What pv kw / battery storage ?

[ecogeorge]

Just looking at electric / solar data today ... May import = 4.1 kwh /day -so far.
Solic immersion managed 145 litres at 82c.... so 2 adult showers and shallow child bath........FREE.
Just updated my signature to reflect my situation.
I have another 800w to install south-but almost horizontal.
Another 200w to install East micro inverter.
Plans for more solar -probably 1-4 x 400w on individual trackers - short of space.
Future shed roof maybe 2kw but 12-18mths away...........
210 litre thermal store installation underway = more excess pv storage with intended woodburner & heatpump input.
Have Gas but 23 yr old boiler is condemed and on last legs -will not be replaced..........
Have ripple energy 7000kwh investment
Just thinking outloud ........... What solar pv capacity and battery storage to gain 4.1kwh daily to be net zero in May.
Accept 7000w in Ripple gonna be useful......
But -next winter no gas !!! although have a 23kw woodburner c/w boiler for heating/hot water to install.
Any thoughts ??

[Joeboy]

Just looking at electric / solar data today ... May import = 4.1 kwh /day -so far.
Solic immersion managed 145 litres at 82c.... so 2 adult showers and shallow child bath........FREE.
Just updated my signature to reflect my situation.
I have another 800w to install south-but almost horizontal.
Another 200w to install East micro inverter.
Plans for more solar -probably 1-4 x 400w on individual trackers - short of space.
Future shed roof maybe 2kw but 12-18mths away...........
210 litre thermal store installation underway = more excess pv storage with intended woodburner & heatpump input.
Have Gas but 23 yr old boiler is condemed and on last legs -will not be replaced..........
Have ripple energy 7000kwh investment
Just thinking outloud ........... What solar pv capacity and battery storage to gain 4.1kwh daily to be net zero in May.
Accept 7000w in Ripple gonna be useful......
But -next winter no gas !!! although have a 23kw woodburner c/w boiler for heating/hot water to install.
Any thoughts ??

That adds up to about a 5kW system? I produce around 3.8MWh pa on a mostly South facing system of that size and it does have various shading issues on sections of it in the morning and late afternoon. Plus the Far North reality. With all that said it generated 25kWh yesterday.

By that reckoning you'll be more than capable of hitting the 4.1kWh daily mark you have set.

My West facing small array which is pretty unshaded but orientation limited generates 3kWh+ on a decent May day. It is 915W in size and majority of it is very old. This system is run off of microinverters. Secondhand panels about the 250W original spec range coupled with less expensive M215 Enphase micros will give you a pleasant surprise.

Our sons two panel 800W Hoymiles system is unshaded until 3pm. It generates just over 7kWh on these fine May days. I was very proud when his two panel system passed 250kWh generation. A bit of a Dad moment!

I am very much a fan of these spot micro systems for smaller or awkward spots. The figures are small but they are getting it done in what would otherwise be dead space.

If you go batteries you'll need to be able to control the storage & distribution of the power. That means a hybrid inverter mcs certified.

I'm sure you've read the diy battery thread? The storage capacity and professionalism available via Colin Deng is well worth a look. Couple with a decent bms and you are up and running. You can run a 16S (16 batteries) string and have over 280Ah of stored power. On a 48V system that's up about 14kWh of storage.

Andy is doing just this soon (but with much bigger capacity) so hopefully he'll share as he goes? The beauty of this approach is that you can go again later on and end up with 28kWh or upwards. The cost is minimal as you'll have tools & bits&Bob's left over from the first build.

Absolutely applaud you for aiming to go fully off gas. We are beyond our first full year of zero gas and it is a very nice place to be. Maybe in another year SWMBO will suggest removing the gas meter and thus the S/C?

On a side note and was speaking to Andy about this the other day. The inverter aircons available today act as miniature ASHP's for not too much money. Well, not too much compared to a full.G or A SHP install. We run one in Turkey in our lounge and in heat mode it consumes 400W only. I am amazed at the heat but more than that its the chilly blast from the external unit,it really hits home then what these units are actually doing. Pulling heat from air. Akin to magic to me.

All the best and it reads like you are well underway!

[sharpener]

I don't expect to import anything from April to September unless I need to recharge the car in a hurry. In winter we can mostly survive on E7 night rate alone. The extra 3.2kW of panels has made a big difference, they were intended mainly to help with the 12kW(t) heat pump but that has not yet been installed so I can't tell you how it will work out.

The original 7.55 kWh battery was however not big enough to cope with cooking the evening meal in winter so I added a third Pylontech module. I am putting in a 270 l thermal store as being cheaper than a fourth module and with a longer life expectancy.