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  1. I agree with Plonkster that you can safely oversize the panel capacity. In addition of the inverter being able to lower the output from the panels another reason is that because of temperature/dirt of the panels and losses in the electrical circuit you will usually not achieve the published capacity of the panels.
  2. Water harvesting and use, same logic as solar systems.

    here is my proposal how to avoid water day zero and NEVER ever get into this situation again: short term: 1. force government to declare state of emergency (to avoid any legal problems). Have to be creative how to do this. Western cape has a lot of leverage! Big portion of South African GDP! 2. Identify and publish all big users of water (pipes/sluices/boreholes) removing water from major western cape water storage locations). 3. Appoint and publish names of managers for each big “pipe/sluice/borehole” removing water from major western cape water storage locations. 3. Define and communicate maximum daily quota of water allowed to be removed by each big pipe/sluice/borehole from major western cape water storage locations (this has to be done in an autocratic way. We have no time for lengthy democratic debates. Hence the need for a state of emergency. 4. Monitor, manage and publish consumption for each big pipe/sluice/borehole on a 24 hour cycle and switch off supply after quota has been reached (put facilitates in place to enforce law enforcement to avoid unrest and distribute emergency supply of water) 5. Have daily action center meeting with the managers of every big pipe/sluice/borehole drawing water from all major western cape water storage location and review balanced scorecard and corrective action plans and publish result of meeting. 6. Request each manager of “his/her big pipe/sluice/borehole” to define, monitor and manage his/her target (with balanced scorecard and corrective action plans publicly published). The manager of the “Cape Town city user pipe” could for example manage consumption in the following way: - set weekly targets for every household/business based on the quota allocated to him/her - request each household/business to report weekly water consumption and if target has not been met why not - establish a task force to monitor and follow up on households/businesses not reporting or not meeting targets - publish consumption of all users “in his pipe” and corrective action taken by the taskforce how to bring noncompliant users in line with the target 7. Identify and publish (with Names of the responsible manager) all existing and possible short term augmentation projects. Review status and corrective action plans in daily action center and publish results. medium and long term: 8. Compile implement and regularly review and publish a long term strategy how to provide a sustained water supply to the population of the western cape (strategy and reviews to be endorsed and approved by independent bodies like engineers or universities) 8. lobby to change the law to make water resource management in the western cape the responsibility of the province instead of the government.
  3. Eskom collapse?

    The more electricity generated with PV and Wind the bigger the need for storage will become. Fortunately the cost of locally producing and storing electricity with renewable energy is coming down all the time. Soon it will be cheaper than buying it from the big power producers. More and more of the traditional power stations (the coal ones first) will disappear. If the Eskom's of this world are not adapting they will not be able to survive. Some villages, towns and cities will become self sufficient. A city like Cape Town with lots of sunshine and wind could on day easily become independent from Eskom. It could look something like this: - most residential houses and businesses have (with incentives) from the city installed enough PV and hot water generation and storage capacity to cover 80% of their demand - The city will provide the rest (outsourced to private companies) with its own Wind, PV and hydroelectric power generation capacity. For emergency back up hydrogen powered gas turbine generators will be used. - Because of the intermitted generation of electricity there will be a big requirement for electricity usage adaptation and storage. This will be done by producing excess water with the desalination plant, and by pumping water into storage dams high up in the mountains. What do you think? With our politicians it will probably not happen soon!
  4. Water harvesting and use, same logic as solar systems.

    I agree with you, the washing machine is the biggest water guzzler. We use 200 liters per wash!!! (14kg top loader). They should ban the sale of top loaders. City should also encourage more rainwater harvesting (like Eskom did with solar hot water geysers). Even with the little rain we had last winter I easily filled my 40'000 L tank.
  5. Balancing series connected lead acid batteries

    thanks for the quick great help. Much appreciated.
  6. Balancing series connected lead acid batteries

    thanks guys. You are right. Would cause a nice fire! I will look at the HA02 balancers. From your experience is it necessary to balance the 2 strings in addition to the batteries in the strings?
  7. this issue has probably been discussed before but I could not find an answer. to achieve equal voltage on all batteries in a series string is it possible to interconnecting them in parallel? What are the pros and cons?
  8. To Grid Tie or Not to Tie

    I am about to go through the process. Plan is to register with reverse power blocking. Will let you know how it goes
  9. thanks Plonkster got it. Yes please put me in contact with a Pr. Eng or installer here in CT who can help me with the NRS097-2-1 compliance.
  10. thanks for the compliment. I was lucky with the roof orientation. All panels face exactly north at an angle of 25 Deg. The 11 panels next to the water panels are in string 1. The other 11 panels are in string 2. I also like the Goodwe inverter. I did however have a problem. The inverter made some funny noises under heavy PV load (not when only using batteries as power source). It also showed string 1 always at a lower output even after switching the cables coming from the roof around. Jack Song from Goodwe and his R&D engineers identified the noise based on my audio recording as a result of an old control board. He send me a new board with the latest firmware (1212) and now the inverter is dead quiet and both strings show identical power output. I use EzManage to monitor and program the inverter. There is another issue I have noticed. However Jack told me that it is normal and nothing to be concerned with. When the panel output exceeds the demand from the inverter (happens often because I had to set export to 0 Watt) sometimes the inverter moves the string voltage below and not above the maximum power point to reduce string output. The string voltage can go as low as 120 Volts in bright sunshine to control power output. Maybe it is my imagination but the inverter seemed to get much hotter running the strings at low voltage and high current vs high voltage and low current to control string output. What do you think?
  11. thank you for the reply. I am a retired electrical engineer. The PV system is my hobby. I would like to try to get the approval done with the help of a registered Pr. Eng. myself. In the meantime I will disconnect the system from the grid. attached are some pictures of my system:
  12. Hi, I have a 4.4kW PV system which is connected it to the grid without official approval from the city. I did the installation myself. The system works very well and now I want to make the grid connection legal. I am not interested to feed power back into the grid. The inverter is programmed for 0 watt export. The house has a Landis and Gyr prepaid meter. Can somebody who knows the Cape Town situation please advice what the best way to do this is? Details of system: - 22 x 200W mono panels (connected in two series strings of 11 panels each) - Goodwe GW5048ES 5kW hybrid inverter - 8 x 12V 200Ah lead carbon batteries (connected in 2 series strings of 4 batteries each)