System for an off-grid cottage

[Gozado]

For doing the laundry, there's also the bicycle option:

or

although they seem to just let the dirty water run out, whereas there could be other uses for it.

 

[IdlePhaedrus]

I reckon for a small cottage you will do just fine with a 3kw system (panels + inverter).

I have had similar since 2014 (single person). I'm grid connected and I have batteries for the essentials only during load shedding so the setup on that score is slightly different. No lithium, just lead acid.

Gas oven & stove, A+++ fridge (European standard), gas geyser (swappable with electric one if necessary).

What I have found with this is that in summer on sunny days I use far less than the panels produce, but in winter I use more than they produce.

This is primarily due to the angle of the panels (30 degrees), consumption and location (Cape Town).

If the cottage's consumption patterns are similar to mine, you might consider giving the panels a steeper angle aimed at optimising for autumn/winter/spring rather than summer. For me, this is the biggest bug bear with my system.

WRT to gas geysers. They are a laugh a minute, especially if they are situated outside and the wind is blowing. Give careful consideration to where it is installed in this regard and get a good one.

On a rand to rand basis a solar geyser would be a better option in the (very) long run I expect, but gas is a good place to start.

 

[B-1]

What's the budget?

 

[Colin62]

I reckon for a small cottage you will do just fine with a 3kw system (panels + inverter).

I have had similar since 2014 (single person). I'm grid connected and I have batteries for the essentials only during load shedding so the setup on that score is slightly different. No lithium, just lead acid.

Gas oven & stove, A+++ fridge (European standard), gas geyser (swappable with electric one if necessary).

What I have found with this is that in summer on sunny days I use far less than the panels produce, but in winter I use more than they produce.

This is primarily due to the angle of the panels (30 degrees), consumption and location (Cape Town).

If the cottage's consumption patterns are similar to mine, you might consider giving the panels a steeper angle aimed at optimising for autumn/winter/spring rather than summer. For me, this is the biggest bug bear with my system.

WRT to gas geysers. They are a laugh a minute, especially if they are situated outside and the wind is blowing. Give careful consideration to where it is installed in this regard and get a good one.

On a rand to rand basis a solar geyser would be a better option in the (very) long run I expect, but gas is a good place to start.

Thanks for those comments, I agree that 3kW would probably be OK, but there’s not a huge saving between them and a 5kW so that’s what we went for in the end. Also opted for a solar geyser in the end.

We’ll play it by ear a bit with the solar panels. It’s not too bad to add a few of them later if we’re a bit short (probably will be).

 

[Colin62]

What's the budget?

In a word, the budget is shot.

There was some optimistic feelings that R25000 would be enough, but they spent about R45000 in the end. We came up with an option to help make it affordable - I paid for the battery, because I pushed hard to avoid lead acid. If it proves to be the right choice, they’ll pay me out for it, if not I’ll take it and use it myself. I’m helping out with this but also using it as part of my learning curve for my own system, and am happy to invest a bit in that.

 

[B-1]

In a word, the budget is shot.

There was some optimistic feelings that R25000 would be enough, but they spent about R45000 in the end. We came up with an option to help make it affordable - I paid for the battery, because I pushed hard to avoid lead acid. If it proves to be the right choice, they’ll pay me out for it, if not I’ll take it and use it myself. I’m helping out with this but also using it as part of my learning curve for my own system, and am happy to invest a bit in that.

What are all the components they bought out of interest sake?

 

[Grouter]

WRT to gas geysers. They are a laugh a minute, especially if they are situated outside and the wind is blowing. Give careful consideration to where it is installed in this regard and get a good one.

You're using the wrong gas geyser. Modern gas hot water heaters don't give a **** for the wind: regardless of which way it's blowing.

 

[Colin62]

What are all the components they bought out of interest sake?

Kodak 5kW inverter, 100Ah 48V lithium battery (can’t remember the brand quoted on, and they’re organising the installation themselves at this stage) and 4 200W panels as a start.

I’m pretty sure the panels will need adding to soon, but that at least do-able. The battery is over half the total cost, and you can’t trim much off the budget there while still buying a 48V lithium battery.

 

[Rocket-Boy]

Kodak 5kW inverter, 100Ah 48V lithium battery (can’t remember the brand quoted on, and they’re organising the installation themselves at this stage) and 4 200W panels as a start.

I’m pretty sure the panels will need adding to soon, but that at least do-able. The battery is over half the total cost, and you can’t trim much off the budget there while still buying a 48V lithium battery.

If they are getting the system installed then getting longer rails to self install additional panels later will be a good idea.

 

[airborne]

Something like this from Banggood
Its a Chinese thing

I bought an American one for over R6000 in 2000 and I see they now around R30 000. The Air 400 or something like that, I sold it many years ago to a friend. Stupid move

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That BangGood turbine is 24v, would you need 2 too feed a 48v system?

Washing machine has a heating element. It draws a lot of power, keep that in mind.

Just set the heat to cold or select a cold cycle, that's what I do on my Defy front loader.

 

[itareanlnotani]

Kodak 5kW inverter, 100Ah 48V lithium battery (can’t remember the brand quoted on, and they’re organising the installation themselves at this stage) and 4 200W panels as a start.

I’m pretty sure the panels will need adding to soon, but that at least do-able. The battery is over half the total cost, and you can’t trim much off the budget there while still buying a 48V lithium battery.

I would suggest buying larger watt panels. You can't really mix and match, so buy something you'll buy using in future. I'd suggest at least 300w+. If you can't afford, buy less of larger. Not more of smaller.*

*going to depend to some degree on the inverter specs for max amp /volts, but you should be able to plan that better for future. If you do go with 200w panels, you'll probably be replacing them completely when you upgrade.

 

[B-1]

Kodak 5kW inverter, 100Ah 48V lithium battery (can’t remember the brand quoted on, and they’re organising the installation themselves at this stage) and 4 200W panels as a start.

I’m pretty sure the panels will need adding to soon, but that at least do-able. The battery is over half the total cost, and you can’t trim much off the budget there while still buying a 48V lithium battery.

I was looking for the model detail to try get a better idea of things but dont stress too much. Hopefully you got the MKSII, King or another one that can blend solar and battery. That will help quite a bit as it doesnt switch to battery when you exceed the solar capacity.

 

[TheChamp]

I was looking for the model detail to try get a better idea of things but dont stress too much. Hopefully you got the MKSII, King or another one that can blend solar and battery. That will help quite a bit as it doesnt switch to battery when you exceed the solar capacity.

Most or even all of them can blend solar and battery, it's blending of solar and mains that is exclusive.