Solar panels during outage

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galway_blow_in

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So we have eighteen roof panels,an inverter and an EDDI but no battery as well used everything we generated

I emailed the installer who carried out the installation last July about augmenting the system to allow us to harness power during this storm inflicted lengthy outage, he claims we don't need a battery?

Is this expensive? IMG_20250131_212800.jpg
 
Huawai equipment is known to be a bit more expensive than many rivals, but it's also well regarded, AFAIK.

I'm not familiar with the device mentioned, but it sounds useful, if it directs power to specific devices, or even rooms. Far better than just getting a 3 pin plug socket and related equipment wired in to the invertor.

Regardless, I would want one or probably even two 5kw batteries installed, as part of any upgrade that you consider. Otherwise, where does the power cover from, if there's a power cut at night, for example?

Having installed a battery with my system, I'm happy that I did.
 
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An electrician can give better input, but I’ll take a crack at it from what I understand.

One option lots of people are using at the moment during an outage is the emergency output of their solar inverter or Vehicle-to-Load output of their electric vehicle. This basically gives you a three pin socket and you can use extension leads to plug in things in your home provided your solar battery or car is charged. Dead handy, but if you have appliances that are hard wired (boiler, lights etc) you’re out of luck.

Another option is that you feed power into your existing fuseboard from a separate source. There will generally be an automatic or manual switch that allows you to take power either from the grid or another source. These are common in the US and generally used to connect a generator (owned or rented) to your house. But with the right solar inverter or electric vehicle there is nothing to stop you connecting them instead. This is a much better setup because you can power anything in the home, even hardwired stuff like lights/alarm. Obviously you can only use as much power as the supplying device can support, so you might have to flick off some of your fuses for stuff like heatpumps, ovens, EV chargers or anything else you don't need. This is basically what the Huawei device is aiming to achieve.

One other factor is that your solar panels themselves are not legally allowed to generate power and send it to the inverter when the grid power is offline in a standard setup. The idea of this is that if the fire brigade had to come to your home for an emergency, they know they will not encounter live wires if they simply cut the grid off to the house. If you want your panels to be able to generate while the grid is off, you must provide an isolation switch for the panels on the outside of the house so the fire brigade can see it. It’s worth noting that to get the SEAI solar PV grant, installers are not permitted to put this setup in-place, but an electrician could do it properly after the fact.
 
You can modify the power supply to your gas or oil central heating system. These systems are low wattage. Disconnect the supply cable and then install a 13 amp socket beside the existing panel or switch. Connect the supply cable to the back of the socket.

Then connect a length of flex from the central heating system to a 13 amp plug. Plug the 13amp plug into the new socket.

You now have the facility to run your heating system from a generator or a small portable inverter.

A small cheap 12 volt inverter could be connected to the starter battery of any car. If the power cut is for an extended time the car engine could be run for periods to keep the starter battery charged.

This can be set up at very little expense.
 
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@S class
"A small cheap 12 volt inverter could be connected to the starter battery of any car. If the power cut is for an extended time the car engine could be run for periods to keep the starter battery charged.

This can be set up at very little expense."

Thats exactly what I did, I had a car battery charged to power fridge with inverter then used car engine, only issue with car is that you have to be careful that bonnet doesn't blow back during windy weather.
An electric car battery in theory is a good solution but is only practicle during short outages and you need to know exactly when the power is returning. Its not a solution for people in West of ireland still without power and its not going to work heat pumps etc for prolonged periods.
A deep cycle battery would be a good solution that I might buy but they are expensive and probably scarce in current environment.
Also a camping stove that works off of domestic gas cylinder I also have . only cost 50euros in Aldi and used it many times during power cuts
 
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joe sod said:
An electric car battery in theory is a good solution but is only practicle during short outages and you need to know exactly when the power is returning
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Yeah look you’re not going to run a heatpump for any meaningful period of time, but your average EV today has a 50kWh+ battery, which will run a typical fridge/freezer for 50 days. It would run a heating boiler and circulation pumps for much longer again. There is no need to know when the power is returning, just drive up the road to where there is power every few days and charge.
 
A small petrol generator is very useful.

I got a 700 watt generator about 20 years ago for 35 euro in B&Q.
In that time period I only used it once when there was a scheduled all day maintenance power cut in my parents house. It ran the central heating, fridge and the television for the day. They also had a two burner camping gas stove. They were warm and happy all day.

There was a power cut several years ago (Dublin). My daughters were home and I said I would start up the generator, but they said they were fine. They were using Gameboys or something similar.
The power came back after 2 hours.

My present and previous broadband modem is powered by a 12 volt DC supply. I have rigged up an old jack plug lead with 2 crocodile clips to attach to a spare car battery. During the next power cut I reckon that with broadband WiFi and a tablet or laptop I will be okay for media and internet entertainment. With a camping gas burner I will be fine for any short time power cuts. If the house gets too cold I will hook up the generator to the central heating and fridge.
 
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S class said:
I got a 700 watt generator about 20 years ago for 35 euro in B&Q.
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I remember seeing those small generators in Aldi about 15 years ago for 50 euros, was tempted to buy one but never did, never seen them again. Id say very difficult to get generators now even before the storm because so many used in Ukraine now due to that idiot Putin.
 
Petrol engine generators are extremely noisy, we have a Tesla but unfortunately you can't draw power from Tesla like you can with the likes of Kia

Will probably just get the solar panel battery added and the change over switch
 
Question for those with a decent mathematical brain, were we to fit a battery and obviously the change over switch (which isioates the house from the grid so as not to injure line repair operators)

Would we see enough power generated from solar alone to power the house for several days?, we accept it would be necessary to use the power sparingly,we have gas for cooking and two solid fuel stoves

Had occurred to me it might be more fruitful to change the Tesla for say a BYD as you have a battery which you can recharge at the relevant charge points around the area , this would be more expensive but would leave us covered for events like the one which just happened

PS , electricity was only restored this morning with us
 
From April to September, maybe. Shorter days in December, even if sunny probably wouldn't. Combination of solar and battery charged at night should work.
 
galway_blow_in said:
Would we see enough power generated from solar alone to power the house for several days?
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With two EVs and a heatpump we are suing 50-100kWh a day at the moment, our 14 solar panels are generating 3-4kWh per day. In the summer that is flipped and we generate far more than we consume, but of course storms and power outages rarely occur then.

However if all you wanted to do was keep a fridge/freezer and some lights on then the panels would be close to meeting your requirements.
 
Yes,we would just like to have light in the evening and keep fridge - freezer running,be nice to be able to watch a little TV too

So would one solar battery be sufficient or would you need two even for the above at this time of year?
 
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