Noob Solar / battery questions and confusion about potential cost savings?

gefnew

So obvious really, missed that one.
thanks anyway.

Pulpdiction

marchesini46 said:

Pulpdiction said:

Pricing doesn't look too bad, but mixed reviews on Growatt batteries from what I have seen.  Also given your high usage you might want to consider a larger than 4kw system if you have the room and can get permission.  Also depends on the orientation of the roof and shading, but presumably all of that is taken into account.  A 4kw system might cover your use in May - September but it'll get no where near for most of the rest of the year if you are using 550kw/h, at approx 18kw/h per day then you'd need a bigger system and battery for the winter, some days you'll generate nothing. 

Yes, the more I look into it, it appears the proposed system seems to be not powerful enough for my needs.  Is there a chart that shows how much electricity is generated on cloudy v sunny days inc number of panels etc?

But I don't think you are too far away given the optimal cost vs saving.  Maybe consider a slightly larger battery, or system or look at a solar hot water diverter as well depending on your hot water set up.  

What batter size should I be looking for?  Also, what is a solar hot water diverter?

I am in a not too dissimilar position and have gone for a 8.2kw givenergy battery, but they have a new 9.5kw battery coming out.  I think that is the minimum you should be looking at.

If you have a hot water tank you can get a device like a myengergi eddi that will divert excess solar production to heat your water.  If you have a combi boiler that is a non starter.

Reed_Richards

Pulpdiction said:

If you have a hot water tank you can get a device like a myengergi eddi that will divert excess solar production to heat your water.  If you have a combi boiler that is a non starter.

Well it's still possible but you would need to add a hot water tank and some extra plumbing.  Storing excess generation as heat that you use later is cheaper than storing it in a battery.  

marchesini46

Pulpdiction said:

I am in a not too dissimilar position and have gone for a 8.2kw givenergy battery, but they have a new 9.5kw battery coming out.  I think that is the minimum you should be looking at.

If you have a hot water tank you can get a device like a myengergi eddi that will divert excess solar production to heat your water.  If you have a combi boiler that is a non starter.

Is the battery you suggest, something you are adding to an existing install or are you still researching the options? Can you share a recommended supplier / installer?

The hot water tank device doesn’t seem a bad shout either - if I go with a larger number of panels. The device seems reasonably priced but is it tricky / expensive to fit to our Megaflow system?

arty688

Reed_Richards said:

Pulpdiction said:

If you have a hot water tank you can get a device like a myengergi eddi that will divert excess solar production to heat your water.  If you have a combi boiler that is a non starter.

Well it's still possible but you would need to add a hot water tank and some extra plumbing.  Storing excess generation as heat that you use later is cheaper than storing it in a battery.  

but is very limited to what you can use the stored energy for and your saving should be measured by the gas price vs export price.

Reed_Richards

marchesini46 said:

The hot water tank device doesn’t seem a bad shout either - if I go with a larger number of panels. The device seems reasonably priced but is it tricky / expensive to fit to our Megaflow system?

It should be an easy task for an electrician to fit a diverter device.  The only issue if you have a battery is that this may temporarily discharge to the mains when it ramps down its power output and you need to ensure that this is not detected as excess solar power causing the diverter to activate and drain the battery.

Alnat1

You might also find, like I am, that the amount of electricity you use drops once you get solar. This is due to the fact you're looking at the numbers and stats and realising where you can make small changes and adjustments that add up to big savings.

After having a solar and battery system installed early March 21 I'm now a little obsessed with How Low Can We Go. Hubby needs a bit more training yet but he's learning that I'll tut if he puts the toaster on before the kettle has finished boiling!

marchesini46

Alnat1 said:

You might also find, like I am, that the amount of electricity you use drops once you get solar. This is due to the fact you're looking at the numbers and stats and realising where you can make small changes and adjustments that add up to big savings.

After having a solar and battery system installed early March 21 I'm now a little obsessed with How Low Can We Go. Hubby needs a bit more training yet but he's learning that I'll tut if he puts the toaster on before the kettle has finished boiling!

I’m as a father of two teenage sons, whereby they think light bulbs and switches automatically turn themselves off and a house runs on fresh air so it’s ok to leave your TV and PS5 on while you pop out to the park for 2/3 hours 😂, I didn’t want to be a grumpy dad and berating them at every opportunity. So if I can get my bills down significantly, I’ll be a happy bunny. If we do decide to go down this solar / battery route, we can also be more mindful of when we use the power hungry appliances ie tumble dryers etc. 

Can I ask how much you managed to save on a monthly basis to give me a real world comparison?

marchesini46

Reed_Richards said:

marchesini46 said:

The hot water tank device doesn’t seem a bad shout either - if I go with a larger number of panels. The device seems reasonably priced but is it tricky / expensive to fit to our Megaflow system?

It should be an easy task for an electrician to fit a diverter device.  The only issue if you have a battery is that this may temporarily discharge to the mains when it ramps down its power output and you need to ensure that this is not detected as excess solar power causing the diverter to activate and drain the battery.

That’s reassuring to know it’s not going to be silly money.  Lots of options to consider though so I guess it’s comparing the figures of how much of our gas bill is for heating and how much is heating our hot water? I don’t suppose you know of how I can find out that split?

Magnitio

marchesini46 said:

I’m as a father of two teenage sons, whereby they think light bulbs and switches automatically turn themselves off and a house runs on fresh air so it’s ok to leave your TV and PS5 on while you pop out to the park for 2/3 hours 😂, I didn’t want to be a grumpy dad and berating them at every opportunity. So if I can get my bills down significantly, I’ll be a happy bunny. If we do decide to go down this solar / battery route, we can also be more mindful of when we use the power hungry appliances ie tumble dryers etc. 

Can I ask how much you managed to save on a monthly basis to give me a real world comparison?

When they next go out and leave the TV and PS5 on, go into the settings of each to put them in eco mode, or to automatically go to sleep when not in use. On PS5, it's something like: System Settings > System > Power Saving and Rest Options

They will need to understand the cost of energy when they go to Uni or leave home, so it's worth educating them.