Good day All 

Compliments of the Season!! 

I am currently i need of some information and advise. I require to power 4kwh for 24 hours 24/7. I currently have 6 x 550 watt Solar panels, 5kw Sunsynk inverter and 6kw Greenrich Lithium battery which would be enough to carry the load during the day but my concern is during the night time hits as well as in winter. 

Been doing some research into a wind turbine but have not really found something for residential use. 

Any assistance or advise would be highly appreciated. 

 

Edited December 28, 20241 yr by Lylef

3 hours ago, Lylef said:

Any assistance or advise would be highly appreciated. 

You have not even got 4kW's worth of Solar panels, so this will not work, I would say you need, probably 96kWh's worth of battery capacity and much, much more solar to be able to power the load + recharge the batteries and even the inverter is likely not capable, unless you're happy to add some separate MPPT's to the mix... unless you are talking about a 4kWh load over 24 hours, in other words, 200W continuous load... maybe...
Depending on where you are how much cloudcover do you get? Wind, I cannot recommend it, since in most residential locations wind power is not much, unless you can put up a 60 to 100m tower and put a turbine on top, even then how often/reliable is the wind where you are? You may need to look at a backup generator to add to the power mix when its cloudy for a few days, assuming this does occur...

Hi thank you for the response.  Was thinking of adding another 6 x solar panels to the mix but still have the issue of the night time and winter days. Was thinking of going with a Gen but what about fuel costs as well the noise level. Any other thoughts for a cost effective option?

6 hours ago, Lylef said:

I require to power 4kwh for 24 hours 24/7

To understand what you want, are you saying you're base load is 4kW continually throughout the day, making up a daily usage of 96kW each day, or are you saying you're total daily usage is 4kW each day?  

Hi Tim. The usage is 3.3KW to 4kw per hour not per day.

You'd need around 25kW or more worth of panels, and 60kWh or more worth of batteries, with the MPPT's to go with that. It's probably beyond the scale that most residential locations can support.

Maybe investigate whether you have the option to stay on-grid and change to a time-of-use tariff, then you could add those 6 more panels and maybe 2-3 more batteries. You'd then set it up to carry you through peak hours on battery, run on solar by day, and save money with off-peak power rates at night.

8 hours ago, Lylef said:

Hi Tim. The usage is 3.3KW to 4kw per hour not per day.

I'd say, enlighten us on where, roughly, you are located geographically, also answer the cloudy/windy questions... maybe also mention what consumes all those electrons, are there alternatives, maybe? Let's say you heat a lot of water, doing it directly with evacuated glass tubes would be more efficient and effective, than using PV to power an electric element, but depending on cloud cover etc. this may only be a partial solution...

We are located in the southern suburbs Cape Town. We need to install a server rack running 4 x Dell servers consuming between 750 watt to 1100 watts when maxed. 
 

We actually get wind everyday with some cloud cover as well. My issue is these servers needs to stay on 24/7 and no downtime.

27 minutes ago, Lylef said:

We are located in the southern suburbs Cape Town. We need to install a server rack running 4 x Dell servers consuming between 750 watt to 1100 watts when maxed. 
 

We actually get wind everyday with some cloud cover as well. My issue is these servers needs to stay on 24/7 and no downtime.

From your description, look at the Sunsynk Innagator, however you’ll still have a major challenge of how to power it. Do you have enough space for Solar Panels, in plentiful quantities to be able to charge the Innagator? If you’re in an office type of area, look at putting panels on top of the warehouse if it’s the type of building you have and also building a carport covered with Solar panels because your greatest challenge will be two things:

1. Space constraints (for panels); and

2. Cost constraints (for batteries, cabling; panels). 
You may also look at putting in parallel multiple high voltage inverters (50-100kw each) and the battery bank will be huge, given inclement weather days for autonomy in rainy season as well as winter.

Having a big generator like Kippor 9.5kw or multiples of them would help but again you run into issues of high fuel costs and also maintaining the generator.

Best wishes for your project, but get someone to help with a site visit to give you a comprehensive BoQ. 

Edited December 29, 20241 yr by Moffat

Something like this can be achieved with a HV hybrid installation. The use of a 20kW Sunsynk or even a 30kW Atess & 4 x FreedomWon 40/32HV batteries will do the trick with some good margin. 

This can be done with 48V system but running a residential 5kW machine at 4kW is planning to fail. Sort of like driving a half ton bakkie around with a 400kg load constantly. It just won't last. The other issue one has is the 24hr energy storage. Imagine stacking 5kWh Batteries to make up +-100kWh. You end up with a room full of batteries. Imagine the busbar arrangements. 

In this type of landscape, you install an industrial solution. That involves something that will last and also something that is easy to install & setup.

The batteries will have a smaller foot print & the wiring of the DC battery bus will be much more pleasant. You also have an MPPT that can take whatever amount of PV you require. Something like 16 Panels will go a long way into serving your requirements. 

There are 2 ways to look at a problem like this. The solution that just works without any headaches or one that will require a lot of babysitting...

1 hour ago, Lylef said:

We actually get wind everyday with some cloud cover as well. My issue is these servers needs to stay on 24/7 and no downtime.

Ok, personally I would be skeptical about the value of this wind everyday, but hey, if you can get a wind turbine up at 30+m above the surrounding structures/terrain, then you may be able to generate some power that may help you along, however I have not come across any wind turbines in the 5 to 20kW or even more range that was worth the outlay and here I'd suggest you'd need to consider rolling your own. But homebrewing a wind turbine that will give you a few years worth of trouble free power generation is easier said than done, so I'd discount this as a non-starter...

The servers you are running, are you trying to do crypto mining or what? Is it conceivable you could get away with something more frugal on the converting electrons to heat department? I am assuming this is a commercial setup, if not, then what the heck, you could with some virtualization on even NUC Core i5's with 64Gig or more of memory and some SSD storage, this can do an amazing amount of work, ok, no crypto currency mining, but if that is what you're doing, your budget should stretch to @Steve87's suggested industrial type setup.

 

lol it’s not crypto mining. The servers are commercial as we will be hosting them on behalf of a client. They have big storage arrays etc and we be running backups, vm’s, sql so a Nuc won’t do the trick. 
 

We trying to figure out the best solution to keep the power costs low as well as have the uptime. 

32 minutes ago, Lylef said:

lol it’s not crypto mining. The servers are commercial as we will be hosting them on behalf of a client. They have big storage arrays etc and we be running backups, vm’s, sql so a Nuc won’t do the trick. 
 

We trying to figure out the best solution to keep the power costs low as well as have the uptime. 

The cheapest option - use Eksdom, the grid is stable the last ±9 months.

Add a couple of panels, and a battery or 2, just to be safe if the power fails when solar production stops.

Get 2 x 10kw diesel gennies (one for backup)

Full solar / wind to carry that load will be very expensive!!

@Steve87 Suggestion is spot on, especially if you want to upgrade to 3 phase for more head room. If budget is very tight, at least get another 5kW inverter in parallel to share the load, and give two more MPPT's for panels. To go with a tight budget, FreedomWon 5kW E-Tower batteries are going for +- R14800 each now, and you could run a few banks of these. If you have the funds, 32 panels should take you through most weather situations, wired as 8 panels on the 4 MPPT's if you have 2x 5kW inverters.

20 hours ago, TimCam said:

@Steve87 Suggestion is spot on, especially if you want to upgrade to 3 phase for more head room. If budget is very tight, at least get another 5kW inverter in parallel to share the load, and give two more MPPT's for panels. To go with a tight budget, FreedomWon 5kW E-Tower batteries are going for +- R14800 each now, and you could run a few banks of these. If you have the funds, 32 panels should take you through most weather situations, wired as 8 panels on the 4 MPPT's if you have 2x 5kW inverters.

Hi @TimCam is that price for eTower inclusive of Vat and who is selling?

3 hours ago, Moffat said:

Hi @TimCam is that price for eTower inclusive of Vat and who is selling?

Yip, including vat. At Voltex currently. See below link and look at the page of below R130K.

https://www.voltex.co.za/wp-content/uploads/2024/11/WATTS-for-Africa_booklet_2-DIGITAL_compressed.pdf

 

3 hours ago, TimCam said:

Yip, including vat. At Voltex currently. See below link and look at the page of below R130K.

https://www.voltex.co.za/wp-content/uploads/2024/11/WATTS-for-Africa_booklet_2-DIGITAL_compressed.pdf

 

Wow, great prices. 

1 hour ago, Moffat said:

Wow, great prices. 

Panels are a bit pricey though.