Jakes

Thanks guys. The generator can be next to the inverter, but I'll use 2.5mm.

Guys I need some help please. My (off-grid) system is getting a MicroCare 48V/5kW Bi-directional inverter. I'm adding a petrol generator to charge the batteries on days with little sunshine. According to MicroCare, the inverter can charge the batteries with a maximum current of 50A. Without losses this will be 2400W. Now the questions: Will a 2.5kW generator be sufficient for the job? I also have a 5.5kW, if the small one does not do the job, but I think the 2.5kW one is lighter on petrol. (I haven't tested them both with a 2.5kW load, I'm guessing). Can I use 2.5mm cabtyre with a normal 3-point plug on the end and just plug it into the generator? The inverter has 2 "Live In" terminals, L-IN and N-IN. Should I also connect the earth from the generator to the earth of the inverter? Thanks so long. J

Thanks a mill. I'm also interested in the Narada's. Will you please let me know who the supplier is? You can PM me if you prefer.

Hi McW What prices were you quoted for REXC's

Well done, Chris. Must be a joy not hearing the genny full time, and seeing the reduction in your energy costs. One question: Are you comfortable with your pv-mount and the wind? I moved to the WC recently, and learned some expensive lessons about the power of the wind. I put a pallet with 18 new panels next to the battery house. They were only stacked, not tied down. A week ago the wind lifted 3 of them from the stack, put 1 next to the stack, 1 about 4m away and 1 about 10m away from the stack. Someone came here last week telling a story of an acquaintice who installed R350k worth of panels and the wind flipped the whole installation over shortly after it was cemented into the ground. If I listen to you I think you've gone through a very steep learning curve in a short time. Congratulations.

Guys I'm installing a system at our house in the Karoo. I've got 3750W of PV installed (15x250W panels). I'll buy a MicroCare 100A controller and a 5kW M/C inverter. Which 48V battery pack options would you suggest? I'd like to limit the budget for the batteries to about R70 000. Thanks a million.

Hi Mike Thanks for your offer. I'll be in touch. Problem is that this guy would probably like to be seen as one of the major players in the business.

Hi Chris I bought all the cables, earthing, the combiner box, fuses and switches from their Cape Town branch. It was at a stage where I needed some information on the installation as well, and Nick was very helpfull. They'll get more of my business.

We moved to the Western Cape earlier in the year, probably our last move before they carry us away from here. We decided from the outset to be self-sufficient as far as electricity is concerned. Included in the planning was to buy a decent generator. I found a 13kW silent diesel machine on the internet and paid the guy R45k. The transaction proved to be a donation to the National Nigerian FrodFund. The prosecuting authorities indicated that they are not willing to investigate the matter. I also bought the components for the solar system. I thougt it wise to deal with one of the more prominent internet-based alternative energy outlets. Last year in February I paid for a MicroCare 100A charge controller, a 5kW M/C inverter, 16 x 300W SunPower panels and 24 Willard RT25 batteries. I arranged with the supplier that he'll deliver the components as the house progresses and they become necessary. Some months ago it became clear that the delivery of the components would not go as smoothly as planned. After lots of effort and pleading he delivered 5000W of PV. (20 x 250W Renesola, as he had sold my SunPowers). For the rest of the components it does not pose well. He does not react to my messages and if I do manange to speak to him it appears that he is too busy with imports to supply my components. He appears to indicate that he has run out of cash. He manages to produce more lies than one would think possible from a normal person. He apologizes for "arriving at this point", but indicates that he does not see how he woud be able to supply my components. On his website you can currently order from a very nice array of Load Shed Kits - some of them containing very much the components I paid him for more than a year ago. We're living in a very nice house, but without electricity of any meaningful measure. We're using a 1000W system that came over from the wendy we lived in while the house was being built. I've started doing the homework to re-buy the components, but I'm not in a financial position to buy nearly what I initially planned.

Hi Chris I think you're doing extremely well. Congratulations on your planning, and strongs with our build. Wetkit, what will the practical implication be of using more PV with the Axpert 5kVA than the prescribed 3000W? (Eg. Chris's anticipated 15 x 250W panels). One tends to think that the inverter will not "know" it's more than 3000W, but that could be a risky asumption. My plan is to do something similar.

Alistair I bought most of the accessories from Rubicon in MG. Nick is a knowledgeable, helpful guy.

Hi Regie Thanks for the advice. I'll bare in mind. We have been using a low pressure solar geyser for the last 3 years, where we currently live. It uses a little electrical help, but has saved us a lot. We have made most of the necessary lifestyle adjustments. We're prepared for some more when we move down to the WesternCape. It is our intention to install a stove. The design of our house asks for a centrally mounted one. I've done some reading on a "wet stove", but was not seriously considering it. Maybe I should re-consider. Wk I popped into CPR batteries in Brakpan to start gathering info. They manufacture forklift batteries. I will do some more homework on using a forklift battery. If somebody in the meantime knows about a supplier who could give a decent price on a bank of M-Solar's of 600Ah at 48V, I'll make a plan to rob the other bank for them. Some time ago I bought a couple of kW-hour meters to measure the consumption of some of our appliances. Some information gathered: Double door LG fridge/freezer, 560l, nothing indicating that it's a very "green" appliance. Opened a couple of times a day, serves a family: Measured over 138 summer days - 1.48kWh/day. Bosch freezer, 260l, opened maybe once a day. Measured over 119 summer days - 0.96kWh/day. Samsung bar fridge, 120l, opened maybe once a week. Measured over 119 summer days - 0.29kW/day. Bosch dishwasher. We use its 35

Hi W Thanks for the encouragement. I need that, and a lot more. I'll give you a shout closer to the time of construction, somewhere after winter. I've bought: Sunpower 300W 50V panels.(16) a MicroCare 100A controller a MicroCare 5000W Bi-directional inverter. There's too many panels for the house. The recommendation is for 6 panels, but I made use of the good offer at GW Store for the panels. At R6/W (plus VAT) I thought it good to buy some extra. We hope to get consent from the authorities to also put up some guest/weekend chalets in future. I'd like to make them work off the grid as well. Then there's still the borehole. I haven't got final answers about that, but some of the panels will do duty there. The system voltage will be 48. You agree? I haven't decided about the batteries yet. Would like them M-Solar's, but I'll need a very special "special" to buy 500Ah of those. I'm impressed by what I learn about the batteries of electric forklifts. It seems that their DoD/lifespan ratio is extremely good. It would seem that one could save R20-R30k on the battery bank going that route. They are just far from maintenance free. They need water frequently. The plan is to put the panel structure on the ground, not on the roof. I believe that they can heat up on the roof, influencing their output. Our house will get a flat roof, so it can make sense not to put them there. Like most other users, I've got a bag full of plans to make the panels follow the sun, but I don't know if I'll have decent success. I would still like to add a 1kW wind turbine at some stage. I just need to sell the farm first to be able to pay for that. What else must I know?

Hi SR I've started buying some of the components, as I'll only need the system operational by August. I've bought some solar panels, the charge controller (100A M/C) and the inverter (5000W M/C). I'll buy the batteries closer to the time. I bought more pv than what I need for the house, but there's still a borehole to get equipped as well. GW store supplied.

Hi W I'm using a gps to measure height above sea level. Really don't know how accurate it is, but here goes. The borehole is 255m above sea level. The tank will probably be at 310m. The borehole is 60m deep. I'd like the pump to be about 40m below ground level. The water level seems to stabilize at about 10m below ground level if I pump 1200l/m, which is more than enough for our needs. Reading about the pumps coming from the east, some of them seem to be able to lift the water to a height of 140m, using an 850W/48V motor. The power is supplied by panels of 1000W. Any ideas if I will be able to make this one work?

Hi guys A friend offered me solar borehole pump. It's a lot more than what I will need, but it can make sense to use it. It comes with an MPPT-controller box and the motor/pump combination. There's no solar panels with the pump. The inscription on the pump says: 220V (underscored, for DC) and 3kW. I will not need an output of more than 1kW. Is it possible to use less generating capacity from the solar panels than what the ability of the pump is? I was thinking along the lines of using 5 x 240W/48V panels, connected in series. Can that be done? Thanks again.

Hi Ww That's excellent. From now on I'll prefer to refer to you as Sir Ww. Tell us more about the project: How many hours did it take you? What did it cost? Could you source all the parts locally? What is the turbine's output? (Watts, and how many volts did you plan for?) You seem handy and artistic, even with wood. How did you go about shaping the blades? How do you get a 10m long pole (with a heavy far end) to change a horizontal orientation for a vertical one? Well done.

Yes. There's no Eskom available closeby. I'm also looking forward to a dispensation where I don't pay Eskom their monthly network fee for our new place. I've got half a lifetime behind of that.

Thanks for the guidance. Yesterday I also realised that my attraction to M-Solar batteries and trying to limit the capital outlay will get me stuck with 24V. Let us try and move a little wider then. If we decide to look at more than the Raylites, what batteries would you recommend then so that the system can run on 36V or 48V DC? Somehow my thinking is that "goedkoop koop is duur koop" as far as the batteries is concerned. I've actually got a transport business, and truck batteries are a weak link in our industry, but I'm not saying that they will not be a feasible solution in this application. They just seem to finally greet the living amongst us the moment "deep cycle" is mentioned in their presense. We can obviously try and avoid them cycling too deep. It seems that an Outback 80A controller would cost less than R9 000. That's still acceptable. We can run a MicroCare 5kW inverter off 36V or 48V. R20 000 still seems fair. Can the MicroCare inverter charge the batteries from external 220V like a generator? I'd like not to exceed R50 000 for the batteries, less if at all feasible. Is there an 80A MicroCare MPPT controller? Maybe a last question: If you've got R90 000-R100 000 to spend, what will be on the back of your bakkie and trailer leaving the green shop? Thanks for your input, it makes life interesting.

Hi Guys Thanks for the responses so far. I really appreciate the help. I've also had a response from a supplier here, thank you. The homework thus far would indicate a system as follows: (Mainly dictated by my (lack of) finances). 2000W worth of solar panels. I can expand later, or add a wind charger. A 60A charge controller. 4 x M-Solar batteries. I'm thinking the 3MIL17S-600's would work well. That might be light, but it's more than R30 000 worth of batteries. I'll expand on the battery bank as I expand on my knowledge of how to withdraw money from the Red Bank without a credit card. (I believe you go at 02h30 in the morning). A 5000W inverter. A battery monitor. Maybe a small generator for days on end with no sunshine. Some questions: What is needed for the generator to be able to charge the batteries? Does that ask for a different inverter, like the Oasis of MLT Drives? Will it be easy to add a wind charger at a later stage? Some would certainly think that the charge controller and the inverter are too big. Is there a disadvantage using a larger inverter and controller, other than financial? Can I buy the components and do the installation myself? A chat to a supplier seemed to indicate that they will supply and install R85 000 worth of equipment, and the total account would be for R200 000, if everything goes smooth, he said. Wetkit. I did some homework on a windpomp. It seems that you'll fork out north of R50 000 for an entry level one. For the borehole pump I'm thinking going 220V, with solar panels, a controller, batteries and an inverter. This way one can save between R5 000-R10 000, compared to a solar borehole pump. (Correct me if I'm wrong, I'd love to be). I'd like to hear from suppliers here to quote on the complete system, and to suggest changes if needed. Thanks again. J.

Hi E Thanks so far for your response. Please guide if I should overstep the lines of the forum. I've completed the spreadsheet. Where I couldn't alter the "hours" I halved the "number". Half a hair drier for an hour would be the same as one hairdryer for half an hour. I chose 48V as the system voltage thinking that the cable from the wind turbine might be very long and the higher voltage should make for a thinner cable? I'll supply answers to the questions as they arise and I learn more. The ideal would obviously be to deal with suppliers with knowledge and integrity. If they've got good prices that will make for a nice red cherry on the top. Thanks again. J. Solar Calculator.xls

Hi guys I'm new to the forum, and my contribution can initially not be anything else than a lot of questions. I'll appreciate your input on the way forward for me. We are moving to Robertson, probably later in the year or early next year. The plan is to be totally independant of supplied electricity. I'd like to start purchasing the components now. We will mostly be 2 in the house using gas for cooking (except for a microwave oven) and solar water heating. I've contacted 2 suppliers and the suggestions for the power supply for our house seems to look as follows: (Up to) 10x300W solar panels. (One guy suggests ReneSola panels @ R10/W, the other Tenesol @ R21/W). A 60A charge controller. (MicroCare @ R5 200). A 5kW inverter @ R20 000. (MicroCare from the one guy, an 3kW unknown brand from the other @ R15 000). The battery options vary between R30 000 and R70 000). Now some questions: How would you guys specify the power system? Which batteries do you think will be best to use? I'm specifically trying to find a good value for the money solution. Paying more for batteries that will last longer seems to make a lot of sense, although I will steer away from a R70k battery pack. What are your feelings about the solar panel recommendations? Also as far as brand names are concerned. In my mind it makes a lot of sense to also install a wind turbine to help on cloudy days and to maybe extend the life of the batteries. The suppliers don't really seem to agree with my thinking about a wind turbine. It would seem that our farm lies in a yellow or maybe orange area on the wind atlas, 7-8m/s wind speed. (Although it seems that the measurements were taken at 100m above the ground. So I don't know if I'm jumping the gun to even be looking at those figures). I also need to take water out of a borehole. The borehole depth: 65m, The water level is about 20m below the ground level, the tank will be about 70m above the borehole ground level. The total head will be around 100m if I'm not mistaken. My thinking is that we will not need more than 1 000 litres of water per day. So I'll need a power system for the house and a solar powered borehole pump, and would really appreciate your inputs. Thanks a million. J.