One of the biggest salepersons around moved into South Africa recently. In Solar PV Systems we call that person; “Sir Eskom Loadshedding!”
“Phone and web site enquiries have escalated somewhat since the start of loadshedding,” says Alan Straton from Straton Solar.
“Everyone wants to be free of Eskom and loadshedding and most are of the impression that Solar Power is the magic bullet to do that,” explained Alan.
The price of Solar Panels has plummeted over the last 8 years and the electricity price per unit (Kw) manufactured from a pure grid tie solar installation is now less than 70c per unit amortised over the 20 year expected life of an installation.
On the other hand the price of batteries still needs to reach that tipping point before beginning to plummet.
“Batteries are the next frontier in terms of lower price and higher storage capacity,” says Straton.
Solar PV comes in 3 ‘flavours:
- Grid Tie only (here you will still be affected by loadshedding)
- Grid Tie with Battery Backup, referred to as a Hybrid System (load shedding will not affect you – depending on the size of your batteries)
- Off Grid – Here you are on your own with no connection to the grid at all.
Taking the Nelson Mandela Bay Municipality as an example Straton said:
A Grid Tie system for a single phase installation may only be a maximum of 5 KW in size. This is good enough for an annual average of 960 units of electricity each month (more in summer, less in winter). The pay back on such a system is around 6 to 7 years. IF the system is installed in a business then the payback is from the time of switching on as Section 12B of the Income Tax allows an immediate 100% depreciation allowance on renewable energy installation. If you do not have mission critical items then Grid Tie only is the way to go.
A Hybrid System also operates under the same constraints as the Pure Grid Tie system above. In addition the conversation around batteries is that one must remember when buying batteries for your system you are buying cycles – much like buying 5 litres of petrol for your generator, batteries have a finite life.
Businesses in Nelson Mandela Bay on a Three Phase supply may install far more than the 5 KW limit. Most businesses that have contracted Straton Solar to install a Solar System have opted for a 7KW Hybrid system (to keep essential equipment running during loadshedding) and added Pure Grid Tie in various increasing increments of 10KW.
According to Straton three main battery types are available:
- Lead Acid batteries can have a cycle life of 500 and are the cheapest option. Limitations are that a discharge of greater than 80% will severely curtail the life of the battery and that a full charge again takes 14 to 16 hours. Such batteries need attention to prolong their life. Price per 200 AH ranges from R2000 to R4500.00
- Lithium Ion – popularised by the ‘sexy’ Tesla Powerwall comes with a 10 year warranty and 5000 cycles. At the end of 10 years the Powerwall is said to retain 70% of it’s capacity. Lithium Ion batteries are also available in les ‘sexy’ forms and locally in South Africa – such a system can rage in price from R40 000 to R85 000 for a 5 KW System.
- Making a bid for the title of ‘preferred battery’ is a zinc-bromide hybrid flow battery popularised by Australian company, Redflow. Their Zcell can deliver 10 kilowatt hours (kWh) of stored energy each day. Redflow batteries can charge and discharge 100 per cent of their energy capacity each day, avoiding the damage such performance causes traditional battery chemistries. Redflow batteries can also maintain their nominal 10 kilowatt-hour (kWh) storage capacity throughout their operating life – unlike lithium-based and lead-acid batteries which lose energy storage capacity with use. Redflow warrants its ZBM2 and ZCell zinc-bromine flow batteries for 10 years or 36,500 kilowatt-hours (kWh) output (roughly 3650 full cycles), whichever comes first. Pricing: Unknown.
When one purchases batteries you must be aware that you are essentially buying ‘fuel’ upfront.
“With electric vehicles receiving huge focus from major manufacturers the price of batteries is sure to come down or stay at the same level for higher capacity and more cycles,” said Straton.
For example – solar module pricing was 63¢/watt (around R3000.00 per panel) in 2015 and is predicted to drop to 21¢/watt by 2040 (around R1000.00 per panel).
Driving a similar drop in price of batteries will come from the number of motor manufacturers producing electric vehicles which has skyrocketed recently, with most available batteries exceeding the magical 300 mile (482 kilometre) range mark.
In 2018 production electric cars are available from these manufacturers: BMW, Bolloré, BYD, Chery, Chevrolet, Citroën, COURB, ECOmove, ElectraMeccanica, Fiat, Ford, Girfalco, Honda, Hyundai, Hyundai, JAC Motors, Jaguar, Kewet, Kia, Kyburz, Lightning, Mahindra, Mercedes-Benz, Micro Mobility Systems, Mitsubishi, Motores Limpios, MW Motors, NIO, Nissan, Peugeot, Rayttle, Renault, Smart, Sono Motors, Stevens, Tesla, Venturi and Volkswagen.
Global sales of electric vehicles were around 1.2 million units in 2017, 1.6 million in 2018 and are estimated at 2 million in 2019. The International Energy Agency estimates that the number of electric vehicles on the road worldwide will hit 125 million by 2030.
Local Volkswagen MD, Thomas Schaefer said recently that the tipping point around electric vehicles would be in 2023 when the consumer’s first choice for a new car would be for an electric vehicle over a normally aspirated fossil fuel driven motor vehicle.
Straton Solar gave some estimates for the cost of installation for the various solar system choices (end of 2018 prices):
- Grid Tie – from R17 0000 to R25 000 per KW. Affecting the price are variables such as: Roof type and orientation, roof angle and pitch (ideally the angle should be equal to the latitude of the roof), number of panels required, type of panel required, shadow on the roof, inverter type and warranty, cable runs.
- Hybrid – from R23 000 to R38 000 per KW. In addition to the variables in pure grid tie above, battery variables affect the price in terms of type of batteries, power required, cycles required, space available.
For a private home on single phase power requiring the maximum of a 5 KW system the price range is from R85 000 to R190 000 depending on which variables apply and whether a pure grid tie or hybrid system is required.
To sum up:
- A Solar system should last for a minimum of 20 years
- Three types of systems are available – each increasing in cost: Pure Grid Tie (loadshedding WILL affect you); Hybrid (batteries kick in during loadshedding) and Off Grid – you are on your own and cannot rely on the grid if your inverter, batteries and generator fail.
- Solar panel electricity production degrades by 1% per year.
- Batteries are rated in terms of cycles, retained charge and life due to depth of discharge. Those with high cycles and long life cost more.
- Inverters work on strings with most having two strings. the production is dependent upon all the solar panels in a string working optimally. i.e. no shadow or panel failure. The electricity production out of a string is governed by the ‘weakest chain in the link’.
- Some inverters (more expensive) solve the ‘weakest link’ problem by having an optimiser installed on each panel which gives the ability to ‘dial out’ a problem panel and makes trouble shooting much easier.
“Maximising the production from your solar system is just like compound interest – maximise the production from day one and start now. At the end of the day one needs to trust the installer to supply the best equipment at the best price and which will last the required 20 years of envisaged life,” concluded Straton.
More Info on Is a Solar System the answer to Loadshedding? How much can you expect to pay? here: http://straton.co.za/solar