated backup isolation points will cost roughly R200K