Newbie - Kalla - in the Karoo

[Kalla]

Hi everyone, We are farming in the Karoo, some irrigated pastures and seed growing. There is a 15kW irrigation pump and some three different houses on the farm, two Escom points and an Escom account averaging in the region of R12000 pm. We need to curb our Escom expenses so I am looking into the possibility of generating some solar power to reduce the Escom costs.Hope to find some answers on the forum.

Kalla

[___]

You want to talk to @Chris Hobson, who is from Graaff Reinet area.

If your irrigation pumps can run during the day, the obvious answer is a grid tied three phase inverter (I'm probably warranted in assuming 3-phase, you don't as a rule draw 15kw on single phase!). In fact it would be downright silly to attempt to do this using battery power. I can recommend Fronius. Something like this.

[Kalla]

Thanks Plonkster - wil speak to Chris

 

[KLEVA]

A yes, the Commodore 64 (aka plonkster) has given you a good person to chat too

Welcome Kalla,

Having open land space/farm means that you can have a HUGE solar array, so the generated power itself is not the problem (obviously as long as you prepared to buy all the panels), it's how to store and deliver it to the end points. Chris will definately help with the maintenance side, since I am sure the panels themselves will need regular cleaning in the Karoo to get the best.

Now, admittedly everything will depend on your budget (initial capital). You can go for the option of keeping the houses seperate, and distance apart will come into play when doing the calculation, but that huge 15kW load that you have initially identified might need a seperate solution if you need to keep the costs down. Solving a one off load is easier for us to assist with because we can ask specific questions about that load.

For the purposes of my further comments/questions, I am going to assume this is the ONLY load you are trying to fix (the 15kW irrigation motor - Ignoring the houses for now) - And please, these might seem stupid questions, but I am in IT, not farming:

• single/three phase?
• Does it need to run 24/7?
• Does it matter if it doesn't run when there is no sun?
• further to the above question, if you do need to run it when there is no sun, then for how long?
• Do you have any wind/hydro options available to assist this huge load (for me as a nearly off-grid home-owner a 15kW draw is HUGE)?
• When discussing the DC (Battery/Solar/Etc) parts of the load, we need an idea of distances - AC voltages are less prone to any power drops.

Ok, these are just my immediate questions, but there are bound to be a lot more. Because at a rough guess (based on your R12k figure), you are using about 7000kWh per month or about 240kWh/day - Do you know that that is mostly going to your pump, or do you have other heavy loads?

[Chris Hobson]

So Site lock has decided I am a bad egg and I lost my post. I in the mean time have chatted to Kalla on the phone. 

Just as a point of reference I thought we could look at the savings that can be achieved on solar.

https://powerforum.co.za/topic/2242-happy-client/

 

 

[KLEVA]

@Chris Hobson - Maybe Sitelock has the right idea

@Kalla - With the right amount of Capital investment, I will even guarantee a Eskom saving, it's just whether that saving warrants the capital cost. eg: pay me R14M and I will GUARANTEE that you wont have to pay ESKOM a cent for the NEXT 5 years. Just a joke, but underlines the point. My costs will never recover the price I pay the municipality, but I did it for different reasons. Saving must mean a saving, Solar electricity is difficult to get you to a saving point, so analyse the options carefully. The advantage of having power when ESKOM is offline must also be considered.

[___]

You guys may be over-analyzing this. He has a 12k bill and wants to bring it down. If you can move enough load into the 10AM-3PM slot, then a PV-inverter that covers 80%+ of that load is going to significantly reduce your bill.