Terminal3k Posted April 8, 2022 Posted April 8, 2022 My system is 5kw sunsynk, 12x540w JA, 1 x 5.5 hubble. My battery generally runs out at 12 - 1am. Is it worth it financially long term to buy a second battery? My geyser needs to warm up in the morning in winter time. (see pic) in summer it's generally hot enough for the morning shower without turning on. So in other words, in winter time I would have to buy about 5 units a day and summer time probably about 1-2 units. The other question I have is that once my battery has reached my 30% DOD, then it drains slowly... Is this normal? (see pic) How do I stop it from draining? Quote
MdF Posted April 8, 2022 Posted April 8, 2022 37 minutes ago, Terminal3k said: My system is 5kw sunsynk, 12x540w JA, 1 x 5.5 hubble. My battery generally runs out at 12 - 1am. Is it worth it financially long term to buy a second battery? Morning T, Was in exactly the same place that you are a few months back. The initial install was to cope with loadshedding. That slowly went out the door once I realised just what the system can do. So, then the learning curve was to setup the Work Mode time settings and to shift loads to sunny hours during the day. The plan then was using the battery from midnight to 6am when solar kicked in. But with the new round of loadshedding we had there was not enough buffer to get through the night and make sure there was enough power in case loadshedding started in the morning. Promptly ordered a second battery and installed that soonest. Yes, the expense was there, but now we have enough capacity to get through from 8pm each evening and enough if loadshedding hits. Your investment in a second battery won't be a waste. MdF Buyeye and hoohloc 2 Quote
Beat Posted April 8, 2022 Posted April 8, 2022 2 hours ago, Terminal3k said: My system is 5kw sunsynk, 12x540w JA, 1 x 5.5 hubble. Is it worth it financially long term to buy a second battery? Yes, with your PV power it's almost a must. Be aware that the more battery capacity you have the more sun energy you can harvest and use after sunset and on cloudy days. Quote
iiznh Posted April 8, 2022 Posted April 8, 2022 (edited) Lets say a 5KWh battery effectively can store 4KWh (if you do not use the last 20%) So 4KWh * R2.50 (or insert your electricity price here) = R10 (if you discharge it every day to 20%) * 365 days (best case) = R3650 (of energy stored and saved per year) So if your battery costs R25K then you are looking at 7 years to break even. I reality you might not be able to use 4KWh of stored energy every day so you are probably looking at 10 or more years to break even. Also consider that after 10 years there will be some degredation so less energy stored... And the price of electricity will go up, which will also count in your favour when it comes to repayment. If you consider your ability to work during power outages then the cost of a battery might be a small price to pay. Optimising on power usage might still be a lot cheaper than another battery. What is using your battery power at night? There are other ways to store energy, like eg, extra hot water or heating to a higher temperature. Moving large loads to the grid might also be way cheaper than another battery Edited April 8, 2022 by iiznh questions asked Sc00bs, werner.potgieter and Antonio de Sa 3 Quote
Terminal3k Posted April 8, 2022 Author Posted April 8, 2022 2 hours ago, iiznh said: Lets say a 5KWh battery effectively can store 4KWh (if you do not use the last 20%) So 4KWh * R2.50 (or insert your electricity price here) = R10 (if you discharge it every day to 20%) * 365 days (best case) = R3650 (of energy stored and saved per year) So if your battery costs R25K then you are looking at 7 years to break even. I reality you might not be able to use 4KWh of stored energy every day so you are probably looking at 10 or more years to break even. Also consider that after 10 years there will be some degredation so less energy stored... And the price of electricity will go up, which will also count in your favour when it comes to repayment. If you consider your ability to work during power outages then the cost of a battery might be a small price to pay. Optimising on power usage might still be a lot cheaper than another battery. What is using your battery power at night? There are other ways to store energy, like eg, extra hot water or heating to a higher temperature. Moving large loads to the grid might also be way cheaper than another battery Thanks all. Power at night is just lights and tv/computer. Try to do oven cooking before sun goes down. Quote
Beat Posted April 9, 2022 Posted April 9, 2022 18 hours ago, Terminal3k said: Power at night is just lights and tv/computer. How about fridge and freezer? There might be days coming, when the question no longer arises how much you save, but whether you have electricity or not. TimCam 1 Quote
TimCam Posted April 9, 2022 Posted April 9, 2022 (edited) 1 hour ago, Beat said: How about fridge and freezer? There might be days coming, when the question no longer arises how much you save, but whether you have electricity or not. Unfortunately in certain parts of the country this is already a reality. Currently we have gone 6 days without a break in power, and this is something to celebrate. For our area, mare batteries and more panels are always necessary. Working out the ROI becomes irrelevant when it comes to having power, or not having power. If you have the funds available, you will appreciate the additional battery. Edited April 9, 2022 by TimCam Quote
Scorp007 Posted April 9, 2022 Posted April 9, 2022 This is a great example how each person must work out the best solution. In my area we only have 1 power failure over 24h and that was 36h in 30 years. Due to this stability my main system is grid tied with a 2nd system for LS and if we have an extended outage. Then I use the same panels after switching them over. Low cost vs saving. Return of grid tied only 2.5 years. TimCam and iiznh 2 Quote
iiznh Posted April 11, 2022 Posted April 11, 2022 On 2022/04/08 at 3:31 PM, Terminal3k said: Power at night is just lights and tv/computer. Try to do oven cooking before sun goes down. All Computers have a powersave profile that could save a lot of power (unless you are gaming and need max performance all the time). My PC also auto suspends after 30 minutes of being idle. Once suspended it draws 0.5W. Replace the bulbs with LED (I have also installed movement sensors to trigger my outside lights) Defrost the freezer and check that it does not run 24/7. The thermostat gets stuck and does not effectively switch off the fridge/freezer which means it uses a lot more power than needed. Quote
Terminal3k Posted April 11, 2022 Author Posted April 11, 2022 (edited) 11 minutes ago, iiznh said: Defrost the freezer and check that it does not run 24/7. The thermostat gets stuck and does not effectively switch off the fridge/freezer which means it uses a lot more power than needed. I definitely need to do this! I have changed all my lights to led. Edited April 11, 2022 by Terminal3k Quote
Scorp007 Posted April 11, 2022 Posted April 11, 2022 One of the overlooked items is a laser printer. It draws about 1kw to keep the drum warm. This draw is only a few seconds say every 15min. This chows power while one thinks its idle while the PC is off. Quote
P1000 Posted April 11, 2022 Posted April 11, 2022 29 minutes ago, Scorp007 said: One of the overlooked items is a laser printer. It draws about 1kw to keep the drum warm. This draw is only a few seconds say every 15min. This chows power while one thinks its idle while the PC is off. Something is wrong with your printer, mine only warms up before printing. Quote
Scorp007 Posted April 11, 2022 Posted April 11, 2022 4 hours ago, P1000 said: Something is wrong with your printer, mine only warms up before printing. Then it's my back luck as I had the same operation from my last 3 lasers. All different makes. When you print you can hear it. The rest of the time it is silent but draws power. Quote
CJE Posted April 14, 2022 Posted April 14, 2022 I think it is a personal choice and if you can afford it. I am off grid and if I do not recover all the money spend on the system it is okay I did my part to make my carbon footprint as small as possible. No load shedding, we do not even realize when there a power outage. Quote
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