offgrid electrical connection using generators and battery to run a house

[speedystu]

I have a chance that I might be able to purchase a rural site for my home(self-build).

The problem is my limited budget and timeline( full house completion) does not allow for an over 2k euro connection for a basic electrical connection to run a household for parents and kids aged 2,6,8
I can/want to build a small almost tiny home temporarily (6-24months) while I build the full house.

I am not looking to be off-grid on purpose but from my perspective, it seems I "should" be able to connect a small generator (and one for backup) to a battery and adjust my appliances to reduce power and live normally with a temporary electrical connection until I connect to the grid. STATEMENT This should be cheaper than 2k

Netflix must work 24/7

1 electric shower/ hot water tank
1 cooker oven combo
8 lights - 8 sockets
The heat will be supplied by stoves ( i have already, coal is magic)

Is this doable and if so what would you say is the best way to do it, I have seen people using solar during the day, storing and using the power at night. Can i do this with generators and keep the cost down

 

[Pete999]

I have a chance that I might be able to purchase a rural site for my home(self-build).

The problem is my limited budget and timeline( full house completion) does not allow for an over 2k euro connection for a basic electrical connection to run a household for parents and kids aged 2,6,8
I can/want to build a small almost tiny home temporarily (6-24months) while I build the full house.

I am not looking to be off-grid on purpose but from my perspective, it seems I "should" be able to connect a small generator (and one for backup) to a battery and adjust my appliances to reduce power and live normally with a temporary electrical connection until I connect to the grid. STATEMENT This should be cheaper than 2k

Netflix must work 24/7

1 electric shower/ hot water tank
1 cooker oven combo
8 lights - 8 sockets
The heat will be supplied by stoves ( i have already, coal is magic)

Is this doable and if so what would you say is the best way to do it, I have seen people using solar during the day, storing and using the power at night. Can i do this with generators and keep the cost down

Generator and UPs set up could work if configured correctly!

 

[speedystu]

Generator and UPs set up could work if configured correctly!

Tks Sorry what is
UPs
Source URL: offgrid electrical connection using generators and battery to run a house - https://www.electriciansforums.net/threads/offgrid-electrical-connection-using-generators-and-battery-to-run-a-house.182121/#post-1599542
[automerge]1578315169[/automerge]

Generator and UPs set up could work if configured correctly!

I get it now, some UPS are 100$ and some are a 1000$, or pounds or euros

Should I aim for 1 big one or multiple,

What are decent reasonably priced brands?

Are there fancy out of the box switching panels available eg software?

PS I will get someone to configure but its best i know something first

 

[Lucien Nunes]

Electric (instantaneous) shower is a heavy load, which would dictate minimum generator size of 10-15kVA. Probably not a good idea. Cooker is next heaviest, might get away with 4-6 kVA if you don't turn it all on at once. If you want to run on a £500 generator, you would have to plan your menu accordingly. Heating water in a cylinder with a 3kW immersion element is possible, but it will mean running the generator for some hours. This may be needed anyway for battery charging. Don't anticipate running any cooking / heating / water heating from battery. Ultimately, any heat source that does not involve electricity is likely to be cheaper to run. An LPG cooker would be a better bet IMO.

24/7 power for electronics and miscellaneous small appliances is no problem with a few kWh of battery and an inverter of say 1500-2500W rating. This will allow you to use a hairdryer or vacuum cleaner which although a heavy load, is only on briefly. Small loads like TV can run for many hours. Li-ion batteries expensive but can fast-charge all the way. Lead-acid are cheap but slower charging, hence require more generator run-time. You have to choose between letting the genny run for an extra 4 hours to complete the charge, or the batteries losing capacity prematurely through sulphation. A smallish solar panel for topping off the battery may solve that if there are periods with minimal domestic load, or you divide the battery occasionally and give one section an equalising charge for a day off the solar while the rest carries the domestic load.

On your budget you might go for:
330Ah 24V lead acid battery
50A charger
2500W inverter
4.5kVA generator

Or something. There are many variables - petrol vs. diesel, whether you have a use for the batteries later, etc. This is fairly budget-end of the market and not all products are what they seem. Cheap inverters are utter rubbish, mid-priced ones are distinctly variable in build quality. Same to a lesser extent with generators.

Good luck...

 

[plugsandsparks]

Agree, LPG for heating and cooking is a no brainer, water heating can also be via LPG or low level electric immersion heater in a tank, if you are patient.
That leaves electricity for lighting, internet and small ellectrical appliances.
Small gennys not built to be used continously , so buy wisely.
Good Luck
P&S

 

[speedystu]

Electric (instantaneous) shower is a heavy load, which would dictate minimum generator size of 10-15kVA. Probably not a good idea. Cooker is next heaviest, might get away with 4-6 kVA if you don't turn it all on at once. If you want to run on a £500 generator, you would have to plan your menu accordingly. Heating water in a cylinder with a 3kW immersion element is possible, but it will mean running the generator for some hours. This may be needed anyway for battery charging. Don't anticipate running any cooking / heating / water heating from battery. Ultimately, any heat source that does not involve electricity is likely to be cheaper to run. An LPG cooker would be a better bet IMO.

24/7 power for electronics and miscellaneous small appliances is no problem with a few kWh of battery and an inverter of say 1500-2500W rating. This will allow you to use a hairdryer or vacuum cleaner which although a heavy load, is only on briefly. Small loads like TV can run for many hours. Li-ion batteries expensive but can fast-charge all the way. Lead-acid are cheap but slower charging, hence require more generator run-time. You have to choose between letting the genny run for an extra 4 hours to complete the charge, or the batteries losing capacity prematurely through sulphation. A smallish solar panel for topping off the battery may solve that if there are periods with minimal domestic load, or you divide the battery occasionally and give one section an equalising charge for a day off the solar while the rest carries the domestic load.

On your budget you might go for:
330Ah 24V lead acid battery
50A charger
2500W inverter
4.5kVA generator

Or something. There are many variables - petrol vs. diesel, whether you have a use for the batteries later, etc. This is fairly budget-end of the market and not all products are what they seem. Cheap inverters are utter rubbish, mid-priced ones are distinctly variable in build quality. Same to a lesser extent with generators.

Good luck...

Thank you Lucien, Thanks to you guys I m trying to take some of the luck out of it

If its "doable"

What does the inverter do? Say if its a 220 v generator? (whats the generator outputting?)

What does the ah mean and why is it 24v?

330Ah 24V

What is the major measurement to worry about, is it wattage only?

 

[Pete999]

Tks Sorry what is
UPs
Source URL: offgrid electrical connection using generators and battery to run a house - https://www.electriciansforums.net/threads/offgrid-electrical-connection-using-generators-and-battery-to-run-a-house.182121/#post-1599542
[automerge]1578315169[/automerge]


I get it now, some UPS are 100$ and some are a 1000$, or pounds or euros

Should I aim for 1 big one or multiple,

What are decent reasonably priced brands?

Are there fancy out of the box switching panels available eg software?

PS I will get someone to configure but its best i know something first

Uninterruptable Power Supply (Batteries coupled with Inverters etc)

 

[MJPD29]

It can be done, but most likely to do it correctly you could be near 2k, which would nearly defeat the purpose

 

[Lucien Nunes]

Genny outputs 230V AC. Inverter produces 230V AC too, from battery DC. Battery voltage is your choice, for this power level 24V probably best. 48V offers slightly more efficiency but less products available to suit. 12V is clumsy if you're not tied to it (as in a vehicle).

Ah = amp-hours = battery charge capacity. An ideal 100Ah battery will deliver 1A for 100 hours or 100A for 1 hour etc. For real life batteries the results are somewhat different, their behaviour is complex, but here's a simplified example:

Assume we want to work a 330Ah 24V lead-acid to 70% depth of discharge (discharging fully puts extra strain on a lead acid). Also assume we discharge over 20 hours (quoted capacity assumes this. If you discharge faster, the battery does not give up as much of the stored charge before it reaches minimum voltage. (I.e. it becomes both less efficient and shorter-lived if you work it hard)
70% x 330 = 230Ah

Energy available to inverter, discharging from fully charged to empty:
230 x 24 = 5500 Wh = 5.5kWh (kilowatt-hours, 'units' of electrical energy)

Typical inverter efficiency 91%
Energy available to you at 230V AC:
91% x 5.5 = 5000 Wh = 5kWh

Note that this battery weighing around 200kg will only store about 70p worth of electricity at grid pricing.

Do a power budget to find out what you actually need.
e.g.
100W TV x 4 hours = 400Wh
1200W microwave x 20 mins = 400Wh
60W laptop charger x 3 hours = 180Wh
Total so far 980Wh, all good.
3000W immersion heater x 2 hours = 6000Wh (No can do!)

There are good books about off-grid electrical technique, I can't recommend any particular one.

 

[speedystu]

Genny outputs 230V AC. Inverter produces 230V AC too, from battery DC. Battery voltage is your choice, for this power level 24V probably best. 48V offers slightly more efficiency but less products available to suit. 12V is clumsy if you're not tied to it (as in a vehicle).

Ah = amp-hours = battery charge capacity. An ideal 100Ah battery will deliver 1A for 100 hours or 100A for 1 hour etc. For real life batteries the results are somewhat different, their behaviour is complex, but here's a simplified example:

Assume we want to work a 330Ah 24V lead-acid to 70% depth of discharge (discharging fully puts extra strain on a lead acid). Also assume we discharge over 20 hours (quoted capacity assumes this. If you discharge faster, the battery does not give up as much of the stored charge before it reaches minimum voltage. (I.e. it becomes both less efficient and shorter-lived if you work it hard)
70% x 330 = 230Ah

Energy available to inverter, discharging from fully charged to empty:
230 x 24 = 5500 Wh = 5.5kWh (kilowatt-hours, 'units' of electrical energy)

Typical inverter efficiency 91%
Energy available to you at 230V AC:
91% x 5.5 = 5000 Wh = 5kWh

Note that this battery weighing around 200kg will only store about 70p worth of electricity at grid pricing.

Do a power budget to find out what you actually need.
e.g.
100W TV x 4 hours = 400Wh
1200W microwave x 20 mins = 400Wh
60W laptop charger x 3 hours = 180Wh
Total so far 980Wh, all good.
3000W immersion heater x 2 hours = 6000Wh (No can do!)

There are good books about off-grid electrical technique, I can't recommend any particular one.

This is great, will do a power budget, my wife will think im gone loopy

"Genny outputs 230V AC. Inverter produces 230V AC too"

what is the genny outputting to the battery?
is it not 230v ac?

 

[Lucien Nunes]

You can't store AC in a battery. Transform voltage and rectify to DC to charge battery. Transform and invert to get it back to 230V AC. Put all of that in one box with a transfer relay that passes the power through direct when available, and you've got the UPS that Pete mentioned.

I focused on separate parts, the UPS route is worth a look, or at least the so-called 'combi' inverter, which contains the charger and transfer switch, to which you add the battery. A true UPS is probably a bit pricey as anything large enough to power more than a desktop computer would be proper pro spec.

 

[speedystu]

You can't store AC in a battery. Transform voltage and rectify to DC to charge battery. Transform and invert to get it back to 230V AC. Put all of that in one box with a transfer relay that passes the power through direct when available, and you've got the UPS that Pete mentioned.

I focused on separate parts, the UPS route is worth a look, or at least the so-called 'combi' inverter, which contains the charger and transfer switch, to which you add the battery. A true UPS is probably a bit pricey as anything large enough to power more than a desktop computer would be proper pro spec.

Thank you, i get it now!, AC V DC acdc

I'm going to do that power plan this week, ill share when finished.

I appreciate your input and everyone else, the budget part is what i have to work out, thank you!

I am thinking the electric company would refuse to install the line in my tempory small house so I have to try to plan a safe and budget way around it. I dont want to end up paying twice when the full house is up. Its a tricky one but great ideas here for me to investigate,

 

[James]

An alternate strategy for you to think about.
stay with a 12v dc system.

1 small generator
a good battery bank
a small 1000 to 2000W inverter for occasional use

use 12v led lights
use a 12v travel router or a home router that can be run from 12v via an adapter
you can get 12v tv sets for use in caravans and motor homes
laptops can be run from 12v supply also.

try to limit what you use at 230v to daytime only (when generator is running)
as it has a high current draw off your storage batteries and there is a loss in conversion

you could have say 6 sockets that are connected to the generator and maybe the other 2 from an inverter that is used during the night only.

is it possible to heat your water from a coil in the stove?
cooking would be done with an LPG oven/stove

the above would keep the costs right down but you would have to manage power usage and make some sacrifices, i.e you could not vacuum whilst the wife is using her hair dryer unless the generator was big enough and running.

 

[speedystu]

An alternate strategy for you to think about.
stay with a 12v dc system.

1 small generator
a good battery bank
a small 1000 to 2000W inverter for occasional use

use 12v led lights
use a 12v travel router or a home router that can be run from 12v via an adapter
you can get 12v tv sets for use in caravans and motor homes
laptops can be run from 12v supply also.

try to limit what you use at 230v to daytime only (when generator is running)
as it has a high current draw off your storage batteries and there is a loss in conversion

you could have say 6 sockets that are connected to the generator and maybe the other 2 from an inverter that is used during the night only.

is it possible to heat your water from a coil in the stove?
cooking would be done with an LPG oven/stove

the above would keep the costs right down but you would have to manage power usage and make some sacrifices, i.e you could not vacuum whilst the wife is using her hair dryer unless the generator was big enough and running.

Thank you cool idea to think about.

12v travel router, do you mean for the internet?

I have also just come across generators with avr built-in, is this a good option?

Has anyone had experience sound dead ning a generator, any tips?

My idea is to incase it in a dry shelter in the ground with adequate airflow and exhaust out.

 

[James]

I have at home an 8kw standby genny with a soundproof enclosure and almost silent exhaust. it uses about 1L of diesel per hour and is great. total cost of purchase, install and sound proofing is £2.5K
I was trying to help with a cheep short term solution for you,
have you considered getting a mains supply, dig the trench yourself and make it pass where your new big house will be built, that way it is easy to shorten it when the time comes?

 

[speedystu]

Thanks they are all good points, great to hear of real world examples. Do you have a custom switch you turn to turn off mains when Gennys is on?

 

[James]

4PRO ATS-125A-4P-rs Automatic Changeover Transfer Switch. Buy online ATS, AMF, AVR, ECM, DKG controllers for diesel, gas, petrol gensets including manual start units and auto mains failure generator controls, electronic engine governors, alternator automatic voltage regulators, automatic transfer switches, battery chargers, meters and analyzers, contactors, synchroscopes and automatic synchronizers for multi generating set paralleling and mains synchronization.

DESCRIPTION The ATS-125A-rs changeover switch is designed to automatically transfer load circuits from main power source to reserve source in a wide variety of 1-3 phase applications. FEATURES  Electric motor gear activated switching;  1-3 phase 4 pole operation;  Auto and Manual mode...

www.controllers4generators.com

its not quite the same but similar to this

 

[speedystu]

4PRO ATS-125A-4P-rs Automatic Changeover Transfer Switch. Buy online ATS, AMF, AVR, ECM, DKG controllers for diesel, gas, petrol gensets including manual start units and auto mains failure generator controls, electronic engine governors, alternator automatic voltage regulators, automatic transfer switches, battery chargers, meters and analyzers, contactors, synchroscopes and automatic synchronizers for multi generating set paralleling and mains synchronization.

DESCRIPTION The ATS-125A-rs changeover switch is designed to automatically transfer load circuits from main power source to reserve source in a wide variety of 1-3 phase applications. FEATURES  Electric motor gear activated switching;  1-3 phase 4 pole operation;  Auto and Manual mode...

www.controllers4generators.com

its not quite the same but similar to this

Thank you all, some great ideas here, I will put together a power plan and start pricing from there. I liked all the suggestions,They are all on the table, (too expensive)(wont work)

I thought the very practical suggestion from James was spot on.
have you considered getting a mains supply, dig the trench yourself and make it pass where your new big house will be built, that way it is easy to shorten it when the time comes?
Source URL: offgrid electrical connection using generators and battery to run a house - https://www.electriciansforums.net/threads/offgrid-electrical-connection-using-generators-and-battery-to-run-a-house.182121/

My challenge here is having a proper small house to start with that the electric company will work to. All part of my budgeting and planning to look into.

Again thanks very much to the forum, the help and knowledge is fantastic! good luck with the 20s everyone

 

[marconi]

I support James' idea 100% to dig a trench, lay a cable and connect up to the grid - see #15. I think you would find going off grid with a young family difficult for a capital expenditure of no more than E2000. You will almost certainly have some periods without electricity unless you are very strict in how you use every Joule of electricity. And without building in some operational redundancy equipment breakdowns will be troublesome. You have not yet calculated your running costs ie: fuel.

A project I worked on and designed to provide circa 10kWh nominal battery storage - about 5 kWh in practice and 1.2kW Solar PV to 20 mobile facilities 24/365 cost about £4000 each. Expected lifetime of batteries 3 years. Permanent 3.4kVA LPG Honda open frame pull cord start generator (£500) back-up for 'just-in-case' Mar-Oct and 5 hours battery charging each day Nov-Feb. Electrical sundries for installation £250. Inspection and testing £150. This ran a chest freezer, two larder fridges, electronic till, 75W LED lighting, phone charger 10 hours a day and the refrigeration overnight as well. In comparison to this you are expecting to run much more equipment from an off-grid installation.

Could you arrange a bank loan for the permanent electricity supply?

 

[speedystu]

I support James' idea 100% to dig a trench, lay a cable and connect up to the grid - see #15. I think you would find going off grid with a young family difficult for a capital expenditure of no more than E2000. You will almost certainly have some periods without electricity unless you are very strict in how you use every Joule of electricity. And without building in some operational redundancy equipment breakdowns will be troublesome. You have not yet calculated your running costs ie: fuel.

A project I worked on and designed to provide circa 10kWh nominal battery storage - about 5 kWh in practice and 1.2kW Solar PV to 20 mobile facilities 24/365 cost about £4000 each. Expected lifetime of batteries 3 years. Permanent 3.4kVA LPG Honda open frame pull cord start generator (£500) back-up for 'just-in-case' Mar-Oct and 5 hours battery charging each day Nov-Feb. Electrical sundries for installation £250. Inspection and testing £150. This ran a chest freezer, two larder fridges, electronic till, 75W LED lighting, phone charger 10 hours a day and the refrigeration overnight as well. In comparison to this you are expecting to run much more equipment from an off-grid installation.

Could you arrange a bank loan for the permanent electricity supply?

Thanks for this Marconi Just in the one day, the trench is looking the best option. A avr backup generator with UPS or batt for short term supply(only if they refuse to connect to the small house)
What I have to do is plan my build so that the electric company has a near perfect (small) building to work with. ! The familes power consumption and the under 2k budget wins this one. Thanks everyone for all the excellent ideas.
Re the bank, I'm going off grid with them