hi guys... thinking of small 1kwp (500-600w panelx2) diy for ev charging... which one you prefer?

1. panels --> charge controller --> inverter --> charger/car
2. panels --> hybrid inverter --> charger/car
3. panels --> micro inverter --> charger/car
4. panels --> power station --> charger/car

will 1 and 2 work without battery? otherwise may need a small battery to trick the system... sorry for noob question, got no solar experience

estimated cost 2.5-3k... roi 1.5-2 yrs

car sits at home in the day, plenty of daylight hours...

??? these are the basics for solar pv right?

what is your estimate i should use for 2 panels and 1 inverter for ~1kw system?

This post has been edited by dwRK: May 24 2024, 10:15 PM

the granny brick is rated 2.3kw... usually i think it charges lower around 1.8kw (my main wallbox is 7kw but i set it up for 5kw to reduce cable loss)

originally i was thinking a 1kwp grid tie or off grid for a 1hp aircon for day use... then i was thinking maybe i can use it to slow charge the ev... the ev can limit charging power but i can't remember how low it can go... I'll have to do some more testing to finalize kwp... grid tie will be easiest to supplement ac power...

my usual tnb bill is 250...ev adds 150... so a small system for the ev that i can diy i think will be more cost effective than going 5-7kwp nem for the whole house...

anyways... thank you for taking an interest...

ok... car can limit charging to 6A... so about 1.3kw... so definitely can work... or i can add more panel

so called "ev charger" is a pass through device basically a glorified switch talking to the car to start/stop only... and also limit max draws from the wall so it don't blow you fuse or burn down the house... they can usually work at lower power...

installing beams n trusses... not much profit in it for them...

i think around 1800km... mg4

without aircon your ceiling very hot? then imho... first thing to consider is reduce heat into your house... consider these...

roof ventilation... bubble foil insulation below zinc roof... orchid netting above roof... heat reflecting roof paint... insulated zinc roof as mentioned

next is leakage of cold air from inside the house... no point keep cooling but cold air keep escaping...

sure... just sharing some low hanging fruits... simple things you can do immediately...

id suggest get a good roofing guy do inspection first... dont straight out ask to replace

your red red zinc looks ok... as for wood, the pre war/70s build uses normaly uses good strong wood... nowadays the wood quality very bad... i once climb up into the attic for diy, my previous new house almost fell through the ceiling because wood broke when i stepped on it... yours maybe a few piece just need reinforcements...

if i were you, and i have to get a new roof... i would build it over the old roof and make it strong enough for solar... your solar econs now include new roof you have to decide worth or not

Avangelice... saw your old question in other tered about ev charging but didn't see any satisfying reply... tot i'd share my views here...

option 2 will be most flexible as a dedicated system... you connect power source (panels/tnb/or battery) to the inverter, and charge your ev through the inverter... you then configure supply priority, solar 1st then either tnb or battery for 2nd and 3rd priority... this way if solar power is not enough, it will supplement from tnb/battery... also when you can charge (day/night) is crucial

the remaining question is then balancing/optimizing the capacity/cost... if big might as well just go full nem... if too small then roi no good...

my simple estimates... keep here for my use...

but feel free to comment

sun hours could use 3.3, but if not hitting mileage should be ok i think...

no. car is at home all day, used mostly in early morning n evening... car is the battery

am doing a quick energy/power balance... there are ac/dc conversion losses and cable losses that i didn't include... pv supply just needs to overcome these...

so example, if 410w pv not enough, can try 430w or add extra panel...

also car will charge at whatever power it can get, if not enough it will just takes longer

thanks ... i know about this new costly device

been looking around for mode 4 evse circuit... in the usa, ppl buys used phev/bev batteries and hook them up to their solar but they have different circuits...

thanks... nem is probably what i will do...

just keeping the old brain cells active

some folks just need to know the bottom line.... money in vs money out...

at same voltage same wire type/size... dc losses > ac losses

but pv/dc voltage can be much higher than ac... so less dc losses here

also pv is usually oversized so peak power > inverter power... hence dc losses is immaterial... but inverter to tnb is not so the shorter or bigger cable the better

who is the contractor ?

can still use string because no shading problems... just have to connect properly...

as for which phase more... i would put 2 micros to the phase with highest daytime load...

depends also on sun/roof orientation... 2 sides east and 2 sides west then no issue at all...

if i have a big system, i'd go half-half... string and micro...