Solar panels and battery - any real world reccomendations?

[sparkymark75]

You should try out the Solcast integration with HomeAssistant. I set my overnight soc based on the forecast and Solcast is massively more accurate than forecast.solar.

Solcast is what I’m using. It ran last night for the first time and set my battery to charge to 45% from the grid during the cheap time. Will see how it pans out today but currently I’m not generating much solar as it’s raining!

 

[sparkymark75]

Absolutely none in my case, in fact its quite the opposite, we'd just got used to putting the dishwasher and washing machine on when the suns shinning, but now I charge the battery every night it doesn't matter, and once the additional battery is installed in a few weeks we won't have to worry about using too much either.

1. Charge battery off peak (maximum charge circa 24kWh, 8kw x 3 hours)
2. Solar tops battery up to full - capacity circa 29kWh
3. Excess is exported at more than we paid per kWh to charge the battery
4. Discharge some at peak rate, but keep some back to see us through to 2am and in case of a power cut.
5. Repeat the above

I haven't yet tried Solcast, I came across an integration for Victron Node Red which uses Forecast.Solar and modded that, but may try Solcast, but given my use case as above its not really needed now.

Sounds like you’ve got it nailed down. I only have a single 9.5kW battery so not sure I’d have much spare capacity to sell to the grid. At this point it’s early days and my main criteria was to limit import. Maximising export after usage may be a future endeavour.

 

[katie279]

Solcast is what I’m using. It ran last night for the first time and set my battery to charge to 45% from the grid during the cheap time. Will see how it pans out today but currently I’m not generating much solar as it’s raining!

Yeah, I've got solcast with a modifier calc I've added - it's pretty reliable for the last 90 days or so, I just have a simple modifier that allows me to add/minus a percentage if the BBC forecast is wildly off, I tend to err on the side of caution and slightly increase the charge level!

 

[Welshman]

So after a bit of thinking over the weekend, we decided adding panels in the short term is not the best option. So over then next 12mths im going to put the funds together for an ac coupled inverter and battery, along with project home assistant on a raspberry PI for monitoring and installing some cameras and lights out in the newly restructured garden.

Adding the inverter and battery will give me the option of extending my winter export capacity at peak flux rate or using the low flux rate to charge the batteries and use during the day in the more expensive times.

So thats the plan.

 

[Scottm]

So after a it of thinking over the weekend, we decided adding panels in the short term is not the best option. So over then next 12mths im going to put the funds together for an ac coupled inverter and battery, along with project home assistant on a raspberry PI for monitoring and installing some cameras and lights out in the newly restructured garden.

Adding the inverter and battery will give me the option of extending my winter export capacity at peak flux rate or using the low flux rate to charge the batteries and use during the day in the more expensive times.

So thats the plan.

Agreed, I don't think adding extra panels over extra battery storage is that cut and dry anymore with the new Octopus tariffs. I'm planning on switching to Cosy for the winter months so I'm also looking at adding extra battery storage.

 

[bigmike20vt]

So after a bit of thinking over the weekend, we decided adding panels in the short term is not the best option. So over then next 12mths im going to put the funds together for an ac coupled inverter and battery, along with project home assistant on a raspberry PI for monitoring and installing some cameras and lights out in the newly restructured garden.

Adding the inverter and battery will give me the option of extending my winter export capacity at peak flux rate or using the low flux rate to charge the batteries and use during the day in the more expensive times.

So thats the plan.

imo in britain the battery is as important as the panels..... whilst in summer it may mean you can dump some more flux electricity into the grid, in the winter 6 months i suspect you will be using most of what your battery can store yourself (unless you go big cahoonas on the size of course - but then you will likely be unable to fully charge it in your 3 flux hrs).

 

[Welshman]

imo in britain the battery is as important as the panels..... whilst in summer it may mean you can dump some more flux electricity into the grid, in the winter 6 months i suspect you will be using most of what your battery can store yourself (unless you go big cahoonas on the size of course - but then you will likely be unable to fully charge it in your 3 flux hrs).

my average power use is 5.2kwhs per day....so will go with that for battery for now, so there may be some grid use to start and expand as time and funds allow

 

[bigmike20vt]

my average power use is 5.2kwhs per day....so will go with that for battery for now, so there may be some grid use to start and expand as time and funds allow

cool... similar to mine (remember you wont want to run it fully dry, its better to have a little extra storage and be kind to your battery).
i have 3x2.4kwh units, and discharge only to 20%, giving me a usable 6kwh per day.... i would like more in winter but that was where my cost vs benefit came in.

something similar could be a good fit for you. mine are pylon batteries. not the best but good bang for your buck.

if someone is so inclined i have wondered if it would be worth buying an old nissan leaf battery and stripping that down. it isnt straight forward as the voltages do not match so you cant just plug in and go... but it seems a lot of battery storage for what they go for, if you have the skills to re organise the battery pack

 

[EddScott]

I've received a quote for panels and a battery at home but a friend who already had panels and battery says it's a rip off.

11x405w Longi Black Solar PV Panels - £8,483.63
Solar Edige 3000W 1ph Screenless inverter with Home Wave tech. Solar Edge optimiser S500 Solar Edge WiFi Antenna for Setapp inverter.

Modbus Solar Edge Meter - £485.24

Solar Edge Energy Bank 10Khw - £7,881.58

 

[Ron-ski]

something similar could be a good fit for you. mine are pylon batteries. not the best but good bang for your buck.

if someone is so inclined i have wondered if it would be worth buying an old nissan leaf battery and stripping that down. it isnt straight forward as the voltages do not match so you cant just plug in and go... but it seems a lot of battery storage for what they go for, if you have the skills to re organise the battery pack

Given the price of Fogstar rack batteries it's probably not worth the grief, and to boot you get an 8yr warranty.

 

[Ron-ski]

I've received a quote for panels and a battery at home but a friend who already had panels and battery says it's a rip off.

11x405w Longi Black Solar PV Panels - £8,483.63
Solar Edige 3000W 1ph Screenless inverter with Home Wave tech. Solar Edge optimiser S500 Solar Edge WiFi Antenna for Setapp inverter.

Modbus Solar Edge Meter - £485.24

Solar Edge Energy Bank 10Khw - £7,881.58

It is a bit steep, but then it is SolarEdge system and a sign of the current times. I've not particularly kept up with prices, but in late 2015 I paid £6.6k for a 4kW SolarEdge system without battery.

That £8k for the 10 kWh battery would buy you 30kWh Inc VAT from Fogstar, and a very nice rack cabinet.

 

[sparkymark75]

I've received a quote for panels and a battery at home but a friend who already had panels and battery says it's a rip off.

11x405w Longi Black Solar PV Panels - £8,483.63
Solar Edige 3000W 1ph Screenless inverter with Home Wave tech. Solar Edge optimiser S500 Solar Edge WiFi Antenna for Setapp inverter.

Modbus Solar Edge Meter - £485.24

Solar Edge Energy Bank 10Khw - £7,881.58

Solar Edge premium aside, I paid £4.5k for my solar install back in Sep 2021. That comprised of 12 x 380w JA panels and a Solis 3.68kW inverter. Last week I had a GiveEnergy 9.5kW battery fitted with their 3kW AC coupled inverter. This cost me £5,600. So all in, just a smidge over £10k.

 

[Peteronthesouthcoast]

Agreed, I don't think adding extra panels over extra battery storage is that cut and dry anymore with the new Octopus tariffs. I'm planning on switching to Cosy for the winter months so I'm also looking at adding extra battery storage.

Given that the planet does not have time IMO for us to be "adjusting the deck chairs", installing panels has to be the top priority. Batteries are not very friendly to the planet and investment decisions are being made on the basis that the current supply conditions will continue for the next 10 years. The government might decide to invest in electricity storage although this is unlikely. Octopus, like other species, could become extinct...............

 

[Scottm]

Given that the planet does not have time IMO for us to be "adjusting the deck chairs", installing panels has to be the top priority. Batteries are not very friendly to the planet and investment decisions are being made on the basis that the current supply conditions will continue for the next 10 years. The government might decide to invest in electricity storage although this is unlikely. Octopus, like other species, could become extinct...............

But having extra batteries means that you can move your usage out of peak times when grid energy is cleaner. Over 6,000 battery cycles this will be a net positive, even when you take the footprint of the battery into account.

 

[HungryHippos]

Battery tech should improve as well, especially as we move more cars to EV etc.

I disagree that batteries are bad, there needs to be more R&D into them in general to improve materials, make them more efficient etc, which we'll only really get if we actually use them.

 

[Simon]

Battery tech should improve as well, especially as we move more cars to EV etc.

I disagree that batteries are bad, there needs to be more R&D into them in general to improve materials, make them more efficient etc, which we'll only really get if we actually use them.

Ah yes cause no one’s done any r and d on batteries yet have they

 

[HungryHippos]

Ah yes cause no one’s done any r and d on batteries yet have they

Do point out where I said that, if you can (hint: you can't).

 

[Peteronthesouthcoast]

There are a few issues here.

EV's (and we have one) have a huge battery reserve which could help out the grid. There is nothing new, difficult, or even expensive in doing this. As I understand it, the car makers are dragging their feet on this since they are the ones providing the warranty that comes with the batteries of the EV. The batteries we have in our homes are very small fry.

Investment in more green energy and, crucially, storage for the same will give us electricity generation independence. Buying Putin's gas and importing electricity from European nuclear plants are very short sighted policies. The green option is currently the cheapest.

Even if we accept that a battery will do 6000 cycles, this is still a much less good outcome for the planet than panels.............just saying and causing trouble.

 

[HungryHippos]

The problem with panels alone is they're seasonal, and without some form of storage for the energy they produce, the extra they can produce is sort of wasted.

A lot of the energy providers don't really pay well for pure export as well, even with Flux you sort of need the battery with it to make it work properly.

Wind is arguably better as it works all day and night, and in all seasons, but even that has issues (i.e. no wind! ).

I don't really see how we can move away from needing a backstop of nuclear energy still, for quite a while yet, whilst we absolutely should build out more solar/wind.

 

[Ron-ski]

Newer battery tech is coming, CATL have just launched a condensed battery with an energy density of 500Wh/kg.

To put that into perspective, my 14.5kWh battery weighs 80kg, the same weight as per above would be 40 kWh, almost three times as much. How green they are I've no idea, but I did read the other day that a company can now retrieve 95% of the lithium from old cells.

@Peteronthesouthcoast Not sure if you're talking about indivuals or the government. But its all well and good saying fit more panels, don't bother with batteries, but the average person has limited financial resources, and has to place those were they will be most beneficial to themselves, most of us also don't have room for hoards of panels. Although I do have some ideas for additional panels it probably would not be financially viable, but, if you want to donate so I can add more panels, then let me know