Solar panels and battery - any real world reccomendations?

Peteronthesouthcoast said:
We have 3 inverters. Two are regular inverters and one is a hybrid. The 2 regular convert PV DC to AC send the electricity to the fuse board. The hybrid has the sensor on the AC cables coming from in from the grid. The Hybrid does the decision making and charges/discharges the batteries etc.

I am not technical but it seems to me that an extra standard inverter can easily be installed as long as the fuse board has an empty slot
Click to expand...

Thanks! :)

I guess that might work for me although my system isnt wired into the CU since its while house UPS, main feed is diverted into unit then back to CU
Might not stop me having another though

Might have a measure up see what could realistically fit and likely generation and ROI etc
 
Zeeflyboy said:
Decided to add the third… installer has offered to fit it for free and supply at cost too, because I’ve been nice to them.

He did offer to draw the third one on the wall in chalk too if it helped

15kwh is a nice number I think - our usage typically is around 14-18kwh per day so it will allow moving almost all our usage in winter over to the cheap rate, and do a better job at covering the bad days in the summer months.

I’m pretty sure it’s poor value for money to add the third, but still cheaper than a powerwall so there’s that…
Click to expand...

Looks like the battery is about "2 bricks wide" so you can roughly gauge it with that.

The slight excess capacity will be nice when the solar isn't as good.

If you're on Go then you can also fully charge in the winter and essentially use no peak units at all most of the time.

3rd battery will be the least impactful in terms of savings vs the other two, but out of interest what is the cost for that being added?
 
Last edited:
HungryHippos said:
Looks like the battery is about "2 bricks wide" so you can roughly gauge it with that.

The slight excess capacity will be nice when the solar isn't as good.

If you're on Go then you can also fully charge in the winter and essentially use no peak units at all most of the time.

3rd battery will be the least impactful in terms of savings vs the other two, but out of interest what is the cost for that being added?
Click to expand...

£2400 with delivery

I’ve just signed up for go, the challenge will be actually getting it fully charged in the 4hr time period… in theory it can hit 5kw charge rate with the Solis inverter but that does appear to down regulate with temperature (I could see it slowly increasing from around 3kw at the start as the pack warmed up from the charging) and I assume slows towards the end of the charge too. If it’s a cold snap then it may well prove to be impossible to fully charge from empty if that’s the case.

The economy 7 rate gives a larger charging window but 50% more cost (12p go vs 18p economy 7).

Edit - this is from yesterday (still on economy 7 here 00:30-07:30), you can see the pack charging at about 3.2kw (not sure why, like I said it can theoretically go up to 5… might be the cold?) charging is done by about 3.30 and then when the night rate ends at 07:30 it kicks in… runs out about 6pm. Add the third pack and I don’t think it would have been done by 4:30 - need to figure out if there’s a way to increase the charge rate or if it’s just a temperature limitation.


TgHczpG.jpg
 
Last edited:
Zeeflyboy said:
Decided to add the third… installer has offered to fit it for free and supply at cost too, because I’ve been nice to them.
Click to expand...
Thats good, be sure to post a photo.

I'm going straight in at 14.5kWh of battery, and adding a second (I have space for four), at least I'll know exactly what to buy for the second one.

Main reason is that my system really needs two batteries to provide peak power, it will also make winter charging a breeze, I can just set a SOC level to charge to off peak, and if there's any solar in the day time it will still fit into the batteries.

Yes it will push the ROI further out, but I'm not bothered, ,my original FITS system has paid for itself so that can contribute to the new system ROI.
 
Zeeflyboy said:
Decided to add the third… installer has offered to fit it for free and supply at cost too, because I’ve been nice to them.

He did offer to draw the third one on the wall in chalk too if it helped

15kwh is a nice number I think - our usage typically is around 14-18kwh per day so it will allow moving almost all our usage in winter over to the cheap rate, and do a better job at covering the bad days in the summer months.

I’m pretty sure it’s poor value for money to add the third, but still cheaper than a powerwall so there’s that…
Click to expand...

Look at the "go Faster" tariff, gives you a 5 hour charge window, plus it can start at 9.30PM, battery only needs to last until 9.30pm then.
You also gain the cheap rate in hours that you can make use of them.
 
Last edited:
Zeeflyboy said:
Is go faster still a thing? Don’t seem to be able to find any option for it
Click to expand...

I changed from GO to Go faster last September, I just emailed them asking if they could change me over to Go faster, no fuss or bother they just changed me over(no EV)

Well worth trying via an email to them.

9.30PM start time is a big plus with batteries.

zpVykBh.jpg
 
Last edited:
Troop said:
I changed from GO to Go faster last September, I just emailed them asking if they could change me over to Go faster, no fuss or bother they just changed me over(no EV)

Well worth trying via an email to them.

9.30PM start time is a big plus with batteries.

zpVykBh.jpg
Click to expand...
Go faster has been withdrawn until further notice, I remember seeing posts about it
 
Other thing to remember with Go, Go Faster, Eco7, they are not covered by the CAP price, you pay the full rate on peak hours,(I would be paying 42p if I used any)
 
Last edited:
Guys that are on Go, does your smart meter display show the correct rates?

Just checked this morning after the overnight charge and it still seems to be using the old economy rates for estimating cost which is odd.

Cheers
 
Zeeflyboy said:
£2400 with delivery

I’ve just signed up for go, the challenge will be actually getting it fully charged in the 4hr time period… in theory it can hit 5kw charge rate with the Solis inverter but that does appear to down regulate with temperature (I could see it slowly increasing from around 3kw at the start as the pack warmed up from the charging) and I assume slows towards the end of the charge too. If it’s a cold snap then it may well prove to be impossible to fully charge from empty if that’s the case.

The economy 7 rate gives a larger charging window but 50% more cost (12p go vs 18p economy 7).

Edit - this is from yesterday (still on economy 7 here 00:30-07:30), you can see the pack charging at about 3.2kw (not sure why, like I said it can theoretically go up to 5… might be the cold?) charging is done by about 3.30 and then when the night rate ends at 07:30 it kicks in… runs out about 6pm. Add the third pack and I don’t think it would have been done by 4:30
Click to expand...

You may find it's worth starting the charge a little early so it has more ramp up time in the winter. It will guarantee some peak unit usage but it will also add more charge to the battery as an offset.
 
Zeeflyboy said:
Guys that are on Go, does your smart meter display show the correct rates?

Just checked this morning after the overnight charge and it still seems to be using the old economy rates for estimating cost which is odd.

Cheers
Click to expand...

Agreed with MKW mine became nonsense, I just check the inverter stats now instead.

Validate the octopus website shows usage at the right time and the tariff shows that you're on it properly. The first proper bill you get will have daily breakdown and cost data.
 
Slightly off topic

I pay for 4 sets of energy bills.

1 is with Shell energy
1 is with Octopus
2 are with a much smaller company

The £66/month from the government is paid to Shell and Octopus. However the smaller company is not trusted with the money and this goes directly back into my bank account.

I guess it is a vote of confidence for Octopus as HMG do not believe they will go the same way as Bulb. My Dad always said "Bulbs " do not last forever............
 
Zeeflyboy said:
Guys that are on Go, does your smart meter display show the correct rates?

Just checked this morning after the overnight charge and it still seems to be using the old economy rates for estimating cost which is odd.

Cheers
Click to expand...

Nope. I gave up arguing with Octopus over it.

I was on eco7 and it displayed both dates as expected. Switched to Go and it’s only ever shown the peak rate. The IHD are not very useful tbh compared to the data you can get via your apps.
 
You must log in or register to reply here.
Back
Top Bottom