Help in getting started with hybrid/off grid. System design.

[Shaman]

Hello

I live in a village in the UK. My goal is self sufficiency before retirement. I am in the planning stages of sorting out solar and batteries. My end goal is to be off grid, but this will take time due to funds allocation! I need to build the system slowly.

What would be an ultimate system that incorporates solar panels (ground mount I’m in thatched house) batteries (Fogstar 15.5kwh) and a backup generator. Short term I know off peak electricity cheaper than diesel. But I want to get rid of utilities companies one day.

In my mind there is a brain box inverter (?) that everything could run off which is app controlled with data logging live and historical. Hopefully I buy this first then as funds permit start to buy everything else. What is important is the flexibility to easily drop in new equipment.

At the heart of everything I’d like a power management system that doesn’t require lcd menus on the equipment itself, some kind of cloud or iPad type control.

In terms of my usage I would say 15.5kwh x 2 be optimal or 1 to get going with grid or generator backup.

Is there a design software available?

 

[scoharri]

I think in this situation purchasing the battery(s) first would be your best choice. The batteries are the most expensive component of a off grid system. Good luck.

 

[Shaman]

Thank you. But what would I need (that forms part of system later) to manage the battery?

 

[EZPZ]

You need a hybrid inverter. Batteries and panels. And some varies disconnects/switches/fuses based on the design and your local code. I wouldn’t buy anything until you know exactly what it will look like initially and what you want to ultimately achieve. Buying things now locks you in to using that component. Battery prices are dropping, new inverters coming to market. Ideally you want to buy everything you need to initially have a complete system that you can use but still then expand later without wasting or having to replace the components you already bought. Buying just panels or an inverter or batteries now that cannot be used makes no sense other than losing value. You need all 3 to have a functioning system. You could also initially run the system without any batteries. Batteries have a management system that manages the battery. The inverter does everything else. Most of the big name inverters will also have apps and websites so you can see what’s happening and also historical data.
Sit down, think about your objectives, both short and long term. Get some of your power usage data from your house from your utility bills. Think about how much you want to spend. Think about your timelines.

 

[EZPZ]

Some good reading is available here https://diysolarforum.com/threads/resources-for-beginners.16207/

 

[再生可能 エネルギー]

Short term I know off peak electricity cheaper than diesel. But I want to get rid of utilities companies one day.

I think that the first step is is to make an Audit of your consumption, maybe use a device like Emporia.

Then, if you plan to make your own DIY system, you could start making a small off grid system with a 48V battery
that you charge using off peak power (maybe Octopus rate) and use the battery and an inverter during peak hours.

You could make a separate subpanel to which you connect some particulars devices, such as your refrigerator,
and use a transfer switch to feed your subpanel either using the grid or using your battery and inverter.

You could use maybe a timer to control your transfer switch, so during off peak hours you will use the grid
to recharge your battery and to feed your subpanel, and during peak hours you turn off the charger and
feed the sub panel using your battery and inverter.

Later on, then you can start to install some solar panels and a Solar Charge Controller to charge your battery
instead of using your charger. But if the weather is bad you still have the possibility use your charger instead.

And gradually your can add more solar panels and additional SCC. So with more solar panels you will start to have
more solar energy to charge another battery and even use a second more powerfull inverter, to run
some appliances, like an heat pump.

Note: If you really want to get rid of utilities companies, you need to plan making a full off grid system
able to handle in-rush current when starting a motor, like a refrigerator, HVAC, water pump. And have
enough storage energy in case of bad weather. In the case hybrid system, you will be still using the
grid to handle in-ruch current and bad weather situations. So you have to determine if the extra cost
of a full off grid solution is worthwhile or if still using the grid with an hybrid solution will be more cost-effective.

 

[50ShadesOfDirt]

Rewrite of your goals:
- build the system slowly: batteries, solar panels (ground mount) batteries, backup generator; get rid of utility one day.
- everything manageable by power management system that doesn’t require lcd menus on the equipment
- my usage: 15.5kwh x 2 be optimal or 1 to get going with grid or generator backup.
- Is there a design software available?

As you are already grid-connected, I'd leave that connection in place and use it as alternate charging source. Choose a system reference voltage (probably 48v). As I'm not in the UK, find out from UK folks what the requirements are for permitting, installation, wiring, etc.

1. Research and implement the Victron Cerbo (management system), as this is pretty comprehensive (if you buy into Victron).

2. Research and implement a backup generator; could be inverter-gen, could be open-frame non-inverter gen with a "ChargeVerter". Putting this in place now, sized for future needs, and you have backup for when grid goes down.

3. research and implement Inverter/charger + battery-bank. This runs parallel to your grid connection and current wiring (so no inspections or permitting (yet). Ties into management system if victron inverter, and would be sized to your current or future usage requirements.

At this point, you have a system running in the garage or on the bench, and it can power loads you hook up to it, and be recharged either by a grid-connected device (at night if lower costs) or by generator.

4. implement solar panels on ground mount. Tie in to victron mppt, and rest of system.

5. plan wiring to reduce/remove grid connection. Leave in just enough grid connection to provide that alternate charging device support.

At this point, you are hopefully running on all your equipment, purchased slowly and piecemeal, each being managed by Victron Cerbo as each comes online.

Design software still seems iffy to me, if the goal is to get it to help you put together all of these pieces; there are online design packages that help solar installers, but not end users or DIY (easily). Good news is that with Victron's book "wiring unlimited" and other such resources, and Visio or other diagramming software (paid or free), you can get pretty close.

You could also have Victron sales org (whoever that is in your region) put together a quote, and this would start you off with a reference design.

Hope this helps ...

 

[Shaman]

Wow thanks for the detailed replies I will digest these now..

 

[SeaGal]

My 2p's worth...

Totally off grid in UK will cost £££ to cover your Winter power demand.

Do you know what your peak and average daily usage will be?

My 6.6kWp panels produce 30kWh per day max in sunny Suffolk in summer. But in December more like 15kWh per week, with min of less that 1kWh / day Today was 8.2kWh, 2 days ago we got 24kWh, March 31st was just 5.4kWh.

So, you will need lots of panels and storage to be off grid unless your usage is very low.

You will also need to consider redundancy with inverters / storage etc. Planning permission will be required for large ground mount.

Plenty of options are available to monitor and control systems. In the UK Solis and Sunsynk are popular. Also consider Victron for robustness and longevity.

 

[Shaman]

My 2p's worth...

Totally off grid in UK will cost £££ to cover your Winter power demand.

Do you know what your peak and average daily usage will be?

My 6.6kWp panels produce 30kWh per day max in sunny Suffolk in summer. But in December more like 15kWh per week, with min of less that 1kWh / day Today was 8.2kWh, 2 days ago we got 24kWh, March 31st was just 5.4kWh.

So, you will need lots of panels and storage to be off grid unless your usage is very low.

You will also need to consider redundancy with inverters / storage etc. Planning permission will be required for large ground mount.

Plenty of options are available to monitor and control systems. In the UK Solis and Sunsynk are popular. Also consider Victron for robustness and longevity.

Can you recommend an over specified inverter model that allows for growth of system? Be nice to be intelligent in terms of functionality.

 

[SeaGal]

that allows for growth of system

Guess that will depend on what size you want to start with and what size you expect to expand to .

I have Solis which are very controllable, but don't (yet) support out-of-the-box parallel operation. The new Solis S6 models do support that, but are not yet ENA Type test approved for grid-connectivity in the UK.

I suspect that the SunSynk (also sold as Deye in UK) will provide the expandability that you are looking for. They have received good reports on this forum and support multiple inverter configurations.

 

[shadowmaker]

Up here going totally off grid would mean a drastic reduction of my daily consumption. My 44kWp system produces 350kWh on a perfect day, but there was few 2kWh days in December with many under 10kWh. At the same time my consumption was 180-250kWh/day depending how cold it was. There's no way to add enough panels to compensate poor Nov-Dec-Jan production here. The only way would be getting rid of ground source heating and going back to oil/wood AND still use generator all the time for those three months. Here it's much cheaper to be grid tied but of course it can change in the future.

I'm live much more north than you, but If you want to go totally off grid, you should plan how to keep your winter consumption low.

I'm using Deye (=Sunsynk) and can recommend it. With it don't need anything extra, just install app and you have remote control over your system.

I'd would start with hybrid inverter (big enough to go off-grid eventually) with some panels while being still grid tied. This way you can start "saving" on electric bill immediately. Then add battery and more panels as funds allow. Generator would be my last purchase before pulling the plug.

I have no experience being off-grid and only one year with solar so far, but that's how I'd do it.

 

[MSRConf]

Think as most folks are saying, for possibly 7 or 8 months of the year, you will be essentially off grid once you have a reasonable solar, inverter and battery setup, but for 3 or 4 months when you really need to heat your home in winter, run a tumble dryer ect then you hit a roadblock vs being "entirely off grid", Thatched roof implies an older house so perhaps not quite as good as a new build at keeping the heat in and the weather out.

Your target ideal state maybe off grid 100% of the time, you can do that with other heating means, Bottled gas or Oil in Winter, but that would be investing and spending cash to meat the goal rather than aiming for lowest run rate cost.

I would love to be off grid, especially when the Energy companies are lifting the standing charges, but its difficult in the UK. My goal has been to get to the lowest run rate, I do that by leveraging the solar through 8 months of the year with the excess heating water or charging car, in Winter I use the batteries as a storage tank for over night cheap electricity, which I use for the other 20 hours of the day. But in Winter there is little option but to switch the central heating on even in a well insulated modern house.

 

[Shaman]

I am working towards being as off grid and self sufficient as possible on my property. The house is a thatched cottage and cold as heck in the winter! I currently have oil heating and am half way through installing a solid fuel/wood Rayburn which will provide winter heating, hot water and cooking. The heating system uses a neutral point so I can switch between oil and Rayburn.

Being totally off grid is expensive like private water supply etc, some things just not worth doing. Same might be for the generator vs grid tie but its one of those things that if it marginal Id choose the generator as I feel cheated by the government and utility companies. I strive for 100% but would be content with 80-90%

 

[Shaman]

Thanks for the answers they are well thought out and given me much to think about.

 

[Shaman]

Rewrite of your goals:
- build the system slowly: batteries, solar panels (ground mount) batteries, backup generator; get rid of utility one day.
- everything manageable by power management system that doesn’t require lcd menus on the equipment
- my usage: 15.5kwh x 2 be optimal or 1 to get going with grid or generator backup.
- Is there a design software available?

As you are already grid-connected, I'd leave that connection in place and use it as alternate charging source. Choose a system reference voltage (probably 48v). As I'm not in the UK, find out from UK folks what the requirements are for permitting, installation, wiring, etc.

1. Research and implement the Victron Cerbo (management system), as this is pretty comprehensive (if you buy into Victron).

2. Research and implement a backup generator; could be inverter-gen, could be open-frame non-inverter gen with a "ChargeVerter". Putting this in place now, sized for future needs, and you have backup for when grid goes down.

3. research and implement Inverter/charger + battery-bank. This runs parallel to your grid connection and current wiring (so no inspections or permitting (yet). Ties into management system if victron inverter, and would be sized to your current or future usage requirements.

At this point, you have a system running in the garage or on the bench, and it can power loads you hook up to it, and be recharged either by a grid-connected device (at night if lower costs) or by generator.

4. implement solar panels on ground mount. Tie in to victron mppt, and rest of system.

5. plan wiring to reduce/remove grid connection. Leave in just enough grid connection to provide that alternate charging device support.

At this point, you are hopefully running on all your equipment, purchased slowly and piecemeal, each being managed by Victron Cerbo as each comes online.

Design software still seems iffy to me, if the goal is to get it to help you put together all of these pieces; there are online design packages that help solar installers, but not end users or DIY (easily). Good news is that with Victron's book "wiring unlimited" and other such resources, and Visio or other diagramming software (paid or free), you can get pretty close.

You could also have Victron sales org (whoever that is in your region) put together a quote, and this would start you off with a reference design.

Hope this helps ...

Sorry I missed this post, much appreciated and great advice

 

[Shaman]

Rewrite of your goals:
- build the system slowly: batteries, solar panels (ground mount) batteries, backup generator; get rid of utility one day.
- everything manageable by power management system that doesn’t require lcd menus on the equipment
- my usage: 15.5kwh x 2 be optimal or 1 to get going with grid or generator backup.
- Is there a design software available?

As you are already grid-connected, I'd leave that connection in place and use it as alternate charging source. Choose a system reference voltage (probably 48v). As I'm not in the UK, find out from UK folks what the requirements are for permitting, installation, wiring, etc.

1. Research and implement the Victron Cerbo (management system), as this is pretty comprehensive (if you buy into Victron).

2. Research and implement a backup generator; could be inverter-gen, could be open-frame non-inverter gen with a "ChargeVerter". Putting this in place now, sized for future needs, and you have backup for when grid goes down.

3. research and implement Inverter/charger + battery-bank. This runs parallel to your grid connection and current wiring (so no inspections or permitting (yet). Ties into management system if victron inverter, and would be sized to your current or future usage requirements.

At this point, you have a system running in the garage or on the bench, and it can power loads you hook up to it, and be recharged either by a grid-connected device (at night if lower costs) or by generator.

4. implement solar panels on ground mount. Tie in to victron mppt, and rest of system.

5. plan wiring to reduce/remove grid connection. Leave in just enough grid connection to provide that alternate charging device support.

At this point, you are hopefully running on all your equipment, purchased slowly and piecemeal, each being managed by Victron Cerbo as each comes online.

Design software still seems iffy to me, if the goal is to get it to help you put together all of these pieces; there are online design packages that help solar installers, but not end users or DIY (easily). Good news is that with Victron's book "wiring unlimited" and other such resources, and Visio or other diagramming software (paid or free), you can get pretty close.

You could also have Victron sales org (whoever that is in your region) put together a quote, and this would start you off with a reference design.

Hope this helps ...

Would you elaborate on the generator options to research? I work from home part of the week in a workshop which uses high wattage tools. I was thinking of separating this off as a separate circuit on a diesel Hyundai generator which could form the backup generator with auto switch somehow?

 

[50ShadesOfDirt]

"2. Research and implement a backup generator; could be inverter-gen, could be open-frame non-inverter gen with a "ChargeVerter". Putting this in place now, sized for future needs, and you have backup for when grid goes down."

You'll want to figure out your requirements (things this gen has to power, if all else fails), your fuel of choice (we use propane, but don't know what you've got available), and type of gen (inverter-gen closed frame, open-frame inverter-gen, open-frame non-inverter gen). I tend to stay away from inverter-gen's, as these are very expensive overall, too compact to work on, have expensive parts embedded in them, and so on. An open-frame inverter-gen bucks this trend, and a few manufacturers are coming out with them. An open-frame non-inverter-gen (tri-fuel), but still with low THD levels approaching an inverter-gen, are coming on the market ... these seem to be the sweet-spot for me. Otherwise, add a chargeverter to the non-inverter-gen models, if your chosen inverter needs it (most AIO's would need it).

Then, size the gen to operate everything you want to power (inverter-charger, tools, appliances) at no more than 75% of gen capacity (the sweet spot here for gen watts). It will recharge the battery-bank through inverter-charger, whenever that gets low. If you have complex shop tools with huge power draws, or other large loads, you can always fire up the gen and run it for that load. We run everything through the inverter & battery-bank, but depending on shop needs, you could get fancy with circuits powering both inverter-charger, and heavy shop loads.

But, gen is there mainly for backup duty if grid down, or solar output (in winter months) isn't where you want it. If you can get a large propane site tank, and propane delivered, now you've got a reliable source of backup power, with little to no fuel mess ... propane also runs clean through the carb, so better for reduced maintenance.

For me, the gen would have to be auto-start, auto-choke (start with a remote fob), and have a "smart port" on it for later ATS integration into automated start/stop based on grid up/down or inverter/battery-bank power levels. You don't want to trudge out to the gen shed thru snow and pull on the starter rope; a gen shed keeps things quiet, and hidden, depending on your 'hood. A westinghouse model fills all my requirements, although I don't really know what's available in the market on your side of the pond.

We are totally off-grid, and run the gen whenever we have more than a few days of cloud cover; still runs no more than a few hours/day, as it refills the battery-bank (buffer), and we run off battery-bank beyond that. Really nothing to it ... we are our own power grid (we can't get a grid connection where we are, without a winning lottery ticket), and it's assembled from off-the-shelf stuff ...

Hope this helps ...

 

[Madcodger]

"2. Research and implement a backup generator; could be inverter-gen, could be open-frame non-inverter gen with a "ChargeVerter". Putting this in place now, sized for future needs, and you have backup for when grid goes down."

You'll want to figure out your requirements (things this gen has to power, if all else fails), your fuel of choice (we use propane, but don't know what you've got available), and type of gen (inverter-gen closed frame, open-frame inverter-gen, open-frame non-inverter gen). I tend to stay away from inverter-gen's, as these are very expensive overall, too compact to work on, have expensive parts embedded in them, and so on. An open-frame inverter-gen bucks this trend, and a few manufacturers are coming out with them. An open-frame non-inverter-gen (tri-fuel), but still with low THD levels approaching an inverter-gen, are coming on the market ... these seem to be the sweet-spot for me. Otherwise, add a chargeverter to the non-inverter-gen models, if your chosen inverter needs it (most AIO's would need it).

Then, size the gen to operate everything you want to power (inverter-charger, tools, appliances) at no more than 75% of gen capacity (the sweet spot here for gen watts). It will recharge the battery-bank through inverter-charger, whenever that gets low. If you have complex shop tools with huge power draws, or other large loads, you can always fire up the gen and run it for that load. We run everything through the inverter & battery-bank, but depending on shop needs, you could get fancy with circuits powering both inverter-charger, and heavy shop loads.

But, gen is there mainly for backup duty if grid down, or solar output (in winter months) isn't where you want it. If you can get a large propane site tank, and propane delivered, now you've got a reliable source of backup power, with little to no fuel mess ... propane also runs clean through the carb, so better for reduced maintenance.

For me, the gen would have to be auto-start, auto-choke (start with a remote fob), and have a "smart port" on it for later ATS integration into automated start/stop based on grid up/down or inverter/battery-bank power levels. You don't want to trudge out to the gen shed thru snow and pull on the starter rope; a gen shed keeps things quiet, and hidden, depending on your 'hood. A westinghouse model fills all my requirements, although I don't really know what's available in the market on your side of the pond.

We are totally off-grid, and run the gen whenever we have more than a few days of cloud cover; still runs no more than a few hours/day, as it refills the battery-bank (buffer), and we run off battery-bank beyond that. Really nothing to it ... we are our own power grid (we can't get a grid connection where we are, without a winning lottery ticket), and it's assembled from off-the-shelf stuff ...

Hope this helps ...

Best summary of "how to think about your generator needs" I've read. Well done.

 

[Shaman]

"2. Research and implement a backup generator; could be inverter-gen, could be open-frame non-inverter gen with a "ChargeVerter". Putting this in place now, sized for future needs, and you have backup for when grid goes down."

You'll want to figure out your requirements (things this gen has to power, if all else fails), your fuel of choice (we use propane, but don't know what you've got available), and type of gen (inverter-gen closed frame, open-frame inverter-gen, open-frame non-inverter gen). I tend to stay away from inverter-gen's, as these are very expensive overall, too compact to work on, have expensive parts embedded in them, and so on. An open-frame inverter-gen bucks this trend, and a few manufacturers are coming out with them. An open-frame non-inverter-gen (tri-fuel), but still with low THD levels approaching an inverter-gen, are coming on the market ... these seem to be the sweet-spot for me. Otherwise, add a chargeverter to the non-inverter-gen models, if your chosen inverter needs it (most AIO's would need it).

Then, size the gen to operate everything you want to power (inverter-charger, tools, appliances) at no more than 75% of gen capacity (the sweet spot here for gen watts). It will recharge the battery-bank through inverter-charger, whenever that gets low. If you have complex shop tools with huge power draws, or other large loads, you can always fire up the gen and run it for that load. We run everything through the inverter & battery-bank, but depending on shop needs, you could get fancy with circuits powering both inverter-charger, and heavy shop loads.

But, gen is there mainly for backup duty if grid down, or solar output (in winter months) isn't where you want it. If you can get a large propane site tank, and propane delivered, now you've got a reliable source of backup power, with little to no fuel mess ... propane also runs clean through the carb, so better for reduced maintenance.

For me, the gen would have to be auto-start, auto-choke (start with a remote fob), and have a "smart port" on it for later ATS integration into automated start/stop based on grid up/down or inverter/battery-bank power levels. You don't want to trudge out to the gen shed thru snow and pull on the starter rope; a gen shed keeps things quiet, and hidden, depending on your 'hood. A westinghouse model fills all my requirements, although I don't really know what's available in the market on your side of the pond.

We are totally off-grid, and run the gen whenever we have more than a few days of cloud cover; still runs no more than a few hours/day, as it refills the battery-bank (buffer), and we run off battery-bank beyond that. Really nothing to it ... we are our own power grid (we can't get a grid connection where we are, without a winning lottery ticket), and it's assembled from off-the-shelf stuff ...

Hope this helps ...

Hyundai DHY8000SELR Diesel Generator Long Run - Generators Direct

*Please be advised that Hyundai Power Products now have an extended lead time and you may not receive them next day. The current delivery time is estimated at 2-4 working days.* The DHY8000SELR is the long running version of the DHY8000SE, with a large 25L fuel tank which boosts the maximum...

www.generators-direct.co.uk

This is what I am thinking. I would probably not ever run more than 3kw at same time in workshop.. is it an inverter gen or do I need that as an extra?