Help on solar array and Tesla Powerwall

[EcoCloudIT]

Trying to designed a solar array (size) and also work out how much battery storage I would need is proving difficult (for me anyhow).

Our family use about 14Kw per day for the house (3 of us)....we have gas for hot water, gas stove tops, gas fire places for heating....during summer we use the air-con a bit and it puts the load up about an additional 16Kw for the day (as a guesstimate at the moment during the warmer months).

I have travelled 7,500km's and also average around 5km's per KWh....therefore over the 5 months of ownership I need about 10Kw back in to the car each night for the next day of driving (I am assuming I cannot charge at home during the day as I am in and out a lot).

To me it looks like I'll need a 5Kw solar array and 2x Tesla Powerwalls (or 1x Red Flow battery)....at least...maybe more....anyone got some suggestions?

Not sure if reducing the battery store with some wind generation is economical or not? See this turbine looks good (we get a lot of wind and often):
ecowhisper

Oh, I'm in Melbourne also....

-ECIT

 

[paulp]

As a guide, today has been a near perfect 27 degrees in adelaide, and my 3.5kw array produced 19kwh. Melbourne will be less. Summer is around 25kwh, winter more like 10, but sometimes 5kwh.
Designing your system around winter will be a significant number of panels. Since 1 aug last year I have made 5.2Mwh with the system.
A good option might be to call tindo solar. They are a small manufacturer and are very good at providing accurate data, as its all very dependant on location, orientation, and incline angle. Tindo use the enphase microinvertors so everything is online, and the new enphase battery will be available soon to couple to it.

 

[EcoCloudIT]

Thanks Paul

I guess I was trying to determine an estimate on battery and array guesstimate sizes that I may require....if in my budget then all good...would hate to waste the time of small business, however I a guess they're used to people making these types of enquires.....I wonder how many have experience with EV's.

I tend to feel that batteries need to come down around 50% and solar a little more to make it an obvious pure economical buy decision (based on our household and car electricity usage).

-ECIT

 

[paulp]

Thanks Paul

I guess I was trying to determine an estimate on battery and array guesstimate sizes that I may require....if in my budget then all good...would hate to waste the time of small business, however I a guess they're used to people making these types of enquires.....I wonder how many have experience with EV's.

I tend to feel that batteries need to come down around 50% and solar a little more to make it an obvious pure economical buy decision (based on how house and car electricity usage).

-ECIT

Agree batteries are not yet a viable option, but panels now and batteries later should be. Tindo doesnt need low voltage cabling, its all plug an play 240v cables, so a reduced install cost.

 

[NovoCasGreeny]

As Paul said you need to get someone to do a study on your property. They will be able to work out orientation and available space. That will dictate two important things, the output of the system across the year (and seasonal fluctuations) and your usable space. Any decent solar retailer can provide this. They can also normally plug in your usage data and in the case of an EV it is just a matter of putting in a phantom consumption for the day time to charge the batteries so that you can charge the car at night.

The other thing you can also consider is a weekend charge up of the car? slightly more panels gradually charging a few batteries through the week and then discharging these batteries and soaking up the extra capacity through the weekend? It may be a significant amount cheaper to put on extra panels and feed into the grid all week and top up the car at the weekend and only have 1 battery for overnight usage. Ie 5kw of panels =1 7kwh battery. 5kw of panels will push out roughly 40 kwh on Saturday/Sunday. If you're heading out of town then pop to the SC before you go.

 

[Seekay]

Trying to designed a solar array (size) and also work out how much battery storage I would need is proving difficult (for me anyhow).

Our family use about 14Kw per day for the house (3 of us)....we have gas for hot water, gas stove tops, gas fire places for heating....during summer we use the air-con a bit and it puts the load up about an additional 16Kw for the day (as a guesstimate at the moment during the warmer months).

I have travelled 7,500km's and also average around 5km's per KWh....therefore over the 5 months of ownership I need about 10Kw back in to the car each night for the next day of driving (I am assuming I cannot charge at home during the day as I am in and out a lot).

To me it looks like I'll need a 5Kw solar array and 2x Tesla Powerwalls (or 1x Red Flow battery)....at least...maybe more....anyone got some suggestions?

Not sure if reducing the battery store with some wind generation is economical or not? See this turbine looks good (we get a lot of wind and often):
ecowhisper

Oh, I'm in Melbourne also....

Hi ECIT. I run my MS from my PV + wind off-grid system near Canberra. if you are considering wind power I recommend a proper wind survey before you do anything on this front. I design controllers to optimise EV charging according to available generation but if you have grid power available this makes things a lot easier!

 

[Seekay]

My reply is at the end of your 'quote'...

 

[Seekay]

Messed that one up. See my reply at the end of the 'quote' above

 

[EcoCloudIT]

Got it, took a look at your site.

Will make contact with you....

I grew up in Canberra, lived in Hall....whereabouts are you?

-ECIT

 

[Seekay]

Got it, took a look at your site.

Will make contact with you....

I grew up in Canberra, lived in Hall....whereabouts are you?

-ECIT

I am in Wamboin so not far from the Capital wind farm!

 

[Seekay]

My apologies to the moderator, I should not have included information that could be considered commercial

 

[paulp]

My apologies to the moderator, I should not have included information that could be considered commercial

It was good information that contributed to the discussion. Do you make a smaller more suburbs friendly version. Can't see my local council agreeing to a 19m tall structure.

 

[EcoCloudIT]

Yeah...that is what I thought...I'm in the City of Stonnington (Melbourne - Malvern East) and from various construction jobs I'm doing I also don't think they'll let me get away with a 19m pole...but if there is nothing a neighbour can do to stop me (or a council) and it's affordable I'm all for it!

-ECIT

 

[EcoCloudIT]

Wamboin, I know it

Will do my best to give you a call tomorrow Seekay....

-ECIT

 

[TesAus]

It was good information that contributed to the discussion. Do you make a smaller more suburbs friendly version. Can't see my local council agreeing to a 19m tall structure.

My understanding of wind generation is that it is significantly impacted by ground effects (turbulence) caused by other buildings, trees etc. You want the turbine to be located in broadly laminar wind flow, not in eddies created by other obstacles. To avoid ground effects I think you typically need to be 15m plus above the ground.

 

[garyjac]

Providing you do not exceed the maximum voltage for your current inverter you can oversize the array to the point where it will produce the maximum output of your inverter for most of the day. This will increase your general export credit and useable solar power per day. See: Oversizing solar arrays - your questions answered - Roof Juice