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PeterP last won the day on September 17 2020

PeterP had the most liked content!

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  1. You are currently making good return and your system will have a very high IRR, but it seems you are exporting more than what the CoCT SSEG system allows for (ie you are not currently a net consumer). Net consumer is calculated on annual consumption and production so you might still be ok once winter is taken into consideration, but seeing your impressive tracker results, I'm not sure You are missing my point about having the option to add batteries, of course it will be more expensive and thus IRR will be potentially reduced but batteries are all about having power when Eskom can't supp
  2. The Hybrid will still require a battery to function during grid-outage - panels will give no power. The reason to start with Hybrid is to give you the option to add battery later instead of having to buy a new inverter once you decide to do so. The Hybrid will export and work while grid is up like Erastus system at a fractionally higher upfront cost but with the added benefit you can add battery at any time (which anyone with a grid-tie only system would ultimately love to have when there is loadshedding...)
  3. Grid Tied Inverter - which has to switch off when grid is down. I like your example, but would recommend setting up with a Hybrid inverter if the feed-in is attractive in your area as this can be expanded to work when grid is down (only requires battery). Most people going solar, do so to be loadshedding proof - I offer the grid-tie version but once it's clear it has to switch off when grid is down it's mostly a non-starter
  4. Current SA EV prices are ludicrous - we got ours 2nd hand for R193K with 35K on clock - so then it's ok. Future EV pricing will be in line with ICE in a few years. We had to replace the other car anyway, so for us it made sense.
  5. ROI is typically the single most important factor when considering going solar - even though being Loadshedding resilient and producing clean energy are close seconds and thirds. The screenshot gives our savings on a 5.6kWp (320W modules) - 10KVA (Axpert inverters) - 13.5kWh (Solar MD Li-Ion Battery) for the past 3.5 years. Cost of system R200K. Annual solar savings: R25K+ What it doesn't show, is that we have further estimated savings of R25,000-R30,000 per year in avoided petrol purchases and vehicle maintenance as the system is also powering our Nissan Leaf EV. We use the electric
  6. The CoCT Residential SSEG tariff shown is only for customers who feed-in - if you are not feeding in, you pay the same Energy Charge but a reduced Service charge of R171 VAT incl. pm. on Home User Tariff.
  7. The 25% limit is about how much the grid has to pick up when it reconnects after a grid-outage. The grid is designed to handle a % of possible loads off your standard supply - now add feed-in, and if left unregulated, you could have feed-in off over 100% plus your loads exceeding capacity of grid very quickly when grid is restored and everyone's load and feed-back resumes simultaneously. If your embedded generator trips it not really a problem (no worse than switching on 2 geysers at the same time) as it's inconceivable that all other embedded generators (geysers on) trip at the same time
  8. Don't forget Eskom future increases will increase savings thus making financing more viable. I have done the calcs for a couple of customers and in most cases savings will equal or exceed installments in year one - so provided Eskom continues with tariff increases it will be worthwhile.
  9. We are running it in SNG output mode for the time being and this works in terms of negating the E60 Error - but then we lose part of our monitoring systems functionality which the clients paid for.....our monitoring system supplier thinks this can be overcome by changes to the software but it's not high on their priority list to fix
  10. Still stuck with this one - there are no 3-phase loads on the 2 sites where I have this problem. Only response from Voltronics is that it must be a load. Any one have a suggestion as to how one would identify the load causing the feedback? Tried doing Utility to switch to SBU on the one site with a cranky fridge and voila - it displayed E60 error - tried to repeat the feat x3 with no E60 error......not sure what to do.
  11. Let's do the maths on the above 3kW element example. With the heatpump you are saving 1.75kWh per hour of operation (3kW element minus 1.25kWh consumption). With the 3.7kWp extra PV you will be generating an ave. of 16.65kWh/day (North-facing in Cape Town) less the 3kWh to heat geyser for 1 hour = 13.65kWh/day which can be used for other loads or stored in battery. Heatpump saving: 1.75kWh/day PV saving: 13.65kWh/day Cost of PV is about double but life is 25 years vs 10 years for heat pump so that evens out. Running costs will be zero with the PV with an extra 13.65kWh
  12. Heat-pump is more energy efficient but not necessarily more cost-effective. EV Tubes and PV have zero marginal cost, heat-pumps reduce the marginal cost. If the goal is minimizing running costs then zero marginal cost should win. If ROI is not a concern then a heat-pump wins on it's efficiency
  13. Yes but at what cost? For the amount of money you spend installing the heat pump you can have the PV power (at zero marginal cost and 25 year life) to run the normal geyser element plus plenty excess power for other loads when water is up to temp. Heat pumps are more energy efficient for sure by the factor of 3.5 but I'm assuming he is looking at best option financially and if you factor in extra upfront cost, 10 year life and maintenance then the heat pump for such a small system may lose out. But as I said, it depends - if he doesn't have other loads or battery to push the excess PV power in
  14. As with most of these questions - it depends. If you have enough excess PV power during the day to run 2x 1.5-2kW element for 2hours then thats your solution. If your load-profile won't allow the geyser load without having to add panels then it will be slightly cheaper to much of a muchness to add EV-tubes as opposed to adding extra PV panels. Heat pumps are typically only viable on bigger systems for water heating + they require maintenance and have shorter lifespans.
  15. PeterP

    PV Yield?

    Agree with everything Plonkster said except the comment: "It's also cheaper to buy gas for the next few decades than installing a larger solar system" You got gas to come in at around R2/kWh - solar is much less, even with storage. And the solar cost would be fixed whereas gas is likely to go up. Financially gas makes no sense, especially compared to solar.
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