[Shreyans_Jain]

Originally Posted by rsidd

kW is the power. kWh is the storage capacity. Both Powerwalls have 13.5 kWh storage capacity. Their maximum power output is different.

You could even use your microwave or iron or geyser or grill without exceeding that 5.8kW. If you use those for a long time, you'll make a dent in the total backup time.

Originally Posted by ferrarirules

Please reread my statement, I said powerwall type setups. There is nothing stopping us from creating a bigger battery backup setups ourseleves. My colleague and I have been doing research on how to replace DG setups in their society after the NGT order to retrofit them with gas. It is possible. The cost is a bit high today that is due to demand supply problem and lack of local production.

I am talking about output of the system, which is 9kw for the higher model.

It is way too less for a society or a small factory, where backup is provided by DGs of, say, 150kW (conservatively speaking). Converting these existing systems to run on PNG is a one time expense, while piped gas is anyway ubiquitous nowadays and is cheaper to operate on than diesel.

The case for domestic use in more interesting. Here, it is going to be hamstrung by cost. I have a 10kW solar rooftop from Tata Solar (grid tied with net metering), which cost me around 5L back in 2021. No batteries, just the panels and the associated paraphernalia. Now, I can get a brand new CPCB compaint DG of twice that capacity, or a PNG fueled genset + gas connection of twice the capacity for much less than 5L. DGs under 19kW are anyway exempt from CPCB norms, and domestic usage is generally light and infrequent. Second hand DGs of 15kW capacity (very popular in standalone houses) can be had for as little as 1.5-2L, complete with automation panel.

Net net, I do not see any scenario in which a Powerwall type system can be cost effective and viable in the Indian context. In the cost of just the solar equipment that is supposed to power it, you can get conventional backup of much more capacity at a far cheaper price.

For what it is worth, my own house is backed up by a 4kW 48V HKVA inverter, and it runs everything except ACs and geysers (water pump, pressure pump, washing machine, microwave, dishwasher + the usual lights, fans, TV, fridge etc). Entire setup cost was about 60k, IIRC. Solar+Li ion battery type systems just cant compete.

[nidhikapoor]

Originally Posted by Shreyans_Jain

For what it is worth, my own house is backed up by a 4kW 48V HKVA inverter, and it runs everything except ACs and geysers (water pump, pressure pump, washing machine, microwave, dishwasher + the usual lights, fans, TV, fridge etc). Entire setup cost was about 60k, IIRC. Solar+Li ion battery type systems just cant compete.

Was that cost including batteries? Possible to get info on the brand/setup?

[SKC-auto]

Even though the headline is about powerwall, Tesla has another battery product Megapack, it is a 200kwh battery. Somehow if Tesla can prices it below 30lakh, it will be huge win for many apartments.

As I understand, a 125KVA DG costs around 8 lakh, our society spends around 30-35K/month for diesel alone, powercuts here are usually in the day time which is shame considering the solar power we are not able to utilize.

If a Megapack can run the lifts, STP, motors and common area lighting for even 10hrs will be such a wonderful thing. The diesel cost will cover the emi part of the extra 20lakhs it costs over a DG.

[aim120]

Originally Posted by SKC-auto

Even though the headline is about powerwall, Tesla has another battery product Megapack, it is a 200kwh battery. Somehow if Tesla can prices it below 30lakh, it will be huge win for many apartments.

As I understand, a 125KVA DG costs around 8 lakh, our society spends around 30-35K/month for diesel alone, powercuts here are usually in the day time which is shame considering the solar power we are not able to utilize.

If a Megapack can run the lifts, STP, motors and common area lighting for even 10hrs will be such a wonderful thing. The diesel cost will cover the emi part of the extra 20lakhs it costs over a DG.

A inverter of 150kw alone will cost around 25k USD in china and add a 200kwh battery it will cost another 30lakh. So overall it would cost north of 50 lakh in addition of labour+profit and other stuff like wires, switch gear.

Instead all EV car manufacturers should have bi directional capability with a standard communication protocol. Those who want should volunteer their cars for battery cycling, one group replacing the genset and others exporting to the grid. So this way one can export the power and also use as back up.

EVs that come with a inverter have a average 3kw rating i.e 3kw of resistive load. So you would need 40 EVs with a inverter with grid tie function to get 120kw of resistive load around 50% less for inductive loads..

[Shreyans_Jain]

Originally Posted by nidhikapoor

Was that K including batteries? Possible to get info on the brand/setup?

It’s a Microtek, model JMSW5500. It is paired with 4 batteries of 125Ah each. System provides about 30mins of backup on, say, 85% load. Going upto 3-4 hours with judicious use, just lights, fans, fridges and TV. Power cuts are rather short in our area, usually not more than half an hour, and the system is accordingly set up to power more load but for a limited duration only. Increasing this duration will require using heavier 180 or 200Ah tubular batteries which will proportionately jack up the cost.

Originally Posted by SKC-auto

Even though the headline is about powerwall, Tesla has another battery product Megapack, it is a 200kwh battery. Somehow if Tesla can prices it below 30lakh, it will be huge win for many apartments.

As I understand, a 125KVA DG costs around 8 lakh, our society spends around 30-35K/month for diesel alone, powercuts here are usually in the day time which is shame considering the solar power we are not able to utilize.

Megapack is an interesting product, it may find usage in societies subject to pricing. I should think it is purely for backup and does not involve any solar component. Otherwise. it can never be cost competitive against DGs.

I believe you are talking about second hand DGs. New CPCB complaint 125kw DGs from reputed brands cost in tune of 25L.

Originally Posted by aim120

Instead all EV car manufacturers should have bi directional capability with a standard communication protocol.

EVs that come with a inverter have a average 3kw rating i.e 3kw of resistive load.

Valid point. Vehicles like the new Nexon EV LR or the Ioniq5 can totally serve as domestic backups. They can certainly power most domestic inverters in the time of need.