Off the grid

facelesss

Well I'm currently in the process of purchasing a small cottage in the country. It's approximately 1000 sq ft. It's being disconnected from the ESB network for the last 4 years so they are classing as a new connection.
So I've decided to go completely of grid luckily the roof is south facing and has sun all day. So my question is would a 8kw system be sufficient to meet my power needs. My power needs are not big as I'll be using led lighting, no microwave, no kettle or cooker. Biggest power usage would be washing machine and pump for solid fuel heating and well.
I also will have a small wind turbine running as well. Plus a diesel generator for back up. I'm hoping any excess power can be diverted to heat water when battery is full.
It's something I have always wanted to be completely independent and self sufficient. Just wondering does any body have experience of being of the grid in Ireland. Looking forward to hearing your opinions and any helpful information. Thanks in advance.

Gumbo

What size battery will you have?
Also, there will be days where you will get no generation.

You are doing off grid right when you are not using the battery. 8kW PV is loads. You'll still need an alternative power source in Winter wind is a nice compliment.
Don't get a turbine with a blade diameter less than 2m, under that is chocolate tea-pot country.
In fact don't get a wind turbine until a year after a data logging anemometer.

East-West is a better array orientation for off grid.

facelesss

Looking at a 10kw lithium power bank which should have enough capacity for dull days

40kWh would be frugal. Does is need to be lithium ion for any particular reason?

The average household will use 10kWh a day. 5kWh is entirely attainable if you are energy conscious. I'd spec the system to hold it's own for a week without positive input.

facelesss

Sir Liamalot wrote: »

40kWh would be frugal. Does is need to be lithium ion for any particular reason?

The average household will use 10kWh a day. 5kWh is entirely attainable if you are energy conscious. I'd spec the system to hold it's own for a week without positive input.

I'll be a single household who will have very little consumption. A only big draw would be pump for heating and fridge. Specifying a system for 50kw is cost prohibitive. The reason I'm choosing a lithium power pack they have alot more usable energy. They can be up to 90% drained without a problem.

Wanderer78

What kind of money would you be talking of to set up such a system?

I believe li-ion can be drained 60% without a problem.
You can get 60kWh OPzS or forklift batteries for less than 10kWh of Li-ion.

I've yet to see a li-ion battery that is suitable for off-grid.
Ie. user serviceable, readily available non-proprietary ancillaries, interchangeable cells, large enough capacity at a reasonable cost to be practically useful.

KCross

Sir Liamalot wrote: »

I've yet to see a li-ion battery that is suitable for off-grid.

Is the Tesla Powerwall not suitable? Notwithstanding the price, of course.

Sir Liamalot wrote: »

Ie. user serviceable, readily available non-proprietary ancillaries, interchangeable cells, large enough capacity at a reasonable cost to be practically useful.

I agree on the cost element. However, if you are already off-grid and look to get a new electric connection it costs €2k so you can immediately take that off the headline price of any Powerwall type systems which might bring it closer to being viable.... probably still not quite there but its something to consider in your calculations on capital cost.


However, the other elements you mention, like user serviceable etc... are they really required? The move seems to be towards plug 'n play systems (Tesla Powerwall, Nissan xStorage etc) rather than swapping out cells which is more akin to DIY systems. Having a decent warranty would be more important I think.

We buy lots of things that have proprietary elements in them including our cars, phones etc so I don't think the non-proprietary piece is an absolute requirement.... great if they would but thats not in the manufactures best interest so thats unlikely to happen for a very long time, if ever.

facelesss

Sir Liamalot wrote: »

I believe li-ion can be drained 60% without a problem.
You can get 60kWh OPzS or forklift batteries for less than 10kWh of Li-ion.

I've yet to see a li-ion battery that is suitable for off-grid.
Ie. user serviceable, readily available non-proprietary ancillaries, interchangeable cells, large enough capacity at a reasonable cost to be practically useful.

Here's some reading. I'm doing as much research about this subject as I can all new to me.

https://www.victronenergy.com/blog/2015/03/30/batteries-lithium-ion-vs-agm/

Gawd no the powerwall is completely unsuitable. It doesn't yet work without a mains connection. You can only charge it from solar, the advertised price is not the final installed price. It requires an internet connection. It's just for gridders with giving energy away for free issues.

Is serviceability necessary if you are on your own out in the boonies with power problems?...you tell me. How long do you think a warranty return/replacement will leave you powerless for?

Modular systems and spares is how we make things reliable. Rugged, simple with no points that a single failure takes down an entire system.

AGM are anemic batteries they won't compare well to anything useful, grand for boats where spillage is a legitimate concern, no place in static traction.

Off grid power is going to be at least 3 times the cost of conventional...the €2k connection fee is a dangling carrot. You'll spend that on an inverter.

Tubular plate OPzS flooded lead acid traction are the best the market has to offer and have been around proving themselves in telecoms for decades.

Ever notice how people who talk about batteries say li-ion and those who use them are running lead acid...there's a reason for this!

Effects

KCross wrote: »

a new electric connection it costs €2k so you can immediately take that off the headline price of any Powerwall type systems

Probably a minimum of €2k. It cost me about €2,200 to connect to an existing pole that was only 4 metres from my meter cabinet.

KCross

Effects wrote: »

Probably a minimum of €2k. It cost me about €2,200 to connect to an existing pole that was only 4 metres from my meter cabinet.

The cost for a new connection (€1951) is regulated and is supposed to be a flat fee per connection assuming you are 500m(rural) or 50m(urban) from a transformer.

https://www.esbnetworks.ie/docs/default-source/publications/esb-networks-dac-statement-of-charges.pdf?sfvrsn=21


You shouldn't be charged more than that unless you're getting a higher spec connection (16kVA+)

Effects

I'll have to look into that so. I was waiting about 6 months from when I applied. They told me they couldn't give me a price until the engineer had made a visit to see how much work was involved.