Elon Musk Reveals The Solar Roof & Powerwall 2

michaels

Love_Solar wrote: »

Here are some prices and information for you about the Tesla Powerwall and Powerwall 2 Battery.

Tesla Powerwall with SMA inverter.
Costs (priced from Wind and Sun)
Tesla Powerwall £3275.00 + VAT
SMA Sunny Boy Storage inverter @ £974.00 + VAT
SMA Energy Meter @ £296.00 + VAT
Labour to fit £300 to £500 approx.

If you want to charge the battery from E7 electric you need the SMA Home manager @ £285 + VAT.

We have a Tesla Powerwall installed and use 16 kWh of electric per day.
Our Solar PV system generates 3500 kWh per year.
Before the Tesla battery was installed we used 40% of our generation 1400 kWh or £168.00. Now with the battery installed we are using all the generated solar power.
We are also charging the battery on E7 and then releasing this power during the day as our solar PV system is only generating 3 to 4 kW per day now. (November time)
We are using this power first thing in the morning when demand is high and we would normally buy expensive electric at this time, expensive electric being 12p per kW.
The battery requires 6.8 kW to fully charge the battery and will discharge to zero 6.4 kW.
It’s best to keep the battery fully charged than fully discharged over the winter months.

The powerwall 2 will be available in February 2017 and has its own internal inverter.

Cost taken from the Tesla website.
Powerwall 2 cost is £5400 + installation and supporting hardware at £1000
Total estimated cost is £6400 and this cost includes VAT at 20% (£1000)
website
tesla.com/en_GB/powerwall

If you want more information about the SMA sunny boy storage and Tesla Powerwall battery go to the SMA website and contact either SMA direct or a SMA advance Installer.
sma-uk.com/partner-search.html

For advice in the Lincolnshire area contact Lovelace Electrical (Boston)

So does your solar get converted into AC then back into DC to charge the batteries, then back to AC when you use it suffering losses at each step?

tunnel

Love_Solar wrote: »

Here are some prices and information for you about the Tesla Powerwall and Powerwall 2 Battery.

Oh......Hello again
Nice to see you are still in business
You really need to edit the last part of your post as touting for business on MSE is against the rules even if you are only offering "advice"

Love_Solar

SE (SolarEdge) were the first to bring to the market a DC to DC Tesla Powerwall battery system back in January this year 2016. They now have a DC to AC system.
SMA have a DC to AC only system, which was available from August this year.

The benefits of the SMA / Tesla powerwall system is that.
It’s retro fit to any solar PV system.
It requires a energy meter to monitor the import and export from the National grid.
Can send email alerts in case of any errors or warning issues.
Uses sunny portal to view all sorts of data for your storage system.
It wont effect your existing warranty with your original installer (if still trading).
Can be charged from cheap rate electric, can be programed for any time and what charge you want.
Doesn’t effect your FIT payments, as the battery is after your generation meter.

Love_Solar

The solar PV generation gets converterd into AC and goes through your generation meter as normal. Your property uses what is required at the time of generation. What would normally be exported is then diverted into the battery via ther SMA inverter. Yes there would be a loss to convert this but it would be exported any way, so what difference does it make!. When power is required it converters the DC power back into AC power through the SM invereter to power what is needed.

I have charged the battery from E7 several times and it takes 6.8 kW to charge from 0 to 100%.
I have programed it to charge from 0.30 am to 7.30 am every day at present at 1 kw per hour. My E7 time clock switches over at 7.35 am, so in the morning times I want to use the cheap rate electric as much as possible and only discharge the battery when normal rate kicks in.

I know the system is very expensive at this time and its not for everyone, but when the price of electric rises which it will everyone will be looking at battery storage.
The new powerwall 2 is a game changer, £5 K for the powerwall + £4 K for solar panels and installation and the VAT would be at 5% not 20%.

I pay 12p for normal electric during the day and 6 p for cheap rate E7 electric at night. You have to get the best you can for a battery system.

Customers beware if you change your orginal inverter to a battery storage inverter and charge the batteries from E7 and discharge it during the day you may be commiting fraud.
Your FIT provider will pick up the extra generation over the winter time from your generation meter readings and you could lose your FIT payments altogether. You may also lose the warranty with your orginal installer for changing the solar PV system.

tunnel

Love_Solar wrote: »

The new powerwall 2 is a game changer, £5 K for the powerwall + £4 K for solar panels and installation and the VAT would be at 5% not 20%.

Would that be £4k for a 3kWp system, same as you were pushing last year?

Love_Solar wrote: »

Customers beware if you change your orginal inverter to a battery storage inverter and charge the batteries from E7 and discharge it during the day you may be commiting fraud.
Your FIT provider will pick up the extra generation over the winter time from your generation meter readings and you could lose your FIT payments altogether. You may also lose the warranty with your orginal installer for changing the solar PV system.

I don't get this bit? Are you saying that the battery wall is capable of discharging its full capacity in one go(ie, exporting) rather than gradually through your own consumption.
Surely the powers that be would have closed that loop hole before allowing the systems to be sold to market

Martyn1981

Love_Solar wrote: »

I have charged the battery from E7 several times and it takes 6.8 kW to charge from 0 to 100%.

Doesn't that mean that your warranty is now void? I understood that the warranty was:

First 2 years - 740 cycles to 85% DoD or 5.4kWh out of the 6.4kWh available.

Years 3-5 - 1,087 cycles to 70% DoD or 4.6kWh.

Years 6-10 - 2,368 cycles to 60% DoD or 3.8kWh.

Love_Solar wrote: »

Customers beware if you change your orginal inverter to a battery storage inverter and charge the batteries from E7 and discharge it during the day you may be commiting fraud.

Is that possible? I thought you'd need an AC battery system to charge from the mains. Can the PV system inverter with a DC redirect to the batts from the PV, also charge them from the mains AC? Wouldn't that require the inverter to be able to do AC-DC as well as its normal DC-AC? This sounds more like an islanding system/inverter?

Love_Solar wrote: »

I know the system is very expensive at this time and its not for everyone, but when the price of electric rises which it will everyone will be looking at battery storage.

It's not so much that it's not for everyone, in fact, I'd suggest it is almost for everyone.

The issue is the price, which is 100% non-economic at the moment ...... and I'm a huge fan of storage, and have been, and will continue to be like a kid on Xmas Eve waiting for Santa to bring me an economic storage option.

But till that time, which will come, we need to be patient. Assuming 5,000 cycles at 100% DoD (which it won't do), then that's 32,000kWh, ignoring all losses.

£5k / 32,000kWh = 15.625p/kWh in storage costs, that's before considering the value of the leccy, which is between 3.3p and 4.9p in export, or perhaps 7p in E7.

In reality, and using Tesla warranty DoD's, we'd get 18,000kWh of storage from £5k which is 27.8p/kWh in additional storage costs.

So, in reality we need the price to fall to a third, for it to start to be viable.

As for leccy prices rising enough, well, it'll help a bit, but as I explained long ago, they simply won't (can't) rise very far, this is simply a PV salesman's myth, as the current prices (nuclear and RE) are now known, and in the case of RE are still falling fast. Plus any large increase in the wholesale cost of electricity, is heavily diluted by the fact that the retail price is 2 or 3 times more anyway. So generation costs doubling from 4p to 8p (+100%), would 'only' increase the retail cost from say 12p to 16p (+33%).

The NAO (see page 40) predict wholesale prices (in 2016 money) peaking at £70/MWh in 2027, then falling to £60/MWh by 2035. That's a relatively small increase on the 'usual' £50/MWh, and even the current suppressed £36/MWh we are seeing due to the very low oil price and gas' price link to it.

So in reality, we are 'only' looking at a 2p to 3p increase in leccy prices, above normal inflation. Or if you prefer, a return to 2008 prices when we saw a huge (but short) spike in wholesale prices to around £80-£90/MWh.

Martyn1981

Martyn1981 wrote: »

£5k / 32,000kWh = 15.625p/kWh in storage costs, that's before considering the value of the leccy, which is between 3.3p and 4.9p in export, or perhaps 7p in E7.

Apologies, not sure if that's easy to understand. What it shows is that by buying E7 at say 7p/kWh, and adding on the 'wear and tear' (reduced value, life expectancy) of the storage system, the actual cost of leccy becomes 22.6p/kWh (perhaps 25p/kWh including system losses).

Clearly, until the cost of storage comes down, you'd be better off just buying normal daytime leccy, rather than time-shifting E7 into the day.

And if your leccy price is sub 15.6p/kWh* then you should import it, rather than purchase a storage system.

* More like 20.5p/kWh if you include the 'real' value of the export, or 22p/kWh including system losses.